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JOURNAL OF THE SOCIETY OF
MOTION PICTURE ENGINEERS

VOLUME XXXIX • • • JULY, 1942

CONTENTS

The Carbon Situation and Copper Conservation

E. A. WILLIFORD 3

Experiences in Road-Showing Walt Disney's Fantasia

W. E. GARITY AND WATSON JONES 6

The Future of Fantasound EDWARD H. PLUMB 16

Mobile Television Equipment

R. L. CAMPBELL, R. E. KESSLER, R. E. RUTHERFORD,

AND K. V. LANDSBERG 22

The Application of Potentiometric Methods to De-
veloper Analysis JOHN G. STOTT 37

Continuous Replenishment and Chemical Control of
Motion Picture Developing Solutions

H. L. BAUMBACH 55

The Practical Aspect of Edge-Numbering 16-Mm Film

H.A.WiTT 67

A New Electrostatic Air-Cleaner and Its Application to
the Motion Picture Industry HENRY GITTERMAN 70

Current Literature 75

•

Society Announcements 77

(The Society is not responsible for statements of authors.)

JOURNAL OF THE SOCIETY OF
MOTION PICTURE ENGINEERS

SYLVAN HARRIS, EDITOR
Board of Editors

ARTHUR C. DOWNES, Chairman

JOHN I. CRABTREE ALFRED N. GOLDSMITH EDWARD W. KELLOGG

CLYDE R. KEITH ALAN M. GUNDELFINGER CARLETON R. SAWYER

ARTHUR C. HARDY

Officers of the Society

*President: EMERY HUSE,

6706 Santa Monica Blvd., Hollywood, Calif.
*Past-P resident: E. ALLAN WILLIFORD,

30 E. 42nd St., New York, N. Y.
*Executive Vice-President: HERBERT GRIFFIN,

90 Gold St., New York, N. Y.
** Engineering Vice-President: DONALD E. HYNDMAN,

350 Madison Ave., New York. N. Y.
*Editorial Vice-President: ARTHUR C. DOWNES,

Box 6087, Cleveland, Ohio.
** Financial Vice-President: ARTHURS. DICKINSON,

28 W. 44th St., New York, N. Y.
* Convention Vice-P resident: WILLIAM C. KUNZMANN,

Box 6087. Cleveland, Ohio.
* Secretary: PAUL J. LARSEN,

1401 Sheridan St., N. W., Washington, D. C.
*Treasurer: GEORGE FRIEDL, JR.,

90 Gold St., New York, N. Y.

Governors

*MAX C. BATSEL, 501 N. LaSalle St., Indianapolis, Ind.
**FRANK E. CARLSON, Nela Park, Cleveland, Ohio.

*JOHN G. FRAYNE, 6601 Romaine St., Hollywood, Calif.

*ALFRED N. GOLDSMITH, 580 Fifth Ave., New York, N. Y.
**EDWARD M. HONAN, 6601 Romaine St., Hollywood, Calif.

*I. JACOBSEN, 177 N. State St., Chicago, 111.
**JOHN A. MAURER, 117 E. 24th St., New York, N. Y.

*LOREN L. RYDER, 5451 Marathon St., Hollywood, Calif.

* Term expires December 31, 1942.
** Term expires December 31, 1943.

Subscription to non-members, $8.00 per annum; to members, $5.00 per annum, included
in their annual membership dues; single copies, $1.00. A discount on subscription or single
copies of 15 per cent is allowed to accredited agencies. Order from the Society of Motion
Picture Engineers, Inc., 20th and Northampton Sts., Easton, Pa., or Hotel Pennsylvania, New
York, N. Y.

Published monthly at Easton, Pa., by the Society of Motion Picture Engineers.

Publication Office, 20th & Northampton Sts., Easton, Pa.

General and Editorial Office, Hotel Pennsylvania, New York, N. Y.

Entered as second-class matter January 15, 1930, at the Post Office at Easton,

Pa., under the Act of March 3, 1879. Copyrighted, 1942, by the Society of Motion

Picture Engineers, Inc.

THE CARBON SITUATION AND COPPER CONSERVATION*

E. A. WILLIFORD**

The meeting of the Atlantic Coast Section of the Society on May 21st was devoted
to the question of "Wartime Conservation in Theater Projection" The paper that
formed the basis of the meeting has already been published, in last month's issue of
the JOURNAL.

At the end of the presentation, the following discussion, on the carbon situation and
the conservation of copper, was contributed by Mr. Williford.

I appreciate your request that I tell you something about the car-
bon situation. Fortunately, the basic materials for the manufacture
of projector carbons are petroleum products, of which ample supplies
are available. We do not see any possibility of there being any
shortage of these materials.

For high-intensity type carbons, however, certain rare-earth
minerals are used to produce the brilliant white source of light, and
these rare-earth materials have been supplied principally from India.

Before America entered the war there was several years' supply
of this material in the United States and, according to my latest
information, there is still several years' supply here. More is coming
in as shipping facilities are available. Brazil also contains large
deposits of these minerals which could be used if the Indian source
is cut off. There are even deposits of this material in the United
States, although the costs of obtaining it would be quite high as
compared with Indian costs, or even Brazilian costs. In any event,
there does not appear, at this time, to be any prospective shortage
of these rare-earth minerals.

For "Suprex" carbons, high-intensity negatives, and a few other
types of projector carbons it has been necessary to curtail our use
of copper in the copper plating. As you know, the war needs for
copper are greatly in excess of any visible supply and it is up to every

* Presented at the meeting of the Atlantic Coast Section at New York, N. Y.,
May 21, 1942.

** National Carbon Company, New York, N. Y.

4 E. A. WlLLIFORD [J. S. M. P. E.

one of us to do all we can to use as little copper as possible, and to
salvage every bit that we can.

For some months now we have been using our advertising space
to promote the idea of burning carbons at lower current, peeling the
copper plating from any butt ends remaining, and saving the copper
drippings from the lamp-houses. Many projectionists have been
doing this and, in accordance with War Production Board instruc-
tions, have turned these peelings and drippings over to scrap dealers,
even though the value might be so small that they receive no com-
pensation in return.

In our own Research Laboratories intensive studies have been
given to reducing the amount of the copper plating, and also elimi-
nating it entirely, if possible. For the moment, we are producing
thinner plated carbons, and as of today, our stocks of the 6.5-mm X
9-inch Orotip "C" negatives of the older standard plating thickness
type have been exhausted. Within a few days all other types of
carbons with the standard plating will, likewise, be out of stock and
shipments thereafter will be of the new thinner plated variety which
we have called Victory carbons.

The industry is extremely fortunate in that some of our research
program over the past few years culminated very recently in the
development of a new 8-mm diameter "Suprex" positive. Even
with the Victory plating, these carbons will give the same light on
the screen as the old carbons with 5 amperes less current and with
approximately 20 per cent saving in carbon consumption. At 65
amperes, which is the maximum current for both the old and the new
Victory carbons, the screen light is considerably greater and the
carbon consumption also is considerably less.

In the case of the 7-mm positive — 6-mm negative combination,
it will be necessary to reduce the current on these carbons with result-
ing loss in screen light. The amount of this reduced illumination is
only about 15 per cent, however. If the power source can be operated
at 56 amperes and the new 8-mm — 7-mm trim used, the same screen
illumination can be obtained with a saving of about 30 per cent in
carbon consumption, but at an increased power consumption of
approximately 12 per cent.

These new carbons will be marked with white ink to distinguish
them from the standard product which has been labelled with blue
ink. The maximum permissible current will be printed on each
carbon beside the trade-mark. The unit carton will have a special

July, 1942] CARBON SITUATION AND COPPER CONSERVATION 5

label indicating not only the maximum allowable current for the
type of carbons contained in the package, but also showing the
weight of copper drippings that can be recovered from the lamp-
houses, from a package of 50 such carbons. This weight has been
carefully calculated, based on the minimum thickness of copper
plating applied, and allowing for about 10 per cent loss through
carelessness in handling. It represents what can be readily salvaged
and unless or until the government advises you otherwise, we suggest
that you save these drippings and any peelings from the butt ends of
carbons until you have a quantity sufficient to give or sell to a scrap
dealer. At the present time government regulations do not permit
you to dispose of this copper scrap to any other person. The copper
plating on the new Victory carbons is so thin that it is doubtful
whether any plating remaining on the stubs can be salvaged. On
the other hand, by the use of carbon savers, all carbons can be burned
to stubs of not over 1 inch in length, in which case the amount of
copper thus lost will be very small indeed.

We are glad to have been able to make this constructive change
in the interests of copper conservation for the promotion of our
national war effort and know that each t>f you will cooperate in this
program of copper conservation, even though it may mean extra work
and some inconvenience to you in your daily job.

EXPERIENCES IN ROAD-SHOWING WALT DISNEY'S
FANTASIA*

WILLIAM E. GARITY** AND WATSON JONESf

Summary. — A discussion of the various problems encountered in the road-show-
ing of "Fantasia" with the multiple-track Fantasound equipment. The experiences
and conditions encountered are presented as a guide for the further development of
this very important field. It is expected that this system will add greatly to the dramatic
presentation of pictures and will, in some form, replace our sound-reproduction sys-
tems.

Fantasia was the result of an idea that grew over a period of three
years from a "standard" one-reel "short" to a multi-million dollar
road show that required the largest outlay of sound equipment that
has been used commercially in the theater to date. Many new
methods and procedures were found necessary to achieve the results
that were desired for the final product. These new methods and
procedures applied not only to the sound technic but the pictorial
aspect as well. In order to appreciate fully the amount of artistic
and engineering work that was expended on Fantasia it is interesting
to review some of the highlights of our experience over a period of
about three years prior to the premiere of the picture in New York on
November 13, 1940.

During the latter part of the year 1937 Walt Disney conceived the
idea of making a cartoon "short" using as a basis some well known
musical selection that lent itself to cartoon animation. A serious
effort was made to interpret the composer's musical ideas pictorially
as well as to record music that would blend into the picture and
provide a combined, indivisible form of entertainment. The Sorcerer's
Apprentice was chosen for the original, and was recorded in January,
1938, by 100 musicians conducted by Leopold Stokowski.

The Sorcerer's Apprentice was recorded at the Pathe Studio, Culver

* Presented at the 1942 Spring Meeting at Hollywood, Calif. ; received May
1, 1942.

** Walt Disney Studio, Burbank, Calif,
t RCA Manufacturing Co., Hollywood, Calif.

ROAD-SHOWING FANTASIA 7

City, Calif., on a production stage that was altered acoustically for
the occasion. Our theory was to make a multiple-channel recording
that would have satisfactory separation between channels so that
suitable material would be available from which to obtain any de-
sired dynamic balance in re-recording the original material. In the
effort to obtain satisfactory separation between channels, a semi-
circular orchestra shell was constructed in the stage. The shell was
then divided into five sections by means of double plywood partitions.
Two difficulties were encountered with such a set-up; one was poor
low-frequency separation; the other was the inability of the musi-
cians at the rear of the sections to hear the music from the other
sections, to such an extent the tempo was impaired. This condition
was improved, at a sacrifice in separation, by having the musicians
move nearer the front of the shell sections. As work progressed on
the animation and re-recording of the material, Walt Disney decided
to add other musical selections and to present a full-length presenta-
tion that would be outstanding in its scope. It was at this time that
discussions first took place regarding special equipment for the show-
ing of the picture. The goal that we hoped to reach was the repro-
duction in the theater of a full symphony orchestra with its normal
volume range and acoustic output as well as the illusion that would
ordinarily be obtained with a real orchestra. Many ideas were
investigated, equipment was designed, and tests made of various
combinations of equipment that would give the ultimate in a sound
and picture entertainment. For a further description of these in-
vestigations the reader is referred to a paper on "Fantasound" by
Garity and Hawkins in the August, 1941, JOURNAL.

The best combination of music and recording conditions was de-
sired for the additional selections, and it was decided therefore to
abandon the Sorcerers set-up .and to record the Philadelphia Orchestra
in the Academy of Music in Philadelphia. This decision had two
points in its favor; one being the fact that the acoustic properties of
the Academy are excellent, and the second being that this orchestral
group has been organized for many years and their musical talent is
rated as one of the highest. At the time of the decision to do the
recording at Philadelphia it was not known exactly what the music
requirements would be in order to achieve the dynamic and musical
balance necessary to the picture story being told. So that this re-
quirement might be fulfilled in the re-recording of the original ma-
terial, a multiple-channel recording was made and it was, of course,

W. E. GARITY AND W. JONES [J. S. M. P. E.

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July, 1942] ROAD-SHOWING FANTASIA 9

necessary to install nine studio-type recording channels in the Acad-
emy.

The recording machines were located in the Academy basement,
and since the inside of the building is constructed of wood, many
safety measures had to be taken. No more than eighteen rolls of raw
stock were allowed in the Academy at one time, and in order to insure
a sufficient quantity of film for each recording session, a film-delivery

FIG. 2. Installation in the Carthay Circle Theater, Hollywood.

truck was converted into a suitable loading room and was parked
outside the building during recording sessions. All loading and un-
loading was done in this truck. The work of installation and record-
ing was supervised by the authors, who spent the entire spring of 1939
in the Academy basement.

EQUIPMENT PROBLEMS

To appreciate fully some of the problems encountered in the design
of the road-show units it is necessary first to see what constitutes a
complete unit. Each Fantasound road-show equipment consisted

10 W. E. GARITY AND W. JONES [J. S. M. P. E.

of sound reproducers, amplifiers, and loud speakers so arranged as to
reproduce sounds from a multiple sound-track film run in synchro-
nism with the picture film. The level and distribution of sound to the
various stage and auditorium loud speakers was automatically varied
in a predetermined manner by means of the control-tone and program
sound-tracks on the multiple sound-track film. Fig. 1 is a block
diagram of the Fantasound equipment as used for the reproduction
of Fantasia. This system consisted of three separate program ampli-
fier and loud speaker channels, and a control- tone channel; two
selsyn-operated multiple sound-track reproducers; two selsyn -
operated sound-heads ; two selsyn distributors ; three two-way stage
loud speaker systems; auxiliary theater auditorium loud speakers;
and amplifiers and necessary operating facilities. Fig. 2 shows the
equipment as installed in the Carthay Circle Theater, Hollywood.

Power Supply. — All equipment was furnished for 60-cycle power.
The amplifiers and power-supply units required 110-125-volt single-
phase current; the selsyn distributor 220 volts, three-phase. Where
power fulfilling these requirements was not available, the necessary
rotating equipment or transformers were supplied for the particular
job. In order that the line- voltage variations would have the least
effect upon the sound output level, the a-c input voltage to the
exciter-lamp supply was regulated, and regulated supplies were em-
ployed to furnish plate power for the variable-gain amplifiers and
tone rectifiers, and polarizing voltage for the phototubes.

Stage and Projection Room Space. — Due to the fact that each road
show unit consisted of eleven 62-inch racks of amplifiers and power-
supply units, in addition to the other items indicated in Fig. 1, there
existed quite a problem in finding space in the average theater for the
various items. The wiring and operating facilities of the equipment
were so arranged that it was necessary to install a minimum of six
racks in the projection room in addition to the two multiple sound-
track reproducers. This was further complicated by the fact that
many theaters available and suitable for road-show attractions
generally did not have much of a projection room, if any. Power-
switching facilities were contained in one of the racks installed in the
projection room so that the additional five racks could be mounted
outside the projection room if space was not available therein. The
two selsyn distributors on which were mounted the necessary starting
and remote-control devices were located outside the projection room
where conditions permitted. The speaker-field supply rack was so

July, 1942] ROAD-SHOWING FANTASIA 11

arranged that it could be mounted on the stage proper, near the
loud speakers, in order to conserve wire runs; however, in some
theaters this was not advisable due to the differences in local rulings
as to whose duty it was to turn on and off the power to the rack.
Space behind the picture screen was generally available for the loud
speaker systems. The screen had to be moved up or down stage in
many theaters in order to get the best distribution of sound. The
three loud speaker systems required an average width of 44 ft, and it
was always necessary to change the masking draperies on either side
of the screen in order to obtain satisfactory sound transmission from
the side loud speakers.

Inter- Apparatus Connections. — The model road-show unit that was
first manufactured made use of Cannon-type plugs and fittings for
all inter-apparatus connections. Due to the large number of cable
connections necessary, it was impossible to have a different type of
plug for each circuit, and there was always the possibility and hazard
of plugging a cable into the wrong position, with resulting damage to
equipment. After a nation-wide survey of city inspectors concerning
the use of rubber-covered cables and plugs on equipment located in
projection rooms in a theater on a road-show basis, we found there
existed many rulings, some definite and others rather vague. Some
city inspectors would agree to the use of rubber-covered cables
provided the show did not run longer than thirty days or so. Others
would not agree to rubber-covered cables in the projection room on
any condition. In one installation no exposed conduit was permitted,
due, no doubt, to a safety measure as well as a "projection room
beautification program." For the foregoing reasons all cables and
plugs were eliminated and Greenfield or rigid conduit was used for all
installation wiring.

Emergency Features. — Since this was a major project so far as the
amount of sound equipment to be used was concerned, and it was to
be a "two-a-day" show with road-show prices, some emergency
feature was desired in case of failure of the Fantasound system. In
case of failure of the control-tone variable-gain part of the system,
switching facilities were provided whereby the control-tone section
could be by-passed and the three program channels could operate
with the volume range that existed on the program tracks themselves.
This still involved the use of a large percentage of the equipment, and
further simplification of the emergency feature was thought desirable.
The sound-track on the picture film was a standard variable-area

12 W. E. GARITY AND W. JONES [J. S. M. P. E.

composite of the sound material that was located on the three program
tracks of the multiple-track film. By means of one switch which
actuated a relay system, the sound was transferred from the Fanta-
sound set-up to the emergency channel, making use of the standard
sound-track on the picture film, the emergency amplifier, and the
center-stage loud speaker. Theater experience proved that the
equipment was very reliable, and even though the number of com-
ponent parts in the road-show unit was many times that of a standard
theater set-up, the number of sound outages were no more than is
experienced in a standard theater. The sound outages that did occur
were caused in the majority of instances by operating failure rather
than equipment failure. Such successful performance with the large
quantity of equipment involved indicates the high degree of per-
fection that has been reached in present-day engineering and manu-
facture of theater sound equipment.

Audio Power Requirements. — The success of any high volume range
reproduction depends greatly upon having equipment with sufficient
undistorted power-handling capacity. The Fantasound equipment
has three 60-watt amplifiers for the stage speakers. This proved
satisfactory for the majority of installations ; the New York unit used
additional power. The full capacity of the system was usually
reached on peak levels during the performance.

Equipment Testing and Program Level Adjustments. — The experi-
mental work on the multiple-channel reproducing system indicated
that slight differences in level between channels would give the effect
of motion of the sound from one loud speaker to another. For this
reason we found it necessary to provide facilities for readily checking
the levels of the channels in order that the sound-perspective at the
time of reproduction would be the same as intended during the re-
recording of the picture. A portable- type bridging input amplified
volume-indicator having a range of —50 to +40 db (6-mw reference
level) was provided for making all measurements. Multiple-track
test-films and film-loops were used for making such measurements as
level balance, gain-change characteristics, push-pull balance of the
sound-track, and frequency response. Bridging jacks only were used
at points in the circuits where routine measurements were to be made.
Switches were so connected that resistance loads could be substituted
for purpose of measurement. Vacuum-tubes having any bearing on
the characteristics of the control-tone variable-gain section of the
system were aged, balanced, and matched. This simplified the work

July, 1942] ROAD-SHOWING FANTASIA 13

for the field personnel in the routine maintenance of the equipment.
Operating Features. — The routine show-operating details were kept
as near to standard theater practice as possible ; however, due to the
use of a selsyn motor system and separate film reproducers, there did
exist some difference in operating technic. There were three stations
for the operating of the sound-control and motor systems. The
motor controls for the selsyn system were operated by a sequence-
switching arrangement that was quite foolproof. Suitable pilot-light
indicating devices were employed for all control stations, and change-
overs could be made from any station at any time. It was general
operating practice to allow the selsyn motor on the picture machine
and the multiple-track reproducer to remain "in lock" during the entire
show, and because of this very little trouble was experienced from
"out-of-sync" conditions. The power circuits were so designed that
the entire system could be turned on by one switch, and during nor-
mal operating times such was the practice.

Manual switching was provided for monitoring the tone or pro-
gram channels individually. This was fairly satisfactory with the
exception that the volume range of the recording was too great for
projection-room monitoring. With any reasonable adjustment for
satisfactory high-level sounds it was impossible to hear the low-level
sounds over the machine noise. Future equipment should be de-
signed with a volume-compressor stage in the monitor amplifier and
possible means for monitoring the combined channels.

Shipping Facilities. — All equipment was shipped from the factory
in caravan packing units. Such packing facilities would no doubt
have been satisfactory for the transfer of the equipment between
installations. The weight of a complete Fantasound equipment was
approximately 15,000 Ibs; it was packed in forty-five cases and re-
quired one-half of a standard freight car space.

The following information was obtained from eight Fantasound
installations, and indicates the general conditions that were en-
countered. Six of the installations required that a new or a larger
capacity three-phase service be run to the projection room. The ma-
jority of the six were new services, as no old services were available.
In some theaters adequate single-phase power was not available in
the projection room. Such additional power-line runs to the projec-
tion rooms were always costly and time-consuming. In three of the
theaters it was necessary to enlarge the projection room, as sufficient
space was not available for all the equipment nor was there space

14 W. E. GARITY AND W. JONES [j. S. M. p. E.

nearby that could be used. This item made a large increase also in
the installation cost. As a general rule the projection rooms en-
countered were poorly arranged and too small for a first-class in-
stallation of the entire equipment. It must be remembered, how-
ever, that these theaters were not usually first-run motion picture
houses, but were theaters that could be engaged for such a road-show
project.

In some of the earlier installations the right and left stage speakers
were placed as far out to either side as conditions would permit. Pre-
liminary tests indicated that this was undesirable, as there was an
objectionable sudden movement of the sound when shifted from one
loud speaker to another. The condition was corrected by moving
the side speakers nearer the center by such an amount that a smooth
transition occurred when the sound was shifted from one speaker to
another. The correct separation of the theater stage speakers for
obtaining a sound illusion similar to that obtained at the time of re-
recording depends to a certain extent upon the general acoustic
properties of the re-recording monitoring room and the location and
spacing between the monitor speakers. Due to the fact that the
Disney re-recording monitoring room is a 600-seat theater of average
theater acoustic properties, it was more or less an easy matter to
anticipate the final results.

The normal undistorted audio-power output of the equipment was
220 watts, which proved satisfactory for most theaters. In the
Broadway Theater (New York) the power was increased to 400 watts
and three additional loud speaker systems were added to the stage
complement to handle the additional power.

The music and the control-tone tracks for Fantasia were re-recorded
with the idea that a certain volume-range could be used in the
theater showing the picture. This volume-range as chosen, which
consisted of a 40-db control-tone range and a 30-db range on the
music tracks, was found to be greater than could be tolerated in the
theater. It was general practice to use the high-level section of the
music as the point at which the gain-controls were set for the correct
level. If the low-level portions of the music were below the theater
noise-level, the volume-range was reduced by changing the ratio of
the control-tone level to the variable-gain amplifier output. The
music was re-recorded with a one-to-one ratio; however, in some
theaters it was necessary to use a ratio of eight to .five. This means
of controlling the volume-range of sounds that have already been

July, 1942] ROAD-SHOWING FANTASIA 15

recorded was found to be very useful and necessary for the successful
presentation of the picture. The best audience reaction to the high-
level musical passages occurred when the level was at a certain value,
which varied from theater to theater and was determined by trial and
error. A decrease of 2 db in this level resulted in a decided "let-
down" of audience reaction as the "thrill," or "punch" was lacking.

Conclusions. — The outstanding success of Fantasia in its limited
number of runs with Fantasound has demonstrated the value of this
means of increasing the dramatic value of a picture.

There were three primary reasons for the discontinuance of the
use of Fantasound:

(1) The amount of equipment required and the time necessary to make the
installation.

(2) Because of the time element attractive theaters were not available to us,
as the first-class houses in the various communities had established policies and
the installation of the equipment would generally require darkening the house for
a few days.

(5) The advent of wartime conditions precluded the possibility of developing
mobile units that would have lessened installation time and costs.

(4) The variation in the regulations throughout the country, both as to operat-
ing personnel and local ordinances, materially affected the operating and in-
stallation costs.

(5) Space factors of the projection room in particular were problems of major
importance.

We are convinced that, with greater simplification of equipment in
keeping with the available space in the theater, the elimination of the
separate selsyn sound-track reproducer, and the combining of the
multiple-track on the composite print, future sound reproduction
will employ multiple-track reproduction with automatic volume
control, and, something that was not used in Fantasound, the auto-
matic change of frequency-response with volume. We can only
express our own opinions and the opinions of those who worked with
this equipment; viz., having used the multiple-track system, no
matter in what form, the ordinary sound-track reproduction is flat
and dull by comparison. We can not say what the problems of
original recording would be for the live-action producer. We can
assume they will be many and various, but we are sure that with
study and ingenuity they can be overcome, and the final results will
be worth while.

THE FUTURE OF FANTASOUND

EDWARD H. PLUMB**

Summary. — A non-technical discussion of Fantasound from the musician's point
of view. The use of Fantasound is reviewed as a basis for discussing ways in which
it can be used in the future.

Fantasound has been demonstrated to the public only in Walt
Disney's Fantasia, but to accept or reject Fantasound on the basis
of its use in that picture would be unjust. Fantasia is a remarkable
showcase for an experiment in sound engineering because it uses
music as a vital function of the picture. However, the dramatic
effectiveness of Fantasound was limited by three conditions peculiar
to this production.

(1) During its actual picture footage Fantasia uses only music
on the sound-track. This eliminates the possibility of placing and
moving dialog or sound-effects in the multiple speaker system that
Fantasound includes. Dialog and sound-effects are the "real"
sounds of the movies with which the audience is thoroughly familiar.
Because of this familiarity it is quite possible that the location of
these sounds in the theater could be more easily registered than the
placement of musical sounds.

(2) The music that Fantasia interprets was conceived long before
sound-film was available for use. The compositions were designed
for concert performance and were so well designed for that medium
that any orchestral changes made to improve reproduction greatly
affected their basic character.

(3) The original recording of the entire orchestral performance
of Fantasia had been completed before it was known what dimen-
sional effects would be available in the theater. It was thus im-
possible to guess what method of recording would be most efficient
for reproduction in Fantasound.

* Presented at the 1942 Spring Meeting at Hollywood, Calif. ; received May
1, 1942.

** Music Department, Walt Disney Studio, Burbank, Calif.

THE FUTURE OF FANTASOUND 17

This is in no sense to be interpreted as an apology for Fantasia or
the methods used in it. It is merely a description of certain ob-
stacles that would not be confronted in the usual feature.

The future of Fantasound depends upon the efficiency with which
the original sound material can be transferred to film and upon the
dramatic effectiveness of the total result. These related factors
dictate the future of Fantasound because they represent, respectively,
the expenditure necessary and the expenditure warranted by box-
office returns.

Before suggesting a method of recording an orchestra that might
be practicable for future productions in Fantasound it seems advis-
able to describe briefly the method employed in Fantasia. During
the original performance, each of six sound cameras recorded the
close pick-up of a particular section of the orchestra. A seventh
camera recorded a blend of these six close pick-ups, and an eighth
recorded a distant pick-up of the entire orchestra.

. In preparing the final re-recorded tracjc from this original material
several weaknesses became apparent. Because of acoustical pick-up
the separation between the six sections of the orchestra was merely
relative. In the material on the woodwind channel, for instance,
the woodwinds usually predominated, but material from other sec-
tions of the orchestra was definitely present. Many times, because
of differences in performance level, the material from adjacent sec-
tions would be as loud as, or louder than, the woodwinds directly
picked up. This lack of complete separation was not an insur-
mountable obstacle in creating an artistic balance for ordinary re-
production, but it greatly limited the dramatic use of orchestral
colors in Fantasound. If we wished, for dramatic reasons, to have
a horn call emanate from a point to the right of the screen, our pur-
pose would be confused by hearing the same call, at a lower volume, on
every other speaker in the theater. Greater separation in the original
recording could have been achieved only by greater segregation of
the sections or by moving the microphones closer to the individual
instruments. To go any further than we had gone toward segrega-
tion of sections or close pick-up would have impaired quality of
performance in one case and recorded tone quality in the other.
On the point of efficiency of the Fantasia recordings we must observe
that only one-third of the material recorded on chosen performances
was used in the final dubbing. The unused film contained sound
that was too repetitious of other channels, too poor in quality, or,

18 E. H. PLUMB [j. s. M. P. E.

during long sections, too unimportant in the design of the composi-
tion to help the total result.

Since the completion of Fantasia we have recorded orchestral
performances of five compositions for possible use in Fantasound.
It is not likely that these can appear as productions for a long while,
but the method that was used may provide a possible approach to
future Fantasound projects. The recordings were much less expen-
sive and, there is every reason to believe, can be much more effective
dramatically than the Fantasia recordings. We concentrated upon
the achievement of two qualities of Fantasound that seem to us to
be important — the illusion of "size," possible to attain by proper use
of a multiple-speaker system, and recognizable placement of or-
chestral colors important to the dramatic presentation of the picture.

For the illusion of "size" or "spread," we used a three-channel
recording set-up. Channel A was fed by a directional microphone
far enough from the instrumentalists to cover the entire left half of
the orchestra. Channel B recorded the right half of the orchestra.
Channel C recorded a distant pick-up of the entire orchestra. This
three-channel system recorded the "basic" tracks of the composition.
It is important to note that in planning the material for these "basic"
tracks any orchestral color or passage for which we might have special
dramatic use was omitted from the performance. The recording of
this special material will be described later.

In reproduction over the Fantasound system this method of re-
cording the basic tracks has great flexibility. To regain the natural
spread of the orchestra, the A channel (left half of the orchestra)
appears on the left stage speaker, the B channel (right half of the
orchestra) appears on the right stage speaker, and the C channel
(distant pick-up) appears on the center speaker. The distant pick-
up appearing in the center adds an illusion of depth which is bene-
ficial and also provides a more practical "cushion" for the solo in-
struments or other special material that would normally appear in
the center. The "panpot" (described by Garity and Hawkins in
the August, 1941, JOURNAL) can execute practically any variation
of this reproduction plan that could be demanded. Each track
can appear on any one stage speaker, any two stage speakers in
whatever balance desired, or on all three stage speakers in any bal-
ance. The house speakers can be added to the left and right stage
speakers in whatever set balances desired, or they can replace the
left and right stage speakers so that sound comes only from left and

July, 1942] THE FUTURE OF FANTASOUND 19

right house and center stage (as in "Ave Maria" in Fantasia).

In the recording of what I have termed special material — material
whose location it is important to register — we employed the only
method that assures absolute separation. The section of the basic
track with which the special material is to synchronize is used as a
playback on earphones available to conductor and instrumentalists.
The physical difficulties of this method can be minimized by careful
planning of the orchestration. It is usually possible to avoid the
occurrence of the same melodic passage or rhythmic pattern in both
the special and basic material. This makes synchronization less
critical and also allows more freedom in performance of the special
material. As advantages, the playback method offers complete
control of the volume relationship between special and basic material ;
complete freedom in locating or moving the -special material; and
freedom to choose the pick-up, in recording the special material,
that produces the finest quality in reproduction.

As an example of the use of the playback method, in The Swan of
Tuonela, by Sibelius, there is an English horn solo that is vitally
important in the design of the composition. We knew that this
English horn should be a principal actor in dramatizing the score.
We had recorded the composition played by the complete string
orchestra omitting, among other instruments, the English horn.
We then recorded the English horn alone, using the performance by
the strings for the playback. A relatively distant pick-up was used,
which gave the tone of the English horn brilliance, but also lent a
feeling of mystery in character with the subject. Because of the
complete separation achieved it is possible to submerge the solo in
the rest of the orchestra or to make the solo stand out in a clear relief
physically impossible to attain in concert performance. The solo
can locate as its source one of the three stage speakers or, by balanc-
ing its volume between two speakers, can seem to locate a definite
point between them. The solo can come from the left or right unit
of house speakers without the stage speakers or, if power or diffusion
are desired, can come from every speaker in the theater. The solo
can move in such a way that it seems to follow the pattern of a pic-
torial effect; it can change from offstage to onstage; or it can change
its source, by a smooth, irregular movement of the panpot dial, so
that it seems to float through the theater. I have mentioned a
single composition and only a few of the effects possible. However,
it is clear that the restrictions offered by this tentative method are

20 E. H. PLUMB [j. s. M P. E.

infinitely less than those offered by the method used for Fantasia.
(The Fantasia score contained only one example of complete separa-
tion— the solo voice and chorus of "Ave Maria" were recorded by
the playback method to an orchestral accompaniment recorded a
year and a half before. The vocal performance of "Ave Maria"
was the last material to be recorded for Fantasia, and we were able
to use everything Fantasound had to offer. It is interesting to note
that for many of those in the audiences — at least in New York and
Los Angeles — Fantasound was "turned on" only for "Ave Maria.")

The advantages of volume range are probably more obvious than
the advantages of other features of Fantasound. To be able to use
the upper volume range without distortion and the lower range
without submerging the tone in ground-noise has been the dream of
every dramatically minded sound-director since the advent of sound
reproduction. Experience shows us, however, that this greatly
extended volume range still has important natural limits. If sound
is reproduced so low that it is unintelligible or so high that it causes
physical discomfort, there must be adequate dramatic reason.
Either extreme is likely to irritate.

Dialog and sound-effects, as material for use in Fantasound, have
one decided advantage over music. They do not have to be recorded
differently from the customary recording of ordinary sound. Their
placement, movement, and extended volume range are all accom-
plished after they are normally put on the film.

Dialog is the only sound medium in whose reception the audience
has been well rehearsed. The average member of the audience has
heard the sounds that the screen sound-effects imitate, but he does
not ordinarily analyze their character or location with any great
care. He has listened to music but, perhaps wisely, he does not
bother himself with the details of its complex pattern. In the recep-
tion of speech, however, he has trained himself to register, in great
detail, character, pitch, volume, and location. Location of sound-
source is an unconscious function of his daily group conversation,
group work, and group play. It is reasonable to expect, then, that
when dialog placement has dramatic meaning it will be efficiently
received by the audience — at least, more efficiently received than
the placement of sound-effects or music. Because of the visual
limitations of the screen, dialog, in Fantasound as in ordinary repro-
duction, comes normally from the center of the stage. For this
purpose the center stage speaker is adequate. Because the ear is
critical of voice placement, however, it is not far-fetched to attempt

July, 1942] THE FUTURE OF FANTASOUND 21

the location of characters by changing the speaker source. If an
actor appears in the area at the extreme left of the projected frame,
or if the implied location is slightly to the left of the projected frame,
placement of the voice on the left stage speaker supports the illusion.
Such use of the three stage speakers creates the possibility of dialog
between extreme left and extreme right or between center and either
side without greater sacrifice of intelligibility than would exist in
dramatic productions on the stage. Obviously the device could be
over-used to the point of annoyance, and should be limited to dra-
matic situations that are definitely improved by the illusion. In
the treatment of off-stage voices the house speakers could be used
to advantage. When a voice, or a group of voices, comes from the
left or right unit of house speakers, an effect of reverberation is added
to the original recording. The loss in intelligibility and in point-
source definition could have dramatic value because they imitate
these same losses in the reception of real sounds from a distance.

Fantasound is able to make its greatest contribution in combining
dialog, music, and sound-effects. In ordinary reproduction one of
these three mediums must, with rare exceptions, be dominant while
the other two are sacrificed. In Fantasound it is possible to follow
the continuity of the dialog clearly and still receive the full emotional
impact of the music, or the dramatic realism of atmospheric sound-
effects. As a possible use in the theater, consider that the center
stage speaker would be saved exclusively for on-stage sound — dialog,
music performed on the screen, or realistic sound-effects. The
house speakers and, at a lower level, the side stage speakers would
project music or general sound-effects at a level natural for them.
As long as the music or effects are pertinent to the story being por-
trayed they will not distract and would not cause the dialog to be-
come unintelligible. This physical separation of sound-tracks also
reduces to a minimum the unpleasant phenomenon produced when
a well-modulated track is "pinched."

If these comments seem to wander it may be because Fantasound
is at the wandering stage of its development. We have the tools and
we have not decided what we intend to build with them. These
tools may not be available in the theater "for the duration," but
this might be an excellent period during which to develop a practi-
cable, effective plan for using them. It is within the power of Fanta-
sound, as an idea, to revitalize the industry. This power, however,
can not be fully developed until script, direction, music, and recording
are planned with Fantasound as an organic function.

MOBILE TELEVISION EQUIPMENT5

R. L. CAMPBELL, R. E. KESSLER, R. E. RUTHERFORD, AND
K. V. LANDSBERG**

Summary. — While portability is a necessary requirement for outside pick-up
equipment, several advantages result when portability is carried into the studio.
To equip a studio of adequate size with fixed equipment for operation of several cam-
eras involves considerable time and expenditure. However, with portable studio
equipment, the entire equipment installation can be located to suit studio needs, as
well as moved to different studios or outside locations. ,

The dolly type equipment is described in some detail and systems for program con-
trol are discussed. Some of the design features discussed are portable and flexible
synchronizing equipment; electronic view finders; oscilloscope monitors; and other
operating facilities.

In the course of the development of television equipment, many of
the improvements and simplifications resulting in better apparatus
from the standpoint of performance and convenience of use are really
the applications of ideas developed in allied fields that have been
transferred to meet television design requirements. It may also be
said that television equipment design must follow, to some extent, the
established precedents and engineering practices (e. g., radio broad-
casting equipment). When the precedent is followed too closely,
however, difficulties are likely to appear in operation and maintenance
because of the inherent complexity of the television system. In
sound broadcasting there is only one electrical signal comprising the
intelligence to be transmitted. In television there are five separate
electrical waves (sometimes more depending upon the system em-
ployed) which are combined and transmitted simultaneously to be
used at the receiver in order to reproduce the picture. To make up
this composite television signal wave, several electrical wave-forms
not appearing in the final signal must be generated in order to obtain
the television system operation as we know it today. From this it
can be seen that the operation of a television camera is by no means as

* Presented at the 1941 Fall Meeting at New York, N. Y.; received October
20, 1941.

** Allen B. DuMont Laboratories, Passaic, N. J.

MOBILE TELEVISION EQUIPMENT 23

simple an operation as setting up and operating a microphone for
sound work.

With the above in mind, the purpose of this paper is to describe a
type of television camera equipment designed both for studio and out-
door use with respect to its function in a television operating plant.
Particular components of the system to be described are (1) mobile
camera control dolly ; (2) electronic view-finding system ; (3) flexible
synchronizing equipment; (4) sweep-driven control apparatus; (5)
interchangeability of units; (6) cross-control of camera dollies; and
other operating features. Particular reference will be made to me-
chanical considerations as well as some novel electrical features used
in the equipment.

One application of this equipment would be for broadcast studio
operation. The economic factors involved in equipping a studio
solely for television operation are likely to be out of proportion to the
anticipated return on the investment in the case of most broadcasting
stations or other operating enterprises. Using the studio-type port-
able equipment, television programs can be presented with a minimum
of installation difficulties. The cameras and camera-control equip-
ment are merely rolled into the studio (together with adequate port-
able lighting fixtures) and the show is on. In the case of remote work,
special events, etc., the same equipment can be wheeled into a small
truck, and unloaded and quickly set up for operation into a video line
or relay channel.

A familiar and important requirement of portable equipment is
weight. Considering the number of complex circuits involved in a
television system, it can be seen that this problem is much more se-
vere than in the case of equipment for remote sound work. Consid-
erably more apparatus is involved, and the question that immediately
arises is, "Shall we have a few heavy units or shall we have several
small, light-weight units?" In this equipment the latter was chosen
for the following reasons :

(1) The most logical electrical arrangement was to split the system into
several units according to their functions.

(2) Standard mechanical chassis arrangements could be adopted for ease of
manufacture.

(5) Servicing of all units was to be as convenient as possible.

(4) No unit should be a two-man job to carry.

(5) Future improvements can be added by replacing a unit at a time if de-
sirable.

24 CAMPBELL, KESSLER, RUTHERFORD, LANDSBERG [J. S. M. P. E.

(6) Television cameras using different types of pick-up tubes may be used on
the same equipment chains.

The camera and corresponding control equipment are arranged to
operate in single or dual chains. In the case of a single chain, this
equipment is divided into units as follows :

(1) Synchronizing generator (9) Camera monitor

(2) Blanking sweep and power unit (10) Camera monitor power supply

(3) Camera (11) Camera control power supply

(4) Camera power supply (12) Line amplifier

(5) Electronic view.-finder (13) Line amplifier power supply

(6) View-finder supply (14) Line monitor

(7) Camera control (15) Line monitor supply

(8) Shading generator*

For a dual chain, the equipment required is :

(1) Synchronizing generator 1 (9) Camera monitor 2

(2) Blanking sweep and (10) Camera monitor supply 2

power unit 1 (11) Camera control power

(3) Camera 2 supply 1

(4) Camera power supply 2 (12) Line amplifier 1

(5) Electronic view-finder 2 (13) Line amplifier power

(6) View-finder supply 2 supply 1

(7) Camera control 2 (14) Line monitor 1

(8) Shading generator** 2 (15) Line monitor supply 1

In Fig. 1 is shown the apparatus outlined above arranged for dual
chain operation. On the camera-control dolly are the synchronizing
generator, power units, camera-control units, monitors, and line equip-
ment. With each camera connected to the main equipment dolly is
the auxiliary camera power-unit and the view-finding apparatus.
This assembly is then connected back to the camera-control dolly by
means of the camera cable, interlocked a-c power cable, and view-
finder video cable.

For studio use the camera equipment proper is sometimes mounted
on a studio platform dolly having a pedestal arranged to take the
Akeley gyro tripod head shown in the figure. The camera dolly plat-
form supports the camera equipment and the cameraman, and it can
be moved about the studio for camera "dolly" action shots.

Synchronizing Generator. — The synchronizing generator used in this
equipment is of the flexible fully electronic type and generates the
DuMont synchronous wave (Fig. 4) . The generator can be operated

* For use in conjunction with iconoscope cameras.
** For use in conjunction with iconoscope cameras.

July, 1942]

MOBILE TELEVISION EQUIPMENT

on any of the standards listed below, and can be easily converted to
other standards that may be desirable without affecting the standard
chosen for regular operation.

Lines/frame

441**
525*
625**
343 f
441 j

Fields/second

60
60
30

120

Interlace

2:1
2:1
2:1
2:1
2:1

The synchronizing system may be switched to any one of the above
standards by means of a single wave switch and a few simple adjust-
ments.

FIG. 1. Dual camera chain equipment.

The complete generator is housed in two units, viz., the synchro-
nizing generator unit and the blanking sweep and power unit. Fig. 2
shows the front panel of the synchronizing generator unit with the
cover removed. At the top of the unit is a monitor CRO (cathode-
ray oscillograph) which is connected to all circuits provided with
front panel adjustments. This CRO is of the "automatic" type;
that is, the timing axis is automatically synchronized to the signal
selected by the monitoring selector switch by means of an additional

* F. C. C. (49851) "Television Report," May 3, 1941; also Donald G. Fink,
National Television System Committee, Doc. No. 505L-200M1.
** Experimental Standards,
t Color Standards.

26 CAMPBELL, KESSLER, RUTHERFORD, LANDSBERG [J. S. M. P. E.

deck on the selector switch. Because of the many complex circuits
involved in a synchronizing generator, and because it is desirable
during operation to check the performance of the entire instrument

FIG. 2. Synchronizing generator with front cover
removed.

without shutting down or throwing it out of adjustment, this monitor
CRO is considered essential.

Fig. 3 is a block diagram of the synchronizing system employed in

LINE AMPLIFIER

LINE MONITOR

FIG. 3. Diagram of scanning and synchronizing system.

the equipment. The synchronizing generator can be divided into
units according to the function of the various circuits.

Unit No. 1 (1} Monitor CRO

(2} Frequency divider circuit

July, 1942] MOBILE TELEVISION EQUIPMENT 27

(3) Composite synch wave generator

Unit No. 2 (4) Composite blanking

(5) Master sweep generator

(6) Power supply

The monitor CRO has been explained above. The frequency divider
unit consists of transformer-coupled relaxation oscillators arranged
to divide in accordance with the line and frame scanning standards
selected. The switch to different standards is accomplished by means
of a multiple deck wave switch, connected to the oscillator and asso-
ciated circuits, whereby the optimal circuit constants are selected for
operation on the scanning standard chosen.

Vertical Synch f\j\se

f Interval — — t

<•

H- Horirontal Scanmnq Interva I
V' Vertical Scanmnq Interval

H Synch
Pulse Interval c
.OOH — •[•

A/TY\AA_/U\}JWAT\T\P

Expanded View of Section C-D K+*f — f

e>f Vfertical Pi/lit. Interval Micro»«cond Scale

V4*w Only

FIG. 4. DuMont synchronizing signal.

The composite synchronizing signal generator circuit develops the
synchronizing wave as shown in Fig. 4. Use of this type of signal
makes it possible to minimize operating difficulties in the field so far
as synchronizing generator performance is concerned. This is prin-
cipally due to the fact that the composite synch signal consists of two
signals that are relatively simple to generate. Furthermore, im-
proved vertical synchronizing performance is attained at the re-
ceiver.* In the composite synch signal generator is the shaping cir-
cuit for horizontal pulses, the high-frequency carrier pulse generator
for the field pulses, and the mixing and output circuits.

The blanking, sweep, and power unit contains the circuits indi-
cated in its name. Power for all circuits in the generator is supplied

* National Television System Committee, Doc. No. 325R-200D31.

CAMPBELL, KESSLER, RUTHERFORD, LANDSBERG [J. S. M. P. E.

from this unit by means of a well filtered, regulated supply. From
the generator unit, driving pulses are fed to the sweep generators
which control the scanning circuits on the cameras, monitors, and
shading generators.

Horizontal and vertical blanking voltages are derived from the re-
spective sweep signal generators and shaped in the blanking generator
circuit. They are next mixed to form a composite blanking wave
which is fed to the camera-control unit.

CAMERA

CAMERA CONTROL

To L.n,

SHADING GENERATOR

LINE AMPLIFIER

| —^VIDEO AMPLIFIER P — |

CAMERA

CAMERA CONTROL

SHADING GENERATOR

FIG. 5. Diagram of video system.

Low-impedance outputs are provided in the synchronizing gener-
ator unit to feed a single or dual camera chain with the following sig-
nals:

•

(1} Horizontal sweep

(2) Vertical sweep

(5) Composite blanking

(4) Composite synch

By means of the synch distribution unit, several camera chains may
be controlled from one generator if desired. For normal operation
on dual chain, and with reasonable cable lengths, the synch distribu-
tion unit can be eliminated.

Video System. — Fig. 5 shows the video system employed in a dual
chain. The video signal generated in the iconoscope output resistor
is fed to the preamplifier in the camera, where correction for capaci-
tance of the iconoscope output circuit is accomplished by means of a
peaking stage in this amplifier. A cathode follower output stage on
the preamplifier feeds through the main cable to the camera-control
amplifier, which will be described later.

July, 1942]

MOBILE TELEVISION EQUIPMENT

Camera. — Fig. 6 shows the camera equipment. In the camera are
the video preamplifier (Fig. 7), camera sweep circuits, a type 1850
iconoscope, camera blanking circuits, and protective circuits. Power
for these circuits is fed from a separate cable from the camera power
unit. The amount of power dissipated in the camera itself is such
that the heat generated by the tubes would be excessive, especially
when used in a "hot" studio or out in the sun. Therefore, it has
been found desirable to isolate
those tubes generating most of
the heat and place them upon a
deck on the exterior of the
camera. The lens mechanism is
operated by means of a handle at
the side, and provisions are made
for interchanging lenses in the
approximate range of 6*/2 inches
//2.5 to 16 inches //3.5.

Camera Control. — In the cam-
era control unit are the following
circuits :

(a) Video blanking amplifier
(6) Camera horizontal sweep con-
trol and keystoning circuit

circuit

(d) Pedestal control

(e) Iconoscope beam control
(/) Iconoscope rim light control
(g) Monitor and view-finder video

supply circuits.

FIG. 6.

Camera equipment (Icono-
scope).

The camera cable terminates in
the r.ear of this unit, and all

signals feeding the camera pass through the camera control unit.
(Note : The video signal to the view-finder is fed over a separate small
co-axial cable.) A test-circuit for checking the plate currents of ampli-
fier tubes in the camera control is connected by means of a switch to a
meter on the front panel. The camera video amplifier comprises
five stages and two blanking clippers.

Of interest in the camera control unit are the blanking circuit and
the pedestal control circuit. The former utilizes a low-impedance
diode limiter for clipping the blanking pedestal after mixing, and be-

CAMPBELL, KESSLER, RUTHERFORD, LANDSBERG [J. S. M. P. E.

yond this point in the amplifier is the pedestal control which is a simi-
lar diode circuit, but has a variable d-c bias control for adjusting the
amplitude of the pedestal in accordance with lighting conditions.

The video output circuit of the camera control consists of a high-
level cathode loaded stage which feeds the line amplifier and a low-
level cathode loaded stage for feeding the monitor, view-finder, and
shading generator CRO. Fig. 8 is an interior view of the camera con-
trol on the wiring side. Power for the camera-control unit is ob-
tained from a separate, regulated supply to which the camera power
and view-finder power units are interlocked.

View-Finder. — In motion picture production, probably the most
important technician is the cameraman. His successes or failures

FIG. < . Camera preamplifier.

are very probably due to his ability, before the shot is taken, to visu-
alize how the particular scene will appear when projected on the
screen. By means of the electronic view-finder, the television cam-
eraman has an instantaneously developed picture before him at all
times. View-finding by means of matched lenses is an alternate
method by which the cameraman can monitor his work. This
method is expensive, however, and does not lend itself readily to quick
interchangeability of lenses, sometimes required during programs.
For these reasons the electronic method of view-finding was chosen.
Besides being able to determine the pictorial value of the scene before
the camera, the electronic view-finder is used as the focusing monitor.
Thus, the cameraman can adjust the optical focusing instantaneously,
and since he is in control of the camera, he can anticipate to some ex-

July, 1942]

MOBILE TELEVISION EQUIPMENT

tent the position of the focusing handle and thus maintain the optical
focus at all times. As an auxiliary to the electronic view-finder, a
framing device of some variety or other, or a Mitchell finder, is some-
times attached to the camera for the purpose of providing finding
facilities outside the field taken in by the camera.

The electrical arrangement of the view-finder is as follows : A high-
intensity 5-inch electrostatic- type cathode-ray tube is sweep-driven
from signals to the camera. The sweep voltages are applied to plates
of the cathode-ray tube by means of amplifiers located within the
view-finder unit. The video signals fed to this unit are tapped off a

FIG. 8. Camera control unit, wiring side.

monitor line in the camera control and fed to a video amplifier in the
view-finder unit. Power and control circuits located in the view-
finder supply-unit are fed to the view-finder by means of an inter-
connecting cable. (Controls are provided on the view-finder unit for
maintaining the adjustments of brightness, contrast, and electrical
focus, similar to those employed in television receivers.) Figs. 9 and
10 show the internal arrangements of the view-finder and view-finder
supply-units, respectively.

Shading Generator. — The shading control generator is a separate
unit in the equipment and is used only in conjunction with iconoscope

CAMPBELL, KESSLER, RUTHERFORD, LANDSBERG [J. S. M. P. E.

cameras. The shading signals are derived from the horizontal and
vertical master sweep signals from the synchronizing generator.

FIG. 9. View-finder interior view.

FIG. 10. View-finder supply, interior view.

From these sweep
ated in this unit :

signals the following shading voltages are gener-

(a) Horizontal saw-tooth

(&) Horizontal parabola

(c~) Horizontal sine

(d) Vertical saw-tooth

(e) Vertical parabola
(/) Vertical sine

July, 1942] MOBILE TELEVISION EQUIPMENT 33

These signals can be controlled both in amplitude and phase so that
many varieties of composite shading voltage can be obtained. These
signals are mixed in a common amplifier whose output is fed into the
iconoscope output circuit by means of a line in the camera cable. In
the shading generator are the following circuits.

(a) Shading generation, mixing, and output circuits

(&) Shading CRO

Video from the corresponding
camera control is fed to the
shading generator CRO in order
to monitor the shading signals.
The time axis on this CRO is
driven from either the horizontal
or vertical sweep depending upon
the setting of a switch on the
front panel. Thus, the operator
selects the line-frequency sweep
for checking horizontal shading,
and the field-frequency sweep for
checking vertical shading. A
regulated supply is used to power
all the units in this circuit. Fig.
1 1 shows the shading generator.

Camera Monitor. — On each
camera chain is a monitor unit

connected by cable to the camera FIG. 11. Shading generator,

control corresponding to the

camera being operated. This monitor is usually placed directly on top
of the camera control or shading generator for the convenience of
the operator. The camera monitor is powered from the camera
monitor supply by means of an interconnecting cable. Since elec-
trically the camera monitor is identical with the view-finder, it need
not be described further here. Fig. 12 shows a camera monitor unit
and Fig. 13 the monitoring system in general.

Line Amplifier. — Normally, the camera-control units generate
video signals at sufficient level for feeding monitor lines and control-
ing a camera chain as outlined above. However, the signals from the
two cameras must be selected or mixed, as the case may be, and then

34 CAMPBELL, KESSLER, RUTHERFORD, LANDSBERG [J. S. M. P. E.

mixed with the synchronizing signal to form the composite television
signal. This is accomplished in the line amplifier, which contains the
following circuits :

(a) Video switching unit

(6) Synch mixing amplifier

(d) Four auxiliary output stages

(e) Monitor CRO

Push-button switching of cameras is accomplished in the switching
unit by selecting one or the other of camera-control video signals.
The composite synch signal from the synchronizing generator is fed

to the line amplifier, as well as
the two video signals. Just be-
fore the output stage, a mixing
circuit is provided to introduce
the synch signal with the video.
A synch gain control is provided
for maintaining the proper per-
centage of synch signal to video.
In the event that separate synch
transmission is used, this signal is
cut at this point and fed directly
from the generator to the trans-
mitter or relay apparatus. Fig.
13 shows the line amplifier unit.
The main output stage of the
line amplifier is a heavy-duty
cathode follower stage which

normally feeds a 75-ohm line at an approximate level of 6 volts.
In addition to this stage, three low-level stages are provided for
75-ohm monitor lines, such as program directors, auxiliaries, and
local monitor. The monitor CRO is for the purpose of monitoring
the signal out on the various lines. The video signal applied to the
CRO is normally connected to the main output line. However,
by means of a plug-in arrangement at the back, this CRO can be
used to check all input and output terminals on the unit. Power
for the line-amplifier unit (excepting CRO power, which is a built-
in unit) is obtained from a separate supply which is identical to that
used for powering the camera-control unity. Fig. 14 shows the tube
side of the line amplifier.

FIG. 12. Camera monitor unit.

July, 1942]

MOBILE TELEVISION EQUIPMENT

Line Monitor. — The line monitor unit is used for checking the signal
selected by the switching unit (Fig. 13). In addition to monitoring
the video signal fed out on the line, this unit serves also to monitor
the synchronizing performance of the entire system. The viewing
unit of the monitor is identical with the camera monitor previously
mentioned, with the exception of the driven sweeps, and is powered
from a supply unit also identical with the camera monitor supply. In
addition to this supply, however, is a synchronizing wave from the
composite scanning unit for separating the synchronizing wave from
the composite signal and applying it to the horizontal and vertical
sweep oscillators of this monitor in the same manner as in typical

CAMERA
MONITOR

CAMERA
CONTROL

SHADING
GENERATOR

1 SHADING C R 0

CAMERA

Idta |

SUPPLY

S.eep

SYNCH
GENERATOR

LINE
MONITOR

To TranmlHr

FIG. 13. Diagram of monitoring system.

home television receivers. This line monitor, while intended prima-
rily for operation with the DuMont synchronizing signal, is arranged
to operate on synchronizing signals having rectangular field pulses as
well as those of the radio-frequency type.

Control Dolly and Operation. — The camera-control dolly is alight-
weight frame on 10-inch pneumatic wheels occupying a floor space of
64 X 28 Y2 inches for a dual chain. The height of the control desk
is 30 inches, and the operating desk slides into the unit when not in
use. Single or dual equipment is controlled from the camera-control
dolly by the camera-control operator. He has control over the elec-
trical performance of the video system, including -the synchronizing
generator. Each camera is operated by a cameraman who, with the
aid of the electric view-finder, follows the action, maintains the focus,

36 CAMPBELL, KESSLER, RUTHERFORD, LANDSBERG

and is in general control of the pictorial value of the subject matter
being picked up by his camera. There are provisions for interphone
connections by which this operator is in communication with the
two cameramen and also with the terminal point to which the video
signal is being supplied. A sound program control-unit is sometimes
mounted on the camera-control dolly. When sound facilities are con-
trolled here, some of the duties of the video control operator can be
taken over by the sound man.

FIG. 14. Line amplifier, tube side.

BIBLIOGRAPHY

1 ZWORYKIN, V. K., AND MORTON, G. A.: "Television," John Wiley and Sons
(New York), 1940.

2 FINK, D. G. : "Principles of Television Engineering," McGraw-Hil1\Book Co.
(New York), 1940.

3 ENGSTROM, E. W.: "An Experimental Television System, Part I," Proc.
IRE, 22 (Nov., 1934), p. 1241.

4 WILSON, J. C. : "Television Engineering," Pitman & Sons (London), 1937.

5 BEERS, G. L., SCHADE, O. H., AND SHELBY, R. E. : "Portable Television
Equipment," /. Soc. Mot. Pict. Eng., XXXV (Oct., 1940), p. 327.

6 CASTELLANI, A.: "II Sincronismo in Televisione," Estratto delta rivista, Radio
Industria, No. 23, Luglio, 1936 (Milano).

7 CAMPBELL, R. L.: "Television Control Equipment for Film Transmission,"
J. Soc. Mot. Pict. Eng., XXXIII (Dec., 1939), p. 677.

8 GOLDSMITH, T. T., CAMPBELL, R. L., AND STANTON, S. W.: "A New Method
of Synchronization for Television Systems," J. Soc. Mot. Pict. Eng., XXXV
(Sept., 1940), p. 254.

THE APPLICATION OF POTENTIOMETRIC METHODS
TO DEVELOPER ANALYSIS*

JOHN G. STOTT**

Summary. — Potentiometric titration methods are applied to routine developer
analyses in order to simplify and speed up the operation and to minimize the human
error arising from judgment of color change end points, etc. A brief theoretical treat-
ment of potentiometric titrations is included, and new tests for elon, hydroquinone,
and carbonate are outlined. Previously published methods for bromide and sulfite
are also included. Detailed procedure outlines are included along with a discussion
of the problem of pH vs. the alkali content of a developer. A glossary showing step-
wise procedure operations required to accomplish the analyses has been compiled along
with a complete equipment and chemical reagent list. The precision of the methods
is evaluated by a table showing analysis data on carefully mixed known developers.

In recent years the literature of photographic technology has
yielded many schemes and procedures relative to the quantitative
chemical analysis of photographic solutions. Many of these sugges-
tions have dealt with but one or two of the common constituents of
photographic solutions, particularly in the studies on developers,
whereas a complete quantitative chemical analysis giving accurate
data on all of the important constituents is essential in order to
evaluate the actual photographic function of the developer. While
all these contributions have been of value, it has been difficult for
the motion picture laboratory chemist to segregate this maze of data
and to arrive at a working procedure that will lead to rapid and con-
sistently accurate results in the routine analysis of photographic de-
velopers.

The first corhplete working procedure for MQ developer analysis
was published by Evans and Hanson1 in 1939. The need for further
clarification and extension to more general types of solutions was
realized by R. B. Atkinson and V. C. Shaner, co-authors of
"Chemical Analysis of Photographic Developers and Fixing Baths"2
published in 1940 and based, upon a careful study of the literature as

* Presented at the 1942 Spring Meeting at Hollywood, Calif.; received April
15, 1942.

** Eastman Kodak Company, New York, N. Y.

38 J. G. STOTT [j. s. M. P. E.

well as on their own work. The working procedures outlined call for
a minimum of equipment and technical skill and give accurate and
rapid results.

With this information at his disposal, it is possible for the motion
picture laboratory chemist to run complete chemical analyses on
photographic developers with sufficient speed that the data obtained
can be of immense value in production processing.

It is the purpose of this report to construct a procedure of analysis
such that all the more important constituents of an MQ developer may
be determined by the application of one primary method of end point
evaluation, the only variations from this standard procedure being
in pretreatment of the developer solutions and in titrating reagents
used. This is accomplished by the application of potentiometric
methods to end point determinations. Thus the entire ' 'heart" of
these analysis methods is some type of sensitive potential measuring
device; without this instrument these methods are useless. All the
work of this paper has been done using a Beckman pH Meter, Labora-
tory Model G, which is so constructed that it can be instantly con-
verted from a £H-measuring device to a potential-measuring device
with a range of - 1300 to +1300 millivolts.

THEORETICAL TREATMENT

Since these analysis methods depend entirely upon potentiometric
methods, it will be desirable to outline briefly the theory behind the
phenomenon in order to understand more clearly what is happening
during the course of a potentiometric titration.

When a metal is placed in a solution of its ions, such as a silver
electrode in a solution of silver nitrate, an equilibrium is set up be-
tween the metal and its ions in the solution that can best be repre-
sented by the following equation:

Ag° +± Ag+ + . ie •

silver silver electrode

metal ion transfer

A potential difference exists between this silver electrode and the
solution of silver ions, the magnitude of the potential difference
depending upon the concentration of silver ions. This silver elec-
trode potential can be measured if a reference electrode is placed in
the solution and connected to the silver electrode through a potentio-
meter set-up. The reference electrode must be one that has a known

July, 1942]

POTENTIOMETRIC METHODS

potential and does not affect the reaction at the silver electrode.
Such a standard electrode is the saturated calomel electrode which
maintains a constant potential in respect to the solution regardless of
the other electrode in the solution or the ions in the solution itself.

Suppose that we are interested in determining the bromide concen-
tration of a solution. A silver electrode and a saturated calomel
electrode are placed in the pretreated solution, and the leads from the
electrodes are connected to the potential measuring device. The
potential of the silver electrode is then measured during titration with

PICA

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FIG. 1. Typical bromide determination.

a standard silver nitrate, plotting a curve of the measured potential
vs. the units of silver nitrate added.

Upon addition of the first portion of silver nitrate to the solution
containing bromide, nearly all the silver is removed from the solution
as solid silver bromide. A small amount of silver ion remaining in
solution in equilibrium with the silver bromide determines the po-
tential of the silver electrode. A second addition of silver nitrate
results in a further precipitation of silver bromide ; and since bromide
ions are still present in excess, the amount of silver ion in solution is
still the small amount in equilibrium with silver bromide, increased
slightly due to the decreased bromide concentration. Since the
change in silver ion concentration is very small, the potential change

40 J. G. STOTT [j. s. M. P. E.

is also small. However, when the bromide concentration becomes
small, that is, when we approach the end point of the titration, the
addition of the same increment of silver nitrate causes a much greater
change in the silver ion concentration and the potential changes are
greater, until at the end point we obtain the maximum slope in the
plot of potential vs. silver nitrate. Such a curve is shown in Fig. 1.
The end point of the titration is the point of maximum slope or the
midpoint of the straight-line portion of the vertical part of the curve.
The last portion of the curve represents the change in potential as
the silver ion is increased, but since each addition increases the con-
centration by a lesser increment than the preceding one the slope be-
comes less.

This type of reaction involving the precipitation of the constituent
to be determined is but one of the types of reactions that may be
studied by this method. Oxidation-reduction reactions may also be
studied by measuring the change in the concentration ratio of the
oxidized and reduced form of a substance using an inert electrode.
Such a reaction is illustrated by the titration of an oxidation agent,
such as iodine, with a reducing agent such as hydroquinone. In this
titration the reaction of the oxidant may be expressed as follows :

I2° <=± 21- 2e

iodine iodide electron

ions transfer

The potential changes in the solution are due to the changing ratio
of free iodine to iodide ions, and the rate of change of potential with
added hydroquinone will follow a course similar to that in the silver
nitrate-bromide system.

Before a given substance can be determined by the method out-
lined above it must be certain that interfering substances have been
removed. This pretreatment of solutions prior to titration will be
described in detail in the procedure outlines for the analysis of each
constituent.

This treatment of the theory underlying potentiometric titrations
is merely an outline, and the reader is referred to texts on the subject
for a more complete treatment of the subject.3

PROCEDURES

These procedure outlines will deal with the actual operations re-
quired in pretreatment of solutions prior to titration, along with a
brief explanation as to the reason for carrying out these operations.

July, 1942] POTENTIOMETRIC METHODS 41

All the titrations will be carried out in a similar manner by determin-
ing the potential of the unknown solution after each addition of a
unit volume of reagent, and by plotting the potential in millivolts vs.
the volume of reagent added. When the final titration curve has
been drawn, the equivalence point of the titration is located as
previously described, and a simple mathematical calculation will give
the final analytical result. When further experience has been
obtained in conducting potentiometric titrations, the need for plotting
the titration curves in all the determinations will be eliminated since
violent fluctuations of the potentiometer needle begin to occur near
the equivalence point. Then the actual location of the equivalence
point amounts to determining the maximum potential change ob-
tained upon the addition of small volumes of reagent. This method
of equivalence point evaluation has proved sufficiently accurate in
this laboratory to be within slide -rule accuracy. Since the bromide
and chloride determinations are made on the same solution by means
of locating two equivalence points on a titration curve having two
breaks, it will always be necessary to plot a titration curve for this
analysis. However, in routine analysis where a rough estimate of
the bromide content is possible, the titration may be carried out
without plotting up to the beginning of the first break in the curve,
after which point the plot must be made for most accurate results.
The carbonate determination also requires a plot since the inflec-
tion points of the curves must be carefully followed in order to get
accurate values. However, a scheme similar to the bromide-chloride
determination may be employed in this determination in order to
save time and tedium.

Vigorous stirring of the solution during titration is essential. This
has been accomplished in this laboratory by employing a small non-
sparking motor equipped with a glass stirring-rod which operates
throughout a titration. The actual set-up used in this laboratory is
pictured in Fig. 2. Many refinements and variations of this set-up
are possible, but this simple arrangement has proved most satisfac-
tory.

Schematic condensations of instructions are always valuable in
this type of work, and thus a stepwise procedure for each analysis
will be listed in the glossary at the end of this paper. A complete
list of the equipment and reagents needed to conduct this analysis
work will also be included in the glossary as an aid to installation of
proper laboratory facilities.

J. G. STOTT

[J. S. M. P. E.

Hydroquinone. — The method of separating the hydroquinone from
the rest of the developer solution by extraction from the acidified
developer with ethyl acetate has been previously worked out.4-5
The time-consuming and difficult operation has always been the
determination of the hydroquinone in the organic solvent after
extraction. This present method makes use of the fact that ethyl
acetate is somewhat soluble in water. A 2 5 -ml sample of developer is
placed in a 150-ml extraction funnel and a few drops of 0.04 per cent
thymol blue solution are added. The solution is then acidified with
1 : 1 sulfuric acid until the solution turns red, and then 1 ml of acid

FIG. 2. Typical apparatus set-up.

is added in excess to assure complete extraction of the hydroquinone.
Exactly 50 ml of ethyl acetate are added to the extraction funnel and
the solution is shaken thoroughly for a few moments. The water
layer is then drawn off into a second 150-ml extraction funnel and the
operation is repeated using another 50-ml portion of ethyl acetate.
One extraction removes only 92 per cent of the hydroquinone, and
thus two extractions are necessary in order to obtain maximum
accuracy. The water layer is drawn off again and saved for the elon
determination. The two 50-ml portions of ethyl acetate are then
mixed together in one of the extraction funnels, and 25 ml of SO2 wash

July, 1942] POTENTIOMETRIC METHODS 43

solution are added (100 gm sodium sulfite, 10 gm boric acid, and 1.0
gm of potassium hydroxide1). This wash solution removes all the
sulfur dioxide formed by decomposition of the sulfite in the developer
upon acidification and extracted by the ethyl acetate. This mixture
is shaken thoroughly and the water layer is drawn off and discarded.
Ten mis of the ethyl acetate extract are then pipetted slowly
into 200 ml of water acidified with 2.0 ml of 1 : 1 sulfuric acid while
the solution is being vigorously stirred. When all the ethyl acetate
has gone into solution, platinum and calomel electrodes are immersed
in the solution, the leads are. connected to the potentiometer, and the
instrument is balanced. The solution is then titrated with 0.01 N
eerie sulfate, and the equivalence point is located as previously out-
lined. With the volumes of developer and ethyl acetate, and the
concentration of eerie sulfate used in this outline, the following cal-
culation gives the hydroquinone concentration of the developer :

(ml of eerie sulfate to equivalence point) X 0.22 = gm of hydroquinine per liter

In cases where the hydroquinone concentration of the developer is
unusually low or unusually high, the volumes of developer and ethyl
acetate used may be varied to give increased accuracy or to save
titrating time. If the ratio between the developer volume and the
extract fraction is changed, then the volumetric factor must be
changed accordingly to give correct results.

Ceric sulfate is used in this titration because of its high oxidation
potential giving a large potential change at the equivalence point,
and because of the fact that eerie ions will not add or substitute on the
hydroquinone molecule and thus introduce extraneous reactions hav-
ing a considerable temperature vs. potential coefficient. Precise
temperature control is not essential in this titration since an absolute
potential is not required but rather the rate of change of potential on
addition of unit volumes of reagent.

Eton. — The water layer resulting from the two ethyl acetate
extractions in the hydroquinone determination is used for the elon
determination since almost all the hydroquinone has been removed
by the acid extraction. This hydroquinone-free water layer is again
placed in a 150-ml extraction funnel and several drops of a 0.04 per
cent thymol solution are added. The pH of this solution is then
adjusted by adding 2.0 TV sodium hydroxide until the color of the
solution turns blue. At this pH the elon will be extracted from the
solution by ethyl acetate. Exactly 25 ml of ethyl acetate are then

44 J. G. STOTT [j. s. M. P. E.

added to the funnel, and the mixture is shaken for a few moments.
The water layer is then drawn off into a second 150-ml separately
funnel to be re-extracted, and the above extraction is repeated twice
more with 15 ml of ethyl acetate and then 10 ml of ethyl acetate.
The extraction is done three times to extract a maximum of elon from
the solution since only about 80 per cent is extracted at each opera-
tion. Three extractions will remove about 99.2 per cent of all the
elon, and thus the error from this source is minimized. The three
portions of ethyl acetate are then thoroughly mixed together and
placed in a 50-ml burette. The tip of the burette is then immersed in
400 ml of water acidified with 4.0 ml of 1 : 1 sulfuric acid, and 25 ml
of the ethyl acetate are added slowly to the solution while it is being
vigorously stirred. When the ethyl acetate has gone into solution
completely, the titration is run using 0.01 N eerie sulfate in precisely
the same manner as described for the hydroquinone determination.
With the volumes and concentrations used in this outline, the elon
content of the developer may be calculated by the following relation-
ship:

(ml of eerie sulfate to equivalence point) X 0.0688 = gm of elon per liter

Once again the volume ratios may be altered to conform to the
desired accuracy of the determination.

Sulfite. — The quantitative determination of sulfite in a developer
is accomplished in a manner previously described.2 The determina-
tion is based upon the following reaction :

Na2SO3 + H2O + I2 -+ 2HI + Na2SO4

A portion of the developer is placed in a 50-ml burette. Ten milli-
liters of 1.0 N iodine are placed in a 600-ml Erlenmeyer flask and
diluted with 100 ml of water which has been acidified with 5.0 ml of
concentrated hydrochloric acid. This solution is then titrated with
the developer until the brown color of the solution bleaches out.
This end point may be determined potentiometrically, but in this
laboratory experience has indicated that this is entirely unnecessary.
In fact no starch indicator is needed since the titration is accurate to
within one drop of developer by observing the color change from the
characteristic brown color of the iodine to a colorless solution. Using
the volumes and concentrations herein mentioned, the sulfite content
of the developer can be calculated from the following relationship :

630

. . , — : — - = gm of Na2SO3 per liter

ml of developer required

July, 1942] POTENTIOMETRIC METHODS 45

Bromide and Chloride. — It has been pointed out by Evans, Hanson,
and Glasoe1 that "The photographic influence of the presence of
chloride in the two developers used was investigated over the range of
concentrations from 0 to 8 gm per liter and it was found to have no
effect. However, the sensitivity to bromide was such that if the
bromide analysis included the chloride so that the chloride was replaced
by an equivalent amount of bromide, an appreciable error would arise."
Former methods of determining the halide content of a developer2
have employed the absorption indicator technic which makes no dis-
tinction between the bromide and chloride in the developer. It has
been the experience in this laboratory that if the total halide content
of the developer is used for precise control work regardless of whether
only part of that halide has an actual photographic effect, the actual
function of the halide can not be accurately predicted. In working
developers it has been found that the ratio between the bromide con-
tent and the chloride content does not remain the same over ranges of
total halide concentration, and thus it would seem that a determination
distinguishing between the two halides is necessary for precise labora-
tory control.

A method for determining bromide and chloride in a developer by a
potentiometric titration had been worked out in this laboratory.
However, the method proposed by Evans, Hanson, and Glasoe1
proved to be more accurate since their treatment of the solution prior
to titration proved more effective and complete, and thus interfering
substances were better eliminated. Therefore this basic method is to
be outlined herein.

A 100-ml sample of developer is boiled to complete the reduction of
any silver held in solution by the sulfite and then treated with 40 ml
of 1 : 1 sulfuric acid to decompose all the sulfite. The acidified solu-
tion is then boiled to drive off all the dissolved sulfur dioxide and the
solution is allowed to cool. Eighty cubic centimeters of a solution of
sodium acetate, 150 gm to a liter of water, are added, and silver and
calomel electrodes are immersed in the solution and connected to the
potentiometer. The solution is then titrated with a standard silver
nitrate solution (14.27 gm per liter), and a plot is made of potential vs.
volume of silver nitrate added. The first break in the curve will
come at the bromide equivalence point, and a continuation of tin
titration will reveal the chloride equivalence point. Since only the
bromide is of importance, as has been pointed out, the titration may
be halted at the bromide equivalence point. The concentration of

J. G. STOTT

[J. S. M. P. E.

the silver nitrate is so adjusted that by dividing by 10 the number of
milliliters of silver nitrate consumed in reaching the bromide equiva-
lence point, the grams per liter of potassium bromide are immediately
computed.

ml of std. AgNO3 (14.27 gm/liter)
10

= gm of KBr per liter

An illustration of the resulting plot when both the bromide and the
chloride are titrated is given in Fig. 3.

Sodium Carbonate. — The majority of methods proposed for the
chemical analysis of sodium carbonate in a developer have made use
of ,a gas evolution technic. In this type of analysis the developer

TFRd

OMID
dlNA"

E+CH
JON (

LORIDE

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10-.

>«<

WITH

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LOM

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ECT

ROJDE

120

CHID

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INT

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?«0

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0 no

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FIG. 3. Typical bromide plus chloride determination.

solution is treated with some reagent that ties down the sulfite in the
solution either by converting it to sulf ate or by forming some complex
salt so that no sulfur dioxide will be formed upon acidification. The
sample of developer is then acidified in some closed vessel so that the
evolved carbon dioxide can be collected and measured. Such a
method of analysis was worked out in this laboratory involving the
collection of all the gas in a gas burette with a leveling tube attached,
and the measurement of the total gas volume. This total quantity of
gas was then transferred to a Hempel absorption pipette filled with a
solution of potassium hydroxide, and the carbon dioxide was selec-

July, 1942] POTENTIOMETRIC METHODS 47

lively absorbed. The resulting gas volume was re-measured and the
difference between original and final volumes gave the volume of car-
bon dioxide evolved from the developer upon acidification. A simple
calculation then gave the sodium carbonate content of the developer.

This method, because of its basic gas evolution technic, has several
serious limitations, and experience in this laboratory has indicated
that this analysis is not always trustworthy. One case arose in this
laboratory where calcium carbonate peeling off the sides of developer
tanks coated with hard-water scale caused an error in the final calcu-
lated result of about 35 per cent of the actual sodium carbonate con-
centration of the developer.

It has been found in this laboratory that a titration of carbonate
developers with standard acid leads to an end point that is inde-
pendent of calcium carbonate sludge, and can be used as a method for
determining carbonate. Such a titration is based upon a measure of
the pH of a solution after each addition of acid, and has an end point
similar to the previous potentiometric end points. The point at
which the alkali is all used up or converted to a less alkaline salt gives
the greatest changes in £H with small additions of acid. Such pH
measurements are usually made with a glass electrode but in the case
of the usual photographic developers the course of the titration may
be followed more easily by means of potential measurements made
with a platinum electrode. Evans and Hanson6 have shown that a
stable potential could be measured in an MQ developer, and that this
potential changed rapidly with pH. The true chemical nature of
this potential is controversial but for the purpose of a carbonate
titration this is of no importance, since the end point is determined
by the point of maximum change of potential and not by any con-
sideration of the actual value of the potential itself. However, it
has been found by Cameron7 that potentials measured in developer
solutions are affected by the amount of air or oxygen present so that
vigorous and fairly constant agitation should be used during the
carbonate titration.

A 10-ml sample of developer is pipetted into 200 ml of distilled
water. Either a platinum or a glass electrode is used for this titration
with the calomel electrode as the standard once again. The solution
is titrated with 0.10 N hydrochloric acid and a titration curve of
potential or pH vs. volume of acid added is made. The first break
in this curve represents the conversion of all the sodium carbonate to
sodium bicarbonate. The curve form will appear as illustrated in

J. G. STOTT

[J. S. M. P. E.

Fig. 4, and the equivalence point is located as is illustrated by finding
the exact midpoint of the straight-line portion of the curve. The
following calculation with the volumes and concentrations used will
give the actual sodium carbonate concentration of the developer.

(ml of 0.10 N HC1 to equivalence point) X 1.06 = gm of Na2CO3 per liter

In cases where other alkalis stronger than carbonate are present in
the developer, this acid titration type of analysis will give a quantita-
tive measure of their concentrations. If the above calculation is
used even if other alkalis, such as sodium hydroxide, are present, the
total alkali content of the developer will be computed in terms of

DET5RMirjATIO|N US NG
N.HCL

TTG

ASS VS. CM.OK

CARfrONA

FIG. 4. Typical sodium carbonate determination.

sodium carbonate. This will give a measure of the active alkali in
the developer computed as if sodium carbonate were the only alkali
present. This would not necessarily correlate with the photographic
activity that would result if carbonate were the only alkali present.

£H. — In line with the determination of the sodium carbonate in a
photographic developer is the controversial question of the correlation
between the ^?H of a developer and its photographic activity.

It has been impossible in the work conducted in this laboratory to
associate photographic changes with pH measurements while all
other constituents of the working developer in question remained
constant. A working developer in continuous production was studied

July, 1942] POTENTIOMETRIC METHODS 49

while the sodium carbonate concentration of the developer was
progressively decreased. The pH of the developer was periodically
checked with both a common glass electrode and one of the newer-
type glass electrodes having no sodium ion correction, and complete
chemical analyses also were made at the same time. The control
strips processed at the time of developer sampling indicated that
little or no correlation between pH and photographic results could
be found. However, a determination of its carbonate concentration
gave a close measure of its photographic activity and a direct correla-
tion between these two variables could be established (Table I).

TABLE I

Gamma vs. pH vs. Carbonate Concentration — Eastman Fine-Grain Positive Type

1302

pH (Glass Electrode with Carbonate Values,

No Naf Error) Gamma Gm per Liter

10.38 2.86 68.0

10.14 2.82 38.7

10.12 2.77 37.0

10.11 2.75 35.8

10.10 2.72 22.4

10.08 2.70 18.0

10.10 2.70 18.0

10.08 2.69 19.1

10.09 2.70 18.5

This difficulty has been noticed particularly in the case of positive-
type developers of the carbonate type having high pH values. The
impossibility of predicting the alkali concentration from pH measure-
ments on a positive-type developer is further substantiated by the
data in Table II.

Thus it is felt that a careful chemical analysis of the active alkali in
a positive-type developer using an acid titration technic is essential in
order to predict the activity of the developer Formerly, the empha-
sis has been placed upon pH measurements with the chemical analysis
data functioning as supplementary information.

However, in the case of negative-type developers having lower pH
^values, more correlation between the pH of the developer and its
activity can be established. Moreover, since a chemical determina-
tion of the borax concentration of a developer is time-consuming and
of low accuracy, this method of analysis is omitted in favor of a
measurement of the pU of the developer. Although it is not felt

50 J. G. STOTT [J. s. M. P. E

TABLE II

Table Showing Analysis Data vs. Developer Formula
Positive Developers

Analyzed Data, Mixed Formula, Per Cent

Gm per Liter Gm per Liter Error

Developer P-l

Elon 2.80 3.00 -6.7

Sodium sulfite 78 . 9 80 . 0 -1.4

Hydroquinone 14.5 15.0 —3.3

Potassium bromide 4.05 4.0 +1.25

Sodium carbonate (anhydrous) 38.0 40 . 0 —5.0
£H 10.00

Developer P-2

Elon 1.40 1.50 -6.7

Sodium sulfite 39.3 40.0 -1.75

Hydroquinone 7.22 7.50 —3.7

Potassium bromide 1 . 99 2 . 00 -0.5

Sodium carbonate (anhydrous) 19.4 20.0 -3.1
PR 10.06

Developer P-3

Elon 0.69 0.75 -8.0

Sodium sulfite 19.8 20.0 -1.0

Hydroquinone 3.63 3.75 —3.2

Potassium bromide 1 . 03 1 . 00 +3.0

Sodium carbonate (anhydrous) 10.30 10.00 +3.0
£H 10.22

Developer P-4

Elon 0.25 0.25 ±0.0

Sodium sulfite 29.2 30.0 -2.6

Hydroquinone 4.72 5.00 -5.6

Potassium bromide 0.78 0.75 +4.0

Sodium carbonate (anhydrous) 23.1 . 23.0 +0.43
£H 10.30

that this is the ultimate in proper control of borax-type developers,
too little practical experience and data have been obtained in this
laboratory to warrant a more positive commitment.

DISCUSSION

It is felt that the aforementioned procedures outline a standardized
technic for the chemical analysis of photographic developers. The
analyses are simple and require a minimum of equipment and techni-
cal skill, and yet incorporate factors that tend to eliminate the so-

July, 1942] POTENTIOMETRIC METHODS 51

called "human error." It must be kept in mind, however, that to
date little data have been published regarding the actual function of
each constituent of a developer or the magnitude of the photographic
change introduced by a given change of one or more constituents.
No universal equation can be formulated for this probem, unfor-
tunately, since the equation would hold for only one type of film being
processed in one developing machine functioning under one set of
conditions. Thus chemical analysis of developers as an instrument of
processing control is invaluable, but in studying photographic changes
in terms of developer analysis, the data must be tempered with con-
siderable experience and knowledge of processing conditions until
further technology in this field is introduced.

The author wishes to express his sincere appreciation to D. E.
Hyndman and H. E. White for their unfailing encouragement and
many helpful suggestions. Likewise, the many suggestions and
constructive criticisms of R. M. Evans of the Kodak Research
Laboratories, and Mr. George Kelch and Dr. Harold Frediani of the
Fischer Scientific Company have proved invaluable in the completion
of this work.

REFERENCES

1 EVANS, R. M., HANSON, W. T., JR., AND GLASOE, P. K.: "Synthetic Aged
Developers by Analysis," /. Soc. Mot. Pict. Eng., XXXVIII (Feb., 1942), pp.
188-206.

* ATKINSON, R. B., AND SHANER, V. C.: "Chemical Analysis of Photographic
Developers and Fixing Baths," /. Soc. Mot. Pict. Eng., XXXIV (May, 1940), pp.
495-496.

3 KOLTHOFF, I. M., AND SANDELL, E. B. : "Textbook of Quantitative Inorganic
Analysis," The Macmillan Company, New York, N. Y. (1936), pp. 461-468,
478-486.

4 PINNOW, J.: Zeitschrift wiss. Phot. (1912), p. 289.

'LEHMANN, E., AND TAUSCH, E.: Phot. Korr., 71 (Feb., 1935), p. 71; 71
(March, 1935), p. 35.

• EVANS, R. M., AND HANSON, W. T., JR.: "Chemical Analysis of MQ De-
velopers," /. Soc. Mot. Pict. Eng., XXXII (Mar., 1939), pp. 307-320.

7 CAMERON, A. E. : "The Potentials of Platinum Electrodes in Photographic
Developers," /. Phys. Chem., 42, (April, 1938), p. 521.

GLOSSARY
Schematic Condensation of Analysis Procedures

Hydroquinone — Platinum and calomel electrodes

(1) Pipette 25 ml of developer into 150-ml extraction funnel.

(2) Add few drops of 0.04 per cent thymol blue solution.

52 J. G. STOTT [J. S. M. P. E.

(5) Add 1 : 1 sulfuric acid until the solution is red, then 1 ml in excess.

(4) Add 50 ml of ethyl acetate and shake for one minute.

(5) Remove water layer to second extraction funnel and repeat No. 4.

(6) Remove water layer and save for elon determination.

(7) Mix two ethyl acetate portions and add 25 ml of SO2 wash solution.

(8) Shake for a few moments and remove and discard water layer.

(9) Pipette with vigorous stirring 10 ml of ethyl acetate extract into 200 ml

of water and 2.0 ml of 1 : 1 sulfuric acid in a 1000-ml beaker.
(10) Titrate to equivalence point with 0.01 N Ce(SO4)2 and record volume

Calculation:

(ml of 0.01 N Ce(SO4)2) X 0.22 = gm of hydroquinone per liter
Elon — Platinum and calomel electrodes

(1) Place sample from Hydroquinone No. 6 in 150-ml extraction funnel.

(2) Add few drops of 0.04 per cent thymol blue solution.
(5) Add 2.0 N NaOH until solution turns blue.

(4) Add 25 ml of ethyl acetate and shake for one minute.

(5) Remove water layer to another 150-ml extraction funnel and repeat No. 4

using 15 ml of ethyl acetate.

(6) Remove water layer to extraction funnel and repeat No. 4 using 10 ml of

ethyl acetate.

(7) Discard water layer and mix three portions of ethyl acetate extract.

(8) Place 50 ml of ethyl acetate in burette and add 25 ml with vigorous stir-

ring to 400 ml of water arid 4.0 ml of 1 : 1 sulfuric acid in a 1000-ml
beaker while tip of burette is below surface of water.

(9) Titrate with 0.01 N Ce(SO4)2 to equivalence point and record volume.

Calculation:

(ml of 0.01 N Ce(S04)2) X 0.0688 = gm of elon per liter
Sulfite

(1) Place portion of developer in 50-ml burette.

(2) Pipette 10.0 ml of 1.0 TV iodine into 600-ml flask with 100 ml of water and

5.0 ml of cone. HC1.

(3) Titrate iodine solution with developer until brown color disappears and

record volume.

Calculation:

630

; — = gm of Na2SO3 per liter

ml of developer to end point

Bromide and Chloride — Silver and calomel electrodes

(1) Boil 100 ml of developer in 1000-ml beaker for several minutes.

(2) Add 40 ml of 1 : 1 sulfuric acid and boil for few minutes more.

(3) Allow to cool and add 80 ml of sodium acetate solution and 100 ml of dis-

tilled water.

(4) Titrate with std. AgNO3 solution (14.27 gm per liter) to equivalence point

of bromide and to chloride if desired. Record volume.

July, 1942] POTENTIOMETRIC METHODS 53

Calculation:

ml of AgNO3 to bromide equivalence point

— — — - = gm of KBr per liter

Sodium Carbonate — Glass or platinum vs. calomel electrodes

(1) Pipette 10 ml of developer into 200 ml of water in 1000-ml beaker.

(2) Titrate through carbonate-bicarbonate equivalence point with 0.10 N

HC1, plotting acid volume vs. potential curve. Determine equivalence
point from curve.

Calculation:

(ml of 0.10 N HC1) X 1.06 = gm of Na2CO3 per liter

EQUIPMENT

(This list will include a small overstock in order to accommodate breakage without
hindering continuation of work.)
Quantity Type of Equipment

1 Beckman £H Meter, or similar device for potential measurements

1 5-inch platinum electrode with 30-inch shielded leads

1 5-inch glass electrode with 30-inch shielded leads (optional)

1 5-inch silver electrode with 30-inch shielded leads

1 5-inch calomel electrode with 30-inch shielded leads

1 Electrode holder

1 Small non-sparking electric motor complete with stirrer

1 8-inch hot plate

1 Wash-bottle, complete

3 150-ml extraction funnels with ground-glass stop-cock and ground-glass
stopper

2 Burette stands with porcelain base
2 Fisher double burette holders

1 1000-ml volumetric flask with ground-glass stopper

2 250-ml volumetric flasks with ground-glass stopper
2 100-ml volumetric flasks with ground-glass stopper

4 50-ml burettes
1 2000-ml beaker
4 1000-ml beakers
4 600-ml beakers
4 250-ml beakers
4 100-ml beakers

4 600-ml Erlenmeyer flasks
1 1000-ml graduated cylinder

1 250-ml graduated cylinder

4 100-ml graduated cylinders -

2 50-ml graduated cylinders
2 10-ml graduated cylinders
2 25-ml pipettes

2 10-ml pipettes

54 J. G. STOTT

2 5-ml pipettes

2 2-ml pipettes

2 1-ml pipettes

1 Ring stand

2 2I/2-inch iron rings for extraction funnels

8 500-ml reagent bottles (brown glass with ground-glass stoppers)

Assorted cork stoppers and rubber stoppers

Assorted glass stirring rods

Assorted glass tubing

Assorted rubber tubing
4 90-degree ring stand clamps
4 Pinch-clamps

CHEMICAL REAGENTS

(Stock should always contain listed quantities.)
Raw Chemicals

Quantity Chemical

2 lb Boric acid (C. P.)

5 gal Distilled water

5 lb Ethyl acetate (C. P.)

2 lb Hydrochloric acid (concentrated)

1 lb Potassium hydroxide sticks

2 lb Sodium acetate

2 lb Sodium hydroxide

2 lb Sodium sulfite

5 lb Sulfuric acid (cone.)

Standard Reagents and Solutions

Quantity Solution

500 ml £H = 10.0 buffer solution
500 ml 0.10 N eerie sulfate (Ce(SO4)2) (stock solution)
500 ml* 0.01 N eerie sulfate (Ce(SO4)2) (working solution)
500 ml 1.0 N hydrochloric acid solution (stock solution)
500 ml 0.10 N hydrochloric acid solution (working solution)
500 ml 1.0 AT" iodine solution

500 ml Std. silver nitrate solution (142.70 gm per liter) (stock solution)
500 ml Std. silver nitrate solution (14.27 gm per liter) (working solution)
500 ml Sodium acetate solution (150 gm per liter)
500 ml 2.0 N sodium hydroxide solution
500 ml 0.04 per cent thymol blue solution

500 ml Wash solution (SO2) — 100 gm sodium sulfite, 10 gm boric acid, 1.0 gm
potassium hydroxide

* In mixing 0.01 N Ce(SO4)2 solution from the 0.10 N Ce(SO4)2 stock solution,
care should be taken to add 5 ml of 1 :1 sulfuric acid to each 100 ml of 0.01 N solu-
tion to be made. Ceric sulfate is insoluble in pure distilled water, and the acid
must be added to prevent precipitation of eerie sulfate upon dilution of the 0.10 N
stock solution.

CONTINUOUS REPLENISHMENT AND CHEMICAL

CONTROL OF MOTION PICTURE DEVELOPING

SOLUTIONS*

H. L. BAUMBACH**

Summary. — The chemical reactions that take place in a photographic developer
are discussed in detail. It is pointed out that, following the determination of a
chemical formula that produces optimal photographic results, the concentration of
every important ingredient of this solution may be held constant by the use of con-
tinuous replenishment and chemical control. After a discussion of the theoretical
considerations involved, details are given for the establishment of picture negative,
variable-density sound negative, and positive systems in use at the Paramount West
Coast Laboratory.

INTRODUCTION

The ultimate that the user of photographic materials can ask of his
developing solutions is that they remain absolutely constant, day
after day and month after month, at exactly the values necessary to
obtain optimal results. In order that the developer may produce
consistent results, it is essential that the concentration of each impor-
tant ingredient remain constant. One method of obtaining this con-
dition involves the use of a replenishing solution that is added in an
amount directly proportional to the use of the chemicals within the
developer and is compounded in such a manner that the concentra-
tion of every ingredient of the developer remains exactly the same,
at the constant value desired.1 This method is called one of con-
tinuous replenishment, because replenishing solution is added as the
developer is used, and at any subsequent time the developer is in
exactly the same condition that it was at the start. The life of the
solution is thus indefinite, and the amount of film that has been
processed with it is not significant.

When a solution of this type is used to develop a photographic
image, a chemical reaction takes place whereby the developing
agents, i. e., hydroquinone and metol, sodium sulfite and silver halide,

* Presented at the 1942 Spring Meeting at Hollywood, Calif.; received April
14, 1942.

** Paramount Pictures, Inc., Hollywood, Calif.

56 H. L. BAUMBACH [J. S. M. P. E.

react to form hydroquinone and metol monosulfonates, metallic
silver, and hydrobromic acid. The continued development of photo-
graphic film in a developer thus causes a decrease in the concentra-
tions of hydroquinone, metol, and sodium sulfite, and the formation
of additional hydroquinone and metol monosulfonates and hydro-
bromic acid. The decrease of concentrations of the developing
agents and sodium sulfite results in a decrease in the rates of reaction
of these substances with silver halide and hence extends the time
necessary to produce a given density or gamma on a photographic
film.

All the substances involved in the reduction of the latent image are
quantitatively exhausted from the developing solution, but it does
not follow that all the products of the reducing reaction remain in the
developer. The quantities of products retained depend upon the
extent of diffusion of the ions from the gelatin layer back into the
developing solution, the rate of which may be influenced by many
factors, such as the amount of developer or film agitation, the develop-
ing time, the condition of the gelatin layer, the temperature, etc. One
would expect, for example, that a more nearly equivalent quantity of
bromide ion would be liberated within a negative developer where
the developing action is quite slow, than would be liberated in a
positive developer with its high rate of development.

The products of the development reaction may all influence sub-
sequent action of the developing solution. The developing-agent
monosulfonates are themselves developing agents of somewhat less
reducing power than the parent substances; their developing action
is of concern only in a developer of high pH value. The bromide ion
has a pronounced effect upon the developed image; an increase in
concentration of potassium bromide of 0. 1 gram per liter may reduce
the density of a developed image by as much as 0.20 but for other
types of film this same increase will have a negligible effect upon den-
sity. The hydrogen ion liberated by the developing action slows the
rate of development by reducing the ionization of the developing
agents; the extent of this effect is primarily dependent upon the
buffering salts present, for large amounts of salts of weak acids will
absorb hydrogen ions to form the weak acid so that there is little
change in the pH of the solution.

Every item involved in the reaction of development of a photo-
graphic image results in the reduction of the activity of the solution
toward continued development action. A decrease in the concen-

•July, 1942] DEVELOPING SOLUTIONS 57

tration of hydroquinone, a decrease in the concentration of metol, a
decrease in the concentration of sodium sulfite, an increase in acidity,
and an increase in the concentration of bromide ion act to cause a
lengthening of the developing time required to produce given density
and gamma values for an emulsion.

In addition to the action of silver halide upon a developing solution,
there is the reaction involving the oxygen of the air; while this re-
action is much the same as 'the previous one, there are important
differences. The reaction involves hydroquinone, metol, sodium
sulfite, and oxygen that has dissolved, to form the familiar developing
agent monosulfonates, practically inert sodium sulfate, and sodium
hydroxide. Concentrations of hydroquinone, metol, and sodium
sulfite are reduced, thus causing less developer activity, but the liber-
ation of sodium hydroxide increases developer activity by raising the
pH and hence increases the extent of ionization of the developing
agents. The effect of the increase in pH may more than counteract
the loss in developing-agent concentration, as is illustrated by the
action of a developer of the class of D-76, which gains in activity as it
is subjected to air oxidation.

It is evident that any developing solution that is being used in a
developing machine involves factors and reactions that are related in
a very complex manner. Every reaction involving hydroquinone
and metol reduces the concentrations of these agents, but does so at a
rate that depends upon the amount of film developed in a given time,
the density of the developed image, the extent of developer oxidation,
the amount of dissolved oxygen, the />H, the concentration of sodium
sulfite, the temperature, and doubtless other factors. With use, the
concentration of sodium sulfite also decreases, but the pH may either
increase, decrease, or remain the same. Sensitometric or visual
measurements of a particular film give few clews concerning the
actual condition of the developer after it has been subjected to use.

It is necessary to use adequate methods of chemical analysis that
permit a careful study of the behavior of each developer ingredient
under each condition of use. The type of developing machine used,
the kind of film being processed, the exposure of the film, the method
of circulation, the values of gamma and density selected, the rates of
travel of the film through the machines are factors that compel a
critical analysis to be made of each situation, in order that an accu-
rately operating, continuously replenished system may be designed.

The usual method of developer maintenance is based upon the

58 H. L. BAUMBACH [J. S. M. P. E. *

addition of enough additional metol to counteract the density-de-
pressing effect of increasing amounts of bromide ion, until a condition
is reached for which the loss of emulsion speed can not be compen-
sated. Here the useful life of the developer ceases, and it is normally
discarded and a new batch is prepared. A continuously replenished
system is based upon the addition of a bromide-free solution to the
developing solution at a rate sufficient to dilute the bromide liberated
and hold it at a constant concentration. In addition to diluting the
bromide as it is formed within the developer, the ingredients that are
used up in the reaction are to be replaced by the replenishing solution
at exactly the precise rate necessary to maintain their concentrations
at a constant value.

While it is true that continuously replenished systems lead to con-
siderable economy of operation, the prime reason for their use lies in
the uniformity of the resulting photographic quality. Under the
batch system of replenishment, it is not usually possible to cause a
developing solution to change in the concentrations of all its ingredi-
ents in precisely the manner that maintains uniform values of density
and gamma or a uniform picture or sound quality, whereas it is evi-
dent that the exact maintenance of every developer ingredient at the
concentration that produces good film quality must result in much
closer adherence to standards than is possible with the batch system.

THEORY OF CONTINUOUS REPLENISHMENT

With an absolutely constant developing solution as a goal, it is first
necessary to determine the important factors that influence the rate
of development for a given emulsion. Painstaking research made in
this laboratory, and doubtless duplicated elsewhere, shows that the
following factors pertaining to the processing of film require consider-
ation in order that the processing may be stabilized; factors not in-
cluded pertain chiefly to film manufacturing and handling variations.

(1) Strength of the developing solution.

(2) Degree of developer agitation.
(5) Temperature of the developer.

(4) pH of the "short-stop" or fixing solution.

(5) Temperature during film drying.

(6) Humidity during film drying.

Of these variables, only the first presents any real control problem.
Numbers 2, 3, 5, and 6 are mechanical problems for which engineering
equipment is available. Number 4 is a chemical problem moderately

July, 1942] DEVELOPING SOLUTIONS 59

easy to control. The important chemical variables that influence
the photographic strength of the developer are :

(A) Concentration of hydroquinone.

(B) Concentration of metol.

(D) Concentration of bromide ion.
(£) pH.

Other factors, such as concentrations of other halides, alkalinities,
and developing agent monosulfonates, have some effect, and these
effects are important when used developers are to be synthesized, as
Evans, Hanson, and Glasoe have shown,2 but they need not be con-
sidered in a stabilized system of continuous replenishment, because
such variables are of second-order magnitude. To explain the man-
ner in which a continuously replenished system is derived, let us use
a typical positive developer of the following formula as an illustration :

Hydroquinone 4 . 00 gm per liter

Metol 1.00

Sodium sulfite 40.0
Potassium bromide 2 . 50

pH 10.10

If these concentrations are required in order to produce good film
quality, the attempt to maintain every ingredient constant requires a
certain specific procedure. The only item over which the chemist
has no direct control is the rate of release of bromide ion from the film.
Since bromide ion can not easily be removed from the developer, it
can only be diluted. This rate of release is primarily proportional to
the rate of film travel through the machine and to the integrated
density of the silver deposit. It is evident that, for the sample case
above, it will be necessary to add one liter of bromide-free solution to
the developer for every 2.50 grams of bromide liberated by the film,
if the concentration is to remain constant at 2.50 grams per liter;
hence a release of 3.4 ounces of bromide ion, expressed as potassium
bromide, by 10,000 feet of exposed film in one hour requires dilution
at the rate of 10 gallons per hour. The total quantity of developing
solution that is present is of no concern. Whatever quantities of
other ingredients that are used up in developing this 10,000 feet of
film must be added to the replenisher in addition to the concentra-
tions of these substances already present in the developer.

The rate of release of bromide ion thus becomes the determining
factor for the rate of replenishment, and when only one certain con-

60 H. L. BAUMBACH [j. S. M. P. E

centration of bromide ion is permissible, the replenishment rate be-
comes fixed at the figure that satisfies the condition of equilibrium.

Since the rates of exhaustion of the developing agents and the sul-
fite are in proportion to the rate of release of bromide ion, it is possible
to replace these substances by using the same solutions that are neces-
sary to dilute the bromide, even though it is ideally necessary to use
two different replenishing solutions to maintain a developing solution,
where each would correct for the specific type of oxidation that the
developer undergoes. For the halide oxidation, one solution would
dilute the bromide, correct for the acid liberated, and replace the
hydroquinone, metol, and sulfite used; for the air oxidation, the other
solution would correct for the alkali, and replace the hydroquinone,
metol, and sulfite in different proportion without diluting the bro-
mide. The latter replenisher would contain the same concentration
of bromide that was present in the developer. In actual practice,
the errors introduced by combining these two replenishers are quite
small, because there is little of one type of oxidation without the
other.

Chemical analysis must be used to show the necessary amounts of
hydroquinone, metol, and sulfite that are to be added to a replenisher
to replace these items within the developer. The pH of the replen-
isher must be adjusted to the value that produces the desired pH
within the developer; this value may be higher, lower, or the same,
as conditions indicate.

From the above discussion, the general statement may be made
that the replenisher must be stronger in hydroquinone, metol, and
sulfite and weaker in bromide than the developer that is being main-
tained. The rate of addition of replenisher for a given type of film
development is determined by the rate of release of bromide and by
the bromide concentration that is being maintained.

DERIVATION OF A CONTINUOUSLY REPLENISHED PICTURE NEGATIVE

DEVELOPER

Before any continuously replenished system can be considered, it
is necessary to make a complete chemical study of the reactions that
take place in the developer as it is used.3

Fig. 1 is a record of various chemical analyses for batches of picture
negative developers, where the concentrations of hydroquinone,
metol, and bromide are plotted against film footage. This developer
was being replenished by the addition of a relatively concentrated

July, 1942]

DEVELOPING SOLUTIONS

solution of metol at a rate indicated by sensi tome trie tests. With
use, the developer increased in bromide concentration because the
replenishment rate was not sufficient to obtain proper dilution. No
effort was made to replace hydroquinone since it was necessary to
utilize the decrease in ratio of hydroquinone to metol to compensate
for the influence of the increasing bromide upon emulsion speed.
When the concentration of hydroquinone became low, most of the
developer activity was carried by the metol, and there was no further
opportunity to compensate for bromide; at this stage the developer

10 20

THOUSAND FEET

FIG. 1. Analyses of picture negative developer batches for
various film footages.

needed to be discarded. Near the end of the useful life of the devel-
oper, but before the occurrence of any serious emulsion speed loss, the
concentrations were as follows:

Hydroquinone
Metol

Sodium sulfite
Potassium bromide

0.50 gm per liter
0.80
50.0
0.300

The average of many tests showed that 3000 feet of developed film
released 1.0 ounce of bromide into this developer. Since the total
amount of bromide present in the 450 gallons of developer was 18
ounces and since each strand of the developing machine handles 3000

H. L. BAUMBACH

[J. S. M. P. E.

feet of film per hour, in each hour it is necessary to add 25 gallons of
bromide-free replenisher for each strand if the bromide concentration
is to remain constant. Further tests showed that during this hour
there were used up 4 ounces of hydroquinone, 1.5 ounces of metol, and
2 pounds of sodium sulfite. Therefore, in the 25 gallons of bromide-
free solution that must be added per hour, per strand, these amounts
of chemicals are needed in excess of the concentrations present in the
developer at equilibrium. While chemical analyses have furnished
the information necessary to determine replenishment needs, it is
important that the rate of replenishment be made proportional to the
rate of film travel through the machine. Charts have been prepared
that indicate the correct rate of replenishment for any combination of
development times, and since the system of replenishment is based
entirely upon film footage, any errors that are the result of unusual
film exposures are self -correcting and not accumulative.

j— -+-— f-.-+—+--(-H— -h-4— 4— -I

SODIUM SULFITE

-METOL AND SULFITE-
BOOST

CONTINUOUS REPLENISHMENT-

0 10 20 30

FOOTAGE - THOUSAND FEET

FIG. 2. Analyses of picture negative developer during establishment
of continuously replenished system.

Fig. 2 shows the analyzed concentrations of the picture negative
developer during the installation of this system. The developer was
handled as a batch and replenished as such until 40,000 feet of film
had been processed, after which it was replenished continuously.
This developer might have been prepared synthetically at the desired
equilibrium concentrations with identical results.2

July, 1942]

DEVELOPING SOLUTIONS

A CONTINUOUSLY REPLENISHED SOUND-TRACK NEGATIVE DEVELOPER

The principles that were outlined for the derivation of a picture
negative developer apply equally well to the formulation of a similar
system for sound-track negative. The chief difference lies in the
character of the negative film ; the sound-track area is much smaller
than that of the picture ; and the density and gamma values are some-
what different. Hence for each foot of film developed, the sound-
track uses considerably less of the developing agents and releases
considerably less bromide than does the picture. This difference
would make it possible to replenish the sound-track negative devel-
oper at a much lower rate, but instead, advantage is taken to operate
the developer at a lower bromide concentration in order to obtain
maximum emulsion speed.

CONTINUOUS REPLENISHMENT

>•• °2

12-18-41

12-19-41 12-21-41 ( 12-22-41

•>

e i

o
e

•

0-02
• 04

> 0

o e

• •

BATCH SYSTEM

7-2-41 1 7-3-41 1 7-6-41 J 7-7-41

»>

>ENSITV

5 § i

> 0--.

J^_0 0

•

••

e 7-~«-_

° *"x.

X«^

• •

^^»

-04

^ft

II 10 IS 20 2S 30 3ft 4O 45 90

THOUSAND FEET

FIG. 3. Calculated densities at constant gamma for sound-track
negative under continuous replenishment and under the batch system.

For a development rate of 4000 feet per hour this developer re-
quires dilution at 35 gallons per hour in order to maintain a potassium
bromide concentration of 0.160 gram per liter. Because so little
chemical action takes place in this developer, the replenisher formula
is very little stronger in developing agents than is the developer. So
little metol is used that only an additional ounce in 300 gallons is
necessary in the replenisher. Air oxidation is the dominant oxida-
tion in this developer ; consequently the pH of the replenisher is made
considerably less than that of the developer so that the developer pH
remains constant.

Continuous replenishment has been of great advantage in this

64 H. L. BAUMBACH [j. s. M. P. E.

developer, especially with the use of fine-grain negative films. Tests
have shown that these films are three times as sensitive to a bromide
concentration change as the conventional type ; consequently careful
chemical control is very important.

Fig. 3 compares, for four consecutive days in each case, calculated
values of density for a given gamma as plotted against film footage,
for the two types of developer systems.

It is evident that continuous replenishment has improved the
accuracy of development and eliminated differences between be-
ginnings and ends of runs.

A CONTINUOUSLY REPLENISHED POSITIVE DEVELOPER

Because positive emulsions can be made to give good quality when
the bromide concentration is high in a developer, and because it is not
important to maintain a high emulsion speed of film used for this pur-
pose, positive emulsions can be processed with much greater economy
than can negative emulsions. A continuous system of replenishment
yields from 100 to 150 feet of developed film for each gallon of re-
plenisher used in a negative system, whereas there are 1200 feet of
film processed for each gallon of positive replenisher used.

As was the case with the negative systems discussed previously, it
is necessary to select the desired bromide concentration for this
system, but since almost any reasonable figure can be tolerated, it is
convenient to use a figure that results from another factor. If no
squeegee is used to return the volume of developer carried off by the
film as it leaves the developing unit, an amount of developer is re-
moved that is primarily a function of the film footage and only secon-
darily a function of the speed of the film through the machine. There-
fore, replacement of the volume of developer lost, as film is processed,
by an equal volume of replenisher will maintain the total volume of
developing solution at a constant figure and result in an equilibrium
concentration of bromide. As our particular system is designed, the
bromide comes to equilibrium at a concentration of 3.50 grams per
liter. The system of continuous replenishment for the positive
developer thus is greatly simplified; it operates solely upon the
basis of maintaining the total volume of developer constant and the
adjustment of the rate of replenishment to values necessary to satisfy
this condition.

The greatest amount of development, of all three systems, occurs
in the positive system ; and this fact, coupled with the small amount

July, 1942] DEVELOPING SOLUTIONS 65

of replenisher used per foot of film developed, causes the positive
system to have the greatest differential in ingredient concentrations
between replenisher and developer. For example, in order to main-
tain the hydroquinone concentration at 2.0 grams per liter in the
developer, it is necessary to adjust this concentration to about 6.0
grams per liter in the replenisher. Consequently the positive
developer requires the most frequent chemical analyses of all the
systems in order that it may be controlled.

ERRORS AND CHEMICAL CONTROL METHOD

In the systems of continuous replenishment that have been dis-
cussed, the proper replenishment rate has been determined, either
directly or indirectly, as a function of film footage passing through
the machine ; the actual exposure that the film has received and the
amounts of silver actually developed have not been considered. It
would be expected that differences in integrated developed film den-
sity would require modification of the replenishing solutions, and
such is actually the case. However, the large volumes of developer
solutions that are used contrast with the small degree of chemical
action that takes place, and over moderately short periods of time
the developing solution concentrations will show no change. To
make the system of continuous replenishment practicable for use in a
production laboratory, it is necessary to adjust the replenishment for
an average processing condition and then, by periodic chemical
analysis, to make correction of the developer to its "standard" for-
mula. If the chemical analyses are frequent enough and correction is
made immediately, the developer ingredients are held very close to
constant values. It is impracticable to make corrections in the re-
plenisher formula to correct for errors in the developer formula unless
these errors are consistently in one direction.

Experience has taught us that the number of analyses that are
needed for efficient control of the developers is not excessive. For
the picture negative developer, pH determinations are made every
two hours of use, bromide determinations are made every day, and
analyses for hydroquinone, metol, and sulfite are performed twice a
week. The entire system is so close to equilibrium that the greatest
error that could be attributed to chemical inaccuracies is ±0.01 in
density units. The sound-negative developer is controlled in similar
fashion, with the one exception that the hydroquinone, metol, and
sulfite analyses are performed weekly instead of twice every week.

66 H. L. BAUMBACH

Here the replenisher is so nearly like the developer, because of the
small chemical action involved, that the system is extremely stable.
The positive developer requires analyses for />H and for bromide
every four hours, and daily analyses for hydroquinone, metol, and
sodium sulfite. Under these conditions this developer is easily con-
trolled to ±0.02 density unit.

Chemical analyses are made upon developers for pH by the use of
the Beckman Laboratory ^vlodel pU. Meter fitted with a Type E
glass electrode. Determinations of £H upon fixing baths are made
with the Beckman Industrial Model pH Meter, equipped with the
conventional type glass electrode. Analyses for hydroquinone and
for metol are made by the extraction of the developing agents with
ethyl ether and titration with standard iodine solution.4 Analyses
for sodium sulfite are obtained by the titration of a known quantity
of iodine with the developer.5 Analyses are made for bromide by the
potentiometric titration of the acidified developer with silver nitrate,
using a silver electrode and a calomel electrode.6

REFERENCES

1 EVANS, R. M. : "Maintenance of a Developer by Continuous Replenishment,"
J. Soc. Mot. Pict. Eng., XXXI (Sept., 1938), p. 273.

2 EVANS, R. M., HANSON, W. T., JR., AND GLASOE, P. K.: "Synthetic Aged
Developers by Analysis," /. Soc. Mot. Pict. Eng., XXXVIII (Feb., 1942), p. 188.

EVANS, R. M., HANSON, W. T., JR., AND GLASOE, P. K. : "Iodide Analysis in
an MQ Developer," /. Soc. Mot. Pict. Eng., XXXVIII (Feb., 1942), p. 180.

3 EVANS, R. M., AND HANSON, W. T., JR.: "Chemical Analysis of an MQ
Developer," /. Soc. Mot. Pict. Eng., XXXII (Mar., 1939), p. 307

4 BAUMBACH, H. L. : "The Chemical Analysis of Metol, Hydroquinone, and
Bromide in a Photographic Developer," /. Soc. Mot. Pict. Eng., XXXIII (Nov.,
1939), p. 517.

6 ATKINSON, R. B., AND SHANER, V. C. : "Chemical Analysis of Photographic
Developers and Fixing Baths," J. Soc. Mot. Pict. Eng., XXXIV (May, 1940),
p. 485.

6 CROWELL, W. R., AND LUKE, W. W. : "The Potentiometric Determination of
Halides in Photographic Developers," University of California at Los Angeles.

THE PRACTICAL ASPECT OF EDGE-NUMBERING 16-MM

FILM*

H. A. WITT**

Summary. — The use of the edge-number and how it is generally applied in the
industry, and the advantages of edge-numbering at 16 frames as a standard for 16-mm
film are discussed.

It has been long-accepted practice to edge-number 16-mm film in relatim to 35-mm
frames. Such practice has proved advantageous in complex films, such as one con-
structed of some 16-mm film combined with 35-mm to complete a final subject in
finished form on 16-mm, still maintaining all the advantages gained in the past
practice by the use of 35-mm.

It has long been essential in all branches of the industry to edge-
number 35-mm film. Without the benefit of edge-numbering, many
hours of additional work would be necessary in handling the multitude
of details in the assembling of a motion picture production. Edge-
numbering is found to be of practical value in the laboratory as
designations of the raw-stock in relation to the sensitometric strips;
as indications to the laboratory for the printing of rushes or desig-
nated portions of takes to be printed in some abnormal manner; for
indicating trick effects ; and for cataloguing and identifying prints in
vaults. It has proved invaluable in the final assembling of any nega-
tive where a selection is made in terms of feet of film.

Although none of these would seem to indicate any necessity for a
definite standard, the 16-frame interval between edge-numbers has
become accepted practice and the majority of those involved in such
detail work have become accustomed to such designations.

If we are to adopt the newly recommended practice of edge-
numbering 16-mm film at intervals of 40 frames, we should have a
new designation bearing no relation to the 35-mm edge-numbering
with reference to frame count.

* Presented at the meeting of the Mid-West Section, Feb. 24, 1942; and at the
1942 Spring Meeting of the Society at Hollywood, Calif.
** Wilding Picture Productions, Inc., Chicago, 111.

68 H. A. WITT [j. s. M. P. E.

As to the relative merits of edge-numbering at 40-frame intervals
or by any other method, let us take a practical case of a simple pic-
ture and follow it through its various steps.

To the cameraman, any scheme of edge-numbering would be ac-
ceptable, inasmuch as he uses it mainly for the designation of trick
effects or printer light corrections. The laboratory requires no special
method of edge-numbering inasmuch as its use is mostly for reference
and selection.

The film editor, however, has a very definite use for the edge-
number. It is used for the designation and selection of material,
storage, and an indication of synchronism of sound and picture when
edited as separate track and picture. A film editor could have for
final assembly into a picture the following combination :

a 16-mm picture,

a 35-mm sound-track, to be edited into a picture interspersed with standard
library stock footage (35-mm).

The 35-mm track and picture are edge-numbered at intervals of 16
frames and the 16-mm picture at 40 frames. In synchonizing pic-
ture action with the voice track, the editor has two different designa-
tions and as he progresses to the layout of his optical work for normal
dissolves or fades from his 35-mm stock picture library material to his
16-mm picture, his procedure becomes highly involved. The possi-
bility of error is greatly increased because of the usual practice of
specifying for such trick effects a fine-grain duplicating master posi-
tive or dupe negative and of ordering such material through the labo-
ratory according to edge-number.

If we are to revert to the practice of numbering the working print,
we should have a problem which is unresolvable under the newly
recommended practice, because we now have a 35-mm sound-track
that should bear some designation comparable to that of the 16-mm
film being run in combination with it.

In the final assembly of the negative the edge-number is used pri-
marily as a reference in selecting material, but the actual assembly
becomes somewhat complex due to the material that is being matched.
In the final assembling of the 16-mm negative track and 16-mm nega-
tive picture, the following are to be checked and matched :

16-mm re-recorded sound-track (negative),
16-mm original picture (negative),
16-mm dupe picture (negative),
35-mm sound-track print,

July, 1942] EDGE-NUMBERING 16-MM FILM 69

16-mm picture print,
35-mm library picture print.

It is obvious that with these various types of film sizes and edge-
number designations, a considerable loss of time and great likelihood
of error on the part of the editor will result.

In the steps necessary to the final completion of this picture, the
edge-number designations are frequently of prime importance in
either selection or layout. We need comparable designations for both
35-mm and 16-mm film. The suggestion has been made that 16-mm
film be numbered at intervals of 16 frames, or 32 frames. A 16-frame
interval would be too small to be of any real value, but by using a 32-
frame interval and omitting the even numbers and using a star or
other identifying mark at the 16th frame, the system would become
comparable to the 35-mm.

A NEW ELECTROSTATIC AIR-CLEANER AND ITS APPLI-
CATION TO THE MOTION PICTURE INDUSTRY*

HENRY GITTERMAN!

Summary. — A brief description of the principles and early development of elec-
trostatic precipitation, and a brief description of a new air-cleaner using the electro-
static principle that generates practically no ozone. Reference is made to recent ap-
plications of the new precipitator .

The theory of electrostatic precipitation is not new. In 1824
Hohlfield described the action of an electrical discharge upon smoke.
However, no practical significance was attached to his discovery. In
1884 Sir Oliver Lodge made the first practical use of the principle of
electrostatic precipitation in the removal of fumes from a lead
smelter.

Around 1906 Dr. Cottrell was successful in making use of this
principle in the removal of fumes in zinc and lead smelters. Dr.
Cottrell was able to patent his method, turning the patent over to the
Research Corporation. This corporation has been successful ever
since in collecting troublesome fumes in any number of industries.
Nearly all of us are familiar with the Cottrell precipitators which
this corporation has installed in the smokestacks of many of our
public utilities. The Cottrell system uses extremely high voltages
and high currents, which in turn cause the generation of huge amounts
of ozone, for which reason the system has never been practicable in
cleaning atmospheric air for breathing purposes, or where the action
of ozone could be detrimental to product or equipment.

Principle. — It was not until 1931 that Mr. G. W. Penney, manager
of the Electrophysics Division of the Westinghouse Research Labora-
tories, was able to announce an air cleaner using the principle of
electrostatic precipitation that generated practically no ozone. The
functions of charging and collecting the solid particles in the air were

* Presented at the 1941 Fall Meeting at New York, N. Y.; received February
2, 1942.

** Westinghouse Electric & Manufacturing Co.; New York, N. Y.
70

NEW ELECTROSTATIC AIR-CLEANER

separated and the necessary operating voltages reduced to 13,000
volts maximum. This was accomplished through the use of a
collecter cell, consisting of cylindrical rods alternating with fine tung-
sten wires. Thirteen thousand volts is applied between the wire and
the rod, creating a strong electrostatic field. As the particles in the
air-stream pass through this field, all the particles receive a positive

SOJKCf Of

POSITIVE HKH

FIG. 1. Operation of electrostatic air-cleaner.

Uncleaned
Air

Mechanically
Cleaned Air

Electrostatically
Cleaned Air

FIG. 2. Relative efficiency of air-cleaning methods ( 10,000 cu-f t of
air through each sample).

charge. Immediately following this electrostatic field in the line of
air-flow are placed parallel plates 5/i« mcn apart. These plates are
charged with 6000 volts d-c. The positively charged particles are
attracted to the negative plates, grounded and deposited. Fig. 1
illustrates this principle.

An outstanding improvement due to this development is the fact

H. GlTTERMAN

[J. S. M. P. E.

that for the first time electrostatically cleaned air can be breathed.
A power-pack is used to supply the direct current needed for the
operation of the ionizer section and the collector section. This
power-pack consists essentially of transformers to increase ordinary
110-120- volt single-phase, 60-cycle current to the voltages required.
This current is then rectified by means of rectifier tubes. A pul-
sating direct current results, which is smoothed out into a pure di-
rect current by means of capacitors.

^^^^gmjjjmjmmjjm Extremely small currents are needed.
-— • <M|jL~' , For example, 40,000 cubic feet of air

per minute can be cleaned with an
|3 expenditure of only 400 watts.

IfcjlH Efficiency. — All our experimental

work to gain an idea of comparative
efficiency has been based upon a par-
ticle-count system of testing. On this
basis we find that the best of air-filters
can remove only about 32 per cent of
the particles in the air-stream. On
the other hand, electrostatic precipi-
tation removes as much as 97 per
cent of the particles. The average
commercial air-filter removes in the
neighborhood of 10 per cent of the
particles. It is safe to say that elec-
trostatic precipitation is the most
efficient method of air- cleaning ever
developed.

Fig. 2 illustrates the comparative
efficiency of an ordinary air- filter
with electrostatic precipitation. This
method of testing is known as "the
blackness test." The actual test con-
sists in drawing air through a standard

laboratory cloth for a given length of time on the dirty-air side
of the air-cleaner. The same procedure is followed on the clean-
air side until a spot of equal discoloration is arrived at. The ratio of
the time needed to accomplish this is then evaluated and a per-
centage of efficiency is obtained. As an example, suppose that it
would take one minute to get a certain blackness on the dirty-air

FIG. 3. Standard collector cell.

July, 1942] NEW ELECTROSTATIC AIR-CLEANER 73

side and ten minutes to get equal blackness on the clean-air side.
We would then have a ratio in time of 1 :10 or 90 per cent efficiency.

Fig. 3 shows a standard collector cell. It is 8 inches wide, 36 inches
high, and 24 inches deep. This cell is capable of handling 600 cubic
feet of air per minute. The velocity of the air is 300 feet per minute.

In Fig. 4 we see illustrated the method of placing the cells in an
ordinary air-distributing duct. It is obvious that this method admits
of great flexibility in fitting the cells into the duct. The cells have a
foundation consisting of a bedplate that inclines the cells at an
8-degree angle from the vertical. Water is used to wash the cells and
remove the precipitate. The inclination of the cells permits easy
drainage in the cleaning operation.

FIG. 4. Method of placing cells in ordinary air-distributing duct

Self-contained units with one to three cells are available for small
installations. It is only necessary to attach them to a source of air
and the proper duct work, combined with a blower system.

Application. — For a number of years after Dr. Penney 's original
development of this equipment, various trial applications were
made in the field. Refinements in design were made and finally in
1938 the apparatus was officially announced as a commercial
product.

Since then hundreds of installations have been made. For in-
stance Precipitron-cleaned air is supplied to huge steel mill motors
and generators for cooling purposes. It has been found that the old
methods of air-cleaning allowed many particles to enter the motors

74 H. GlTTERMAN

and generators, causing damage to the insulation. In addition,
periodic shut-downs were necessary in order to blow out the dirt that
had accumulated. Through the use of Precipitron air-cleaning,
these troubles have been eliminated.

In commercial applications — offices, restaurants, stores — it has
also been found that Precipitron air-cleaning preserves interior
decoration by removing the small particles that discolor and dis-
integrate furnishings. Lighting efficiency can be maintained at a
maximum since dust does not accumulate on lighting fixtures, walls,
or ceilings.

Certain particles in the air-stream are organic in composition, and
when these particles get into air-conditioning and ventilation ducts
they putrify and generate obnoxious odors. Electrostatic precipi-
tation removes these particles from the air-stream and permits more
pleasant breathing air. As a result the amount of fresh air brought
into ventilating and air-conditioning systems can be reduced and
great savings in cooling and heating energy effected.

The optical and film industries also have been benefited greatly by
this method of air-cleaning. These industries need the cleanest air
possible in their manufacturing and processing divisions. All the
major film-manufacturing concerns use this method of air-cleaning.
Many of the optical instrument manufacturers have found it indis-
pensable in their process work.

Little if any work has been done in electrostatic air-cleaning
connected with the air-conditioning of modern theaters. It is
obvious that great economies and improvements can be made through
the use of this equipment for such applications. We hope to be
able to announce successful applications in the near future. Ap-
plications for Precipitron air-cleaning exist in nearly every industry,
since dust is a universal problem.

CURRENT LITERATURE OF INTEREST TO THE MOTION PICTURE

ENGINEER

The editors present for convenient reference a list of articles dealing with subjects
cognate to motion picture engineering published in a number of selected journals.
Photostatic copies may be obtained from the Library of Congress, Washington, D. C.,
or from the New York Public Library, New York, N. Y. Micro copies of articles
in magazines that are available may be obtained from the Bibliofilm Service, Depart-
ment of Agriculture, Washington, D. C., at prevailing rates.

American Cinematographer

23 (June, 1942), No. 6

Visual Suggestion Can Enhance "Rationed" Sets (pp.
246-247)

Technical Progress of Russia's Film Industry (pp. 248-
249, 285)

Animated Cartoon Production Today (pp. 250-251, 282-
285), Pt. Ill — Animation

Training Films in the U. S. Navy (pp. 252-253, 281-282)

Choosing Film Materials for Professional 16-Mm Pro-
duction (pp. 254, 278)

A.S.C. and Academy to Train Camera Men for Army
Service (pp. 255, 278)

Debunking Filtering (pp. 262, 274, 276)

Making Composition Work for You (pp. 263, 272, 274)

British Kinematograph Society, Journal

5 (Jan., 1942), No. 1
Film Editing (pp. 2-9)

Future Trends in Laboratory Practice (pp. 10-19)
Difficulties in Producing Imbibition Prints from a Tri-
Pack Original (pp. 20-26)

Educational Screen

21 (May, 1942), No. 5
Motion Pictures — Not for Theaters (pp. 180-182), Pt. 37

International Projectionist

17 (Mar., 1942), No. 3

Projection Room Uses of Tube Data (pp. 7-9, 20)
Color of Light on the Projection Screen (pp. 10-12)

J. W. HOWE
G. L. IRSKY

C. FALLBERG
W. EXXON, JR.

J. A. LARSEN, JR.

A. J. STOUT
P. TANNURA

S. COLE

I. D. WRATTEN

M. V. HOARE

A. E. KROWS

L. CHADBOURNB
M. R. NULL, W. W.

LOZIER, AND D. B.

JOY

CURRENT LITERATURE

Optical Illusions Producing Three-Dimensional Effects

(pp. 16-18) T. M. EDISON

Conserving Critical Materials in the Projection Room
(pp. 19, 23)

17 (Apr., 1942), No. 4
Reducing Trouble-Shooting to Systematized Procedure

(pp. 7-8, 22)
New 13.6-Mm Carbons for Increased Screen Light

9-10)

L. CHADBOURNE

M. T. JONES, W. W.
LOZIER, AND D. B.
JOY

Theater Equipment Goes to War (p. 11)

Review of Projection Fundamentals (pp. 12-14), Pt. I.

Kinds of Electric Current
Underwriters Code as It Affects Projection Rooms

(pp. 16-19)

Motion Picture Herald

147 (May 16, 1942), No. 7
New Screen Aids Television for Theaters (p. 93)

147 (May 30, 1942), No. 9
Wartime Conservation in Theater Projection (pp. 23-26,

31)

Determining the Efficiency of Your Reflector-Lens Sys-
tem (pp. 27-28) C. E. SHULTZ

Optical Society of America, Journal

32 (May, 1942), No. 5
Visual Sensitivities to Color Differences in Daylight

(pp . 247-274) D . L . MACADAM

The Photographic Reciprocity-Law Failure and the

Ionic Conductivity of the Silver Halides (pp. 299-303) J. H. WEBB

SOCIETY ANNOUNCEMENTS

1942 FALL CONVENTION

HOTEL PENNSYLVANIA, NEW YORK, N. Y.
OCT. 27TH-29TH, INCLUSIVE

After a very successful convention at Hollywood last May, the Society has de-
cided to continue holding its meetings twice a year, at least so long as the holding
of conventions does not interfere with the war effort. In fact, it is felt that the
continuance of technical activities in societies such as our own is important in an
age such as the present when both peacetime and wartime activities are so highly
technologic.

The Fall Convention will be held at the Hotel Pennsylvania, New York, Octo-
ber 27th to 29th, inclusive. These dates have been chosen in view of the fact that
the Acoustical Society of America will hold its convention at the same place on
October 30th and 31st. Those who are interested in the activities of both organi-
zations may thus take in both conventions in one trip. Details of the Fall Con-
vention will be published in the next issue of the JOURNAL. Those contemplating
presenting papers should communicate with the Office of the Society at the
earliest possible date. (See inside front cover.}

ADMISSIONS COMMITTEE

At a recent meeting of the Admissions Committee, the following applicants
for membership were admitted into the Society in the Associate grade:

BRIGGS, ALLEN GOEHNER, W. R.

3117 Calhoun Blvd., 262 Glenwood Ave.,

Minneapolis, Minn. East Orange, N. J.

CHERRY, HERBERT GOLDBLOOM, LeRoY

5310 Magnolia St., 3509 Ingleside Ave.,

Philadelphia, Pa. Baltimore, Md.

FERREL, G. F. HEYER, JOHN

Box 191, 52 Fordholm Road,

Belton, Mo. Hawthorn, E. 2,

FLECK, H. R. Victoria, Australia

Vaporate Co. Inc., HUGHSON, M. R.

130 West 46th St., 141 Brantwood Road,

New York, N. Y. Snyder. N. Y.

78 SOCIETY ANNOUNCEMENTS

LAYFIELD, F. E. SCHLOEMER, GENE

323 South Xanthus, 605 Park St.,

Tulsa, Okla. Rolla, Mo.

SMITH, D. G.

PAGES, M. H. Technicolor Motion Picture Corp.

JT n ' If/' 30 Rockefeller Plaza,

Bella Vista, B. A. New York, N. Y.

REISS, MEYER THOMPSON, R. L.

811 Quincy St., N. W., 1005 East Mulberry St.,

Washington, D. C. Evansville, Ind.

In addition, the following applicant has been admitted to the Active grade :

WEISSER, F. E.
Commack Road,
Islip, L. I., N. Y.

JOURNAL OF THE SOCIETY OF
MOTION PICTURE ENGINEERS

VOLUME XXXIX • • • AUGUST, 1942

CONTENTS

PAGE
Cinematography in the Hollywood Studios (1942)

Black and White Cinematography J. W. BOYLE 83
Putting Clouds into Exterior Scenes

C. G. CLARKE 92
Technicolor Cinematography W. HOCH 96

Technology in the Art of Producing Motion Pictures

L. S. BECKER 109

Stop Calibration of Photographic Objectives

E. W. SlLVERTOOTH 1 19

A Review of the Question of 16-Mm Emulsion Position

W. H. OFFENHAUSER, JR. 123

The Production of Industrial Motion Pictures

L. THOMPSON 135

1942 Fall Meeting, New York, N. Y., October 27th to
29th 142

(The Society is not responsible for statements of authors.)

JOURNAL OF THE SOCIETY OF
MOTION PICTURE ENGINEERS

SYLVAN HARRIS, EDITOR

Board of Editors

ARTHUR C. DOWNES, Chairman

JOHN I. CRABTREB ALFRED N. GOLDSMITH EDWARD W. KELLOGG

CLYDE R. KEITH ALAN M. GUNDELFINGER CARLETON R. SAWYER

ARTHUR C. HARDY

Officers of the Society

*President: EMERY HUSE,

6706 Santa Monica Blvd., Hollywood, Calif.
* Past-President: E. ALLAN WILLIFORD,

30 E. 42nd St., New York, N. Y.
^Executive Vice-President: HERBERT GRIFFIN,

90 Gold St., New York, N. Y.
** Engineering Vice-P resident: DONALD E. HYNDMAN,

350 Madison Ave., New York, N. Y.
*Editorial Vice-President: ARTHUR C. DOWNES,

Box 6087, Cleveland, Ohio.
** Financial Vice-P resident: ARTHUR S. DICKINSON,

28 W. 44th St., New York, N. Y.
* Convention Vice-President: WILLIAM C. KUNZMANN,

Box 6087, Cleveland, Ohio.
* 'Secretary: PAUL J. LARSEN,

1401 Sheridan St., N. W., Washington, D. C.
*Treasurer: GEORGE FRIEDL, JR.,

90 Gold St., New York, N. Y.

Governors

*MAX C. BATSEL, 501 N. LaSalle St., Indianapolis, Ind.
**FRANK E. CARLSON, Nela Park, Cleveland, Ohio.

*JOHN G. FRAYNE, 6601 Romaine St., Hollywood, Calif.

*ALFRED N. GOLDSMITH, 580 Fifth Ave., New York, N. Y.
**EDWARD M. HONAN, 6601 Romaine St., Hollywood, Calif.

*I. JACOBSEN, 177 N. State St., Chicago, 111.
**JOHN A. MAURER, 117 E. 24th St., New York, N. Y.

*LOREN L. RYDER, 5451 Marathon St., Hollywood, Calif.

* Term expires December 31, 1942.
** Term expires ^December 31, 1943.

Published monthly at Easton, Pa., by the Society of Motion Picture Engineers.
, Publication Office, 20th & Northampton Sts., Easton, Pa.

General and Editorial Office, Hotel Pennsylvania, New York, N. Y.

Entered as second-class matter January 15, 1930, at the Post Office at Easton,

Pa., under the Act of March 3, 1879. Copyrighted, 1942, by the Society of Motion

Picture Engineers, Inc.

CINEMATOGRAPHY IN THE HOLLYWOOD STUDIES (1942)

Summary. — Current practices in cinematography as followed in the Hollywood
studios are described. Some of the subjects covered are camera equipment, set light-
ing, operation of camera crews, exteriors and use of booster lights, exteriors taken in-
doors, make-up, diffusion, coated lenses, use of light-meters, color contrast of sets, set
and production designs, value of hard light for exteriors and interiors, stand-ins, air
photography, matching stock shots, Technicolor and bipack, Kodachrome, and mono-
pack.

Black and White Cinematography

JOHN W. BOYLE**

We have come a long way from the time, some twenty years ago,
when one was able to recognize the cameraman by the fact that he
wore his cap backward, just as one could tell the director by his
puttees. No longer does the producer say, "A rock is a rock; shoot
it in Griffith Park." Most of the pictures today are made in the
studios or on the back lot, and it is the job of the director of photog-
raphy to set the mood of the story by lighting the scenes in the
proper key and using what photographic effects he can conceive
and execute on short notice. Although much time is devoted to the
preparation of the story and dialog of a picture, only on rare occasions
is sufficient preparation allowed for the technical problems involved
in set and location planning. Successful pictures result from the
teamwork of the various technical staffs involved, with the pur-
pose of achieving the finest artistic and commercial photographic
results on every picture produced, be it a simple "short" or a
feature.

On some of the more pretentious productions "production design-
ers" have contributed much to further the artistic photographing of

* Presented at the 1942 Spring Meeting at Hollywood, Calif.
** Universal Studios, Universal City, Calif.

JOHN W. BOYLE

[j. a M. P. E.

the picture. These production designers are skilled artists, and are
called in well in advance of the actual production. They become
familiar with the script, cast, and the amount of money that may
be spent on the production, and are able to furnish to the director and
cameraman a series of sketches showing what the actual scenes should
look like. It is hoped that this kind of preparation will come into
general use for all types of pictures.

On this subject, Jack Okey, art director for Alexander Korda's
Jungle Book, has written the following:

Scene from Captains of the Clouds showing use of booster lights for
technicolor exterior shot. (Warner Bros. -First National.)

"The present-day motion picture is without question the most com-
plex medium of expression ever devised by man. It is certainly not
the brain-child of any one person but rather the sum of many indi-
vidual contributions. All creative talents are called upon to contribute
their efforts, the maker of pictures among them. Nothing can paint
a picture of a picture as well as a picture.

"In reality a motion picture is a series of pictures. The man most
fitted to create pictures is an artist, with his highly specialized train-
ing and talent. A man having the power of visualizing an idea and

Aug., 1942]

CINEMATOGRAPHY, 1942

drawing a picture of it that all may see, certainly has a place in the
making of motion pictures.

"If the producer would call upon the artist at the same time he
called upon his writer, and would have him prepare preliminary draw-
ings or paintings of the subject in mind, there is little doubt that the
sketches would help both the producer and the writer to decide many

Effect of water reflections, produced by moving broken
glass reflecting light from shots.

matters ; in fact, the director and the chief cameraman should be in-
cluded in these early conferences. Often a simple sketch will be
of assistance to the writer in showing plainly what might take thou-
sands of words to explain. By predetermining questions in this early
stage, many costly delays and disappointments can be avoided.
Decisions can be made from the sketches as to the desirable lighting
effects, wardrobe, characterization, location, sets, and even the very

JOHN W. BOYLE

[J. S. M. P. E.

spirit or mood of the whole production. During the preparation
period, the artist can make a series of sketches to act as future re-
minders of the many discussions taking place at the time. As the
script develops, a series of sketches, known as continuity sketches, can
be made of the various scenes. They provide advance information,
and make it possible for the departments to predetermine their work
in an intelligent and artistic manner.

"Often on the set, a man under the excitement and stress of the
many responsibilities resting upon him may not be able to recall read-

Dolly shot on location, with booster lights,
rails permit trucking shot of incoming train.

Dolly tracks alongside
(Paramount Pictures.)

ily what he had previously decided to do with a certain situation. A
quick glance at the sketches will recall the entire scheme to him. The
sketches can be referred to in the same way in which the written
script is used. Sketches that break up the written scene into long,
medium, and close shots can stimulate the creative ability of both
director and cameraman. They can be guides to strong, beautiful,
dramatic patterns or compositions.

"The arrangement of the characters on the screen in good composi-
tion can do much to heighten the story. As one simple, well known
example, in a "close-up" of an aggressor the head should be well for-

Aug., 1942]

CINEMATOGRAPHY, 1942

ward on the picture plane, leaving more space behind the head than
in front of it ; whereas the close-up of the defendant should show more
space in front of the head than behind it. Sketches can convey such
things as reminders to all concerned throughout the whole production
period.

"The word 'composition' has appeared here several times. It is a
word almost impossible to define. There are a few elementary rules to
govern the building of a picture, such as rhythm without repetition,
the bearing of one thing upon another, the relative influence of lights

An example of overhead lighting.

and darks, but these are so self-evident that the painter does not
think of them while he is at work. He attacks his subject with his
inherent good taste or talent, composing the drama of the subject
and injecting into it as much beauty as he can conceive.

"I do not mean to infer that there have not been many beautiful
pictures recorded in the past, because there most certainly have.
What I mean to point out is an easier and surer way, a method of sug-
gestion and help, a wiser procedure."

The short time allotted in practice to the cinematographer to read
the script and prepare for production should be emphasized. It
is a common occurrence to finish one picture on a Saturday night and

88 JOHN W. BOYLE fj. s. M. P. B.

be handed a script for a new picture to start the following Monday
morning. The cinematographer must then spend Sunday in ac-
quainting himself with the final version of the script ; arriving on the
set early Monday morning he finds the painters still painting and the
set dressers still at work. However, none of these activities have
deterred the "gaffer" or chief electrician from roughing in the light-
ing and in placing the overhead units on scaffolds above the
set.

With screen stories today overloaded with dialog, it is important
that the picture be kept moving. This calls for much camera move-
ment and the shifting of the cast from one position to another through-
out the set. Such camera movements involve much study in lighting
and composition, and here again it is only by the complete coordina-
tion of all departments concerned that the smooth, finished results
one sees on the screen are possible. The "operative" cameraman
must know his cue to "pan"; the sound technicians must have their
cues and must know when and where to move the microphone without
causing shadows; the mixer must know when to change the fader
setting; the "grip" must know when and at what speed to "dolly"
the camera; the assistant cameraman must be constantly alert and
must anticipate each actor's move and keep the lens focused always
at the proper distance (most scenes, especially those showing two or
more actors in the scene, are shot at "split focus," and since the actors
do not always keep to their marks on the floor, the assistant must use
his judgment) . Other members of the staff must also know their cues;
the electricians, for instance, must known when to dim or brighten
certain lighting units, by the aid of dimmers. A good dimmer opera-
tor will often compensate for errors of the actors in missing their
marks by brightening the light if the actors do not come far enough
forward or by dimming the light if they come too close. It is such
coordination of all departments that makes for success; sometimes a
scene that is perfect from the dialog or action standpoint is spoiled
because someone did not "hit his marks" correctly. Constant at-
tention and expert handling of the various gadgets by these tech-
nicians behind the camera have saved many a production hour for the
company.

While modern camera equipment has somewhat simplified these
tasks, it is not possible for every unit, even in the major studios, to be
equipped with the latest model camera; hence a compromise must
often be effected under certain conditions. For example, it is com-

Aug., 1942] CINEMATOGRAPHY, 1942 89

mon practice to start a scene with a "big head" close-up or insert,
and then dolly back to a medium or long shot. This calls for variable
diffusion, and only on the most modern cameras is variable diffusion
practicable. A compromise adopted in such cases is the use of a
slight amount of diffusion, which softens the extreme close-up some-
what and yet is not objectionable in the long shot. With the new
Fox camera and the latest Mitchell camera, the diffusion is adjustable
from as soft an effect as may be desired for the big close-up to
absolute clearness or no diffusion in the medium or long shot. Since
variable diffusion is usually necessary in making dolly shots, an addi-
tional assistant is required to manipulate the device, which leads to
crowding on the dolly or rotambulator. Metro-Goldwyn-Mayer
Studios have overcome the difficulty by designing a remote-control
device for operating both the follow focus and the variable diffusion.

The "set" procedure is as follows : The set is prepared and dressed,
and the night crew or "swing gang" rigs the overhead lighting units,
deliberately placing on the scaffolds more units than may be neces-
sary, as it is more economical to have the units already in place than
to take time to place them once operations on the set have begun.
The cameraman and chief electrician having learned whether the
scene is to be a night or day sequence, the electrical crew proceeds to
rough in the lighting and wire the necessary fixtures. If the first
sequence happens to be an interior shot with the sun shining brightly
outside, preparations are made to light the set in a rather high, or
day, key. The required, or desired, position of the sun is deter-
mined, and high-intensity arc lamps are placed so as to project a
stream of light through a door or window, or both, and cast shadows in
the proper direction. If both night and day sequences are to be
photographed on the same set, then a decided contrast in lighting must
be achieved by keeping the day scenes in a high key and the night
scenes in a low key.

The director and cinematographer next confer as to the best way in
which to play the action called for by the script, and the cast is called
in and is rehearsed by the director. The cinematographer watches
the action through a finder which he carries about the set; behind
him follows an assistant, who marks the floor with small pieces of ad-
hesive tape indicating points at which the actors stop in their mo-
tions, while the grip marks the various camera positions so that he
may lay the track along which the dolly rolls, since a good percentage
of shots are made from dollies these days. In the meantime other

90 JOHN W. BOYLE [j. s. M. P. E.

members of the cast and the crew watch the rehearsal. After the first
rehearsal the "second team," or "stand-ins/' are brought in, and the
cameraman and gaffer proceed to light them in their various positions.
The camera dolly is put into place on its tracks and a mechanical
rehearsal follows, the stand-ins walking through the action and stop-
ping at the various positions indicated by the tapes on the floor, for
the benefit of the electricians, camera crew, and sound men. The
grips, besides timing their dolly moves and seeing that the dolly oper-
ates with absolute quiet, search in the meantime for stray light-rays
that might strike the lens or the diffusion mediums in front of the lens.
After all lights have been "goboed" and dolly movements corrected,
the lights are adjusted as may have been found necessary, and the "first
team" is called in for a dress rehearsal. This final dress rehearsal with
the actors themselves allows the director and cinematographer to
make final corrections in lighting and movement. It is not unusual
during such dress rehearsals to alter or delete certain lines of dialog ;
such changes in turn necessitate changes in the camera movement and
dolly timing. After such corrections have been made, microphone
shadows eliminated from the camera field, and dolly movements
smoothed out, the crew and cast are ready for a "take." Rarely is the
first take satisfactory unless the scene is a very simple one. Addi-
tional takes, or retakes, are made until a satisfactory one is obtained,
with such lighting corrections being made as might be necessary.

Because of the variability of the weather, the unwanted noises of the
outdoors, and other difficulties, more and more exterior scenes are
being photographed inside the studios. These artificial exteriors are
more convincing today than they used to be because of many technical
improvements and advances. The speed of emulsions has been in-
creased, enabling the cameraman to "stop down" the lens while
using only slightly additional light. The "special effects" men can
assist the illusion by hanging leafy tree branches in such positions as
to cast pleasing shadow patterns on walls and buildings ; slight motion
of the leaves creates a convincing illusion of outdoors. The use of
water and glass surfaces, with the proper reflection and agitation,
leads to many realistic marine effects in both night and day shots.

Make-up in motion pictures compares to retouching of "still pic-
tures"; in other words the artists must be "retouched" before they
are photographed. Naturally there are some whose complexions re-
quire hardly any make-up, but in most cases make-up is necessary to
cover slight skin blemishes and smooth out the skin textures. Arthur

Aug., 1942] CINEMATOGRAPHY, 1942 01

Miller reports that in the production How Green Was My Valley none
of the cast wore make-up except the mother and daughter. The
men were coal miners, and looked the part; however, these same
actors in a modern story with a drawing room setting would no doubt
have been made up. Most of the studios are well organized with good
make-up departments, and their cooperation with the cameramen has
been most helpful.

While there is no question that the new high-speed fine-grain pan-
chromatic emulsions and the improved American-made lenses lead to
clean-cut photography, the modern electrical equipment is also a very
important contributing factor. The lighting units have been brought
well under control; the light can be directed by "barn doors" to the
spots desired ; and numerous other gadgets may be used for screening
and softening the light in certain areas. Dimmers and their operators
play very important parts in almost every scene. Often the camera
and operators are so close to an actor that their shadows appear in
the scene; by dimming the lamp causing these shadows the objec-
tion is eliminated, and the lamp is brought up to its proper bright-
ness after the camera is out of range. Small units are helpful when
working in congested areas, and much credit should be given to the
studio electricians for their ingenuity in handling the small units so
that they deliver the necessary light without being seen by the
camera.

The use of artificial light outdoors is common practice nowadays for
the simple reason that it has been found to be an economy. Lamps
on location allow quicker set-ups. The units are more flexible and
can be placed where desired and, unlike reflectors, need not be placed
where the sun is shining. While both reflectors and lamps are used
on location, the lamps are much better for close-ups and intimate
action ; they can be easily controlled and are not so hard on the artists'
eyes. For lighting wooded sets and sets in congested areas, lamps are
indispensible. It is not unusual to finish a day's work on location
after all the sunlight has gone, in some cases after darkness has set in.
Matching the artificial light with daylight is an art that most of the
men have mastered. Likewise, it is sometimes necessary to shoot
night scenes in the daytime; if the locations are picked with discretion
and the correct filters and booster lights are used, such night exteriors
can be handled economically. When production costs rise for one
reason or another, the studios economize, especially on the lower-
budget pictures, by using standing sets and cloth backings, and by

92 CHARLES J. CLARKE [j. S. M. P. E.

taking other short-cuts. The cameraman is expected to use his art
and imagination in manipulating the lights and the camera so as to
cover up such deficiencies.

Practical cinematography has led to many improvements in the art.
As newer and better films became available they were rapidly adopted,
for which reason the art of the cameraman is constantly changing.
Recommendations and suggestions of the cameramen played a part
in the development and application of the photoelectric exposure
meter; in most studios the meter is used to establish the key
lighting, and, with the increasing use of these precision instruments,
pictures are now being printed very uniformly, despite the widely
varying types of lighting and effects employed.

The method of calibrating lenses by measuring the transmitted
light with a photoelectric meter, as developed by the Camera Depart-
ment of Twentieth Century-Fox under Dan Clark, has eliminated
practially all errors of exposure. A recent test of 150 lenses so cali-
brated, regardless of focal length, make of lens, etc., and used under
identical conditions, gave exact exposure at a given stop. It has
also made possible the effective use of coated lenses, giving greater
contrast and better definition as compared with uncoated ones.

Putting Clouds into Exterior Scenes

CHARLES G. CLARKE*

A landscape that includes a cloud-flecked sky is far more attractive
than the same scene without the clouds, particularly in photographic
landscapes, where, without the benefit of color, the cloudless sky area
is rendered as an uninteresting expanse of monotone. It has long
been a major problem of the studios to be assured of obtaining attrac-
tive exterior scenes, for a great deal of equipment and personnel are
involved when moving a unit out of the studio. It is not possible to
decide suddenly to move out to an exterior location; exterior scenes
must be planned well and at least twenty-four hours in advance.
During the long California summer, weeks on end follow without
clouds of any description, and the cameraman is often faced with the

* Twentieth Century-Fox Film Cprp., Beverly Hills, Calif.

Aug., 1942] CINEMATOGRAPHY, 1&42 93

problem of having to photograph scenes with little or no pictorial em-
bellishment. Heretofore, in the major productions, it has often been
necessary to "dupe" in clouds after the scenes have been made, and
sometimes locations at a distance have been chosen where conditions
indicated that chances of obtaining real clouds were reasonably favor-
able. The budget for the average production does not permit the
great expense of either of these alternatives, so a process had to be
developed by means of which clouds could be produced with depend-
ability and economy.

The process to be described uses appropriate photographic trans-
parencies of real clouds set before the camera, and operates on the
principle that the barren sky acts as a printing light. The trans-
parency reduces the light passing to the film in proportion to the den-
sity gradations of the transparency. On the finished positive the
whitest "cloud" is of the brightness of the unfiltered sky. As photo-
graphic emulsions are especially sensitive to blue light, plain sky areas
are rendered very bright. This characteristic provides a means of
producing bright, fluffy "clouds." Obviously sky-correcting filters
are not used, for if the sky is darkened by filters, the brilliancy of the
"cloud" is destroyed. An appropriate negative of a sky-scape that
has been exposed with good filter correction is chosen. The view
should have a perspective and cloud arrangement that will later form
a pleasing composition when a transparency made from the negative
is combined with an actual foreground setting. When making the
positive transparency, the lower portion is "dodged" off so that the
foreground setting may be photographed through this portion which is
perfectly clear and transparent.

The transparency is set up before the lens of the camera and is
adjusted so that the horizon of the transparency is in proper relation
to the horizon of the actual scene. A wide-angle lens is employed and
the smallest lens-stop possible is used so that the transparency and
the actual scene may be in the same relative focus. In bright sun-
light, stops from// 14 to //22 are usually desirable. As wide-angle
lenses at small stops have great depth of field, the focus may be set
considerably forward of the actual objects in the scene, so that the
transparency and the most distant parts of the actual scene may be in
equally sharp focus. Coated lenses are of decided benefit to the sys-
tem because of the better definition, crisper images, and the lack of the
"hot spot," often encountered when wide-angle lenses are stopped
down greatly.

94 CHARLES G. CLARK [j. S. M. P. E.

The process is used principally on location where transportation is
an important factor, for which reason the relatively small size of 1 1 X
14 inches has been chosen for the transparencies. For stationary
scenes the transparencies are placed about 18 inches from the lens.
For panoramic scenes a device is employed that accommodates films
16 X 40 inches in size. Films are used because they may be curved to
the radius of the panning camera and thus be at a uniform distance
from the lens. To overcome displacement or "slippage" the camera
is so mounted that the nodal point of the lens is at the axis of the
vertical tilt and panoram. For the stationary set-up the transparency
is attached to the usual matte-box supports, while for the panoramic
attachment an auxiliary plate is introduced between the tripod and
the panoramic head. To this plate is attached the holder for the
curved plates, for obviously they must remain stationary while the
camera is panned across the transparency.

This invention has been in use since late in 1939, and many of the
productions of this studio have been released with cloud scenes made
by this process. Among them may be mentioned Brigham Young,
Hudson's Bay Company, Romance of the Rio Grande, The Cowboy and
the Lady, most of the Cisco Kid series, and many others. In many
cases these artificial cloud scenes are edited in with real-cloud scenes,
and even the cameraman who photographed them both is afterward
often at a loss to tell which is which.

Besides the great advantage of being able to create pictorially
beautiful scenes under unfavorable circumstances, the economic
importance of the method is very great. In a production such as the
Romance of the Rio Grande, for example, some forty of the scenes were
made in this manner. If the clouds had been put in by the matte-
shot method the cost would have run into many thousands of dollars.
The complete outfit that was used cost less than $100. The set-up is
quite simple and is accomplished almost as rapidly as an ordinary set-
up. The camerman has the visual effect before him on his ground-
glass. After adjusting the transparency to fit the setting, he is ready
to make the scene. No further tests or experimentation is neces-
sary. No alteration of the negative is necessary, and it is processed
in the usual way.

In addition to simplicity and economy, the method has the advan-
tage over the matte-shot method of being able to place action over the
sky area. In the matte-shot and duping methods, it is necessary to
keep all action below the horizon, lest such action run over into the

Aug., 1942] ClNEMATOGfcAPHY, 1942 95

division line when the sky portions are later exposed in. The cloud
portions of the transparencies are ordinarily perfectly clear, only the
areas between clouds having any density. As long as the action stays
within the "cloud" it may be placed anywhere in the sky. Buildings,
steeples, moving trees, and the like may extend over the horizon.
When it is known that close-ups are to follow extreme long-shots in
the same sequence, a suitable cloud plate is chosen so that the action
may be properly composed in both. Dark objects or silhouettes may
extend through the sky portions with no "ghosting" whatever, for
they are but obstructions to the printing light of the sky.

As the intensity of the skylight varies greatly, from a direct front-
light to an extreme back-light, a great number of transparencies of
different densities would be required to suit all such conditions if some
means of control were not possible. Such a control is provided by a
graduated neutral-density filter. For front-lighted and side-lighted
subjects the light is relatively uniform and control is seldom necessary.
For back-lighted subjects the sky, hence the printing light, varies
considerably from sunrise to noon and on to sundown. For such
shots we carry two densities of the same plate. Adjustments between
these densities are provided by the graduated neutral-density wedges.
If the sky is extremely brilliant and the transparency is rendered too
light in relation to the foreground, the neutral-density filter is ad-
justed so as to retard the sky area only. When the transparency is
rendered too dense in relation to the foreground, the filter is inverted
so as to retard the foreground area, allowing the sky area to "print
up." Location kits contain about twenty different transparencies
including examples of front-lighted, side-lighted, and back-lighted
clouds. In some the composition is arranged so that buildings, trees,
etc., may extend over the horizon on one or both sides. As the plates
may be reversed left to right to suit the composition or lighting condi-
tions, the number of plates required is thereby reduced. From time
to time new transparencies are made, and before being put into pro-
duction their densities are tested photographically. Those that meet
approval are put into the location kits. Needless to say this system
has the hearty approval of the cameramen. No longer do they dread
having to photograph exterior scenes on cloudless days. The direc-
tors likewise, realizing the importance of pictorial beauty in the
productions, have been most coooperative in arranging action within
the limits of the method.

This system is not intended to replace real clouds. It does, how-

96 WINTON Hocn [J. S. M. P. E.

ever, offer a fine substitute when nature has not been generous.
Even when there are real clouds in the sky, the scenes may have to
be photographed at angles that do not include the clouds. Edited
together, scenes with and without clouds are inconsistent. This
method fills in the gaps. Dramatic moods may be created by choos-
ing suitable cloud formations regardless of the actual sky conditions
at the time. Hazy skies, which are so difficult to control with color-
correcting filters, make no difference to the transparency, which re-
quires only a printing light whether it be hazy or otherwise. By
using suitably toned or dye-toned transparencies the method may be
applied to color-photography.

Rear-projection plates may be made at any time after or before the
regular production long-shots have been made. Using the same
transparency for both purposes guarantees that the identical
cloud effects will prevail in each when the final scenes are edited
in sequence. It is impossible to discuss here all the adaptations of
this method. The method is constantly used in this studio, and
extensions and improvements in the technic of using are occurring
constantly .

Technicolor Cinematography

WINTON HOCH*

This essay does not in any way pretend to be a comprehensive
coverage of the equipment, methods, and problems of the Technicolor
cameraman at the present time, but is intended rather to present some
of the items that might be of general interest. Inasmuch as the
general technics of motion picture photography are well known and
have been frequently discussed in the literature, there will here
be presented some of those aspects that are peculiar to, or receive
emphasis from, the fact that the camera is photographing in
color.

These aspects arise in very large part before photography, and of all
the preparation activities that take place before the actual start of
photography, two that are very important to the Technicolor camera-
man are color design of the sets and costume color selection. The

* Technicolor Motion Picture Corp., Hollywood, Calif.

Aug., 19421 CINEMATOGRAPHY, 1942 97

importance of proper color design and costume color selection can not
be overemphasized. The set colors should be chosen with care for
hue, chroma, and value, and with a knowledge of the costumes to be
used, the relative importance of the set, its cutting and physical rela-
tionship to the other sets, and the orientation of these factors with the
script. While it is true that the cameraman can control the set ef-
fect to a large extent by his lighting of it, this color control work must
be carefully handled or the screen result will not be optimum. Obvi-
ously the more adverse conditions the cameraman meets, the more the
production is likely to suffer either in screen result or lost production
time to correct those adverse conditions, or both. These two
factors of set and costume color probably go farther than any other
group of factors in representing the difference between a black-and-
white production and a color production. The net result might be
termed the "color score" of the picture. It might be compared to a
musical score sometimes flashing and brilliant and at other times sub-
dued. It follows that if the problem is ignored, discords usually oc-
cur.

Obviously, without sets and costumes in color, the only colors left
are flesh tones. A very interesting color emphasis effect was demon-
strated in the RKO picture, Irene, where an entire set was designed in
neutral tones and the star wore the only color.

To handle this very important set and costume color contact, the
Technicolor Motion Picture Corporation has available the services of
a color control department to advise on the color design of the sets,
the evaluation of costume colors, and allied problems. This depart-
ment has a background of experience from all productions, and its
experience and highly developed judgment are available, through the
normal functioning of the department, to each new production as it
comes along. This department is the spearhead of the Technicolor
photographic activity.

The make-up problem is handled, as in black-and-white pictures, by
the studio make-up departments, although the color cameraman does
have the responsibility of requesting the "touching up" of the make-up
as it may be necessary, and he very often has special problems that
require close collaboration with the make-up man. For instance, on
exteriors with the actors working in sunshine, they usually begin to
sunburn, and make-up changes must be made in many cases to handle
these gradually tanning complexions. Frequently this means a new
make-up problem in order to keep the camera appearance of the flesh

98 WINTON HOCH [J. S. M. P. E.

tones the same. It can readily be seen that this can become a difficult
job. The reverse is also true. As the troupe begins stage work after
returning from the exteriors, their tanned skins will slowly fade and
the problem of compensating by make-up continues. Occasionally
we have had difficulty due to physical exertion on the part of the
principals, causing faces to flush beneath the make-up, which effects
the camera appearance.

The color camera is very discerning of flesh quality, and we find it
necessary to include in the make-up area the neck and throat, and the
hands and arms if they show. On rare occasions no make-up at all
is used, and it is frequently omitted when photographing babies, as
their clear smooth skin generally needs no correction.

It should be kept in mind that, generally speaking, the primary
function of make-up is to correct extremes in colors, cover blemishes,
and generally reduce the tone range observed in any average group of
persons. If one will note the varying complexions of people, he will
readily appreciate that if three or four persons were lined up side by
side to be photographed, it would be highly desirable and probably
very necessary to correct the flesh tones and greatly reduce the tone
spread. This must not be interpreted as meaning that all flesh tones
should appear alike. Variations of tone are very desirable. It is
the extremes that are undesirable. Obviously a white man with a
heavy tan who photographs like an Indian is not a very convincing
white man. The most critical care is given to the close-ups, especially
of the principals. The care and attention given to the problem are,
of course, directly proportional to the screen importance of the skin
tones.

A great deal of time and money has been spent in solving the make-
up problem, and literally thousands of feet of film have been exposed
and printed on various make-up tests to discover the best make-up
materials and technics for the color camera. A proper make-up
requires highly skilled artistry in its application.

Other important items to the cameraman are his lights. Here,
color photography again introduces an important factor of which the
cameraman must be cognizant, and which must be watched very
closely on certain types of work. That factor is color-temperature.
Our present three-strip Technicolor cameras are balanced to an aver-
age daylight color- temperature. For true color rendition, especially
in the pastel shades and neutral grays, this temperature should
not vary on the set by more than about =*=2500.

Aug., 1942] CINEMATOGRAPHY, 1942 99

There has been in the past some misconception regarding the status
of incandescent lamps (designated in the studios as "inkies") with
respect to Technicolor photography. Some people have understood
that the Technicolor cameras are changed over by filters and prisms to
accept an unfiltered incandescent-lamp color- temperature. Others
have indicated that they thought that the camera automatically cor-
rected any unfiltered inky light that might be added to an arc-lighted
set. These conceptions are wrong.

The filters, prisms, and film of our present three-strip Technicolor
camera are all balanced to daylight and this balance is used both for
exteriors and interiors. This simplifies the production problem a
great deal. First of all, there is manufactured and used only one
set of film emulsions. This means that manufacturing, ordering,
shipping, storing, exposing, and developing are all standardized for
one system, with all the obvious attendant advantages, not the least
of which is a lower negative cost.

This single standard also simplifies set-lighting problems, both in-
terior and exterior. All regular Technicolor lighting units have been
balanced to this daylight color-temperature by actual and repeated
tests with the Technicolor camera. Therefore, they may all be used
interchangeably as far as color-temperature is concerned. The only
other factors governing their use are the very direct functional ones
such as size of unit, light output of unit, operational characteristics
of the unit, the type of light that it gives (that is, whether a "hard"
light or "soft" light), and the unit efficiencies with respect to light
output vs. current input, and with respect to light output vs. the throw
required of the unit for the particular job in hand.

The more common units used for general production are (HI =
high intensity) :

The 150-ampere HI arc

The 120-ampere HI arc

The white-flame Twin Broad arc

Inky Sr. spotlight

Inky Jr. spotlight

Inky Baby spotlight

Among others less frequently used but in many cases no less im-
portant should be mentioned many special converted lamps, a 65-
ampere HI arc spot, and a 10-kw corrected inky lamp.

iOO WINTON Hocrt tj. S. M. P. E.

The light-sources used for photography might be classed in four
general groups as follows:

Daylight

High-intensity arc light
White-flame arc light
Incandescent light

The daylight, of course, is our standard for color- temperature.
The HI arc lights are all corrected for normal work with a Y-l gelatin
filter placed in front of the arc light. This filter was especially made
for Technicolor, using a special non-fading yellow dye supplied by us.
The exact filter strength is determined by camera test. The white-
flame arcs were balanced to a daylight color-temperature by the Na-
tional Carbon Company, and therefore require no filter of any kind.
The incandescent lighting units must fulfill two requirements to meet
the daylight color -temperature standard. They must first be
equipped with incandescent bulbs burning at a color-temperature of
3380 °K, and second, they must be fitted with a tested Macbeth
glass filter. All General Electric bulbs marked C.P. will burn with a
color-temperature of 3380 °K when operated at their rated voltage.
It should be emphasized that the rated voltage must be supplied, and
in the case of the arcs, the proper amperages and proper gap lengths
and positions must also be maintained.

Daylight as a source probably presents fewer troubles, although
very early in the morning and very late in the afternoon trouble is fre-
quently encountered. An interesting difficulty occurred early one
afternoon when the smoke from a forest fire filtered the sunshine to
such a brownish orange hue that it was necessary to abandon the
location for that day.

The conditions just outlined do not have to be met at all times, but
they should be adhered to if a pure white light is necessary and desir-
able for the work in hand. Certainly there is no limit to the effects
obtainable with colored lights. For instance, frequently straight un-
filtered flickering inky lights are used to produce a warm glow on the
costumes and faces to simulate firelight. Artistic sense and experi-
ence must dictate the extent to which colored lights are used. The
colored-light possibilities have been frequently used, perhaps most
recently and extensively in the colored shadow and live action se-
quences in Fantasia. Its first featured use in three-color pictures was
in the first three-color production, La Cucaracha.

Aug., 1942] CINEMATOGRAPHY, 1942 101

The rigging and lighting of a color set is similar in many respects to
that of a black-and-white set, with the exception that lighting units
balanced for Technicolor are the units used, unless effects are in order.
Most Technicolor sets rely upon arc-light units for the bulk of the
lighting. The large sets especially use the larger arc units. Some of
the very small sets are from time to time lighted entirely by corrected
inky light. Inky units are valuable also on big sets as auxiliary light-
ing units. They must be watched for age and cleanliness, as an aged
bulb and a dirty reflector, filter, and lens can substantially reduce the
lamp output. Needless to say, cleanliness is also an asset with arc-
light lenses, and proper maintenance and servicing of all lighting units
are important.

Exterior sets and set-ups are also handled in a very similar manner
to black-and-white set-ups. Scrims, nets, reflectors, and booster
light all play their part. It should be noted that the so-called gold
reflector is not acceptable in color work (unless for effect) for obvious
reasons.

The color- temperature factor is once more introduced when reflec-
tors are extensively worked. The term daylight has been advisedly
used. By definition daylight is the light from the entire sky, includ-
ing direct sunlight if the sky is clear. Sunshine has a color-tempera-
ture of about 5,500 °K, while blue sky has a color-temperature varying
from 10,000° to 20,000 °K. When reflectors are used as lighting aids
they select only the sun, which is reflected into the scene, and in-
troduce a filler light that is warmer in tone than daylight. In ad-
dition, it must be remembered that the so-called silvered suface,
which is usually aluminum or tin, reflects slightly less blue than it
does red and green. This factor also adds slightly to the effect of
a lower color- temperature. For these reasons reflectors are not
considered as desirable as booster light for some purposes. This is
especially true of close-ups where flesh quality is of critical impor-
tance.

Process photography in Technicolor is now largely a matter of
routine. The scenes selected for process work are, of course, subject
to the usual limitations for that type of work, but astonishing results
have been obtained. Progress in this field can be largely attributed
to two factors: improvement in plate quality, and improvements in
background projector equipment. As Technicolor production film
is processed day by day the technical crews improve in skill and the

102 WlNTON HOCH [J. S. M. P. E.

research groups add their contributions, to the end that the process
plates now furnished to the studios are specially printed for the opti-
mum contrast, color-quality, and density required for this type of
work. The equipment combinations of each studio have been photo-
graphically tested for color-balance, and this color-balance is also
taken into account when the plates are printed.

It has been found that background projectors vary appreciably in
the color-quality of the projected light. Generally speaking, the
projectors using reflectors have a little more blue in the light than the
condenser projectors, although this color-quality varies appreciably
depending upon the condition of the reflector and the nature of its
surface, or upon the glass used in the particular condenser set-up in
use. Some condenser lenses have a very pronounced yellowish cast
that is not very desirable for color work.

There has been appreciable .pressure in the last few years aimed at
increasing the background projector outputs. The present high out-
puts have resulted from improvements in carbons, objective lenses,
projector optics behind the objective lens, and lamp house, and in the
successful combination of several projectors for throwing super
imposed, matched, and synchronized images onto the process screen.
Astonishing progress has been made toward increased output, and
fortunately these developments reached the point where they were
incorporated into production equipment before the present war ap-
preciably curtailed progress in this line.

The Academy of Motion Picture Arts & Sciences and many studios
and equipment companies have all contributed to this projector im-
provement problem. As a result, we very frequently photograph
screens in color more than 20 feet wide, and have photographed, in
color, process screens approximately 28 feet wide. This size was used
in the Paramount-de Mille production Reap the Wild Wind. A shot
has recently been made by the same studio using a split screen includ-
ing a total camera spread of 50 feet. This was accomplished with the
aid of two triple relay projectors incorporating the recent improve-
ments previously mentioned. In this emphasis on large screens it
should not be forgotten that miniature screens also have their uses,
and can be successfully handled on the same general basis as the large
screens.

The problems faced by the color cameraman in handling process
photography are generally about the same as those found in all proc-
ess work. However, he must be very color-conscious and on his

Aug., 1942] CINEMATOGRAPHY, 1942 103

guard against an off-color projector light and improperly burning
foreground lights. He must also be very careful of his foreground-
to-background balance, as a background that is carried too high will
often present a burned-out appearance that greatly alters the color
values of the plate, and destroy the illusion of realism that he is striv-
ing to create.

Modern Technicolor camera equipment closely parallels the black-
and-white studio equipment in its principal operational features and
functions. There are available, for the camera, lenses of 25, 35, 40,
50, 70, 100, and 140-mm focal-lengths. They are all in carefully
calibrated mounts that fit onto a master focusing mount on the cam-
era. In almost all cases focusing is accomplished by actual measure-
ment to the focal plane desired, and then the lens is set on this indi-
cated calibration. Repeated tests have shown that this method is
more accurate than eye focusing. Eye focusing is seldom resorted to
unless the focal distance is so short that it exceeds the lens calibra-
tions. The stop calibrations on the lenses are all photometrically
determined and calibrated on an arbitrary arithmetic scale. These
lenses have all been specially corrected for Technicolor work. A very
interesting and very valuable follow-focus aid, which has been
standard equipment since the manufacture of the cameras, is avail-
able to the assistant or technician in the form of a pair of selsyn
motors. One is attached to the lens mount, and the controlling motor
is held in the technician's hand, or fastened to some support if desir-
able, permitting the technician to be 50 feet or more away from the
camera, and yet maintain accurate control over the lens focus. This
is of especial value when the camera is put into the sound "blimp,"
making actual rigid mechanical connection with the lens-mount un-
necessary. This is very helpful on sound shooting inasmuch as the
camera unit inside the blimp is actually floating in rubber and has no
direct mechanical contact with the blimp except through this sponge
rubber.

The non-rigid relationship between camera and blimp suggests
another problem that has been solved in a very successful manner.
That is the problem of attaching a finder for the use of the camera
operator. Obviously, if it were attached to the outside of the blimp,
the camera, inasmuch as it is floating, could be framed differently
from the way indicated by the finder. This was solved by designing a
very compact finder, and attaching the main optical elements to the
camera. Auxiliary optical elements are available for use depending

104 WlNTON HOCH [J. S. M. P. E.

upon whether the camera is used with or without the blimp. This
compact design has the additional advantage that this same finder is
used with the camera for almost 100 per cent of the work; thus only
one finder and one set of mattes are necessary for each camera, and
the camera operator has only one set of finder conditions for which to
make allowances. Auxiliary finder allowances are always necessary
to compensate for the parallax errors both in front of and behind the
focal plane for which the camera is adjusted.

The camera motor arrangement is highly flexible and worthy of
special note. There are eight types of motors and eight combinations
of motor-to-camera gears, all of which can be changed in the field.
The only requirement of the cameraman is to specify the kind of
shooting expected and the electrical current or the kind of distributor
system to be used. The regular cameras can also be successfully
operated running backward at full speed. Speeds higher than 24 pic-
tures per second, either forward or backward, are not permitted with
the standard cameras.

The camera unit has available all the standard camera mounts to
which the industry is accustomed. The wild camera can be mounted
on anything from a camera spider to a high tripod, and on any other
piece of equipment as may be desired, such as dollies, three-wheel
perambulators, four-wheel velocilators, booms, rotating mounts, etc.
The camera, incidentally, has been successfully operated in all possible
positions.

For sound shooting the standard camera is used in connection with
either a "barney" or a blimp. The barney is necessarily not so ef-
ficient from a sound standpoint as the blimp, but it is very useful in a
great many places. The regular blimp is a highly efficient piece of
equipment, and of course requires heavier mounts than the wild
camera, but it can be accommodated on all types of mounts. Those
most popularly used are the blimp "high-hat," four-wheeled "veloci-
lator," and a variety of booms.

There are many items of special equipment available to the Techni-
color photographer that are far too numerous to mention in detail.
Among them should be mentioned, however, the variety of equip-
ment and mounts .used for air photography; the camera blimp and
mounts used for underwater photography; and the speed-cameras
capable of consistent operation at so-called six times normal speed,
or 96 pictures per second.

The question has been asked if an extra standby camera was kept

Aug., 1942] CINEMATOGRAPHY, 1942 105

on the set at all times to replace the camera in use when the film ran
out, because it took so long to thread the Technicolor cameras. This
is not true. The actual threading time of a Technicolor camera is
only about three minutes, for a skilled technician, and many units
work with only one camera. On major production units, however,
an extra camera is usually kept on hand, threaded, to prevent any
possible loss of production time due to many reasons. Some-
times a reduction of the three-minute threading time is desirable, and
when sound shooting is involved and a certain emotional tempo or
mood has been established with the principals, unnecessary mechani-
cal interruptions are highly undesirable. Frequently the director re-
quires two cameras on a shot, and the fact that the supply of extra
cameras is often many miles from the stage has an important bearing
upon the desirability of this extra camera. The additional cost of the
extra camera is a very minor item and the camera usually saves much
more than its cost by the saving of production time.

This equipment has been in service for many years, and has suc-
cessfully met the test of almost all climates, altitudes, and conditions.
The cameras have been in all parts of the world — into the crater of
Mt. Vesuvius, under the sea near Nassau, almost 20,000 feet above
the Andes in South America, in tropical climates, and in subzero
temperatures.

Cartoons and all types of animation photography also should be
mentioned. The bulk of the cartoon and animation work is now
handled by adapted black-and-white cameras using the successive-
exposure method. These cameras are set up with a balanced set of
three-color filters in the optical system at some point, the filters either
rotating or sliding, and the color-exposures are made by exposing
one frame of film through each filter successively. At the head end
of each roll of film a special chart is photographed, permitting the
laboratory to identify the various frames. This negative, after de-
velopment, is printed on a step printer that prints each third frame
only. Thus the records are separated and the prints handled in a
manner similar to other standard prints. This method is limited to
work where no movement takes place during the exposure, and great
care must be exercised in the lighting, exposure, registration, develop-
ment, and color-balance of the film. The cameras must be serviced
to rigid mechanical specifications, and the lenses should be color-
corrected. A great deal of careful work must be done to set up such
a system, and reasonable care observed in the shooting. Once the

106 WlNTON HOCH [J. S. M. P. E.

system is set up, however, these items are handled largely on a routine
basis and with reasonable facility This type of photography can
not be intercut with the standard three-strip negative unless dupe
negatives are made.

Other very valuable technics and facilities that are available and
are very successfully executed in current production today are glass
shots ; double and multiple exposures ; double and multiple printing ;
wipes, fades, and lap dissolves made in the laboratory; and many
combinations of these. The possibilities are numerous.

While speaking of effects photography, fluorescent materials,
paints, inks, etc., should be mentioned. This is a field that has not
received much attention due to lighting equipment limitations ; how-
ever, it can be accomplished in Technicolor. A very simple test was
recently made to indicate some of its possibilities. Fabrics colored
with fluorescent materials were photographed using as an ultraviolet
source a Type 170 M. R. HI arc, covered by a 12-inch ultraviolet
Corning filter. The arc unit was positioned 12 feet away from the
illuminated subject and the spread obtainable with the filter was
about 6V2 feet at this distance. The brightness of the fluorescent
fabrics were sufficient to give an acceptable Technicolor negative with
the camera operating at the normal speed of 24 pictures per second.

Routine studio Technicolor photography has long since passed the
experimental stage. It is now handled with the same efficiency and
dispatch as many black-and-white units. The negative is developed
at night and the negative reports, negative clippings, and estimated
printer points are delivered to the Technicolor cameraman on the set
the following morning. Black-and-white rush prints, if ordered, are
generally delivered the following afternoon, and the color rush prints
are delivered the following evening.

The negative reports and all laboratory contacts are handled for the
cameraman through the Technicolor camera department, which also
checks the daily log sheets, and by these log sheets keeps a very com-
plete record of every production and of every scene photographed on
that production. The records have proved invaluable, not only to
the cameraman, but on many occasions to the director and others
participating in the production. This most excellent coordinating
agency is extremely valuable.

Further production flexibility would be available if a single film
capable of being exposed in any ordinary black-and-white camera
could be used for a full color record. Technicolor's Research Labora-

Aug., 1942] CINEMATOGRAPHY, 1942 107

tory has spent many years in the development of a monopack type of
film that would fulfill this requirement. Progress on the project was
reported by Dr. Herbert T. Kalmus, President of Technicolor Motion
Picture Corporation, to its stockholders in his Annual Report for
1940, as follows:

"Your company's research engineers have also been engaged in co-
operation with Eastman Kodak Company on a process of photography
employing a single negative or monopack instead of the three strips,
and on which three emulsions are superimposed on a single support.
Your company's officers and technicians are frequently asked when
Technicolor monopack prints will be available. Their current inter-
est in the monopack process is not primarily for release prints because
the triple-layer raw film appears inherently to be so expensive that it
could hardly compete in cost with Technicolor imbibition prints in
the long run.

"But your company's officers and engineers do believe that mono-
pack will be developed to be satisfactory for use as originals from
which Technicolor imbibition prints can be made. Such an original
could be exposed through any standard black-and-white motion
picture camera and should thus have mechanical and cost advantages
over three-strip negative.

"Work on this monopack process for originals has been in progress
for several years, and has lately reached a point of decided encourage-
ment for certain purposes. At present the monopack research pro-
gram includes a number of experiments of semi -commercial character
which are promising for photography where camera size, mobility,
operating speed, or other special considerations are of extreme im-
portance. The expectation is that it will first be tried in a limited
way for the special purposes indicated, to be matched and cut in with
the larger part of a picture photographed by the three-strip method.
It should be borne in mind that Technicolor three-strip photography
is constantly improving in quality so that imbibition prints from
monopack have not yet overtaken the present quality of imbibition
prints from three-strip."

The expectation outlined in Dr. Kalmus' report has been largely
realized, and since that time monopack has been used in several pic-
tures, including Dive Bomber and Captains of the Clotids, where shots
from airplane wing-tips and other difficult locations were required;
in the industrial field ; in military training films; and in special-effects
photography where mobility and high speed are important. These

108 WlNTON HOCH

uses of monopack are considered as commercial experiments serving
the dual purpose of fulfilling a special need of increased flexibility in
the field of color photography and of pointing up production require-
ments which are not easily determined even on the large-scale test
basis that characterizes Technicolor's research program.

Technicolor does not consider that the quality of prints from the
monopack method of photography has reached the level of quality of
prints from its three-strip process. This resides in part not in the
absence of progress with monopack research but in the rapid improve-
ment of three-strip Technicolor which, like all phases of Technicolor's
process, receives emphasis from its research group.

The present monopack process, in latitude, visibility, and tone
rendition is satisfactory, but the picture texture, in grain and uniform-
ity, has not attained the smooth, fine texture of three- strip. The
problems involved in correcting these deficiencies are receiving at-
tention and progress is being made.

Technicolor is now and has been for some time definitely on a
routine production basis, with almost all the technics used in black-
and-white available in color also. The experimental phases have
definitely long since left the production field, and have taken their
place in the Technicolor research department, which is currently very
active and from which the results flow quietly but efficiently to the
production field without disturbing changes.

TECHNOLOGY IN THE ART OF PRODUCING MOTION

PICTURES*

LEON S. BECKER**

The motion picture and the automobile were born at the turn of the century and
grew up together. Both have their foundations in science and technology, and both
have profoundly affected our individual and national lives. Their maturity has
placed them among the five largest A merican industries, yet one is fundamentally an
an. An automobile is something concrete, tangible, something real; a motion picture
is light and shadow, laughter and tears, speech and music. The motion picture is an
art as well as an industry. The motivating forces of the film are drama, comedy, hu-
man experience — yet it could not exist except for the organized efforts of the many
craftsmen and technicians that make it an industry. Since art and industry are so
interwoven, a change in technology affects the art of the film, while the demands of the
art bring about technical improvements.

This report illustrates the role that technology plays in the conception of the film as
an art, and the changes that the demands of the art itself have brought about in technic.
The cameraman's universal focus, the soundman's reverberation chamber, the set de-
signer's cloth ceiling — all have their share in telling a story realistically and dramati-
cally. Someone's story idea sets this intricate machinery in motion, and from the
writer, actor, artist, and engineer comes a living entity — a combination of arts that
have been in development since man first learned to record his experiences for posterity.

When we go to the theater to see a motion picture, we usually go
because we want to be entertained. We like to feel the presence of
other human beings around us, because we are gregarious; and we
want to know about their experiences, because we are curious. If
the experiences of the characters on the screen are colorful and told
well, we like the picture and call it entertaining; we recommend it to
our friends. If the characters are colorless and inconsistent, either
because of poor acting or poor story, we say that the picture is dull ;
we do not recommend it to our friends.

Our reaction to a picture is determined by its realism and its
dramatic content. The index of realism is dependent upon how
closely the experiences of the characters in the story coincide with our

* Presented at the 1942 Spring Meeting at Hollywood, Calif. ; received April
20, 1942.

** Warner Bros. Pictures. Inc., Burbank. Calif.

109

110 L. S. BECKER [j. s. M. P. E.

own, or how closely they approach our own ideas of what those ex-
periences would be in a similar circumstance. A picture about
colonial days, for example, can not be made using the speech idioms
or specific behavior of the people of that time, since our ideas of their
behavior are in terms of today — how we would act in the clothes,
carriages, houses of that century. In other words, for realism, ac-
curate physical environment in terms of the material things of every-
day living is necessary, but the psychological processes must be in
those terms we understand today.

The index of dramatic content depends upon the story material
and continuity, the choice of dramatized incidents, camera work,
editing, sound-effects, music, acting, direction, and numerous other
elements. A picture about the Civil War may have an extremely
accurate reproduction of the battle between the Monitor and the
Merrimac down to the last rivet. But unless that battle has drama
for the purposes of the story, adequate acting and direction, and
comparable quality in the other elements, its dramatic content in
terms of the film as a whole will be practically nil.

The industry has achieved a notably high standard of realism from
the standpoint of set design, costuming, research, and the things con-
cerned with the physical environment of the dramatized story.
Sound, lighting, make-up, camera, miniature work, process shots, are
technically adequate and consistently dependable. But it is in the
application of the technical instruments for the purposes of telling a
story dramatically and colorfully that the variation in product occurs,
and that we, as technicians, should attempt to clarify for ourselves
and for the benefit of the industry. The field is obviously vast in
scope, and would require the collaboration of many specialists to
cover the subject adequately. The writer's particular work is in
sound. Therefore this paper, which attempts to explore the region
between the purely technical and the artistic, where the technician's
knowledge of his tools and his individuality and imagination make
the difference between an outstanding production and just another
adequate picture, is written from that point of view.

The story of the motion picture industry as an art is one of con-
tinual growth and development from the time that Muybridge, in
1878, took a series of consecutive pictures to study the motion of a
horse. The purpose was scientific, but the entertainment possibilities
were quickly recognized. Pioneers built crude cameras of various
shapes and sizes, experimented with film of varying dimensions and

Aug., 1942] TECHNOLOGY IN PICTURE PRODUCTION 111

light-sensitive coatings, and photographed anything in motion. The
first films had nothing more than side-show value, and pictures of any
moving objects were sufficient to gain an audience. A moving train,
a falling building, a bicycle rider, were all adequate subjects for the
very short films of that day. The possibilities of the film as a story-
telling medium were not long overlooked, however, and as early as
1898 a series of shots were spliced together to form a continuous
story.

It was not long before the producers of those days recognized that
this new medium, the moving picture, would revolutionize the art of
story-telling. The new freedom in space and time opened up unlim-
ited story possibilities. The film could transport the audience within
a fraction of a second from the equator to the pole, from the highest
mountain peak to the most arid desert. The physical restrictions of
the stage upon action and story locale were shattered. Because of
the new freedom in space and time, the early film stories were built
around physical spectacles, such as forest fires, train wrecks, or
crumbling bridges, that could never have been reproduced satis-
factorily on the stage. Now, for the first time in human experience,
the whole world was truly a stage.

The characters in the first films were "black-and-white" types;
the hero was handsome, strong, and silent, the heroine pure and
feminine, the villain mustached and vile. There was no real delinea-
tion of character, for we must remember that the acting technic was
directly related to the stage of that time, when the melodrama was
popular. The physical limitations of the stage, the poor lighting,
and the distance of the actor from the audience necessitated broad
gestures and easily recognizable heroes and villains.

The mobility of the new camera-eye quickly wrought a change in
acting technic, however. Since the camera and projector could
magnify the image on the screen to many times its normal size and
bring the character that much closer to the audience, the broad,
sweeping gestures of the stage actor had to be subdued in order to be
credible. This modification in acting technic was so rapid that after
a decade of development the exaggerated motions of even the greatest
of the stage stars, when transposed to celluloid, appeared as ridiculous
to the audiences of the silent days as the early silent pictures appear
to us now. In 1912, a picture starring the great French actress Sarah
Bernhardt was released in this country, and was laughed off the
screen. She had used her stage technic for the film.

112 L. S. BECKER tf. s. M. P. E.

In only a few years, therefore, the motion picture had severed many
of its ties with its parent, the stage. In fact, it was such a lusty,
self-willed fellow that it succeeded in changing the ways of its parent.
The appetite of this voracious youngster for greater screen illumi-
nation improved stage lighting, and the comparative richness of screen
sets influenced stage scenery and props. Because of the competition,
stage playwrights had to place greater emphasis upon delineation of
character through dialog, which the screen was unable to do because
it had not yet learned to speak. Conversely, the film writer concen-
trated upon stories of action rather than of character.

But the complementary element in dramatic story-telling was still
lacking in the motion picture — sound, or rather, synchronized sound.
The dramatic need for sound was so strongly felt in the silent days
that directors like D. W. Griffith and von Stroheim suggested sound
by means of pictures and titles, and even made the actors speak their
lines for greater realism, though not a syllable came from the screen.
A title, such as "the sound of the surf told them the sea was near,"
or a picture close-up of a dog howling at the grave of its master, were
used to give the film more realism and dramatic enhancement. Even
lapse of time was measured by "pictorial sound" suggestion — a milk-
wagon clattering on the cobblestones to indicate the arrival of morn-
ing, or a dissolve to the pendulum of a clock to suggest the passage of
time. And, of course, we remember how music and even sound-
effects were invariably an accompaniment for the old silents, either
by a tinny piano, a wheezy organ, or in the case of the first-run movie
palaces, by a 20-piece orchestra with a specially composed score. It
was recognized, therefore, long before the synchronized sound-track,
that since sound and sight together were closer to human experience, a
motion picture plus music or sound suggestion would be more real-
istic— hence more dramatic.

The birth of the sound-film stimulated technical progress to an
amazing degree and resulted in standardizations that proved of great
benefit to the industry. The speed of the projected film was fixed
at 90 feet a minute for the reason that the high frequency voice
sounds, which give to speech intelligibility and to music its timbre
and brilliance, could not be recorded at a slower rate and still retain
their definition. For sound-track development purposes film emul-
sion had to be made more uniform, which not only resulted in more
consistent sound, but in a better picture as well. The camera, though
shackled at first by the unwieldy booths and blimps, quickly regained

Aug., 1942] TECHNOLOGY IN PICTURE PRODUCTION 113

its mobility and even became more articulate. Set lighting was
forced to go to the incandescent lamp, because the arc light was too
noisy for the microphone, and the whole problem of lighting was revo-
lutionized. Set design, film processing, stage construction, and even
make-up were benefited by the new addition to the art.

But as impressive as the technical advances were, the implications
and possibilities of the enhanced medium as a record and interpreta-
tion of life were even more imposing. Here, at last, man had found a
means of transposing his experiences into permanence with the great-
est realism he had ever known. The art-forms of centuries became
available. Both the spoken word and literature were now trans-
latable. Music could heighten the emotional experience to the point
of pain. And certainly acting again was profoundly affected to the
extent of a redefinition of the art in terms of the sound-film. Gra-
dations of character and naturalness were imperative to the realism
of the synthesis of sound and picture.

With the birth of synchronized sound, the spoken word, to the
actor, meant the ability to play a character instead of a type. The
close-up of sound as well as of camera made underplaying the rule
and overplaying a caricature. Subtle relations could now exist
among the characters of a story, and abstract intellectual ideas could
be expressed. The possibility of portraying characters instead of
types opened up wider vistas of possible screen material. The vast
field of human psychology was thrown open to exploration.

When we hear a sound in real life, such as of someone speaking to
us, or from a bird in a tree, we can locate the source of the sound be-
cause we have binaural perception, two separate ears, each of which
transmits its message to the brain independently of the other. If
there are two birds in two different trees, we can not only tell them
apart, but can also distinguish their locations. When we cover up
one ear, we lose the ability to tell the two sounds apart — we put one
of our direction-finders out of commission ; and we lose also our aural
ability to distinguish depth or space, except by loudness. With only
the one ear we have monaural perception. Of course, we still have
our eyes to provide a sense of depth and space-, but a blind man,
whose aural sensitivity has been greatly sharpened, can tell tin- space
and even the size of a room by the lam UM sounds. lletloesit 1>\ the
amount of reflected sound from the walls and ceiling, as compared t<>
the amount of direct sound. Singing in the shower is a popular pas-
time because the ego is bolstered by the reverberation of the room

114 L. S. BECKER [J. S. M. P. E.

and the smoothing out of voice imperfections by the roar of the water.

For the film audience, the source of sound is the loud speaker array
behind the screen. The original source of sound was the microphone
on the studio stage. Since there were one microphone and one re-
cording channel, the sound, for the audience, is monaural. We can
not distinguish movement or position across the screen. But we can
create an illusion of movement to or away from the camera, and even
the feeling of space and environment in the picture, by the use of,
first, loudness, and second, reverberation. A scene shot in a tunnel,
or in a mediaeval castle, will be realistic only when the ratio of re-
flected sound to the original sound is high, and we get the feeling of
space.

With the two-dimensional camera, which bears the same psycho-
logical relation to the eye as monaural sound does to the ear, the
illusion of depth can be achieved by the proper use of lighting and
contrast, just as by the manipulation of loudness and reverberation
with the microphone. And just as the eye can be drawn to particu-
lar persons or objects by the adjustment of focal-length, so can the
ear be arrested by the intensification of important sounds and the
rejection of unimportant ones. If in a scene we wish to draw the
attention of the audience to a child's toy in the center of the floor, we
can, by employing an appropriate lens, focus sharply on the toy and
blur the background. But if we want to draw attention to a music-
box, and yet keep the other props in focus at the same time, we can
have the muxic-box play a tune, which will arrest the ear and draw
the eye.

The ear, however, is much more imaginative than the eye, and can
be used for purposes of suggestion to a much greater extent. The
sound of a coloratura soprano gradually becoming a basso conjures
up a picture of a phonograph record slowing down, but a visual image
of the record slowing down does not define the sound — it might be a
symphony or it might be a baby crying. The ear associates more
imaginatively than the- eye. We hear the sound of crickets and we
imagine night; but a picture of a night scene does not necessarily
make our brain hear the sound of crickets. We associate the chirping
of birds with trees and the country, a siren with an ambulance. The
eye will not violate action experience, but varying impressions to the
ear will be credible to the brain. The implications of these psycho-
logical phenomena for the purposes of the motion picture are tre-
mendous, and have not been fully realized.

Aug., 1942] TECHNOLOGY IN PICTURE PRODUCTION 115

In the decade and a half of the sound-film's existence we have
learned many things. The writer, actor, and director have developed
a mode of approach and a background of technic through experience
as have the technicians. It was learned rather early that if the mo-
tion picture was to be dramatic and realistic, the technical elements
that go into its creation should be so utilized that they return into
oblivion as they do their work. And, axiomatically, if the film is to
be effective as a medium of expression, the elements that go into its
creation must merge into the whole. Music, dialog, sound-effects,
the camera close-up, pan-focus, acting, set design, lighting, cutting,
and so forth can not be utilized alone, but must be used intelligently
in conjunction with each other. For the successful synthesis of these
elements into an organic whole an analysis of these different elements
in relation to each other must be made.

The cameraman has a wealth of devices he can use in unfolding
the story he is telling in conjunction with the other craftsmen. He
can vary the depth of field or the size of the image. He can choose
the amount and kind of lighting to be used in a particular scene to
create a mood or enhance a character. He can undercrank or over-
crank to change the pace. The camera records a two-dimensional
picture, yet the cameraman has a three-dimensional point of view.
He can shoot an object from below or above, from the back or the
side. Through a knowledge of the habits of the eye and of pictorial
composition he can draw the attention of the audience to any object
he may desire for the purpose of the story. It is obvious, then, that
the cameraman must not only be competent technically, but should
also be artistically capable. To him with the director, belongs the
responsibility of making the most of the efforts of the scenic artist,
prop man, actor, and all the other arts and crafts that go into the
preparation of the picture for photographing.

There are, in general, two methods of approach to the problem of
presenting a specific scene to an audience through the eye of the
camera; the objective and the subjective. The camera may record
an incident through the eyes of a fictitious person on the sidelines, or
through the eyes of one of the characters. For instance, we are
shooting a scene of a delirious person in a hospital bed. To put over
the fact that the person is delirious we might show him tossing in his
bed, or we might show the doctor questioning the nurse about his
chart: this is the objective approach. Or, we might photograph the
scene as if through the eyes of the sick man, with the camera going in

116 L. S. BECKER Lf. S. M. P. E.

and out of focus on the objects in the room as he is supposed to see
them in his feverish condition: the subjective approach. The ob-
jective method is more generally used since it is more direct and
straightforward. The subjective method is employed more rarely,
because it usually requires carefully prepared establishing shots to
be successful.

The imaginative employment of sound is as unlimited as the
angles and shadings of the camera. With the wave-filter and equal-
izer, dialog may be improved, or purposely distorted to simulate
telephone or radio quality. Music can be thinned to give it a feeling
of eeriness or distance. The reverberation chamber may give speech
the quality of an empty hall or the illusion of a voice from another
world, and music a bigness for dramatic emphasis. Varying the
speed of the sound-track can make Paul Robeson sound like Minnie
Mouse, or a chair squeak sound like the creaking of an old pirate ship.
In the re-recording process, the proper balance between music, dialog,
and effects can be achieved for maximum enjoyment. Unwanted
sounds can be deleted and others added. A dramatic sequence can
be enhanced and the emotional experience greatly heightened. A
comedy scene can be made more humorous through the imaginative
use of sound-effects and .music. Just as there are fades and dissolves
of the picture image, so can there be fades and dissolves of sound for
time-lapse and continuity.

Since the human mind can not concentrate on more than one thing
at a time, it is necessary, for greatest dramatic effect, to point up
either the visual or the aural element in a scene, but not both simul-
taneously. In John Ford's classic, The Informer, for instance, the
tapping of the blind man's cane on the pavement is a beautiful
example of the subordination. of picture to sound, and the dramatic
impact it can have. We are interested in the picture of the cane only
for information as to the source of the sound : the important thing is
the fear and mounting suspense Gypo feels when he hears the tap of
the cane, which to him is the forewarning of doom. In Algiers, the
scene in which the stool pigeon is killed to the musical background of
the player piano is an illustration of sound in a completely sub-
ordinate role. The climax of the scene is actually the picture — the
close-up reactions of Pepe, members of his gang, and the informer.
The piano and dialog create a mood only — no dramatic punch stand-
ing alone.

Sometimes the impact of the important element can be accen-

Aug., 1942] TECHNOLOGY IN PICTURE PRODUCTION 117

tuated and the pace accelerated through the use of a rhythmic
pattern in the subordinate element. Any device that tends to in-
crease the concentration of the eye or the ear for the end in view is
legitimate. For example, we may have a scene in the box car of a
freight train, showing a man crouched in the corner. The man has
committed a crime and is escaping. We are interested in showing
his reactions by the use of a camera close-up of his face. The visual
element, therefore, is the important one. However, the rhythmic
clickety-clack of the wheels on the rails plus music is used to heighten
the visual picture of the man's abject fear of being caught.

There are times when a rapid shifting of emphasis from sound to
picture to sound can do much toward relieving monotony and build-
ing up the pace. A simple example of a plane trying to find the land-
ing field in a fog, with shifting emphasis from close-ups of the fright-
ened passengers to the sound of the plane's motors from the ground,
back to the interior of the plane, and so forth, illustrates the point.

Dramatically, one of the unfortunate results of the employment of
sound-effects has been its over-use — the cluttering-up of a film with
sound-effects because they are suggested by the environment. Psy-
chologically we shut out sounds in real life — then why not in the
film ? Suppose a scene opens with a mother sewing. She is waiting
for her child to come home from school. Initially, we hear the sound
of a ticking clock in the corner, the laughter and shouts of children as
they dawdle on their way, and the chimes of an ice cream man. The
mother knows that her child is among them. Suddenly we hear the
screech of brakes and a scream. The mother rushes to the window,
the camera panning with her. Now, from the moment she hears the
scream, there is no need for the ticking clock and the noises below.
Everything suddenly goes dead, except the chimes of the ice cream
man.

We achieved two things in this scene with sound: first, the cessa-
tion of the natural sounds after the scream pointed up the woman's
reactions with picture; and second, increased the dramatic effective-
ness by the use of sound contrast in the tinkling chimes. The sus-
pension of background sounds is acceptable, because subjectively it
occurs similarly in real life. Sound contrast is an excellent device
for sharpening the dramatic content of a scene. In Dark Victory,
when Bette Davis realizes that she is going blind, we hear the sounds
of children playing — an effective use of sound contrast.

Another type of sound contrast that could be used very dramati-

118 L. S. BECKER

cally is silence. By its very nature, sound-film, with its almost con-
tinuous use of either sound-effects, music, or dialog, could use silence
as an integral part of the sound technic. Silence could be considered
as a sound-effect, and treated as such. A picture produced some
years ago employed silence very effectively. A musician is shown in
his country cottage composing a symphony. An exterior shot shows
a landscape of pouring rain and strong wind, with occasional lightning
flashes. The sounds of rain, thunder, and howling wind are heard.
The camera moves into the cottage to a close-up of the musician as
he works on the score. The sound suddenly goes dead, simulta-
neously with a picture cut to a face close-up. The manner in which
the musician's deafness was put over had a marked effect upon the
audience, and illustrated what could be done by treating silence in
contrast as a sound-effect.

Sound symbolism has been used effectively in several films either
as a time-bridge or as a binding agent between scenes. In 39 Steps,
the landlady finds the body of the dead woman, opens her mouth to
scream; out of her mouth comes the sound of a train whistle as the
picture dissolves to a train speeding on its way to Scotland. Here
sound, in place of the more usual picture, was the binding agent be-
tween scenes. Sound can be used in association: toward the end of
Goodbye, Mr. Chips, we see a close-up of the old professor and hear
the sounds of the boys arriving at the beginning of the school year,
just as he had heard them many years before. The sounds of the
boys are used in association, and recall the professor's youth as an
inexperienced school teacher. Sound can be used in anticipation of
a dramatic climax: the tapping cane in The Informer, or the child
murderer in M, who whistles five bars of "In the Hall of the Mountain
ICing" each time he is about to commit a crime. Sound can be
suggestive: the train whistle in Vivacious Lady that goes "woo, woo"
at the end of the picture, or when the sound of bells is heard each time
Ginger Rogers and Burgess Meredith embrace in Tom, Dick and Harry.

Much of the really creative work in the use of sound has been in the
cartoon field. The investigations and experiments that Disney and
his associates have made with sound-effects and stereophonic sound
will someday bear fruit and result in much more colorful and dramatic
live-action production. Such devices as the sonovox, as used in
Disney's Dumbo, and the vocoder, which makes speech artificially,
will undoubtedly find their place in telling a motion picture story
more dramatically.

STOP CALIBRATION OF PHOTOGRAPHIC OBJECTIVES*

E. W. SILVERTOOTH**

Summary. — The principle of a null-indicating densitometer has been adapted to
the measurement of camera lens iris settings.

An optical system calibrated in accordance with the described technic is rendered
amenable to precise calculation of the luminous flux per unit area in any part of the
field, with particular stress laid on the axial condition.

It is a matter of common knowledge that the practice of photo-
graphic exposure has had inherent variables, the determination of
which was subject to large, and often in practice, unpredictable errors.
Of these undetermined elements such measurements as absolute
object brightness and the graduations thereof, and effective film
speed with the plurality of factors affecting that rating, were sig-
nificant quantities which so eminently enhanced the essential virtue
of latitude in photographic emulsions.

With the advent of useful scientific methods of light measurement,
coupled with the more general adoption of precise control in labo-
ratory developing procedure, difficulties resulting from correlated
operations made themselves known and in some circumstances be-
came predominant in their effects.

Of these variables, one in particular, the stop calibration of camera
lenses, has received the attention of Technicolor and of 20th Century-
Fox,1 the former in conjunction with their color process, the latter as
a refinement of their new silent camera.

Paramount Studio, recognizing the merit of standardized lens
speed ratings, but at the same time wishing to proceed on a purely
quantitative basis, set up the following requirements to be met in the
operation of a calibrating device :

(1) Results should be reproducible without dependence upon any arbitrary
standard.

* Presented at the 1942 Spring Meeting at Hollywood, Calif. ; received April
14, 1942.

** Paramount Pictures, Inc., Hollywood, Calif.

119

120

E. W. SlLVERTOOTH

[J. S. M. P. E.

(2) The method should be amenable to exact calculation of effective actinic
energy per unit of area in the focal plane.

(5) It should be reproductive of axial densities.

(4) Independent of brightness of light-source.

(5) Independent of amplifier, photocell, and meter linearity, as well as of ampli-
fier gain.

(6) It must be foolproof, accurate, and rapid in operation.

With the above-listed desired properties in mind, a device was con-
structed for use by our Camera Department. Referring to Fig. 1,
light from source A is collimated by the low focal ratio objective B,
forming a parallel beam of uniform cross-section. Either the lens
under test or the standard aperture may be placed at C. The stand-

FIG. 1. Device for stop calibration of photographic objectives.

ard aperture consists of a metal plate with a circular perforation of
area equal to the theoretical aperture of the lens, diminished by a
factor determined from the transmission characteristic of the given
objective. Since studio production camera lenses (treated, in our
case) do not vary widely in this respect, this factor has been assigned
a value of 90 per cent. Untreated lenses, or more highly absorbing
optical systems in wide variety could similarly be calibrated, but with
an auxiliary notation of percentage transmission incorporated in the
engraving operation.

The lens at C is followed by the factor-of-two step-wedge D, thence
by the diffusion disk E and the photocell F. Somewhere in the
vicinity of objective B is included an auxiliary photocell J, illumi-
nated from source A through the adjustable iris H and diffusion disk

Aug., 1942]

STOP CALIBRATION OF OBJECTIVES

121

/. Photocells F and / are meshed to the input of a two-stage direct-
current amplifier2 K the output of which is fed to a zero-center-scale
microammeter, or null indicator L. The sensitivity of the instru-
ment is adequately controlled by means of a meter shunt.
The method of operation is as follows :

(1) The standard stop (one for each focal length lens) is placed at C.

(2) By means of H, a light balance is secured between photocells F and /.

(5) The standard stop is replaced by the lens under test ; the lens iris is adjusted
until balance is again attained.

(4) Wedge D is shifted one stop, and the lens iris setting is altered to compen-
sate. This step is repeated until the lens is completely calibrated.

FIG. 2. Photograph of the device.

Because of the limited window area at E, it is necessary in the
described unit to match standard stops with iris openings of //ll or
//16. A more elegant method would be that of replacing the diffusion
disk E with an integrating sphere of adequate size.

It is evident from the foregoing description that camera lenses so
calibrated will yield duplicate densities in the center of the focal sur-
face under similar conditions of exposure. The importance of this

122 E. W. SlLVERTOOTH

feature is best appreciated when consideration is given to the wide
variation from lens to lens of off- axis illumination curves.3 The very
individuality of this circumstance in a lens system dictates the ne-
cessity for axial calibration if the useful prediction of focal-plane
illumination is to be available for the more significant calculation of
optimum light level requirements on sets. This conclusion is predi-
cated on the assumed condition that the center of the scene is gener-
ally of greatest importance. An interesting ramification of the device
in this connection lies in the possibility of rotating the lens under test
about the rear nodal point, thus conveniently securing information
related to the off-axis flux values.

In conclusion, it is believed that a precision method of lens-stop
calibration has been adequately defined for all practical photographic
applications; and further, that the elimination of an arbitrary stand-
ard for comparison purposes has provided a generally available cali-
brating technic.

REFERENCES

1 CLARK, D. B., AND LAUBE, G. : "Twentieth Century Camera and Acces-
sories," /. Soc. Mot. Pict. Eng., XXXVI (Jan., 1941), p. 50.

* LYONS, W., AND HELLER, R. E.: "A Direct Reading Vacuum-Tube Milli-
voltmeter," Electronics (Nov., 1939), p. 25.

3 BENFORD, F.: "Illumination in the Focal Plane," J. Opt. Soc. Amer. (May,
1941), p. 362.

A REVIEW OF THE QUESTION OF 16-MM EMULSION

POSITION*

WM. H. OFFENHAUSER, JR.**

Summary. — There are several standards anomalies in 16-mm little realized no
only by many engineers but also by many of those who daily use the medium.

While there is but one 35-mm emulsion position — the standard position, the emul-
sion facing the light-source — there are two emulsion position in 16-mm — the "stand-
ard" position, in which the emulsion faces the screen; and the "non-standard" posi-
tion, in which the emulsion faces the light-source. What the non-standard position
films may lack in millions of feet used per month, is made up in great measure by
their 5 to 1 processing-cost ratio and their higher first cost.

Commercial projection equipment generally has ignored these more costly films
and chosen to compete in the low-cost low-quality black-and-white print market.
Not one projector manufacturer supplies as standard equipment today a directional
loud speaker of suitable efficiency and transient characteristics for high-quality re-
production; only one manufacturer supplies as standard equipment a sound pro-
jector whose sound optics are one-half mil in width and may be refocused properly to
project "non-standard" emulsion position prints.

While 16-mm black-and-white print quality is generally bad and the resultant pro-
jected picture and sound likewise bad when compared with 35-mm theatrical projec-
tion, this condition can be corrected almost overnight if Government specifications for
16-mm prints and for 16^mm sound projectors and loud speakers will call for modern
16-mm materials, modern specialized 16-mm methods, and modern equipment.
Unit cost increases for the improved quality are inevitable; the increase in effective-
ness, however, will far more than compensate for the relatively small increases in
unit costs that result. One commercially available system for achieving the desired
standard of quality is described.

It has become quite common in the last few years for a projectionist
of 16-mm film to ask himself the question: "Which side is up on this
film?" and in many cases the quality of the projected show, in par-
ticular the sound quality, hinged on whether the all-important answer
was right or wrong. When a 16-mm sound-film is properly threaded
in a projector, the emulsion of the film may face the screen, which

* Prepared at the request of the Standards Committee; presented at the 1942
Spring Meeting at Hollywood, Calif.

** Precision Film Laboratories, New York, N. Y.

123

124 W. H. OFFENHAUSER, JR. [J. S. M. P. E.

position is called the "standard emulsion position," or it may face
the projector light-source, the "non-standard" emulsion position.
Sixteen-mm sound-films for projection today may be expected to be
found in both kinds.

When the original emulsion position question was first brought up
for consideration, it was the feeling of ah1 concerned that reversal
originals would be of key importance, and accordingly, the present
standard 16-mm emulsion position was agreed upon. Since in a cam-
era the emulsion of the film faces the lens, the standard emulsion posi-
tion in a 16-mm projector therefore would be the position in which
the emulsion also faces the lens of the projector. (The film used is
the original film — the original reversal.)

Optical reduction printing from 35-mm was then made to conform
to this standard, and since the decision was made, all reduction print-
ing equipment for copying 35-mm to 16-mm has been adjusted to pro-
duce only standard emulsion position prints. In the meantime,
original reversal film with sound as a potential source never really
developed, and in the earlier stages of 16-mm sound-film, practically
all 16-mm sound-films available for projection were made by optical
reduction from 35-mm original negatives.

Later on, the cost of 16-mm film for amateur use became prohibi-
tive, and with the improvement of films, lenses, cameras, and pro-
jectors in 8-mm, amateur interests began to be transferred almost
entirely to this medium. Today, the relative costs and the technical
results of the 8-mm medium are such that we can safely say that 16-
mm is almost exclusively a professional medium and 8-mm is almost
exclusively an amateur medium. We must, therefore, consider the
question of 16-mm emulsion position in the light of the fact that
16-mm sound-films produced from 16-mm originals are almost entirely
of commercial origin.

Emulsion Position in 35 -Mm Practice. — When 35-mm negative is
threaded in a camera, the emulsion of the film faces the camera lens.
When this negative after development is contact-printed, the emul-
sion of the print faces and is in contact with the emulsion of the
negative. When the print that results is then threaded in a 35-mm
projector, the emulsion on the print is opposite that of the emulsion
on the negative, and, therefore, the emulsion of the print faces the
light-source of the projector. This emulsion position of the print is
called the 35-mm "standard emulsion position." When 35-mm film
is used, therefore, its application, so far as emulsion position is coti-

Aug., 1942] 16-MM EMULSION POSITION 125

cerned, is quite simple. Essentially, all original 35-mm black-and-
white picture is taken as negative, and prints are made by contact-
printing upon positive raw film. Despite the rapid and continued
growth of the industry, even including the introduction of sound, the
35-mm medium still remains a negative-positive medium in which
films are still developed and printed in exactly the same way they
have been handled for some forty years or more.

Our 35-mm standards recognize the standard emulsion position as
the one and only emulsion position to be used in 35-mm release prints.
Once a projector has been installed in a theater and adjusted to give
the proper size of picture on the screen and to scan the sound-track
in the proper manner, no further adjustment is required except for
maintenance. Any 35-mm film received for projection will automat-
ically be in proper focus for both the picture and the sound ; there are
no non-standard emulsion position 35-mm films released for commer-
cial use.

Since negative-positive processing is and always has been the only
processing generally available in 35-mm, it was only natural that the
jargon of the industry would take account of that fact. It is not un-
common, therefore, for the terms, "original" and "negative" to be
used interchangeably in 35-mm slang, and many who are beginning
to work in both media after having worked previously only in the
35-mm medium, attempt to carry over the interchangeability of
terms into 16-mm, where the use in that manner is definitely in
error.

The Early History of 16 -Mm Reversal Film.— About 1924, the East-
man Kodak Company made available to the American market a
16-mm film product that is still unknown in commercial 35-mm
films — reversal. In order to encourage amateur movie making, it
was necessary to eliminate, if possible, the second piece of film, the
print, in order to reduce the cost of the product to the user.

Reversal had, commercially, two important advantages. The
same piece of film was returned to the customer that the customer sent
to the company for processing (which avoided alibis on the part of the
customer), and at the same time, the second piece of film normally
necessary, that is, the print, did not have to be made.

Reversal was recognized, in our 16-mm standards only by the cap-
tion, "In the projector, the base (not emulsion) side of the positive,
made ... by the reversal process . . . faces the light source." It is
interesting to note that even at this late date, duplicate reversals

126 W. H. OFFENHAUSER, JR. [J. S. M. P. E.

are given no formal consideration whatever in our dimensional stand-
ards, despite the fact that they became commercially important as
early as 1931.

Reversal and Kodachrome — What They Are. — Reversal (in the
broadest sense) may be most simply defined as a direct positive.
When properly handled, black-and-white reversal film is one of the
finest materials available for use today as a 16-mm picture original.
It always produces a reduction in grain size; the larger grains are
most affected by the first, or negative, exposure that the film re-
ceives, but these larger grains are later removed in the subsequent
bleaching operation, leaving only the smaller grains of the emulsion
to make up the final image. A study of the relative graininess of
optical reductions from 35-mm negatives in comparison with original
reversal as a 16-mm original material appeared in the JOURNAL in
November, 1940, in a paper entitled "Commercial Motion Picture
Production with 16-Mm Equipment," by J. A. Maurer.

Kodachrome goes a step farther; the final image in Kodachrome is
a grainless dye image. Just as in the case of reversal, the silver emul-
sion in Kodachrome is bleached out after the initial exposure and
development; dyes form the image in development after the second
exposure. Practically, Kodachrome has one other advantage: its
development is usually less contrasty than that of reversal. This,
too, makes for an improved original.

Kodachrome as an original 16-mm material has another advantage
that can hardly be overlooked in these days of emergency. It is
possible to print excellent Kodachrome sound duplicates at the same
time excellent black-and-white prints are being made. This is pos-
sible since the Kodachrome sound duplicates are manufactured from
the Kodachrome original and a positive black-and-white sound-track,
while the black-and-white prints are made from a black-and-white
duplicate negative of the picture and from the original negative sound-
track.

Early History of 3 5- Mm Sound- Film. — When sound-film was com-
mercially introduced in 1929, it was forced to adapt itself to the nega-
tive-positive procedure of the 35-mm picture. It is obvious that if
the sound is to appear on the same piece of film with the picture in the
combined print, both picture and sound must be developed in the
same developer solution. This sound -recording procedure was
pinned down into a negative-positive procedure to conform with the
processing of the picture. The production of the release prints from

Aug., 1942] 16-MM EMULSION POSITION 127

the original negatives was quite satisfactory so long as the sound
negative could be made in relatively long lengths without splices.

In the early stages, scenes were quite long, often as long as two
minutes. As the sound motion picture grew, the length of the indi-
vidual scene became shorter and shorter until now the average length
of a scene is considerably less than one-tenth of what it was in 1929.
For this and other reasons, a demand for re-recording and for lip
synchronization grew, all of which implied a large number of scenes
per reel, and, consequently, a large number of splices in the original
sound negative. It was only logical, therefore, that the industry
would attempt to produce some sort of direct sound positive which,
when re-recorded for release purposes, would eliminate one copying
step between the original sound-track and the release print. (Direct
positive — to — re-recorded negative — to — release print.)

In the case of sound, however, reversible film did not come to the
rescue as it did in the case of the 16-mm picture in 1924. Another
difficulty had arisen which is characteristic of all silver emulsions in
some degree that would prevent the successful application of rever-
sible film in this manner. For want of a better description, it will be
called here the "graying" effect. In the JOURNAL are to be found
numerous papers on the subject of envelope and other types of film
distortion in which this graying effect plays an important part. We
have been counter-acting this distortion effect in the negative by at-
tempting to produce an equal and opposite effect in the print by the
choice of proper exposure and of proper development of the print.
In this procedure, we have been more or less successful, and this
method is the one that is preferred commercially today.

An attempt was made, however, to record directly on fine-grain posi-
tive stock with the recording system optics and the electrical ele-
ments so modified as to produce a direct positive. The distortion in
the direct positive was considered low enough in certain cases to be
ignored. For purposes of identification, we shall call this form of
direct positive recording "optical reversal" to distinguish it from
"chemical reversal." The term "optical reversal," while not strictly
correct, will be assumed to include the recording of variable-density
direct positives such as variable-density toe-recorded sound-film.

The successful direct positives required film of the fine-grain, high-
resolving-power type. Due to the difficulty of obtaining enough
exposure and for other reasons, direct positives have not been com-
mercially adopted. The customary 35-mm procedure is to record

128 W. H. OFFENHAUSER, JR. fj. S. M. P. E.

the original sound as a negative, edit it, then make a 35-mm sound
positive — and then re-record that 35-mm sound positive using the
resulting sound negative for making the release prints.

Early History of 16-Mm Sound-Film. — After the initial failure in
1930 of 16-mm sound negatives made by re-recording, direct 16-mm
sound remained dormant for a number of years. A 16-mm sound
camera put in its appearance in 1932, operated by the single-system
method. So far as sound was concerned, this unit fell heir to the poor
resolution encountered in the commercially unsuccessful re-recording
attempts of 1930. One important factor in the failure of this unit
was that the film used did not have satisfactorily high resolution since
it was a negative-type film.

It was evident that the only commercially practicable solution in
16-mm would be double-system sound-recording — just as it had been
the solution in 35-mm sound-recording. It was not long afterward
that 16-mm double-system sound-recorders were put on the market.
Plans were being formulated for their marketing as early as 1936.

Current Status of Direct 16-Mm Sound. — By far the largest volume
of direct 16-mm sound is produced by the double-system method
with negative-positive processing of the sound-track. Studies have
been made of the application of reversal to sound, but it has been
concluded so far that what we have called the "graying" effect pre-
vents any reasonable use of the distortion cancellation technic such
as we daily find so valuable in negative-positive 16-mm commercial
operations. This factor becomes more important as the number of
copying operations required between the original and the release
print increases; this is especially true of variable-area sound, with
which there has been more commercial experience in the 16-mm
medium.

Kodachrome Sound Duplicating and Its Implications. — At the pres-
ent time, practically all sound to be duplicated on Kodachrome is
recorded as a negative, and a black-and-white positive track print is
made from that negative. It is the positive sound-track print that is
used in the printing operation to the combined duplicate. For the
purpose of this discussion, it makes little difference whether the
original sound-track is recorded originally on 35-mm film or on 16-mm
film.

It seems likely that one of the reasons why so few direct sound posi-
tives can be used for Kodachrome printing is that the distortion due
to the graying effect is excessive. This does not mean, however, that

Aug., 1942] 16-MM EMULSION POSITION 129

all positives are afflicted with the same handicap ; positives of the dye
type seem to be less affected by this peculiar characteristic of silver
emulsions. Considerable development and research work has been
carried on in this direction that seems to hold promise for the future.

The 16-Mm Emulsion Position Question. — It can be seen from the
foregoing that the 16-mm emulsion position question can not ade-
quately be dealt with in a casual manner. Reversal and Koda-
chrome, which do not exist commercially in 35-mm motion pictures,
are used almost to the exclusion of negative in 16-mm for picture
originals. Kodachrome sound duplicates, of which there are possibly
some quarter of a million feet per month or more currently used in
16-mm, do not exist in 35-mm at all. These distinctions between 35-
mm and 16-mm would certainly seem to merit some form of standards
recognition.

A few years aeo, the author submitted to the Standards Committee
of the Society a memorandum classifying the methods of producing
16-mm release-prints then in use. Sixteen-mm sound-prints may
be produced by a wide variety of methods. They may be classified as
follows :

Class 1. Film Width of Original

(a) Originals supplied on 35-mm.

(b) Originals supplied on 16-mm.

(1) 35-mm picture with 16-mm track, or

(2) 16-mm picture with 35-mm track.

Blow-ups from 8-mm picture to 16-mm are not uncommon even now, and it is
possible that this procedure will grow.

Class 2. Sound Recording Processes

(a) Variable-density. Full-width, squeeze, push-pull; with or without noise

reduction.

(b) Variable-area. Unilateral, bilateral, duplex, others (such as multiple).

Class 3. Processing Methods

(a) Negative-positive processing (where the image black-and-white aspect is
reversed in printing).

(6) Second exposure or direct positive processing (a positive from a positive,
such as a reversal dupe ; a Kodachrome dupe.

(c) Single exposure processing (where the image is reversed optically or elec-
trically, as in the case of a sound-track master record made for direct
playback, one exposure and one processing).

Combinations of these classes are not at all uncommon ; our standards, if com-
prehensive, should encompass any reasonable combination of any or all of the

130 W. H. OFFENHAUSER, JR. [j. s. M. P. E.

preceding classes, methods, or sizes. At the present time, we are especially con-
cerned with:

(1} Reduction of 35-mm negatives, both picture and sound, to 16-mm.

(2) Combinations of a 16-mm original with a 35-mm original (such as Koda-
chrome or reversal picture and 35-mm negative track, or 35-mm negative
picture with 16-mm negative track).

(5) Direct 16-mm where the picture original is either a 16-mm negative, rever-
sal, or Kodachrome, and the sound-track is an original 16-mm negative.

The Problem of 16- Mm Prints from 35 -Mm Originals. — Whenever
16-mm prints are needed from 35-mm originals, one important ques-
tion must be answered before the sound is recorded if the final result
is to be of optimum quality. It must be definitely decided whether
35-mm prints are to be made at all; if they are, it is manifestly im-
possible to record a single sound-negative that is suitable both for 35-
mm prints and for 16-mm reduction prints due to the difference in the
recording equalizing required. The reason is readily apparent if we
examine the equipment situation.

If a Hollywood studio sound-track is run upon a 35-mm sound
system that meets the specifications of the Academy of Motion Pic-
tures Arts & Sciences, the result is standard. The reason is that the
recording is so made as to reproduce most effectively upon equipment
with the Academy characteristic.

Such a negative, if optically reduced without fidelity loss, would
also operate most satisfactorily with equivalent equipment having
Academy characteristics. The characteristics under such conditions
are:

CO The slit width should be 1.3 mils multiplied by 36/90 (the film-speed
ratio) or one-half a mil. One manufacturer of projectors, Eastman Kodak, manu-
factures equipment with that slit width ; no other major manufacturer does.

(2) The resolution of the 16-mm film should be in the inverse ratio of the film
speeds, or 90/36 = 2.5. Fine-grain 16-mm film accurately controlled will readily
approximate this requirement when compared with regular 35-mm positive as
commercially processed.

(3) A really good optical printer designed to expose fine-grain 16-mm film with
the proper chromatic and intensity characteristics, will "hold up" in our comparison
with the usual 35-mm non-slip printers printing upon regular 35-mm positive.

(4) The amplifiers, obviously, should be at least the equal in signal-to-noise
ratio and in distortion, to 35-mm booth equipment. This is no chore as there is
on the market a wide variety of amplifiers of reputable make and performance
suitable for the purpose. Needless to say, the best 16-mm projector amplifiers,
while somewhat inadequate, are not too far wide of the mark.

(5) Last but not least, the loud speakers must be comparable with those con-

Aug., 1942J 16-MM EMULSION POSITION 131

sidered in connection with the 35-mm Academy characteristic Unfortunately,
this is probably one of the worst 16-mm bottlenecks. While we cling to the idea
that the performance of a 16-mm loud speaker is immaterial just so long as a frail
ninety-pound schoolteacher can lift said loud speaker, we might as well give up
our search for 16-mm sound-quality in projection. In order to obtain performance
somewhat comparable, the loud speaker should have the following character-
istics:

(a) Directional radiation — not much more than a sixty-degree lateral spread

and a thirty-degree vertical spread. This is readily obtained with a suit-
able horn.

(b) Good efficiency ; also obtained if a suitable horn is used.

is used.

A loud speaker, to meet the above requirements, would have to be a directional
horn; the present flat baffle type of equipment is hopelessly inadequate.

Unfortunately, it is not possible to obtain, as regular articles of
commerce, all five of the items exactly as enumerated above.

A Commercial Solution to the Problem of 16 -Mm Prints from 35- Mm
Originals. — There are several obvious commercial steps in the solu-
tion of the problem of good 16-mm reproduction from 35-mm orig-
inals. They are:

(1) Re-record the sound-track using a 16-mm equalizing characteristic. If this
record is made by direct 16-mm on high-resolving-power yellow-dye film exposed
in a good 16-mm sound-recorder through the proper filter, 6-db equalization
broadly tuned at 5500 cycles is sufficient for excellent films. A 6000-cycle low-
pass filter may prove of advantage.

(2} Make a 35-mm fine-grain lavender of the picture, and then make a fine-
grain dupe negative of that lavender.

(3) Make the 16-mm combined prints on fine-grain film, printing the sound
with an optical one-to-one sound printer (contact sound printing is inadequate).

(4) Use a commercial projector that will meet the specifications set forth by
the Non-Theatrical Equipment Committee in the July, 1941, issue of our JOURNAL,
"Recommended Procedure and Equipment Specifications for Educational 16-mm
Projection." A Bell & Howell Utility Filmosound will substantially meet the
requirements.

(5) Use a good loud speaker such as the Bell & Howell Orchestricon. When
projecting, set it in such a position that its horn radiates directly to the audience.

(6) For safety's sake (projection requirements are rarely properly analyzed),
use a matte screen.

The Current Status of 16-Mm with Regard to Emulsion Position.—
When a IG-mm sound-film is properly threaded in a IG-mm pro-
jector, the emulsion of the film may face the screen (which position
is called the "standard" position), or it may face the projector light-

132 W. H. OFFENHAUSER, JR. [j. s. M. P. E.

source (the "non-standard" position). Any well-designed projector
of today should be capable of projecting either "standard" or "non-
standard" prints.

All 16-mm combined prints from 35-mm originals such as those
previously described have the "standard" emulsion position. The
best quality 16-mm black-and-white combined prints from 16-mm
originals also have the "standard" emulsion position. At the present
time the output of such prints amounts to several million feet of film
per month.

Most 16-mm combined Kodachrome duplicates have the "non-
standard" emulsion position. At the present time, the output of such
prints amounts to something like a quarter to a half million feet per
month. When it is considered that the cost of a 400-foot combined
duplicate in Kodachrome is approximately $50, whereas a similar
black-and-white print costs but $9, it becomes even more apparent
that the existence of Kodachrome sound duplicates is entitled to con-
sideration from projector manufacturers especially.

When projecting Kodachrome duplicates, it is found necessary to
refocus the picture ; the emulsion position is non-standard. It would
seem obvious, therefore, that if the picture must be refocused in order
to be clearly seen, the sound optics must likewise be refocused if the
sound is to be clearly heard. The surprising feature in the projection
of Kodachrome sound duplicates is that more than 90 per cent of the
projectors in use are not equipped to refocus the sound optics for
proper projection. Only one manufacturer of 16-mm sound projectors
has so far included this feature on most of his sound projectors as
standard equipment; only one other manufacturer has offered such
a feature as optional on all his machines at slight additional cost.

It is well to remember that, with present-day sound optics, there is no
satisfactory compromise fixed adjustment suitable for both "standard"
emulsion position black-and-white prints and "non-standard" emul-
sion position Kodachrome duplicates. The usual adjustment is in
the form of a small lever with two definite settings.

There are other sources of "non-standard" emulsion position film
today, but the quantity in use in such that they are of minor impor-
tance from the standpoint of volume. It is quite possible that, with
a wider distribution of 16-mm apparatus immediately after the War,
they will acquire additional importance.

The Question of Optical Picture Printing. — In all the foregoing, it
may rightfully be charged that the possibility of optical printing of

Aug., 19421 H>-MM EMULSION POSITION 133

16-mm picture has been ignored in this discussion, and only contact
printing of 16-mm picture has been presumed. This charge is quite
true — and it will no doubt continue to be true, at least for the dura-
tion of the War. If optical printing of picture is as desirable as many
think, why is it that the 35-mm theatrical industry which spends
millions of dollars on its productions and on their exhibition still
makes all its release prints by contact printing? Sixteen-mm costs
must be kept low, very low in comparison with 35-mm costs, and it
would seem that if there is to be a trend in the direction of optical
picture printing, 35-mm should lead the way. Sixteen-mm costs
must be lower than 35-mm costs ; if optical printers are at all worth
using, their disadvantages must be overcome ; their operating speeds
are very low and their first costs and operating costs very high.

While the present War emergency continues, it seems unlikely that
any reputable optical manufacturer can be induced to divert his
energies to the marketing of suitable optics for a 16-mm picture
printer that will correct emulsion position at a price to compare in a
practicable way with the present price for a contact printer.

Conclusion. — At the present time, it seems clear that neither emul-
sion position can be successfully dispensed with as a standardizing
matter. The dollar value of the non-standard prints produced is now
considerable when compared with that of the standard prints. For
the duration of the War, at least, both emulsion positions will con-
tinue to be of indispensable importance.

TECHNICAL APPENDIX

16-Mm Sound Negatives. — Direct 16-mm sound negatives are usually recorded
upon a high-resolving power yellow-dyed film exposed through a blue filter. Two
windings of raw stock are available, Winding A and Winding B. The rules for
their use are:

USE WINDING A for sound negatives for

(1) Kodachrome sound duplicates with the sound-track printed from a fine-grain

sound-track print of the sound negative.

(2) Combined prints from original reversal or Kodachrome picture made from a

fine-grain duplicate negative of the picture and from the sound negative.
(5) Combined prints from 35-mm picture negative and 16-mm sound negative.

USE WINDING B for sound negatives for

(1) Combined prints from original picture negative and 16-mm sound-track nega-

tive.

(2) Fine- grain sound-track prints to be used for re-recording.

134 W. H. OFFENHAUSER, JR.

16-Mm Picture Original. — In 16-mm picture original and in all steps where
sound does not appear on the film, use double perforated film to avoid laboratory
and other handling difficulties.

Preparation Rules. — (1) In all cases, use only double perforated leader with
doubly perforated film, and single perforated leader with single perforated film.

(2) In all cases, splice in the leader with base to emulsion so that the same
side of the film is up on the leader, as on the picture proper.

(5) In all sound-films without picture, mark the head of the film H and the tail
of the film with a T to avoid confusion due to emulsion position.

Emulsion Position of Prints. — Prints with "Standard" emulsion position re-
sult from:

(1) Original 16-mm black-and-white reversal — to — intermediate negative —

to — print (the 16-mm sound negative is recorded upon film of A wind-
ing).

(2) Original 16-mm Kodachrome — to — intermediate black-and-white nega-

tive— to — black-and-white print (the 16-mm sound negative is recorded
upon film of A winding).

(3) Optical reduction from 35-mm negatives.

Prints with "Non-Standard" emulsion position result from:

(7) Original 16-mm negative — to — print (the 16-mm sound negative is recorded
upon film of B winding).

(2) Original 16-mm Kodachrome — to — 16-mm Kodachrome duplicates (the
16-mm sound negative is recorded upon film of A winding. Sixteen-mm
track negative — to — 16-mm black-and-white track print — to — Koda-
chrome duplicate of sound).

A well planned picture takes into account the emulsion position of the release
print and how it is to be obtained quite as much as it does the photographic images
to be recorded on the film.

After the presentation of the above paper at the Convention, a demonstration
film, made as described, was projected with an arc projector on an 8 X 12-ft.
screen through a sound system of the type described, in order to demonstate the
theatrical quality of the sound and picture.

THE PRODUCTION OF INDUSTRIAL MOTION PICTURES
LLOYD THOMPSON**

Summary. — The production of industrial sound motion pictures is similar to
production in the major studios. Limited budgets mean that certain short-cuts must
be taken but the final screen results must be such that the audience is not aware of the
limited budget. If satisfactory results are to be obtained, close cooperation is required
between the director who has his special problems and the technical department which
also has its special problems.

The paper lists a number of these problems and also discusses what can be expected
of industrial producers.

Today industrial motion picture producers are being called upon
to produce a greater variety of shows than ever before. Many of the
productions needed call for the industrial (and I say industrial for
the lack of a better term) technic. To an industry which, of neces-
sity, has been mainly concerned with entertainment production, this
comparison of industrial and entertainment technic may be of interest.

The industrial producer of today must have three things, and it
matters not whether he is using the 35-mm method or the direct
16-mm method of production. These three things are: (1) the
personnel, (2) the experience, (3) the proper facilities.

If he has the above qualifications he must do two things to do busi-
ness at a profit. (1) He must solve his own technical and production
problems so that he can make a finished production both technically
and artistically. (2) He must give his customers true value, and
leave them with the feeling they have enjoyed a pleasant and profit-
able experience.

The production of industrial sound motion pictures is in many
ways carried on the same as the production of straight dramatic
shows. In other ways it is different. Probably the first big differ-
ence is in the amount of money that the producer has to spend. With
enough money many of the problems of any business disappear. It

* Presented at the 1942 Spring Meeting at Hollywood, Calif. ; received April
UM, 1942.

** The Calvin Company, Kansas City, Mo.

135.

136 L- THOMPSON [j. s. M. p. E.

is the solving of many of these problems without spending too much
money that makes the life of an industrial producer interesting and
at times hectic.

A million dollar budget is rather common for a Hollywood produc-
tion. The average cost of an "A" feature is nine hundred thousand
dollars. If someone allots one hundred thousand for an industrial
it becomes news and is given wide publicity. More often industrial
shows are made for three or four thousand dollars. Seventeen or
eighteen thousand dollars is an excellent price for an industrial in
color and sound.

On the other hand the buyer of any picture expects a show that
will train his employees, sell his product, or make the public look with
favor on his product. In other words it must do the job for which
it was intended. To do this it must be at least reasonably well
photographed. It must be edited in a logical sequence and should
unfold on the screen in at least a fairly smooth manner. This, of
course, calls for good planning and good direction.

To turn out a job that will fulfill all the requirements means close
cooperation between every department from the sales department
who sold the picture to the shipping clerk who must see that the
prints are shipped in time, quite often to meet deadlines. This
means the proper personnel with the experience that will enable them
to work together most efficiently. An organization producing indus-
trial shows works most efficiently if the different members of the
group understand the problems involved in the various departments
of the organization.

The sales department must sometimes work for years to sell a
single picture. This means that a long line of prospects must always
be in the process of being sold. Equally important the salesman for
industrial pictures must thoroughly understand the whole production
business of making a show. If not he can easily oversell. We like
to tell the story about a salesman who did not understand the pro-
duction business. This salesman once wrote a scene into a minimum
priced script, showing ten thousand Macedonian soldiers in a V
formation. The scene would have been about two feet long. In
this case the production was not sold and so that problem did not
have to be solved. A smart salesman is the one who does not even
mention the impossible scenes.

Many things have been sold by salesmen that the producer was
unable to deliver, but the ethical producer wants to sell repeat busi-

Aug., 1942] INDUSTRIAL MOTION PICTURES 137

ness and is therefore careful not to promise anything he can not
deliver. The salesman of dramatic shows might be likened to a
salesman of ready-made suits and a salesman for an industrial pro-
duction might be likened to a tailor. The salesman of dramatic
shows may sell whole blocks of pictures to theater exhibitors and
about all the customers know about them is that they will be some
sort of entertainment. On the other hand, an industrial show must
be made to order, and the salesman must at least know how to take
the measurements. If the original measurement is not made right
the chances are that the finished production will be pretty sloppy.

We often read of the difficulties Hollywood directors have with
authors of books that are being made into shows. In an industrial
show this man is usually represented by someone from the advertising
department of the client. This representative can be of great help
and his services are badly needed to be certain that misstatements or
inaccuracies do not creep into the final production. On the other
hand this person can make the director's life miserable for a time un-
less the director has enough salesmanship about him to convince the
advertising man that certain things should be done and others should
not.

Many times it is the representative's first experience with motion
pictures and he lets his enthusiasm carry him away. He may try
to get four or five pictures into one, or he may show so much useless
detail that the picture will be uninteresting to his audience. He may
let the various departments of his company influence him too much
and as a result he will want to show too much of, let us say, the
laboratory. A good director will point out these things and they will
be eliminated from the script. Occasionally the representative can
not be convinced, and no one knows what may happen after that.
It is safe to say, however, that these shows usually end up with re-
takes, re-editing, rewritten script, usually miss the deadline, and are
not as smooth as they should be.

In planning the show the director and the writer must always keep
in front of them the amount of money that can be spent in producing
the show. Here experience counts a great deal, and without this
experience a producer can easily lose his shirt. Most scenarios must
not call for large expensive sets. Many times the shows are shot on
location — as a matter of fact many times they must be shot on loca-
tion. Frequently long shots are made on location and close-ups are
made in the studio, especially where synchronous sound is to be used.

138 L- THOMPSON [j. s. M. P. E.

This technic is, of course, not new or novel. The industrial producer
must avoid using scenes that might be difficult and expensive to shoot.
A simple set may tell the story just as well — and if the audience has
not seen the expensive set they will not miss it. This does not mean
that locations must not be established. They must. Optical effects
are especially useful in establishing such locations.

The industrial script writer and director must always be thinking
of his actors. His budget is limited and this must limit the amount
of high-priced talent that he can use. On the other hand he must use
talent that can give a fairly good performance or the final result will
be distinctly unsatisfactory.

Since the director may have to use talent that is not as experienced
as some of the stars, it means more rehearsals and sometimes more
takes. Direct 16-mm production helps here because more takes can
be made without worrying too much about raw-stock costs. If the
director must limit his number of takes because of the cost of raw
stock, the finished production will probably not be smooth. In
color this item becomes even more important.

A director of industrial shows must interpret a script differently
from the way a director of dramatic shows would interpret it. With-
out the proper experience a director is likely to become too dramatic
and many times when an industrial show becomes too dramatic it
stands out as something distinctly "phoney." Of course this char-
acteristic can quite easily be created by an inexperienced script
writer. An "Elmer Blurp" type of presentation is funny on the radio
or in an entertainment production, but this same sort of technic used
in an industrial show would probably appear utterly ridiculous.

After the picture has been sold and the script written and put into
shape for production, the industrial producer then has the problem
of getting the picture on the film so that it will be good both artisti-
cally and technically.

To do a successful job the picture must have sound that is clear and
easily understood. Volume level and tone quality should be uniform.
It may need music and sound effects. It may need synchronous
sound taken at different locations. If all these things are to fit to-
gether smoothly it will almost always need re-recording. The
photography must also be smooth and easy-flowing. If an editor is
to make a smooth picture he must be able to insert at the proper
places in the photography wipes, fades, dissolves, and so on, that may
have come from stock or from some other show, or may have been

Aug., 1942] INDUSTRIAL MOTION PICTURES 139

made in different parts of the world. To put these effects into an
original is sometimes impossible and nearly always more costly than
doing it in the laboratory. This means that the producer must have
some method of making these effects either in his own laboratory or
be able to purchase them from an outside laboratory. The buyer of
an industrial and his audience are used to all these little refinements.
They compare an industrial show with what they see in their local
theaters. It is therefore almost necessary that the present-day indus-
trial producer be able to give all these little refinements or enhance-
ments in a picture costing perhaps less than ten thousand dollars,
although the theatergoer compares it with one that cost a hundred
thousand dollars.

As we have already stated the director has a limited amount to
spend on talent. Usually the better the talent the easier it is to
record, photograph, and direct. This means that the industrial
producer must always work to get the best quality he is capable of
making in his sound. Most of the sound that he does record will be
played on 16-mm projectors in the field. This means that the quality
must be kept good if the final results in the field are to be satisfactory.
Since top-flight talent can not always be used, this means a double
handicap for the sound recording technician doing an industrial. I
believe that most of us would be amazed at some of the sound that
is regarded as satisfactory in the theaters were it to be taken and
optically reduced to 16-mm and then played on the ordinary 16-mm
projector in the field. It would be almost as enlightening as if the
commercial producer were allowed to set up his equipment on the
best Hollywood stage with a cast of stars and then play his track
back only in a big theater. He would probably be amazed at his own
quality.

During the past few years a number of people have been surprised
at the quality obtained in direct 16-mm recording. In a number of
cases direct 16-mm has shown up better than 35-mm reduced. There
are several things that might account for this technically. It is also
partly due to the experience of the sound man making these tracks.
He knows the unfavorable conditions under which most of these
sound-tracks will be played and he has learned to compensate for
some of the deficiencies that must be expected in the field. It is
much easier to make passable sound when it is to be played back on
the best of equipment. The problem of the industrial producer is to
make sound that is at least passable on almost any equipment en-

140 L. THOMPSON [j. s. M. p. E.

countered in the field. This is no reflection on the manufacturer of
the equipment because a great many of the difficulties in the field are
no fault of his, and as many of the people in the field gain more experi-
ence many of these difficulties will be eliminated.

There are many camera problems in industrial production. Fre-
quently shots must be made in factories and on production lines.
These must be made without stopping the work, or with the least
amount of waste time. This means that it is not always possible to
use as many lights as are wanted or it means that the lights can not
always be placed where the cameraman would like to have them. In
color it means that angles may have to be picked that will keep day-
light from being mixed with Mazda. Here again the 16-mm pro-
ducer has an advantage because he can use much smaller equipment
and angles that would be impossible with larger equipment. In
shooting by the direct 16-mm method, the producer of color pictures
has still another advantage. It is a simple matter to shift from day-
light to Mazda type Kodachrome. The Mazda type Kodachrome
can be used to photograph under photofloods, which are easily obtain-
able and which do not need any special color correction filters. Ex-
perience has shown that the film is not too critical to color-tempera-
ture, and even under rather unsatisfactory conditions good color
pictures can be obtained without too much difficulty. Here again
the experience of the crew is all-important.

There is the problem of music for industrial productions. Music
is a comparatively simple matter when you can go out and hire some-
one to write a score for the picture and hire an orchestra to play it.
This method produces excellent results but it also increases the cost
of the production to such an extent that a great many minimum-
priced industrials or even medium-priced industrials are not able to
put it into their regular budget. The industrial producer has solved
this in several different ways. There are stock music tracks he may
use. There are stock transcriptions available to him, some on a free
basis and some on a royalty basis. However, it is often very difficult
to find the proper music in this library material. There is also at
least one organization that will produce musical tracks on special
order at a comparatively low price.

In the past few years a number of producers have used the elec-
tronic organ as background music. This has been fairly successful,
but music that has been made by this method seems to show up
"wows" rather easily, and unless the projectors in the field are quite

Aug., 1942] INDUSTRIAL MOTION PICTURES 141

free from these wows the music may be objectionable when it gets
into the field. There is still another solution. We have found that
the regular pipe organ such as the one formerly used in most theaters
records very well. It also re-records very successfully, and if the
producer has available an organist who knows how to get the most
out of the pipe organ a great many different types of music can be
played that will produce almost any mood the producer may desire.
It has been found that music made in this manner does not seem to
show up the wows nearly so badly as some other types of music.

Furthermore, if the industrial producer can record special music
for each individual reel, it simplifies the production problems con-
siderably. Once the music has been arranged it can then be recorded
directly onto the film in synchronism with the picture. This sound-
track can then be re-recorded with the voice, sound-effects, and so on.
If all the music is on one track, only one channel of the amplifier
needs to be tied up, and it is much easier to mix it smoothly than if
the music is coming from a number of different sources that must be
cued very carefully. Since the industrial producer must always be
thinking about time and cost, this is important.

A few industrial producers own their own laboratories for develop-
ing their original film, making their first prints and in many cases
making their release prints. If a producer does not own his own
laboratory he should use care in picking such a laboratory and this is
especially true if he is working in direct 16-mm. If the operations
of an industrial producer are extensive enough, it will undoubtedly
be to his advantage to own his own laboratory because he will be able
to do certain things that are almost impossible to get from any com-
mercial laboratory. This is no reflection on the commercial labora-
tories, who are doing a very good job in general, but it quite fre-
quently happens that a producer wants something special. This may
take a great deal of explaining and sometimes a considerable amount
of experimenting to get. If the producer owns and operates his own
laboratory mainly for the benefit of his own productions, he will be
much more willing to try something special once in awhile. I think
we can almost say, then, that an industrial producer must have every-
thing a major studio has, only on a smaller scale and designed to
operate as economically as possible.

FIFTY-SECOND SEMI-ANNUAL MEETING

OF THE
SOCIETY OF MOTION PICTURE ENGINEERS

HOTEL PENNSYLVANIA, NEW YORK, N. Y.
OCTOBER 27th-29th, INCLUSIVE

OFFICERS AND COMMITTEES IN CHARGE

EMERY HUSE, President

E. ALLAN WILLIFORD, Past-President

HERBERT GRIFFIN, Executive Vice-President

W. C. KUNZMANN, Convention Vice-President

A. C. DOWNES, Editorial Vice-President

ALFRED N. GOLDSMITH, Chairman, Local Arrangements Committee

SYLVAN HARRIS, Chairman, Papers Committee

JULIUS HABER, Chairman, Publicity Committee

]. FRANK, JR., Chairman, Membership Committee

H. F. HEIDEGGER, Chairman, Convention Projection Committee

Reception and Local Arrangements

ALFRED N. GOLDSMITH, Chairman

R. B. AUSTRIAN
L. A. BONN
M. R. BOYER
J. C. BURNETT
F. E. CAHILL, JR.
A. S. DICKINSON
W. E. GREEN
J. A. HAMMOND
M. HOB ART

J. FRANK, JR.
G. FRIEDL, JR.

L. W. DAVEE
P. C. GOLDMARK
R. F. MITCHELL

C. F. HORSTMAN

L. B. ISAAC
E. W. KELLOGG

J. H. KURLANDER

P. J. LARSEN
J. A. MAURER
P. A. McGuiRE
O. F. NEU

J. A. NORLING

WM. H. OFFENHAUSER, JR.

W. M. PALMER

H. RUBIN

V. B. SEASE

T. E. SHEA

E. I. SPONABLE

J. H. SPRAY

R. O. STROCK

H. E. WHITE

Registration and Information

W. C. KUNZMANN, Chairman

E. R. GEIB

F. HOHMEISTER

H. K. MCLEAN
P. K. SLEEMAN

Hotel and Transportation

O. F. NEU, Chairman

W. M. PALMER
P. D. RIES
C. Ross

J. A. SCHEICK
F. C. SCHMID

E. S. SEELEY

142

H. A. GILBERT
G. GIROUX

M. R. BOYER
J. C. BURNETT
P. C. GOLDMARK
ALFRED N. GOLDSMITH

FALL MEETING

Publicity Committee

JULIUS HABER, Chairman

SYLVAN HARRIS
C. R. KEITH

Luncheon and Banquet

D. E. HYNDMAN, Chairman

]. A. HAMMOND

O. F. NEU

W. H. OFFENHAUSER, JR.

M. W. PALMER

143

P. A. McGuiRE
F. H. RICHARDSON

E. I. SPONABLE
J. H. SPRAY
R. O. STROCK
H. E. WHITE

MRS. M. R. BOYER
MRS. A. S. DICKINSON
MRS. J. FRANK, JR.
MRS. G. FRIEDL, JR.
MRS. P. C. GOLDMARK

F. CAHILL, JR.

T. H. CARPENTER
L. W. DAVEE

G. E. EDWARDS
J. K. ELDERKIN

Ladies Reception Committee

MRS. D. E. HYNDMAN, Hostess

MRS. H. GRIFFIN
MRS. J. A. HAMMOND
MRS. P. J. LARSEN
MRS. O. F. NEU
MRS. W. H. OFFENHAUSER,
JR.

MRS. P. D. RIES
MRS. E. I. SPONABLE
MRS. R. O. STROCK
MRS. H. E. WHITE
MRS. E. A. WILLIFORD

Projection Committee

H. F. HEIDEGGER, Chairman

W. W. HENNESSY
J. J. HOPKINS
C. F. HORSTMAN
L. B. ISAACS
A. L. RAVEN

F. H. RICHARDSON

P. D. RIES

J. E. ROBIN

H. RUBIN

R. O. WALKER

Officers and Members of New York Projectionists Local No. 306

HOTEL RESERVATIONS AND RATES

Hotel Rates. — The Hotel Pennsylvania extends to SMPE delegates and guests
the following special per diem rates, European plan :

Room with bath, one person $3.85-$7.70

Room with bath, two persons, double bed $5. 50-18.80

Room with bath, two persons, twin beds $6.60-19.90

Parlor suites: living room, bedroom, and bath $10.00, 11.00, 13.00.

and 18.00

Reservations. — Early in September room-reservation cards will be mailed to the
members of the Society. These cards should be returned to the hotel as promptly
as possible to be assured of desirable accommodations. Reservations are subject
to cancellation if it is later found impossible to attend the meeting.

Registration. — The registration headquarters will be located on the 18th floor
of the Hotel at the entrance of the Salle Moderne, where most of the technical

144 FALL MEETING [J. s. M. P. E.

sessions will be held. All members and guests attending the meeting are expected
to register and receive their badges and identification cards required for admission
to all sessions.

TECHNICAL SESSIONS

Technical sessions will be held as indicated in the Tentative Program below.
The Papers Committee is assembling an attractive program of technical papers
and presentations, the details of which will be published in a later issue of the
JOURNAL.

FIFTY-SECOND SEMI-ANNUAL BANQUET AND INFORMAL GET-TOGETHER

LUNCHEON

The usual Informal Get-Together Luncheon for members, their families, and
guests will be held in the Roof Garden of the Hotel on Tuesday, October 27th, at
12:30 P.M.

The Fifty-Second Semi- Annual Banquet and dance will be held in the Georgian
Room of the Hotel on Wednesday evening, October 28th, at 8:00 P.M. Pres-
entation of the Progress Medal and Journal Award will be made at the banquet,
and the officers-elect for 1943 will be introduced. The evening will conclude with
dancing.

LADIES' PROGRAM

Mrs. D. E. Hyndman, Hostess, and members of her Committee promise an
interesting program of entertainment for the ladies attending the meeting, the
details of which will be announced later. A reception parlor will be provided for
the Committee where all should register and receive their programs, badges, and
identification cards.

MISCELLANEOUS

Motion Pictures. — The identification cards issued at the -time of registering will
be honored at a number of New York de luxe motion picture theaters listed there-
on. Many entertainment attractions are available in New York to out-of-town
delegates and guests, information concerning which may be obtained at the Hotel
information desk or at the registration headquarters.

Parking. — Parking accommodations will be available to those motoring to the
meeting at the Hotel garage, at the rate of $1.25 for 24 hours, and in the open lot at
75 cents for day parking. These rates include car pick-up and delivery at the
door of the Hotel.

Golf. — Arrangements may be made at the registration desk for golfing at
several country clubs in the New York area.

Note: The dates of the 1942 Fall meeting immediately precede those of the
meeting of the Optical Society of America at the Hotel Pennsylvania, New
York, N. Y., to be held on October 30th and 31st.

The Convention is subject to cancellation if later deemed advisable in the na-
tional interest.

Aug., 1942]

FALL MEETING

145

TENTATIVE PROGRAM

Tuesday, Oct. 27

9: 00 a.m. Hotel Roof; Registration.

10: 00 a.m. Salle Moderne; Business and Technical Session.
12: 30 p.m. Roof Garden; SMPE Get-Together Luncheon for members, their
families, and guests. Introduction of officers-elect for 1943 and
addresses by prominent members of the motion picture industry.
2 : 00 p.m. Salle Moderne; Technical Session.
8:00 p.m. Museum of Modern Art Film Library; Technical Session.

Wednesday, Oct. 28

9:00 a.m. Hotel Roof; Registration.

9: 30 a.m. Salle Moderne; Technical sessions.

1 2 : 3 0 p. m. Luncheon Period .

2: 00 p.m. Salle Moderne; Technical session.

8:00 p.m. Georgian Room; Fifty-Second Semi-Annual Banquet and Dance.

Thursday, Oct. 29

9: 00a.m. Hotel Roof; Registration.
10:00 a.m. Salle Moderne; Technical Session.
12: 30 p.m. Luncheon Period.

2 : 00 p.m. Salle Moderne; Technical Session.

8:00 p.m. Salle Moderne; Technical Session and Convention adjournment.

Note: Any changes in the location of the technical sessions and schedules of
the meeting will be announced in later bulletins and in the final program.

W. C. KUNZMANN,

Convention Vice- President

S. M. P. E. TEST-FILMS

These films have been prepared under the supervision of the Projection
Practice Committee of the Society of Motion Picture Engineers, and are
designed to be used in theaters, review rooms, exchanges, laboratories,
factories, and the like for testing the performance of projectors.

Only complete reels, as described below, are available (no short sections
or single frequencies). The prices given include shipping charges to all
points within the United States; shipping charges to other countries are
additional.

35-Mm. Visual Film

Approximately 500 feet long, consisting of special targets with the aid
of which travel-ghost, marginal and radial lens aberrations, definition,
picture jump, and film weave may be detected and corrected.

Price $37.50 each.

16-Mm. Sound-Film

Approximately 400 feet long, consisting of recordings of several speak-
ing voices, piano, and orchestra; buzz-track; fixed frequencies for focus-
ing sound optical system; fixed frequencies at constant level, for de-
termining reproducer characteristics, frequency range, flutter, sound-
track adjustment, 60- or 96-cycle modulation, etc.

The recorded frequency range of the voice and music extends to 6000
cps. ; the constant-amplitude frequencies are in 11 steps from 50 cps. to
6000 cps.

Price $25.00 each.

16-Mm. Visual Film

An optical reduction of the 35-mm. visual test-film, identical as to
contents and approximately 225 feet long.
Price $25.00 each.

SOCIETY OF MOTION PICTURE ENGINEERS

HOTEL PENNSYLVANIA

NEW YORK, N. Y.

JOURNAL OF THE SOCIETY OF
MOTION PICTURE ENGINEERS

VOLUME XXXIX • • • SEPTEMBER, 1942

CONTENTS

PAGE

Report of the Projection Practice Sub-Committee of
the Theater Engineering Committee: Projection
Room Plans 149

Motion Picture Laboratory Practices

J. R. WILKINSON 166

A Modern Music Recording Studio M. RETTINGER 186

Production of 16-Mm Motion Pictures for Television
Projection R. B. FULLER AND L. S. RHODES 195

Current Literature 202

Fifty-Second Semi-Annual Meeting, Hotel Pennsyl-
vania, New York, N. Y., October 27th-29th, Incl. 204

Society Announcements 208

(The Society is not responsible for statements of authors.)

JOURNAL OF THE SOCIETY OF
MOTION PICTURE ENGINEERS

SYLVAN HARRIS, EDITOR

Board of Editors

ARTHUR C. DOWNES, Chairman

JOHN I. CRABTREE ALFRED N. GOLDSMITH EDWARD W. KELLOGG

CLYDE R. KEITH ALAN M. GUNDELFINGER CARLETON R. SAWYER

ARTHUR C. HARDY

Officers of the Society

*President: EMERY HUSE,
6706 Santa Monica Blvd., Hollywood, Calif.

* Past-President: E. ALLAN WILLIFORD,

30 E. 42nd St., New York, N. Y.
* Executive Vice-President: HERBERT GRIFFIN,

90 Gold St., New York, N. Y.
**Engineering Vice-President: DONALD E. HYNDMAN,

350 Madison Ave., New York, N. Y.
*Editorial Vice-President: ARTHUR C. DOWNES,

Box 6087, Cleveland, Ohio.
** Financial Vice-President: ARTHURS. DICKINSON,

28 W. 44th St., New York, N. Y.
* Convention Vice-President: WILLIAM C. KUNZMANN,

Box 6087, Cleveland, Ohio.

* Secretary: PAUL J. LARSEN,

1401 Sheridan St., N. W., Washington, D. C.
* Treasurer: GEORGE FRIEDL, JR.,
90 Gold St., New York, N. Y.

Governors

*MAX C. BATSEL, 501 N. LaSalle St., Indianapolis, Ind.
**FRANK E. CARLSON, Nela Park, Cleveland, Ohio.

*JOHN G. FRAYNE, 6601 Romaine St., Hollywood, Calif.

*ALFRED N. GOLDSMITH, 580 Fifth Ave., New York, N. Y.
**EDWARD M. HONAN, 6601 Romaine St., Hollywood, Calif.

*I. JACOBSEN, 177 N. State St., Chicago, 111.
**JOHN A. MAURER, 117 E. 24th St., New York, N. Y.

*LOREN L. RYDER, 5451 Marathon St., Hollywood, Calif.

* Term expires December 31, 1942.
** Term expires December 31, 1943.

Published monthly at Easton, Pa., by the Society of Motion Picture Engineers.

Publication Office, 20th & Northampton Sts., Easton, Pa.

General and Editorial Office, Hotel Pennsylvania, New York, N. Y.

Entered as second-class matter January 15, 1930, at the Post Office at Easton,

Pa., under the Act of March 3, 1879. Copyrighted, 1942, by the Society of Motion

Picture Engineers, Inc.

REPORT OF THE PROJECTION PRACTICE
SUB-COMMITTEE

OF THE

THEATER ENGINEERING COMMITTEE
PROJECTION ROOM PLANS

The projection room plans that follow constitute the third revision
of the original plans published by the Committee in August, 1932.
The two prior revisions were made in October, 1935, and November,
1938. Such revisions are necessary from time to time in order to
keep pace with the changes and developments in the art and practice
of projecting sound motion pictures and to assure that the projection
room is so planned that it will permit maximum efficiency of operation
of the equipment installed within it. The Committee urgently
recommends the adoption of these Recommendations by all architects
and builders in designing and remodeling projection rooms so that
greater uniformity of construction and greater efficiency in projection
will exist in the future.

In following these Recommendations, proper authorities should in
all cases be consulted for possible deviations therefrom as may be
required for conformance to local rulings. All fire-protection require-
ments specified or referred to herein are in accordance with the
National Board of Fire Underwriters and the National Electric code,
which should be consulted for details.

Projection space facilities shall consist of (1) the projection room
proper, (2) film rewind and storage space, (3) a power equipment
room, and (4) a lavatory.

PROJECTION ROOM PROPER

(1.1) Construction. — The projection room shall be of fire-resistant
construction throughout and shall be supported by or hung from
fire-resistant supports. The projection room shall have a minimum
height of 8 feet. The width and depth of the projection room shall
be governed by the quantity and kind of equipment to be installed
within it, and also by whether the film-rewinding and film-storage

149

150

THEATER ENGINEERING COMMITTEE [j. s. M. p. E.

, "1

1 f

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\r e' *

'•

-^ —

j *

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i

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^ysr^y

V-

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FIG. 1 ( Upper). Layout with separate rewind room.

FIG. 2 (Center). Layout with rewind bench and storage cabinet at
end of room.

FIG. 3 (Lower). Layout with rewind bench and storage cabinet
behind projectors.

Sept., 1942] PROJECTION ROOM PLANS 151

facilities are to be incorporated in a separate room or be a part of the
projection room proper.

The minimum width of the projection room, for one projector,
when film-re winding facilities are provided for in a separate room,
shall be not less than 8 feet. For each additional projector, spot-
light, stereoptican, or floodlight machine shall be added an additional
6 feet in width. The minimum depth of the projection room, when
film-rewind and storage facilities are provided for in a separate room,
shall be not less than 10 feet (Fig. 1).

When film-rewinding and storage facilities are incorporated within
the projection room proper, which may be desirable under some
conditions, the minimum width of the projection room when the
film-rewinding and storage facilities are placed in line with the pro-
jectors, shall be not less than 16 feet for one projector. For each
additional projector, spotlight, stereoptican, or floodlight machine, an
additional 6 feet in width shall be added. When film-rewinding and
storage facilities are within the projection room proper and placed in
line with the projectors, the minimum depth of the projection room
shall not be less than 10 feet (Fig. 2).

When film-rewinding and storage facilities are incorporated within
the projection room proper and are located to the rear of the pro-
jectors, the minimum width of the projection room for one projector
shall be not less than 8 feet. For each additional projector, spot-
light, or floodlight machine, an additional 6 feet in width shall be
added. When film -re winding and storage facilities are incorporated
in the projection room proper, and placed at the rear of the projectors,
the minimum depth of the projection room shall be not less than 12
feet (Fig. 3).

Great care should be exercised in selecting the film-rewinding and
storage facilities layout that will be most efficient for each particular
theater. Efficient operation requires that the screw shall be in view
of at least one member of the working projection room staff whenever
a picture is being projected to the screen.

Generous consideration should be given to all probable future needs
for additional projection room space.

The projection room proper shall be so located with respect to the
screen that the vertical projection angle shall not exceed 14 degrees.
Since the ideal projection angle is one of zero degrees, it is recom-
mended that every consideration be given to keep the projection
angle at as near the ideal as possible. Optical axes of the projectors

152 THEATER ENGINEERING COMMITTEE [j. s. M. P. E.

shall be five feet apart. When two projectors are used, the optical
axes shall be equidistant from the centerline of the auditorium; when
three projectors are used, the optical axis of the center projector shall
be on the centerline of the auditorium. Motion picture projectors
shall be given preference over stereopticans, spotlights, or floodlight
machines, for installation nearest the centerline of the auditorium.

(1.2) Floor. — The floor of the projection room shall be sufficiently
strong and solid for the load it is to bear. A minimum strength of
floor construction of 200 pounds per square-foot plus the dead weight
of the construction proper is recommended. A generous factor of
safety should be allowed. A type of floor construction recommended
consists of (1) a reinforced concrete floor-slab not less than 4 inches
thick, (2) a tamped cinder fill above the floor-slab not less than 4
inches thick, and (3) a troweled cement finish above the cinder fill,
not less than 2 inches thick. Items (2) and (3) have been provided in
order to accommodate concealed electric conduits, which should be
installed prior to placing the fill and finish. The cinder fill of the
projection room floor may be eliminated where there is a plenum
space beneath the projection room area proper, and which area is
available for the running of conduit.

(1.3) Walls and Ceiling. — The projection room walls shall be built
of brick, tile, or plaster blocks plastered on the inside with 3/Vinch
cement or acoustical plaster, or all concrete. The core of the wall
shall be not less than 4 inches thick. When plaster block is used, it
shall be supported upon steel framework. All electrical conduits
shall be in masonry chases in the wall construction so that they shall
not project beyond the finished plaster line (see Sec. 6.1). In all
cases, the inside surface of the front wall shall be smooth and without
structural projections. The ceiling shall be constructed of 4-inch
concrete slabs or pre-cast concrete, or of 3-inch plaster blocks sup-
ported by a steel structure and plastered on the inside with 3/4-inch
cement plaster or acoustical plaster. All electrical conduits in the
ceiling shall be concealed (see Sec. 1.10).

(1.4) Doors. — A door shall be provided at each end of the projection
room. Doors shall be not less than 2 feet 6 inches wide and shall be
6 feet 8 inches high. Doors shall be approved fire-doors of a type
suitable for use in corridor and room partitions (Class C openings, as
defined in the Regulations for Protection of Openings in Walls and
Partitions'), shall be self-closing, swinging outwardly, and shall be kept
closed at all times when not used for egress or ingress. It shall be

Sept., 1942] PROJECTION ROOM PLANS 153

possible at all times to open either door from the inside merely by
pushing it. Door jams shall be made of steel.

(1.5) Windows. — Where a projection room is built against the
exterior wall of a structure, one or more windows may be provided in
the wall. Window construction shall be entirely of steel, and the
glass shall be of the shatter-proof type. Adjustable metal louvres
or equal means shall be used to exclude direct light. Extreme caution
should be taken to prevent dirt and dust from entering the projection
room area through windows opening directly to the outdoors.

(1.6) Portholes. — (General) Two portholes shall be provided for
each projector, one through which the picture is projected, known as
the "projection port" (see Sec. 1.7), and the other for observation of
the picture screen by the projectionist, known as the "observation
port" (see Sec. 1.8).

The observation port shall be located above and to the right of the
projection port. The distance between the horizontal centerlines of
the projection port and the observation port shall be 15 inches; the
distance between the vertical centerlines of the projection port and
the observation port shall be 21 inches.

Where separate spotlight, stereopticon, or floodlight machines are
installed in the same projection room with motion picture projectors,
not more than one port opening (see Sec. 1.9) for each machine shall
be provided for both the projectionists' view and for the projection
of the light, but two or more such machines may be operated through
the same port.

(1.7) Projection Ports.— The finished ports shall be 10 inches by 10
inches, measured on the inside wall.

The required height of the centerline of the projection port from
the finished floor varies with the make and the design of the projection
and sound equipment to be used, and also with the vertical projection
angle. The manufacturers of the equipment being installed should be
consulted for these dimensions. In no case shall any part of the
projector be less than 4 inches from the front wall of the projection
room. Table I lists two constants for various angles of projection
which, when substituted in the formula, will permit calculating the
height of the centerline of the port from the finished floor level when
certain dimensions of the projector are known.

(1.8) Observation Ports. — The finished observation port shall be not
greater than 200 square-inches in area, measured on the inside wall of
the projection room. A recommended size for the observation port

154 THEATER ENGINEERING COMMITTEE [J. S. M. p. E.

is 14 inches wide and 12 inches high, when measured on the inside wall
of the projection room.

(1.9) Other Ports. — All other ports, such as for spotlight, stereop-
ticon, or floodlight machines, shall be as small as practicable and in
no case shall exceed 7l/z square-feet in area per machine. The size
and location of these ports will, of course, be determined by the types

TABLE :

Method of Locating Projector Port
h = H + rA - DB

Projection

Angle
(Degrees) A B

0 1.00 0.00

2 1.00 0.04

4 1.00 0.07

6 1.01 0.11

8 1.01 0.14

10 1.02 0.18

12 1.02 0.21

14 1.03 0.25

16 1.04 0.29

1» 1.05 0.33

20 1.06 0.36

22 1.08 0.40

24 1.09 0.45

26 1.11 0.49

28 1.13 0.53

30 1.16 0.58

H is the height of the center of the projector pivot from the floor; r is the
radial distance of the optical centerline above the center of the pivot; D is the
distance of the center of the pivot from the front wall of the projection room;
<t> is the angle of projection; and h is the required height of the center of the port
from the floor of the projection room. Select the values of A and B corresponding
to the angle of projection, and substitute in the formula.

of such machines to be used. These dimensions should be obtained
from the manufacturers of such machines.

(1.10) Acoustic Treatment. — It is recommended that an approved
fireproof acoustical material be applied to the walls above a height of
4 feet from the floor, and on the ceiling of the projection room, to
reduce the transmission of noise into the auditorium and to reduce
projector and machine noise within the projection room proper.

Sept., 1942] PROJECTION ROOM PLANS 155

REWIND ROOM

(2.1) Construction. — The rewind room, if separate from the pro-
jection room proper, shall be of fireproof construction. It shall have
a minimum area of 80 square-feet (Fig. 1).

(2.2) Floor.— (See Sec. 1.2.)

(2.4) Doors. — The door shall be an approved fire-door of a type
suitable for use in corridor and room partitions (Class C openings, as
defined in the Regulations on Protection of Openings in Walls and
Partitions), shall be arranged to be self-closing, swinging outwardly,
and shall be kept closed at all times when not used for egress or in-
gress. Door jams shall be made of steel.

(2.6) Ports. — Where the rewind room is adjacent to the auditorium,
an observation port shall be provided through which the picture
screen may be seen from within the rewind room. This port shall be
at the same height from the finished floor as the observation ports in
the projection room proper (see Sec. 1.6).

(2.8) Observation Port.— (See Sec. 1.8.)

(2.9) Other Ports. — An observation window shall be provided
between the projection room and the rewind room', consisting of a
fixed fireproof frame and polished plate wire glass. This window
shall be not more than 200 square-inches in area, and shall have its
horizontal centerline 5 feet from the finished floor level.

(2.10) Acoustic Treatment. — (See Sec. 1.10.)

POWER EQUIPMENT ROOM

(3.1) Construction. — The room shall be fireproof and shall be con-
structed in accordance with Sections 1.2, 1.3, 2.4, and 1.10. The
size shall be governed by the quantity and kind of equipment to be
installed. Generous consideration shall be given to probable future
needs.

(3.2) Special Equipment. — It is recommended that wherever rotary
power equipment, such as motor-generator units, is employed hav-
ing an input rating in excess of 15 horsepower, such equip-
ment be installed remote from the theater auditorium, such as in the
basement, to prevent acoustical hum or mechanical vibration from
reaching the auditorium section of the theater. Extreme caution
should be taken to insulate properly all rotary equipment that may
be located at the projection room level, regardless of size, against the
possibility of excess mechanical vibration and hum. All arc-supply

156 THEATER ENGINEERING COMMITTEE [j. S. M. p. E.

equipment located in the power- equipment room, including projection
arc rheostats, shall be at least 4 feet from all sound- amplifier units.

LAVATORY

(4.1) Construction. — The lavatory shall be provided with running
water and modern sanitary facilities, with tiled floor and built-in,
flush- type medicine closet.

EXITS

(5.1) General. — Two exits shall be provided, one at each extreme
end of the projection room, permitting direct and unobstructed
egress (see Fig. 1 and Sec. 1.4). Any stairs forming part of these
{exits should have risers not in excess of 8 inches and a minimum
tread of not less than 9 inches. The distance between walls in any
section of the exits shall not be less than 36 inches. Winding or
helical stairs should be avoided. A platform at least equal in length
to the width of the door shall be provided between the door and the
first riser. Neither ladders, scuttles, nor trap-doors shall be used as
means of entrance or exit.

CONDUITS AND CIRCUITS

(6.1) Locations and Sizes. — Locations and sizes of conduits and
wiring for projection control and sound equipment units are deter-
mined by the quantity, types, and designs of the equipment to be
installed. Manufacturers of the equipment should be consulted with
regard to proper layout and sizes of conduit and wiring systems before
floors, walls, and ceilings are finished (see Sees. 1 .2 and 1 .3) . Conduits
shall in all cases be concealed, and all boxes shall be oi the flush type,
when located in the floors, walls, or ceiling. Conduits terminating
in the floor shall extend 6 inches above the finished floor level. The
wiring and conduit layout shall be in accordance with the National
Electrical Code. Wiring shall be provided for the following usual
circuits, and wiring for special or additional equipment shall also be
provided :

(1) Projector mechanism

(a) Drive motor
(6) Change-overs

(2) Projectors, spotlights, and floodlight machines

(d) Arc supply

(6) Arc ballast rheostats

Sept., 1942] PROJECTION ROOM PLANS 157

(5) Sound equipment
(a) A-c supply
(6) Amplifier controls and power-supply units

(d) Ground wire

(e) Sound heads

(4) Projection room lighting

(a) General
(&) Emergency

(5) Theater auditorium lighting

(a) Regular
(6) Emergency

(6) Projection room ventilating system

(a) Normal
(6) Emergency

(7) Projector ventilating system

(a) Normal

(8) Miscellaneous

(a) Stage curtain control

(b) Telephones

(d) Receptacles
(«) Clock outlet

(6.2) Power- Supply to Equipment. — Where line-voltage variations
are greater than =±= 3 per cent, the local power company should be re-
quested to correct the condition. In cases where it is impossible
normally to maintain steady line-voltage to the equipment, suitable
voltage regulators shall be used.

LIGHTING

(7.1) Projection Room Lighting. — Approved indirect or semi-indirect
ceiling fixtures of the vapor-proof type shall be used for general illu-
mination, and should be arranged to be lighted from either the normal
or emergency lighting circuit. A single reel-light of the vaporprool
type with wire guard shall be centrally located on the projection
room ceiling, and shall be equipped with sufficient approved cord to
allow extension of this reel-light to all parts of the projection room
proper.

Individual ceiling fixtures of the vaporproof type shall be installed
at the operating side of each projector spotlight, stereopticon, or
floodlight machine. All projection room lighting fixtures shall be
equipped with keyless sockets and shall be controlled from wall
switches. All lights in the projection room and associated rooms

158 THEATER ENGINEERING COMMITTEE [J. S. M. p. E.

shall be properly shaded so as to prevent light from entering the
auditorium through the porthole openings.

(7.2) Rewind Room. — An approved vaporproof ceiling fixture shall
be installed for general illumination. A drop-light or wall-bracket
fixture of an approved vaporproof type shall be provided over the
rewind table. These lights shall be controlled from a wall switch
independently of any lights in the projection room proper.

VENTILATION

(8.1) Projection Room. — The projection room proper shall have the
following ventilating facilities :

(a) Carbon arc exhaust

(&) Fresh air supply

The carbon arc exhaust system shall be a positive mechanical
exhaust system independent of all other ventilating systems of the
theater. Each projector, spotlamp, stereopticon, or floodlight ma-
chine, if of the carbon arc type, shall be connected by a flue to a
common duct, which duct shall lead directly out of doors. Reduction
of the ventilation to each projector as required shall be accomplished
by means of a local damper between the projector lamp-house and
the projection room ceiling, and in addition, by means of the damper
on the lamp-house proper if provided.

This exhaust system shall be operated by an exhaust fan or blower
having a capacity of not less than 50 cubic-feet of air per minute for
each arc lamp connected thereto. The exhaust fan or blower shall be
electrically connected to the projection room wiring system and shall
be controlled by a separate switch, with pilot lamp, within the pro-
jection room proper. There shall be at no time less than 15 cubic-
feet of air per minute through each lamp-house into this exhaust
system. Fig. 4 shows the general arrangement. The ducts shall be
of non-combustible material, and shall be kept at least 2 inches from
combustible material or separated therefrom by approved non-
combustible material, not less than 1 inch thick.

The fresh-air supply to the projection room shall consist of not less
than two intake ducts located at or near the floor and at opposite
ends of the room, and shall be connected into the main air-supply
ducts of the building. There shall be no connection between this
air-supply system and any of the exhaust systems of the projection

Sept., 1942]

PROJECTION ROOM PLANS

159

room. It is recommended that gravity-operated dampers connected
to the emergency port-hole release system be installed in the fresh-air
intake registers to prevent smoke from entering the main theater
fresh-air duct system, in case of a fire in the projection room area.

u=9- *;.£'"•""

FIG. 4. Equipment ventilation system: blower capacity 400 cu-ft
per min; minimum air movement through lamp houses with blower idle,
15 cu-ft per min.

The projection room exhaust system shall be a positive mechanical
exhaust system having a normal capacity of not less than 200 cubic-
feet per minute and having an auxiliary emergency capacity of not
less than 1000 cubic-feet per minute for operation in emergency, i. e.,

FIG. 5. General and emergency ventilation system: normal blower
capacity 200 cu-ft per min; emergency capacity 2000 cu-ft per min.

(A) Switch and pilot lamp for normal operation, inside projection room ;
(B) switch and pilot lamp for emergency operation, outside door of pro-
jection room; also connected to port fire-shutter control mechanism.

(Two or more fresh-air intakes required at or near the floor at opposite
ends of the room.)

fire. The ventilation system shall terminate in ceiling grilles in the
projection room, which shall not be less than two in number. In no
case shall this room exhaust system be connected into any of the
ventilating systems of the theater proper. The emergency position
of this fan shall be controlled by a switch (Fig. 5) operated auto-

160

THEATER ENGINEERING COMMITTEE [j. s. M. P. E

matically by the shutter control system, when the latter is actuated
either manually or by melting of the fusible links. This exhaust fan

FIG. 6. Example of port shutter construction. Although this construction
shows rivets, spot welding is preferable.

shall be electrically connected to the emergency lighting system of
the building. Control shall be provided for manual operation of this

Sept., 1942]

PROJECTION ROOM PLANS

161

fan from a point immediately outside the projection room proper, in
addition to the emergency control in the shutter system.

(8.2) Rewind room. — The general ventilation of the rewind room,
i. e., fresh-air supply and room exhaust, shall be a part of the pro-
jection room fresh-air supply system and the projection room exhaust
system. There shall be no connection between the projection arc
exhaust system and any part of the rewind room ventilating system .

Film cabinets, if of the single-compartment type shall be vented to
the outside air by means of a gravity vent (see Sec. 12.2).

(9.1) Port-Hole Shutters. — Each port opening shall be provided with
a gravity shutter of approved construction. The shutter and its

I__M

FIG. 7. One of many possible arrangements of the port fire-shutter control.
The automatic switch operates the exhaust fan and emergency lights.

guides shall be constructed of not less than No. 10 gauge iron and the
shutter shall be set into the guides not less than 1 inch at the sides
and bottom, and shall overlap the top of the port opening not less than
one inch, when the shutter is in a closed position. Shutter guides
shall be of welded construction, and should be built into the masonry
of the projection room walls (Fig. 6). Shutters shall be suspended,
arranged, and so interconnected that they will all close upon the
operation of some mechanical releasing device or the operation of
some fusible link, so designed to operate automatically in case of fire
or other emergency requiring immediate and complete isolation of
the projection room from the other portions of the building. Each
shutter shall have its individual fusible link above it. A fusible link-
shall be located also above each upper projector magazine which upon

162 THEATER ENGINEERING COMMITTEE [j. s. M. P. E.

operation shall close all the port shutters. There shall be provided
also a suitable means for the manual release of the shutter system
from any projector head and from a point near each door within the
projection room. Shutters shall be free-acting. Shutters on open-
ings not in use shall be kept closed always. It is recommended that
shutters be closed each night at the close of the show as a daily check
on their operation. Fig. 7 shows a recommended method for arrang-
ing the port shutter system. All large shutters such as for spot-
lamps, stereopticons, and floodlight machines (when used) shall be
hung in counterweighted systems to facilitate manual operation. All
such large shutters, however, shall be so arranged that the release of
the regular shutter system will close the large ports also.

(9.2) Noise Transmission. — The Committee recommends the use
of means other than glass in projection ports to prevent transmission
of noise from the projector room to the auditorium, such as by re-
ducing the free aperture of the port to the minimum size necessary to
pass the projection beam, or by the use of fireproof sound-baffles.
Observation ports shall be fitted with a good grade of plate glass set
in metal frames at an angle to the vertical to avoid direct reflection,
and such glass shall be easily removable from the projection room side
for cleaning. The purpose of this glass is to reduce noise trans-
mission into the auditorium.

HEATING

(10.1) General. — Proper provision shall be made for heating the
projection room. The same facilities used for heating the theater
shall be extended to the projection room.

PAINTING AND FLOOR COVERING

(11.1) Painting. — The color of the walls shall be olive-green to the
height of the acoustical plaster. The latter shall be painted in
accordance with the instructions of the manufacturer of the material,
and preferably a dull buff color. The ceiling shall likewise be painted
in accordance with these instructions but in a white color. All iron-
work of the projection ports shall be covered with at least two coats
of flat black paint.

(11.2) Floor Covering. — Where local regulations permit, the floors of
the projection room and rewind room shall be covered with a good
grade of battleship linoleum cemented to the floor. The floor cover-
ing shall be laid before the equipment is installed.

Sept., 1942] PROJECTION ROOM PLANS 163

EQUIPMENT

(12.1) Projection Room. — All equipment to be used in the projection
room, including the projectors, arc lamps, sound equipment, etc., shall
be of approved type.

All shelves, furniture, and fixtures within the projection room suite
shall be constructed of metal or other non-combustible and approved
material. An approved metal container shall be provided for hot
carbon stubs. Adequate locker space for projectionists' clothing
shall be provided.

(12.2) Rewind Room. — In the rewind room shall be provided an
approved fireproof film-cabinet or safe, a rewind table, approved
rewind equipment, a mechanical film-splicer, an approved film-scrap
can, and an approved storage cabinet for film-leaders, snipes, etc.t
used only at various intervals.

The film-cabinet, or safe, shall be capable of holding 25,000 feet of
35-mm film on standard reels. Doors on film-cabinets or safes shall
be of the automatic tight-closing type, and either of the single-reel
compartment or single-compartment type. Film-cabinets of the
single-compartment type holding in excess of 50 pounds of film
(10,000 feet) should be vented to the outside air by means of a gravity
vent. The vent should not be less than 36 square-inches in area for
each 50 pounds of film stored. This vent shall be constructed of
non-combustible material and shall be kept at least 2 inches from any
combustible material, or shall be separated therefrom by approved
non-combustible material not less than one inch thick. Film-
cabinets of the single-compartment type having a capacity of more
than 50 pounds of film (10,000 feet) also should be equipped with an
automatic sprinkler-head, of the 3/4-inch size, connected to the
theater water-supply. It is recommended that pressure at such
sprinkler head be not less than 15 pounds.

All tables, racks, and all furniture shall be of metal or other ap-
proved non-combustible material, and shall be kept at least four
inches away from any radiator or heating apparatus. Tables shall
not be provided with racks or shelves beneath them whereon may be
kept film or other materials.

The film-scrap can shall have an automatic, self-closing lid, and
shall be of approved type. It is recommended that a type designed
to keep scrap-film immersed in water at all times be used.

Quantities of collodion, amyl acetate, or other inflammable cements

164 THEATER ENGINEERING COMMITTEE [J. s. M. P. E,

or liquids kept in the rewind room for any purpose shall not exceed one
pint.

No stock of inflammable materials of any sort whatever shall be
permitted within the rewind room except as mentioned above.

Film shall be kept in the film-cabinet at all times except when it is
being projected, rewound, or inspected. Any films in addition to
those used for the current showing or in excess of that permitted by
local authorities shall be kept in their original shipping containers.
Film-leaders used occasionally may be kept in an approved cabinet
designed for that purpose.

All film splices shall be made with approved mechanical cutting
and splicing machine. No hand cutting or splicing shall be per-
mitted.

(12.3} Fire-Extinguishing Equipment. — Local authorities having
jurisdiction with regard to fire-extinguishing equipment should be
consulted regarding the proper types, numbers, and locations of such
equipment.

It is the recommendation of this Committee that fire-extinguishers
of the carbon tetrachloride or carbon dioxide types be considered for
use in projection rooms, as they have proved to give the most effective
protection for the specialized equipment within the projection room.
In addition to their being the most effective fire extinguishers, they
do not cause the ruin of the precision equipment installed within the
projection room proper, if it is necessary that they be used for any
emergency.

MISCELLANEOUS

(13.1) "No Smoking" signs shall be posted in prominent places,
and matches should not be carried by any employee having access
to the projection room.

(13.2) Operation. — Motion picture projectors shall be operated by
and shall be in charge of qualified projectionists who shall not be
minors. A projectionist should be stationed constantly at the oper-
ating side of a projector while it is in operation. A proper factor of
safety in operation, as well as avoidance of imperfect operation of
projection equipment or unjustified interruptions of service can be
attained only by having an adequate personnel in the projection
room.

(13.3) Action in Case of Fire.— In the event of film fire in the pro-
jector or elsewhere in the projection or rewind room, the projectionist

Sept., 1942] PROJECTION ROOM PLANS 165

shall immediately shut down the projector and all arc lamps, operate
the port shutter release at the point nearest him, turn on the audi-
torium lights, leave the projection room immediately, and notify the
manager of the theater or building.

THEATER ENGINEERING COMMITTEE

ALFRED N. GOLDSMITH, Chairman
Sub-Committee on Projection Practice

C. F. HORSTMAN, Chairman

H. ANDERSON R. R. FRENCH E. R. MORIN

T. C. BARROWS E. R. GEIB J. R. PRATER

H. D. BEHR M. GESSIN F. H. RICHARDSON

K. BRENKERT A. GOODMAN H. RUBIN

F. E. CAHILL, JR. H. GRIFFIN J. J. SEFING

C. C. DASH S. HARRIS R. O. WALKER

A. S. DICKINSON J. J. HOPKINS V. A. WELMAN

J. K. ELDERKIN L. B. ISAAC H. E. WHITE

J. FRANK, JR. I. JACOBSEN A. T. WILLIAMS

J. H. LlTTENBERG

MOTION PICTURE LABORATORY PRACTICES*
JAMES R. WILKINSON**

Summary. — The function of laboratory service to studio production departments
and to the release distribution field is discussed. The size and scope of laboratory
operations are illustrated graphically by an organization chart showing the number
of sub-departments. These in turn are classified into three major divisions, namely,
Control, Processing, and Maintenance. Analysis of individual department activity
begins with the Control division, and emphasis is placed upon the recent trend toward
more scientific approach to the problems of processing. Discussion continues with the
Processing division, starting with negative development, and the processing method of
each successive department is described showing the inline flow of the work for both
studio and release print operations. Problems relating to proper mechanical and elec-
trical maintenance are also discussed.

The motion picture laboratory is, essentially, a service organiza-
tion. Its operations, while of an extremely technical nature, are not
creative in any sense of the word, and possibly because of this fact its
efforts are unsung and little in the way of publicity has been released
from the industry relative to its activity or its contribution to motion
picture entertainment. Papers on the subject have been written by
G. M. Best and F. R. Gage, and by C. L. Lootens.1

The scope of laboratory service normally embraces the studio pro-
duction division, i. e., Camera, Sound, and Editorial departments;
also the distribution division, including both Foreign and Domestic
departments. Viewing the laboratory as a part of a major studio or-
ganization, it is considered as a single department similar to the
Camera, Make-up, or Art departments. Actually the laboratory is
one of the largest of the studio units, normally employing from 150
to 250 workers, and is itself divided into approximately twelve sub-
departments, each with its operating foreman and a crew ranging
from five to thirty workers. The specialized nature of the various
laboratory operations foster this departmentalization and, under ex-

* Presented at the 1942 Spring Meeting at Hollywood, Calif. ; received May
10, 1942.

** Paramount Pictures, Inc., Hollywood, Calif.
166

MOTION PICTURE LABORATORY PRACTICES

167

isting conditions, it is very seldom that an overlapping of depart-
mental activities occurs.

To assist in visualizing laboratory operating methods Fig. 1 shows
a typical organization chart and the relationship of the various de-
partments to the supervising personnel. While the chart is typical
of the average laboratory, variations can and do occur within the
individual plants. Laboratory activities seem to be naturally di-
vided into three rather separate and distinct divisions, namely, the
Control division, the Productive or Processing division, and the Sup-

S<4>«rin»«n4«nt

FIG. 1. Laboratory organization chart.

porting or Servicing division. Within these divisions the depart-
ments are identified as follows :

Control Sensitometry

Chemical
Processing Negative Developing

Negative Assembly

Negative Cutting

Printing

Positive Developing

Positive Daily Assembly

Release Inspection

Projection

Timing

168

J. R. WILKINSON

[J. S. M. P. E.

Service Mechanical Maintenance

Electrical
Shipping and Receiving

Before analyzing the various departmental functions it might be
well to state briefly the nature of the work performed by the labora-
tory. Fundamentally it comprises the development of exposed nega-
tive, both sound and picture, and developing of positive rush prints
for studio purposes; also the timing, printing, development, and
shipment of completed prints for release distribution. The work for

Shipping BL
Recei

I Negative Develop. Negative

&. Assembly [Cutting

FIG.

2. Production line of daily
release print operations.

and

both production and distribution divisions generally passes through
the plant at the same time, yet the segregation of the work for the two
divisions is rather clean-cut. Each normally follows a fairly straight-
line method of procedure and the physical arrangement of depart-
ments, starting with the receiving room, is so planned to route the
work through the various operations back to the point where distri-
bution, is effected, with a minimum amount of lost motion. Fig. 2 il-
lustrates the progressive in-line flow of daily and release operations.

CONTROL DIVISION

Sensitometry Department. — Yielding first place only to the sound
department, in the technical nature of its work, the laboratory has

Sept., 1942] MOTION PICTURE LABORATORY PRACTICES 169

made noteworthy progress during the past few years in the more
scientific approach to its processing problems. In the control division
this progress has been particularly marked. Sensi tome try, actually
the junior of all laboratory departments, has assumed a measure of
importance undreamed of originally. It is now the function of this
department, through countless tests and calculations, to establish the
optimal exposure and development specifications for both negative
and positive materials, whether for sound or picture purposes.

The wide increase in the use of specialized emulsion coatings, plus
the intensive research program conducted prior to the general adop-
tion of fine-grain film, has made necessary the broadening of sensito-
metric methods to include many tests not originally a part of classical
sensi tome try. This, in turn, called for the development of new types
of equipment and, as a result, the dynamic analyzer together with im-
proved photoelectric densitometers,2 have become two of sensi -
tometry's most useful tools. Other equipment includes the 116 sen-
sitometer; the microdensitometer ; a sound-reproducer with suitable
amplifiers, filter circuits, and volume indicator; a projection micro-
scope; and a cathode-ray oscillograph.

It is not the intent here to go into the technical details of classical
sensitometry. The subject has been amply covered by D. Mac-
kenzie and by L. A. Jones.3 However, it is appropriate to review
here some of the present duties and responsibilities of this department.
A partial list of its activities include the following items :

(1) The testing of all emulsions, whether negative or positive, to determine
their characteristics. On certain emulsions the determinations of only speed and
contrast are sufficient; while on others, such as are used for sound recording, dub-
bing prints, master positives, etc., a very detailed and complete analysis is made.
In addition to density and gamma characteristics they are checked for frequency
reponse, distortion, printer gamma, grain size, etc.

(2) The exposure, measurement, and analysis of the 116 gamma strips to aid
the chemical department in its chemical control. This applies to all processed
film.

(5) The recording of densities on all sound-track negative and the selection of
the proper printing light to give a correct print density.

(4) Furnish complete reports to the sound department on daily sound print N
as well as special copies such as preview prints. These include the gamma, dens-
ity, and dynamic test data.

(5) The checking of variable-area sound-prints by the use of the caiuvllatum
or cross-modulation test,4 by frequency response and by projection microscope
examination.

(6) The checking of variable-density sound-prints by the use of intcnnodula-

170

J. R. WILKINSON

[J. S. M. P. E.

tion,5 delta-db, frequency response, light-valve gamma, and projected gamma
tests. Fig. 3 shows typical graphs for cross-modulation and intermodulation
analyses. Areas of print densities giving minimal distortion are clearly indicated.

(7) The checking of printer equipment for exposure, field coverage, printer
gamma, light increment, contact, image shift, flicker, and noise introduced by
mechanical imperfections such as worn gears, backlash, etc.

(8) The checking of developing machine equipment for 96-cycle hum, direc-
tional effect, and drying imperfections.

(9) Continuous collaboration with engineers of the sound department with a
view to constant improvement in quality or technic.

The influence of sensitometric activity is felt throughout the labora-
tory, but its greatest importance lies in its relation to the chemical de-

X -MODULATION CURVE
VARIABLE AREA

-.>-

~*J^,-

. _ i«~_ t'tfi- - —

PWNT DENSITY

TYPICAL INTER-MODULATION CURVE
FOR VARIABLE DENSITY

FIG. 3. Typical intermodulation and cross-modulation curves for
sound-processing control.

partment through the establishment of specifications and processing
tolerances that govern developing activities.

Chemical Department. — The chemical department might readily
be termed the heart of the laboratory. It is here that all processing
solutions originate, and are pumped and circulated through a maze
of hard-rubber piping to the various negative and positive developing
machines. Fig. 4 shows a general view of tanks and equipment. In
no other department has there existed a greater opportunity for
scientific progress. The photographic process wherein a silver halide,
which has been exposed to light, is reduced by a developing agent is
one of the oldest of the arts. The action itself is a simple scientific
phenomenon that is well known, yet it sets in motion a train of

Sept., 1942] MOTION PICTURE LABORATORY PRACTICES 171

complex chemical reactions which, due to the volume methods of
modern technic, affect the very foundations of our work. Dr. C. E.
Kenneth Mees states :6

Until recently, photographic science tended to consist of a chaos of observa-
tions, some of them of real value and others of very doubtful value, with little in
the way of theories to connect them properly. It is only within the last few years
that fact after fact has been falling into place in an ordered network.

Just as it is the function of sensitometry to establish the complete
range of specifications and tolerances for all developing procedure, so

FIG. 4 General view of Chemical Department installation.

it is the responsibility of the chemical department to establish and
maintain chemical control over all solutions. Each developing bath,
whether it be picture negative, sound negative, or positive, is de-
signed for a specific purpose and is so compounded that it will produce
the best possible quality for its particular task and do so continuously.
Since film development is a continuous operation it is only logical that
solution replenishment likewise be continuous and proportionate to
the bath exhaustion occasioned by the footage volume. The detail
of procedure and the benefits to be derived from continuous replenish-
ment are described by H. L. Baumbach.7

172

J. R. WILKINSON

[J. S. M. P. E.

Both developing solutions and replenishes are prepared from
chemicals that are tested in advance for their purity. These chemi-
cals are supplied and controlled within certain tolerances which, in
many instances, are more exacting than C. P. limits. Water that has
been filtered, softened, and chemically analyzed is used, and is avail-
able hot or refrigerated as well as at room temperature. It has been
established8 that large volumes of footage passing through a de-
veloping solution cause reactions that necessitate control over its

FIG. 5. Corner of chemical storage room.

chemical constituents; namely, hydroquinone, metol, potassium
bromide, sodium sulfite, and the alkalies that affect the pH. Fixing
baths likewise require control for their silver content, hardening ac-
tion, pH, stability, and rate of fixation. These controls are funda-
mental in nature and are based upon established chemical reactions
during analyses. Standard solutions of iodine, silver nitrate, and
potassium thiocyanate are used for this purpose, and £H measure-
ments are determined by the Beckman pH meter (laboratory model)
using the glass electrode. In no sense is the system of solution con-
trol dependent upon any particular film of any manufacturer.

Sept., 1942] MOTION PICTURE LABORATORY PRACTICES 173

Chemical control, due to its extreme sensitivity, makes it possible
to narrow processing tolerances, and once these have been established
the chemical department must maintain solutions at constant values
for all important ingredients regardless of wide variation in film foot-
age. Cleanliness is strongly emphasized and all solutions are care-
fully filtered to remove the insoluble by-products of development.
Silver from fixing baths is reclaimed electrolytically in a continuously
replenished system. In the discard the last traces are precipitated by
zinc.

Occasionally sensitometric measurements will reveal a variation in
emulsion characteristics of sufficient proportions to require modifica-
tion of the developing solution. When this occurs, changes in concen-
trations are performed, and the developer is modified quickly and ac-
curately to its new standard, thus maintaining the quality of the prod-
uct at the optimal point.

The processing of tremendous volumes of footage, normally handled
by a release laboratory, requires vast quantities of chemicals. Fig. 5
shows a partial view of the supply maintained. These chemicals are
costly and the chemical department foreman is forced by necessity to
become somewhat cost-conscious. The first consideration in every
laboratory is the quality of the product. The laboratory is well able
to defend this position and can point with forceful argument to the
fact that chemicals are the least expensive of the many ingredients
used in the processing of pictures. However this attitude does not
justify, nor does it make a virtue of, wastefulness. The alert
chemical engineer observes, with no small concern, the large unused
portion of chemicals in the average discarded solution. While a rela-
tively new development, it is becoming increasingly the practice to
analyze these solutions, quantitatively, for their known content. The
solution can then be modified and made suitable for a different func-
tion. This is but another instance of chemical control which has now
advanced to the point where solutions may be held completely within
specifications at all times. The photographic element enters into con-
sideration only when emulsion characteristics require a change in
formula balance.

Exact developing formulas are of no great significance. This is due
to the differences in the types of developing machine, variations in
operating speeds, degree of turbulation, etc. However, it is possible
to present what can be considered an average Hollywood formula for
positive, picture negative, variable-density sound negative, and van-

174 J. R- WILKINSON [J. S. M. p. E.

able-area sound negative developers. The densities obtained with
these formulas are obviously dependent upon (1) exposure, (2) de-
veloping time, and (3) developing machine characteristics. The for-
mulas, together with the gamma range within which they operate are
as follows :

Positive

Elon 1 . 50 grams

Hydroquinone 3 . 00 grams

Sodium sulfite 40.00 grams

Potassium bromide 2 . 00 grams

£H* 10.20

Water 1.00 liter

Gamma range 2 . 00 to 2.75

Picture Negative

Elon 1 . 50 grams

Hydroquinone 2 . 50 grams

Sodium sulfite 75.00 grams

Potassium bromide 0 . 50 gram

£H* 8.90
Water 1 . 00 liter

Gamma range 0 . 60 to 0 . 70

Variable-Density Sound Negative

Elon 0 . 50 gram

Hydroquinone 1 . 00 grams

Sodium sulfite 55. 00 grams

Potassium bromide 0 . 25 gram

£H* 8.90

Water 1.00 liter

Gamma range 0.35 white-light exposure,

to 0.85 with ultra-
violet exposure

Variable- Area Sound Negative

Elon 1 . 00 gram

Hydroquinone 10 . 50 grams

Sodium sulfite 50 . 00 grams

Potassium bromide 1 . 50 grams

pH* 10.20

Water 1.00 liter

Gamma range 2 . 75 to 3 . 10

* The pH values of the positive and variable-area sound developers are ob-
tained with sodium carbonate. The negative picture and the variable-density
sound developers are buffered solutions, and the pH values are obtained by borax
buffered with boric acid.

Sept., 1942] MOTION PICTURE LABORATORY PRACTICES 175

PROCESSING DIVISION

Negative Developing Department. — In describing the work of the
departments that were grouped earlier in the processing division, it
seems logical to start with negative development. It is the first of
the many operations that culminate in the final release print for ex-
hibition. Early pioneers within the industry gave much thought to
the development of their negatives, and the reason for this is obvious
even under changed and modern conditions. Exposed negative repre-
sents value, and it is not unusual for the negative of a single day's
work on a picture to have actually cost from ten to twenty thousand
dollars. Obviously, only trained personnel and operating equipment
that has been perfectly maintained can be entrusted with this im-
portant task. Guesswork is out of the question and all hazard, as far
as is humanly possible, must be eliminated.

Much has been written and more will be written regarding the theo-
retical considerations of negative development. The subject is large
in scope and productive of considerable divergence of opinion. It is
well known that the overall gamma or contrast of the final screen print
is the product of the negative and the positive gamma. It therefore
follows that compensation for variation in negative gamma can be ob-
tained by an inverse variation of the contrast of the positive bath.
Normal picture negatives, in Hollywood, are developed within a
gamma range of 0.60 to 0.72, and positive solutions are adjusted to
give satisfactory screen quality at both extremes. A negative in the
low-gamma range requires very full exposure and fairly rapid de-
velopment. By this procedure grain size is held to a minimum;
however, emulsion speed is proportionately reduced. These condi-
tions may be graduated progressively over the gamma range to the
other extreme, where exposure is held to the minimum, development
is prolonged, grain size is increased, and the emulsion speed is fully
utilized or even forced. Excellent results can be and are obtained by
developing to a gamma of 0.66, which is in the center of the range. In
a properly balanced negative solution, development to a gamma of
0.66 permits full advantage to be taken of emulsion speed, yet de-
velopment need not be extended to a point where grain size becomes
objectionable. This procedure likewise has its economic advantage in
that extremely high levels of illumination by the cinematographer are
avoided.

There are two schools of thought regarding negative development.

176 J- R. WILKINSON [j. s. M. P. E.

Certain laboratories are using what is commonly known as the test-
system while others are developing to a constant gamma. Those us-
ing the test-system require the cameraman to make tests for the labo-
ratory whenever a change in set-up or an important change in light-
ing occurs. These tests are broken out of the exposed roll of negative,
properly identified, and developed in advance to a standard time.
The negative developer, after examining the developed tests may, at
his discretion, increase or decrease the development time on scenes
that he believes could be improved by greater or lesser development.
In developing to a constant gamma the solution is controlled to give
constant gamma and density at a given developing time, and all nega-
tive is developed to this standard. It is not the purpose of this paper
either to acclaim or condemn these two systems or to argue the
relative merits of the two systems. It is sufficient to acknowledge
that major studio laboratories are employing both systems at the
present time with apparently satisfactory results.

Negatives of both sound and picture are developed on continuous
developing machines. These machines are often identical in type, dif-
fering only in speed of operation and nature of solution. Both density
and gamma specifications for sound-track negative vary over a wide
range. Specifications are affected not only by the type of recording
system used, i. e., variable-area vs. variable-density, but also by varia-
tions in emulsion speed, contrast, frequency response, and distortion
characteristics of the several different fine-grain recording stocks now
widely used. The sound department makes the decision relative to
optimal negative processing levels, and upon being notified of these
specifications, the laboratory adheres to them rigidly until subsequent
tests dictate a change in levels.

Prior to actual developing operations the machines are serviced
and solutions are tested both analytically and by sensitometric
strips. The negative has been made up into rolls of practical size for
efficient machine operation, and development proceeds. On picture
negative the time consumed, from the moment the film enters the
developing solution until it has passed through the various stages of
fixing, washing, and drying and is spooled on the take-up reel, is ap-
proximately forty-five minutes. Sound negative, being a positive
type of emulsion, requires less time in the different stages of machine
development, and passes through the equipment in thirty-five min-
utes. In addition to rigid solution control, temperature and humidity
of the drying cabinets must be maintained within very close limits.

Sept., 1942] MOTION PICTURE LABORATORY PRACTICES 177

Temperature normally runs 80 °F and relative humidity is held at
55 per cent.

Negative Assembling Department. — Following development, the
negative passes to the negative assembling department. Here the
negative is broken down into individual scenes, and is carefully
inspected for defects that may have been caused by the camera or the
developing machine equipment. During this operation the worker
has before him the camera or sound reports upon which all scene num-
bers have been logged. Scenes that have been selected for printing
are segregated from the takes on which no print is desired. The latter
are classified as "out negative," and are carefully identified and filed
in vaults for possible future use. The "print" takes are assembled in
numerical continuity, and a light-card is prepared for each reel. This
card shows the date, the production number, all scene numbers within
the reel, and the type of raw stock to be used for printing and a col-
umn is provided for future printing lights.

As this operation is completed the assembled sound-track negative
is sent to the sensitometry department, where densities are measured
and the proper printing light is indicated on the light-card opposite
each scene. The assembled reels of picture negative, together with
their light-cards, proceed to the cinex testing room and the work of
the negative assembly group is completed.

Timing. — Upon arrival of the assembled negative in the cinex test-
ing room, each scene is carefully examined and test exposures are
made for timing purposes. These tests, when developed and dried
by a standard developing procedure, afford the tinier a strip of single-
frame pictures made by a series of exposures precisely calibrated to
parallel the light-increment steps of the printing machines. By visual
examination of these tests over a uniformly diffused light-source of
approximately 20 foot-candles, the timer selects the particular print-
ing light which, in his judgment, will represent the best visual result
on the screen. Fig. 6 shows the timer checking the cinex tests.

Frequent discussions with cameramen are valuable to the timer in
order that he may understand and faithfully interpret, through the
print medium, the particular type of lighting or key of photography
for which the cameraman or director is striving. This work approaches
the artistic field more closely than any laboratory task and demands
a high degree of skill, experience, and personal judgment.

As the printing lights are selected they are indicated on the light-
card opposite the appropriate scene number. Following printing

178 J. R. WILKINSON [j. s. M. p. E.

and development of the prints, the timer inspects his work on the
screen; and if a scene has been missed widely, corrections are made
and a reprint is ordered. Reprints are costly; thus it naturally fol-
lows that the fewer the corrections the higher becomes the timer's
individual reputation.

Printing Department. — The printing department is responsible for
the printing of all positive film, whether for studio use or for release
distribution. Beyond the fact that these two types of work must both

FIG. 6. The positive timer selects printer lights.

travel through a printing machine past an aperture, they have little
in common. Production work for the studio comprises a large num-
ber of widely varying specialized requirements, while release printing
has been harnessed to mass production methods. Film for studio
purposes is printed on the Bell & Howell Model D printer. These
machines are continuous in operation and are designed for single
printing, either sound or picture. Should composite prints be de-
sired, the printing operation must be repeated, both negatives being
printed to the same positive. All daily rush prints, except in rare in-
stances, are printed on dual film.

Sept., 1942] MOTION PICTURE LABORATORY PRACTICES

179

Due to the variation in negative densities normally encountered,
it is necessary to provide a wide latitude of exposure range for printing
purposes. This range is divided into approximately 30 steps, each
step representing a light-increment of 10 per cent, or 0.06 in print
density. A graph wherein printer-light increment is plotted against
print density shows a linear characteristic. On the Model D ma-
chines the intensity of the light-source remains constant, and the
change in exposure value is accomplished by a variable aperture which
is manually operated. Their normal speed is 62 feet per minute.

FIG. 7. Battery of Bell & Howell 119 A release printers.

The printing of release positive is a volume operation. For this
work a number of the laboratories use the Bell & Howell Model 119A
printers. Fig. 7 shows a typical installation. These machines are
designed to handle quantity footage. They operate at higher speed,
have more automatic features, and both track and picture negatives
are printed simultaneously. Their light-increment and intensity
parallel the values of the Model D machines. They are reversible in
direction, and many copies are printed by simply supplying new posi-
tive stock, the negative itself never leaving the machine.

180

J. R. WILKINSON

[J. S. M. p. E.

Each reel of release positive is accompanied through the plant by a
work-card upon which each successive department logs a record of
machines and personnel handling the film. This work-card origi-
nates in the printing department; and upon completion of the printing
operation, the printed positive is placed in a metal container, the card
is attached, and the material passes to the developing department.

Positive Developing Department. — In the development of positive
film, as in the printing operation, both studio and release work are

FIG. 8(a). Film-developing machine; feed-in end.

handled simultaneously. Here, even less discrimination exists inas-
much as positive solutions are maintained at constant values and the
development requirements of both types of work are identical. Seg-
regation occurs only at the "take-off" end of the developing machine,
where each type of material is routed to its proper department. The
positive developing machine is very similar to that used for negative
but, due to the volume requirements, is geared to operate at much
higher speeds. Figs. 8(a) and (b) show general views of this equip-
ment. A number of considerations affect the developing time of posi-
tive film, but broadly speaking, it ranges between 2x/2 and S1/^ min-
utes. The complete span of the machine's operations requires about

Sept.. 1942] MOTION PICTURE LABORATORY PRACTICES

181

30 minutes, and the close control of temperature and humidity, as
previously mentioned in connection with negative, are likewise im-
portant to the positive development.

Following the development it is general practice to apply some type
of film preservative to the prints. There are a number of film pre-
servative processes in use, all of which are designed to protect the
freshly developed emulsion surface from undue abrasion and damage
as well as to lubricate the edges of the film to facilitate projection

FIG. 8(6). Film-developing machine; take-off end.

without emulsion pick-up. Various aspects of this subject are dis-
cussed in a Bulletin published by The Research Council of The Acad-
emy of Motion Picture Arts & Sciences.9

Daily Assembling Department. — All developed prints that are to be
used by the studio, both sound-track and picture, are routed from the
developing machines to the daily assembling department. Here
they are sorted as to picture, and the sound-track is synchronized to
the picture print. Identification leaders are installed with proper
"start-marks" to facilitate projector thread-up, and all prints are in-
spected in a sound-projection room for both sound and picture quality.
Following this inspection a log of scene numbers is prepared for each

182 J. R. WILKINSON ft. s. M. p. E.

reel, and if defects are present they are noted opposite the proper
scenes. The reels are then delivered to the editorial department
which arranges the screening for the producers. The material is re-
tained in the editorial department and is used by the film editors in
preparation of their first work-print.

Negative-Cutting Department. — As the preliminary editing is com-
pleted and approved, the work-print together with an order for a first
negative cut is sent to the laboratory. From the moment that print-
ing of daily rushes is completed until a picture has received its final
negative cut, the custody of its negative is the responsibility of the
negative-cutting department. Here also is handled the work of break-
ing down all reels into individual scenes. Proper identification is af-
fixed to each scene showing production scene and code numbers, and
all scenes are filed in large fireproof vaults. Reprints are often re-
quired by the editorial department and the filing system must be so
devised that, out of the many thousands of scenes on hand, any desired
scene can be located at a moment's notice.

The work-print received from the editors consists of a sound-track
and a picture print; thus on a 10-reel production there are 20 reels
of negative to be cut. Negative scenes of both track and picture are
brought from the vaults to the cutting room and the negative cutters
proceed to cut the negative, matching each scene to the corresponding
scene in the work-print. As the reel is completed the scenes are
spliced together, and each scene is notched to provide for printer-light
changes. Light-cards are prepared for each reel showing scene num-
bers, scene footages, descriptive data, and printer lights.

Due to the necessary music and sound-effects that are re-recorded
into all pictures, and to editorial changes following test previews, the
first negative cut on a picture is never final. It is quite normal to re-
match the negative to a new and changed work-print at least once
or twice before approval is given for a final negative cut. Prints pre-
pared between the first and final negative cut are for preview, censor-
ship, and studio library purposes. These copies afford opportunities
to both the picture-timer and the sound department for printer-light
balancing corrections prior to release-printing operations. The final
printing lights have therefore been checked and re-checked, thus
bringing the inter-scene balance for both sound and photographic
values to the optimal point.

Release Assembling Department. — The printing and development of
release footage having been previously described, let us pass to the

Sept., 1942] MOTION PICTURE LABORATORY PRACTICES 183

work of the release assembling department. The material has been
delivered to this department from the positive developing machines
and it will be recalled that each reel is accompanied by its work-car
which originated in the printing department. From the information
on this work-card a small paper sticker is prepared and attached to
the protective leader spliced to each release reel. This sticker remains
on the reel permanently, eventually accompanying it to the exchange,
and provides a record of all machine numbers as well as the initials of
the workers who handled the film during its processing routine. It is
similar to the inspection sticker found on many factory-made gar-
ments, and provides a ready reference for checking processing records
should a complaint be received from the field.

Following the installation of leaders and stickers, the reels are in-
spected by projection. All approved reels are sent to the spooling
machine, while those wherein defects have been noted are sent to the
reprint inspectors where reprints are ordered if required. As reprints
are received, they are inspected and cut in, and that section of the reel
is again checked before being released for spooling. After spooling,
the reel is wrapped in tissue paper and placed in an individual con-
tainer carefully marked in advance with the reel identifications. As
the copies are completed in this manner they pass on to the shipping
department for final packing and shipping.

SERVICE DIVISION

Film Shipping Department. — Upon reaching the shipping depart-
ment the completed copies are packed in fiberboard cartons. These
cartons are manufactured to certain specifications of weight and
strength, and conform to the requirements of The Interstate Com-
merce Commission and The National Board of Fire Underwriters.

Five methods of shipment are utilized by the laboratory: ocean
freight, rail freight, railway express, air express, and parcel post.
Packing specifications for foreign shipments vary greatly according
to destination, and the shipping department must be thoroughly in-
formed on all traffic requirements and regulations. Necessary docu-
mentation for export shipments must be provided, and it is the
responsibility of the traffic manager to see that all forms are correctly
executed and properly certified. Under the present stringent regula-
tions this feature has become a considerable problem, and it is not
unusual to execute and certify as many as five sets of documents to ef-
fect an export shipment. Domestic shipments to exchanges are rela-

184 J. R- WILKINSON [J. s. M . P. E.

lively simple and are normally sent by either rail freight or railway
express. The distribution department is advised daily, by teletype,
all the details of each day's shipments.

Maintenance Department. — To effect an uninterrupted flow of work
through the various departments, provision must be made for proper
and efficient maintenance of plant and equipment. This is a major
problem common to all laboratories. Much of the equipment is of
complex design and of high precision, requiring the services of expert
technicians for maintenance and adjustment. Electrical circuits em-
ployed likewise demand engineering knowledge of the highest order.10
A considerable proportion cf the required electrical energy must be
generated as direct current, and the regulation of supply to the vari-
ous power and light-source units must be accurately controlled. This
control for printer-lamps is accomplished by electronic regulators, and
a tolerance of 0.1 volt is maintained constantly.

Equipment of the developing and chemical departments is subject
to the action of chemicals and fumes, making constant care necessary
to insure efficient operation. The proper maintenance and operation
of a large air conditioning installation demands a thorough under-
standing of refrigeration and humidity and temperature control, as
well as the principles of air-washing and filtering. Cleanliness is
vital to laboratory processing and these units must operate at maxi-
mum efficiency at all times.

The laboratory occupies a unique position in that a considerable
portion of its equipment is not readily available for purchase in the
open market. The maintenance staff must therefore be competent to
design new equipment or to modify existing machines to effect the
many improvements in technic that are brought to light through re-
search and experience.

CONCLUSION

In conclusion it may be stated that the various natures of the many
laboratory duties, together with departmental segregation, make the
principles of organization and coordination of utmost importance to
successful operation. Each department not only must function
smoothly within itself but likewise must have an appreciation of the
problems and efforts of the other departments, thus contributing to a
well balanced efficiency in the overall task of service and research.
With the importance of the technical phases of motion picture pro-
duction well established and gaining increased recognition, the labora-
tory takes a just pride in its contribution to this field.

Sept., 1942] MOTION PICTURE LABORATORY PRACTICES 185

REFERENCES

1 LOOTENS, C. L.: "A Modern Motion Picture Laboratory," J. Soc. Mot.
Pict. Eng., XXX (April, 1938), p. 363.

BEST, G. M., AND GAGE, F. R.: "A Modern Studio Laboratory," J. Soc.
Mot. Pict. Eng., XXXV (Sept., 1940), p. 294.

8 FRAYNE, J. G., AND CRANE, G. R.: "A Precision Integrating Densitometer,"
/. Soc. Mot. Pict. Eng., XXXV (Aug., 1940), p. 184.

* JONES, L. A.: "Photographic Sensitometry," /. Soc. Mot. Pict. Eng., XVII
(Oct., 1931), p. 491, and (Nov., 1931), p. 695; XVIII (Jan., 1932), p. 54, and
(March, 1932), p. 324.

MACKENZIE, D. : "Straight-Line and Toe Recording with the Light-Valve,"
J. Soc. Mot. Pict. Eng., XVII (Aug., 1931), p. 72.

4 BAKER, J. O., AND ROBINSON, D. H.: "Modulated High-Frequency Record-
ing as a Means of Determining Conditions for Optimal Processing for Variable-
Area," /. Soc. Mot. Pict. Eng., XXX (Jan., 1938), p. 3.

6 FRAYNE, J. G., AND SCOVILLE, R. R. : "Analysis and Measurement of Distor-
tions in Variable-Density Recording," J. Soc. Mot. Pict. Eng., XXXII (June,
1939), p. 684.

6 MEES, C. E. K.: "Recent Advances in the Theory of the Photographic
Process," /. Soc. Mot. Pict. Eng., XXXVII (July, 1941), p. 10.

7 BAUMBACH, H. L. : "Continuous Replenishment and Chemical Control of
Developing Solutions." Presented at the 1942 Spring Meeting at Hollywood,
Calif.; to be published in a forthcoming issue of the JOURNAL.

8 EVANS, R. M., AND HANSON, W. T., JR. : "Chemical Analysis of an MQ De-
veloper," /. Soc. Mot. Pict. Eng., XXXII (March, 1939), p. 307.

BAUMBACH, H. L.: "The Chemical Analysis of Metol, Hydroquinone, and
Bromide in a Photographic Developer," /. Soc. Mot. Pict. Eng., XXXIII (Nov..
1939), p. 517.

ATKINSON, R. B., AND SHANER, V. C. : "Chemical Analysis of Photographic
Developers and Fixing Baths," /. Soc. Mot. Pict. Eng., XXXIV (May, 1940), p.
485.

9 Committee on Improvement in Release Quality, Report by Film Preserva-
tive Committee, F. L. Eich, Chairman, Tech. Bull., Res. Council Acad. Mot. Pict.
Arts & Sci., (April 14, 1939).

10 LESHING, M., INGMAN, T., AND PIER, K.: "Reduction of Development
Sprocket-Hole Modulation," /. Soc. Mot. Pict. Eng., XXXVI (May, 1941), p. 475
WILKINSON, J. R., AND EICH, F. L.: "Laboratory Modification and Proce-
dure in Connection with Fine-Grain Release Printing," /. Soc. Mot. Pict. Eng.,
XXXVIII (Jan., 1942), p. 56.

A MODERN MUSIC RECORDING STUDIO

M. RETTINGER**

Summary. — This paper represents a broad analysis of a music recording studio
recently completed at the RCA Manufacturing Co., Hollywood, Calif. Discussed
herein are constructional details considered important toward the achievement of good
recording conditions in the stage. In particular, the action of convex wood splays is
considered in some detail, especially in regard to their influence on the reverberation
characteristic of the room.

In planning the remodeling of the local RCA scoring stage, special
consideration was given to the preference among musicians and
music-lovers for rooms which contain a large amount of wood panel-
ing. This preference can be attributed largely to the ability of such
a material to vibrate over a wide range of musical pitch, unlike a panel
of plaster or fiber board. The energy employed to set the wood
sheet into vibration is partly re-radiated in a manner that does not
follow the regular law of equal angle of incidence and reflection. A
vibrating surface, because of its size and shape, may therefore emit
plane or cylindrical waves, although it is excited by spherical waves.
In this sense, the walls of the band shell may also be considered to be
an extension of the instruments — an extension which, although loosely
coupled to the sources of sound, nevertheless emphasizes many of the
frequency components of music sufficiently to lend pleasant support
to the music. It is the sounding board again — a device that mag-
nifies the tonal area of the instrument by creating sustaining surface
sources in proximity to a relative point-source, or sources.

It was deemed desirable to install such wood panels in the form of
convex splays to secure a greater diffusion of the sound in the room.
As is well known, the wavefront of a beam of sound reflected from a
convex surface is considerably longer than that from an equally large
flat surface, provided that the wavelength of the incident sound is
small compared to the dimensions of the reflecting surface. Fig. 1
shows this relationship graphically, and it is seen that the wavefront

* Received April 1, 1942.

** RCA Manufacturing Co., Hollywood, Calif.
186

MODERN Music RECORDING STUDIO 187

reflected from the convex splay is, for the condition illustrated, con-
siderably longer than the sum of the two reflected from the flat panels.
The figure shows also the construction of the wavefronts, analogously
to the optical case, the center of the reflected wavefront coming from
the curved surface being one-half the radius of the convex splay
(assuming the source is at some distance from the surface) .

The fact that the wavefront from a convex reflector is longer tends
also to reduce the interference effect between direct and reflected
sound. This is illustrated in Fig. 2. Since the energy of a propaga-
ting wavefront varies inversely with the square of ats length, the re-
duction of the interference effect is appreciable, a factor that may

FIG. 1. Illustrating length of reflected wavefront
from convex splay and flat panels.

assume considerable importance in the recording of slow-moving
music.

A convex splay is also excellent insurance against echoes in a room,
particularly when it is intended to keep this surface reflective. For
this reason, convex surfaces are helpful in providing a smoother decay
of the sound, as well as one that is more nearly logarithmic with time,
since the reverberation persists longer in the direction in which echoes
occur in a room.

One may therefore summarize the advantages of properly designed
convex wood panels in a confined space as follows :

(1) More uniform distribution of the sound pressure, due to the longer wave-
front of the reflected sound, particularly pertinent for the high frequencies.

(2) Creation of surface sources of sound, also helpful in increasing the diffusion
of the sound in the room, and being of special importance for the low frequencies.

188

M. RETTINGER

[J. S. M. P. E.

(5) Provision of a wall or ceiling section that is more absorptive for the low
than the high frequencies. The fact that work is being done on the panel in
moving it, and that sound is radiated from the back as well as front, describes the
device also as a relatively efficient low-frequency absorbent.

(4) Reduction of interference effect between direct and reflected sound.

(5) Production of a relatively smooth sound-decay curve.

(6) Erection of reflective surfaces which will minimize echo.

The use of vibrating wood panels in a room has, in the past, some-
times given rise to a cautious consideration of the resonance qualities
of such a construction. The uninitiated believe that a pronounced
tone-bias is produced by such a vibrating panel. Indeed, one is fre-

SOOWO PRESSURE. WER-FEREHCE. PRODUCED V Cwt^tX REFLECTOR

SOURCE

FIG. 2. Sound pressure interference effect produced
by a flat and convex reflector.

quently asked "What is the resonance frequency of this or that
splay?"

To avoid such a cautious regard of wood membranes as used in
this room, it may be well to enumerate their resonance qualities thus :

(1) A wood splay of the type employed has many resonance frequencies. Fig. 3
shows the response characteristic of a splay at two points on it, randomly chosen,
and approximately 5 feet apart. The curves were obtained by fastening a
crystal pick-up to the two points and then exciting the splay into vibration by
generating in the room a sound of a continuously varying warbled tone.

(2} The resonance frequencies are not harmonically related.

(5) The amplitude distribution is made up of the various modes of vibration.

(4) Nodes are not sharply defined, owing to the presence of more than one
mode.

Sept., 1942]

MODERN Music RECORDING STUDIO

189

The only pronounced resonance to which a splay of this type is sub-
ject is that produced by the air-chamber back of it. The natural,
low-frequency modes of vibration of this chamber, if it had been kept
reflective, would have been transmitted into the stage in an objec-
tionable measure. In the case where the chamber had been kept
highly reflective, a "hang-over" effect or prolonged reverberation
would have resulted at certain low frequencies, none of which was
desired to have a reverberation time markedly longer than those of
the middle or high registers, a point that will be discussed in greater

FIG. 3.

Response characteristic of a splay at two different points on
splay.

detail later. Hence the space back of the splays was kept absorbent,
and care was taken not to permit the acoustic material to come into
contact with the panel itself, which, to note, consisted of two quarter-
inch sheets of plywood. Application of fiberboard or other sound-
absorbent to the wood surface would have exerted a damping effect
upon the natural modes of vibration of the wood membranes, which
was not considered necessary or desirable for the purpose.

The use of wood panels was welcome also because with their aid it
was possible to achieve a nearly flat reverberation characteristic in
the room. As is well known, the absorptivity of most acoustical
materials is considerably smaller for the low than for the high fre-

190

M. RETTINGER

[j. a M. P. E.

quencies. The only way by which this condition can be reversed is
by employing a thin material which by vibration will absorb the low
frequencies while acting as a reflector for the highs. In order, how-
ever, to avoid a pronounced selective low-frequency absorption it is
desirable to vary the size and radii of these convex splays, as was done
in this room. This condition was further improved by irregular
bracing back of the splays.

FIG. 4. Relation of monaural acoustic perspective and absorptivity.

A nearly flat reverberation characteristic in this room was con-
sidered desirable inasmuch as it was held that the determining factor
for a recording studio is not so much the reverberation characteristic
as what H. F. Olson terms the recorded reverberation characteristic.
It should be said here that the term ''recorded reverberation" is be-
lieved to be somewhat confusing, and that it might be better to speak
of a monaural acoustic perspective when considering the ratio of re-
flected to direct sound-energy density. Fig. 4 gives the equation for
this ratio, which obviously has no dimensions, but merely states how
much more reflected than direct sound exists at any point in the room.
It is this ratio that gives to the recorded sound the impression of

Sept., 1942]

MODERN Music RECORDING STUDIO

191

depth and, indeed, an impression of reverberatoriness, without
actually giving a measure of reverberation time in seconds.

The reason for attaching so much importance to the monaural

Jo *» -a

FIG. 5. Reverberation characteristic of RCA scoring stage.

FIG. 6. Plan and elevation of the room.

acoustic perspective is that the microphone represents but one ear.
As is well known the reverberation in a room appears considerably
longer when observed with but one ear than when observed with both

192

M. RETTINGER

[J. S. M. P. E.

ears. The reason for this lies in an unconscious suppression of re-
flected sound, which appears to the ear as undesirable in the case of
speech, since it tends to detract from intelligibility. In the case of
music the ear accepts a certain amount of this reflected sound, appar-
ently because it tends to improve the quality of the music. It is for
this reason that the reverberation time in music rooms is usually made
longer than in speech room. The microphone, however, records the
true acoustic conditions at the point of its location, and once the sound
is recorded, the ear can during reproduction no longer ignore or dis-
criminate against the reflected sound that was present at the micro -

FIG. 7. Front

of stage.

phone position, since this reflected sound is now part of the direct
sound from the loud speaker.

Now, in order not to obtain excessive ratios of monaural acoustic
perspective for the low frequencies, care must be taken to avoid long
reverberation times for these frequencies. When the average absorp-
tivity at a given frequency is cut in half, the reverberation time in a
room is practically doubled. The monaural acoustic perspective for
this case, however, becomes more than twice, and may reach values
of three or four times, depending upon the value of the reduced
absorptivity. This condition of increased values for the monaural
perspective at the low frequencies is further aggravated by the fact

Sept., 1942] MODERN Music RECORDING STUDIO 193

that the solid-angle of reception for most microphones is larger for
the low frequencies than for the high.

Fig. 5 shows the reverberation characteristic of this stage, which
has a volume of 70,000 cu-ft. The measurements were made with a
reverberation meter of the rotating commutator type described by
H. Olson and F. Massa in their book "Applied Acoustics."

Fig. 6 shows a plan and elevation view of the room. The color
scheme was prepared by the well known industrial designer, Mr.
John Vassos, and employs a pastel shade of blue for the splays and a
maroon for the trim (door, baseboard, chair-rail, etc.)

FIG. 8. Rear view of stage.

Several other studios have lately been constructed employing con-
vex splays on the sidewalls with very good results. Among these are
the WFAA and KGKO broadcasting studios in Dallas, Texas, the
RCA recording studio in South America, the RCA film recording
studios in New York, and the Walt Disney scoring stage. The only
undesirable feature in these rooms, including this stage, is presented
by the comparatively large expanse of the flat floor. However, the
use of players' platforms, chairs in the room, and the judicious use of
rugs does much to ameliorate this condition.

The floor of this stage is of the elastically floated type. The joists
rest on resilient steel chairs grouted in concrete. A sound-absorbent
filler is placed between the joists, not only to dampen any resonance

194 M. RETTINGER

effects, but also to assist in reducing the transmission of noise from
without.

The monitoring room is paneled with large sheets of wood veneer
on the sidewalls except for the wall behind the mixing console, which
received acoustic treatment of the type employed in the state. This
acoustic material was selected on account of its smooth absorption
characteristic and because its low-frequency absorption was com-
paratively high. The windows in the monitoring room are double
panes separated by a 4-inch air-space, and the walls between the two
sheets of glass carry sound-absorbent treatment.

BIBLIOGRAPHY

OLSON, H., AND MASSA, F. : "Applied Acoustics," P. Blakiston's Son & Co.
(Philadelphia), 1934.

MAXFIELD, J. P.: "Some of the Latest Developments in Sound Recording
and Reproduction," Tech. Bull., Acad. Mot. Pict. Arts & Sci., Technicians Branch,
(April 20, 1935).

POTWIN, C. C., AND MAXFIELD, J. P.: "A Modern Concept of Acoustical De-
sign," /. A const. Soc. Amer., 11 (July, 1939), p. 48.

MAXFIELD, J. P., AND POTWIN, C. C.: "Planning Functionally for Good
Acoustics," /. Acoust. Soc. Amer., 11 (April, 1940), p. 390.

POTWIN, C. C.: "The Control of Sound in Theaters and Preview Rooms,"
J. Soc. Mot. Pict. Eng., XXXII (Aug., 1940), p. 111.

LOOTENS, C. L., BLOOMBERG, D. J., AND RETTINGER, M. : "A Motion Picture
Dubbing and Scoring Stage," /. Soc. Mot. Pict. Eng., (April, 1939), p. 357.

VOLKMANN, J.: "Poly cylindrical Diffusers in Room Acoustic Design," J.
Acoust. Soc. Amer., 13 (Jan., 1942).

PRODUCTION OF 16-MM MOTION PICTURES FOR
TELEVISION PROJECTION*

R. B. FULLER AND L. S. RHODES**

Summary. — A general report on setting of procedural and dimensional practices
for the production of 16-mm sound motion pictures for television projection.

The paper shows that in the various steps from the original film to the final image
on the television receiver, a considerable percentage of the frame area is lost by "crop-
ping" in the projector, in the iconoscope, and in the kinescope. Unless this loss is
taken into consideration and compensated for in the original planning of films for
television, loss of image area may seriously impair the effect of the motion picture.

The paper makes specific recommendations based upon the conclusions drawn, but
does not attempt, in view of present conditions, to fix final aperture standards any
further than to urge that such standards be set up by the proper group. Many of the
factors directly concerned in production are considered with a view to the ultimate
quality to be attained.

Reference is made to experiences and problems met by the authors in the prepara-
tion of animated cartoons and other films for television broadcasting.

It is believed that both producer and motion picture technicians
can and should review the problems connected with the preparation
of films for television projection and telecasting and analyze the
difficulties likely to be encountered. This might seem to be effort
wasted at this particular time, but the new practices evolving from
this particular field may have present and future values in contri-
buting to the effective preparation and presentation of motion pic-
tures for television use.

In the preparation of motion pictures for television a number of
facts must be taken into consideration in order to guarantee that the
received image will fulfill the requirements of our message. In other
words, we know what effect we want to present to the television
audience, and so we must take into consideration and make com-
pensations for any variations that may occur in the various steps
between film and final image. Roughly, there are at least three

* Presented at the meeting of the Atlantic Coast Section, Feb. 19, 1942; and
at the 1942 Spring Convention at Hollywood, Calif.; received April 16, 1942.
** New York, N. Y.

195

196

. B. FULLER AND L. S. RHODES

(J. S. M. P. £.

elements to be considered. First: the color loss or effect, in black-
and-white or color: although we have a picture to start with that is
clear in respect to its colors will we end up with the same picture?
Second : to what extent will television faithfully reproduce the action,
outline, or detail of the picture? Third: what loss will there be in
the overall frame size in final projection? The last is our primary
consideration.

16-Mm Standard Camera Field
16-Mm Projector Aperture

Television Transmitter Field
[3-5% loss on sides; 2.5% loss
on top and bottom (linear
dimensions)]

Television Receiver Field
[loss ranges from 0% to
about 15% of transmitter
field areal

FIG. 1. Shaded area shows approximate reduction of image from original
16-mm frame to the image on the television receiver.

It is generally acknowledged by a majority of workers in the field
of production of 16-mm films that, while general and fairly widely
accepted standards for dimensions of such film have been set up,
final practice policies and standard dimensions have not yet been
widely adopted or recognized.

In view of the state of flux and experimentation in which the
technique of television now stands, and considering the time re-
quired for developmental work, it is believed appropriate to note
several special factors, paying particular attention to dimensional
practice and procedure.

Moreover, the coming of age of completely satisfactory direct
sound-on-film recording in the 16-mm size has presented many

Sept., 1942 J 16-MM PICTURES FOR TELEVISION 197

problems new to the film-stock and equipment manufacturers and
laboratory specialists, the general producers, and the regular users
of finished films, whether shown on small-size home-projection screens,
or large theater screens, or through the new transmission medium,
television.

At present, for 16-mm sound motion picture film, the standard
projection aperture is 0.380 X 0.284 inch, with an allowable tolerance
of =»= 0.002 inch. It is understood that the projection aperture should
be smaller than the frame on the film for obvious reasons.

Data on actual projection dimensions, as found in the equipment in
various television studios, show variations in detail. One of the
first factors to be considered is the loss of image size. We can not
make a definite statement as to how great this loss is, because we
find that in the several studios, and even in separate items of equip-
ment in the same studio, there is considerable variation. Whereas
in one instance the projector aperture used in one television studio
was slightly smaller than standard, another studio used a slightly
larger projection aperture, and the staff of still another studio implies
that, although standards may have been established, a reduction of
projection aperture dimensions may be tried if demanded by effects
in which they are interested.

The following is an example of the kind of problem that arises in
processing procedure. In one case, several feet of film that had been
optically reduced from 35 mm to 16 mm were included in 16-mm
footage for the remainder. Due to laboratory requirements, com-
pensation had to be made in obtaining the combined release print,
•with the result that the entire footage had proportionately wide
spaces between frames. The laboratory had to mask the entire strip
of film in order that the one section reduced from 35 mm would not
show an objectionable error beyond the frame edge. This necessi-
tated careful alignment in projection and resulted in reduced image
sizes all around.

Now, in discussing this problem of loss of image size we find many
points other than those directly concerned with television projection.
We mention them because, since we are trying to make films that
will present ultimately a desired picture, we must consider any ele-
ment that may change, distort, or affect the picture between, as in
animation, the drawing of the background, and the final picture as
viewed by the audience.

The second point, which is relatively negligible for the most part.

198 R. B. FULLER AND L. S. RHODES [j. s. M. P. E.

is film shrinkage — either in the original negative, in the dupe nega-
tive, and then later, in any film that is stored over a period of time.
Shrinkage will reduce the frame size, but the loss is figured at a
general average of about 0.7 per cent, with an extraordinary maxi-
mum of 2 per cent. Much of this difficulty is well realized and the
laboratories are handling the problem rather well.

In the printing of 16-mm film, with sprocket-holes along one edge
and because of the edge guiding (which is not satisfactorily standard-
ized as yet), the pull-down and the head-to-tail printing often result
in a loss of the true frame.

Now, let us follow an image through the steps required to bring
the image from film to the audience and see what happens to the
frame. Having possibly already lost some of the frame size in print-
ing, reduction, shrinkage or ordinary handling, we are ready to pro-
ject the strip of film into the television camera. The film is projected
onto a photoemissive mosaic enclosed in a glass tube, and the resulting
image is then scanned line by line.

The photoemissive area or mosaic on which the picture is projected
is proportioned like the film frame, roughly in a 4 to 3 ratio. Here
we find differences of opinion and practice. Let us assume that the
image that is projected fills the mosaic. From one studio we hear
that this image is then "overscanned" slightly, in order to insure
proper coverage. This means that the resulting edge must be
masked out, and it is probable that the masking goes slightly further
than the exact amount of overscanning in order to protect against
any slight error of alignment. This results in a loss of about 1/s inch
from top to bottom, and about y4 mch from side to side. Another
studio tells us that it slightly ' 'underscans, ' ' and apparently some degree
of masking is introduced because of possible loss in definition at the
edge. The studio did not so state. At any rate, we note that the
image size and the frame size are being progressively reduced.

Another television engineer said in effect that reduction of the
original film aperture is due in some degree to the non-linearity of
the television scanning procedure.

Two other elements might be included here, although they can
not be detailed at this time, partly because complete technical infor-
mation is not available. The first is keystoning. The image pro-
jected on the photoemissive mosaic is scanned at a 30-degree angle,
so that the field is foreshortened and distorted. This is corrected
before transmission by the "sawtooth voltage," but even though it

Sept., 1942] 16-MM PICTURES FOR TELEVISION 199

is corrected this keystoning can cause some distortion, and, hence,
loss of frame size or proportions.

Another of these undetermined features is difficult to explain because
definite information could not be obtained. We have a feeling that
there is loss of definition at the edge of the screen of the television
receiver. If one looks at the screen from the side, the end of the
tube has a curved surface, which apparently is cause for some dis-
tortion. Many kinescope tubes are "blown" or molded, which
results in a parabolic or irregular arc for the former, while the latter
tube is a two-piece affair molded together, the surface being a true
arc with, consequently, no distortion.

One of the largest losses in area is entirely apart from all the fea-
tures considered above. This is the "personal equation," which
may enter not only at the transmission end, but also at the receiving
end, where the observer may so tune his instrument that no more
than 75 per cent of the image is received. The general average may
be nearer 90 per cent in tuning accuracy, but it is still believed that
losses do occur in this way.

All these losses must be taken into consideration when film is
prepared. While the various factors may occur in lesser degree
than described above, we know that we will be wise to make all
allowances and compensations in the very first steps. Standards
must eventually be prescribed, and to insure faithful reproduction
of the film, it is necessary that we put definite thought into these
problems and arrive at standards that will save us all loss of effects
and many headaches. Let us analize the results of the losses found
above :

(1) In general, the most serious result is that titles and essential
material falling outside the middle two-thirds of the final film image
will be in danger of being cut off. The loss of such material will be
more serious on the sides than on the top and bottom.

(2) In the case of technical and cartoon animation there is a defi-
nite possibility that essential action or picture in the outer thirds
area will be lost, although a trained animator generally attempts
wherever possible to confine his material to the center of the field.

(3) In live photography or studio shots, this loss may impair com-
position or clarity. For example if the scene shows a perfectly nor-
mal actor standing at the edge of the field, the cutting down of the
image may result in only a part of him on the edge of the television
screen.

200 R. B. FULLER AND L. S. RHODES [J. S. M. P. E.

In producing a recent animated cartoon, we had the idea that we
could plan our scenes framed. Each picture was centered in and
surrounded by a gray mat frame of no importance, which we would
gladly lose before losing part of our picture. We are sad about how
quickly this ingenious device was rejected.

However, we suggest that field gauges be set up, to be used by
studios producing for television films, and to be worked out by care-
ful analysis, showing what compensations must be made for the
probable or possible losses.

We suggest also that finders of cameras, both for animation and
straight shooting, have inscribed upon their view-finder lines showing
the image to be received on the kinescope screen. As far as is known,
there is only one make of camera that has a finder that shows only
the projection aperture size, thus automatically showing the camera-
man the final picture.

To sum up, it is shown that the loss of image is more important
than is generally realized, and it is urged that the Society make
careful investigation of the problem.

In our work of preparing films for television we have come upon
a number of problems that may be of interest here. For example,
there are many opinions on the question of the number of tones of
grays discernible, and, of course, a great deal depends upon the sub-
ject and the way in which it is handled. Estimates on the number
of grays discernible in television vary from as high as 25 to as low
as 12. It is important to note that these 12 to 25 shades are not all
regular shades, because of the tendency of television to black out
the darker tones of gray and burn out or wash out the lighter tones.
So, although we can safely allow for 12 shades of gray, 8 of these
shades could be evenly spaced in the middle range, with more subtle
variations, while the extreme darks or lights could be much more
widely spaced. In instances where the film is in color, it should
be remembered, too, that two distinct colors having the same density
may very well come out as identical tones of gray and result in a
serious loss of definition or clarity and effect. A dark red and a
dark blue may be transmitted as the same shade of gray, and thus
care must be taken to consider tones rather than colors.

We have been advised by television engineers that, in general
average gray shades reproduce best when the gamma of the film is
between 2.0 and 2.5 and when the maximum density range is between
1.5 and 2.5. Apparently very superior results are achieved when the

Sept., 1942] 16-MM PICTURES FOR TELEVISION 201

maximum density is between 1.3 for 5 per cent transmission and
1.8 for l!/2 per cent transmission.

For the most part we can say that any film that will project well
on a theater screen will also produce equally fine results on the tele-
vision screen, but we suggest that attention be given to this question
of shades of color advisable in television reproduction, and here the
motion picture may have to compromise with television procedure.

We have developed a few little devices to help us in our work.
We wanted, in one picture we were directing, to achieve perfect
synchronism with a regular piece of music. We played our record
a few times until we knew it by heart. Then we played it into the
film recorder, and as it played, rather softly, we tapped with a pencil
on the front of the microphone. When the sound-track was de-
veloped we knew exactly on which frame every lesser and greater
beat came and also how the phrases broke. Then, with a bouncing-
ball sequence, we counted the frames; the bouncing of the ball indi-
cated the rhythm of the music, with high bounces to give the cues for
the narration. The result was a perfectly timed film.

Another idea that has been favorably received in the NBC tele-
vision studios is what we call the "tuning lead," which consists of a
ten-second (240 frames) film exactly or almost exactly of the same
general tone as our picture. These are used by the engineer to
"tune" the television apparatus. On the ten-second leader are the
words "Scene begins in ... seconds." Every twenty-four frames is a
new number and, as the engineer watches — 10-9-8-7-6-5-4-3-2-1—
there are only six frames of 1. The switch is then thrown and the
film transferred from the monitor screen onto the actual television
screen, perfectly tuned.

In general, television engineering is meeting the dimensional
practices of 16-mm motion picture production rather well; however,
the producers may find it advisable to revise some of the practices
derived from 35-mm procedure and establish further standardization.

CURRENT LITERATURE OF INTEREST TO THE MOTION PICTURE

ENGINEER

American Cinematographer

23 (July, 1942), No. 7

British Film Technicians and the War (pp. 294-295, 334) G. H. ELVIN

Warners Build Improved Scene Slating Device (pp. 296-
297, 333-334) W. STULL

Animated Cartoon Production Today. Pt. IV. Clean-
ups and Inbetweening (pp. 300-303, 331-332) C. FALLBERG

Release-Print Problems in Professional 16-Mm Produc-
tion (pp. 304, 330-331) J. A. LARSBN, JR.

Building a Microphone-Boom for 16-Mm. Sound Home

Movies (pp. 310-311, 328) C. N. ALDRICH

Try Diffused Lighting for Kodachrome Close-Ups (pp.
314, 327-328) R. RENNAHAN

British Kinematograph Society, Journal

5 (April, 1942), No. 2

Speech and the Larynx (pp. 37-44) H. HARTRIDGE

Direct Processes for Making Photographic Prints in

Colour (pp. 45-50) C. E. K. MEES

The Measurement of Screen Brightness (pp. 51-55) H. ETZOLD

Electronic Engineering

15 (June, 1942), No. 172
Harmonic Analysis of Waves, Containing Odd and Even

Harmonies (pp. 13-18) P. KEMP

Television Waveforms (pp. 19-26) C. E. LOCKHART

Institute of Radio Engineers, Proceedings

30 (June, 1942), No. 6
Hearing, the Determining Factor for High-Fidelity

Transmission (pp. 266-277) H. FLETCHER

The Effect of Fluctuation Voltages on the Linear Detec-
tor (pp. 277-288) J. R. RAGAZZINI
The Use of Vacuum Tubes as Variable Impedance Ele-
ments (pp. 288-293) H. J. REICH
202

CURRENT LITERATURE

203

L. CHADBOURNE

E. R. GEIB

H. G. MACPHERSON

L. CHADBOURNE

The Relative Sensitivities of Television Pickup Tubes,

Photographic Film, and the Human Eye (pp. 293-300) A. Ross

International Projectionist

17 (May, 1942), No. 5

War Uses of Motion Pictures Discussed at SMPE Con-
vention (pp. 7-8)

Maintenance and Repair of Loudspeakers (pp. 9-10)

Underwriters Code as It Affects Projection Rooms.
Pt. II (pp. 17, 21)

17 (June, 1942), No. 6

The New Victory Projector Carbons (pp. 7-8)

The Consumption of the Positive Arc Carbon (pp. 13,
25)

Underwriters Code as It Affects Projection Rooms. Pt.
Ill (pp. 17-18)

Some New Routine Precautions in the Maintenance of
Amplifiers (pp. 19-20)

Motion Picture Herald, Better Theaters

147 (June 27, 1942), No. 13

The Film Theater on the Home Front (pp. 13-15)
How Much Can You Reduce Arc Current to Save Cop-
per? (pp. 26-27) C. E. SHULTZ

Photographische Industrie

39 (April 16, 1941), No. 16

Neuere Richtlinien des Kino-Kamerabaus (New Direc-
tions in Motion Picture Camera Construction), (pp.
271-272)

39 (May 28, 1941-July 9, 1941), No. 22-28
Das Auflosungsvermogen bei der photographischen Auf-
nahme (Resolving Power in Photographic Emulsions).
Pts. 1-6 (pp. 351-356, May 28; 371-373, June 4; 385-
388, June 11; 401-403, June 18; 418-420, June 25;
432-434, July 2; 449-452, July 9) H. ROEDER

Deutsche und amerikanische Kinonormen in vergleich-
ender Darstellung (Comparative Representation of
German and American Motion Picture Standards).
Pts. 1-3 (pp. 378-379, June 4; 395-396, June 11 ; 410-
412, June 18) P. HATSCHEK

39 (July 23, 1941), No. 30
Reinton ohne oder mit Vorausreglung (High Fidelity

Sound With or Without Pre-Setting) (pp. 491-492) P. HATSCHEK

39 (Sept. 24, 1941), No. 39

Die Einheiten der Beleuchtungstechnik und ihre wech-
selseitigen Beziehungen (Relative Values for Illumina-
tion Units) (pp. 631-632) P. HATSCHEK

FIFTY-SECOND SEMI-ANNUAL MEETING

OF THE
SOCIETY OF MOTION PICTURE ENGINEERS

HOTEL PENNSYLVANIA, NEW YORK, N. Y.
OCTOBER 27th-29th, INCLUSIVE

OFFICERS AND COMMITTEES IN CHARGE

EMERY HUSE, President

E. ALLAN WILLIFORD, Past-President

HERBERT GRIFFIN, Executive Vice-President

W. C. KUNZMANN, Convention Vice-President

A. C. DOWNES, Editorial Vice-President

ALFRED N. GOLDSMITH, Chairman, Local Arrangements Committee

SYLVAN HARRIS, Chairman, Papers Committee

JULIUS HABER, Chairman, Publicity Committee

J. FRANK, JR., Chairman, Membership Committee

H. F. HEIDEGGER, Chairman, Convention Projection Committee

Reception and Local Arrangements

ALFRED N. GOLDSMITH, Chairman

R. B. AUSTRIAN
L. A. BONN
M. R. BOYER
J. C. BURNETT
F. E. CAHILL, JR.
A. S. DICKINSON
W. E. GREEN
J. A. HAMMOND
M. HOB ART

J. FRANK, JR.
G. FRIEDL, JR.

L. W. DAVEE

P. C. GOLDMARK

R. F. MITCHELL

C. F. HORSTMAN
L. B. ISAAC
E. W. KELLOGG

J. H. KURLANDER

P. J. LARSEN
J. A. MAURER
P. A. McGuiRE
O. F. NEU

J. A. NORLING

WM. H. OFFENHAUSER, Ji

W. M. PALMER

H. RUBIN

V. B. SEASE

T. E. SHEA

E. I. SPONABLE

J. H. SPRAY

R. O. STROCK

H. E. WHITE

Registration and Information

W. C. KUNZMANN, Chairman

E. R. GEIB

F. HOHMEISTER

H. K. MCLEAN
P. K. SLEEMAN

Hotel and Transportation

O. F. NEU, Chairman

W. M. PALMER
P. D. RIES
C. Ross

J. A. SCHEICK
F. C. SCHMID

E. S. SEELEY

204

H. A. GILBERT
G. GIROUX

M. R. BOYER
J. C. BURNETT

P. C. GOLDMARK

ALFRED N. GOLDSMITH

FALL MEETING

Publicity Committee

JULIUS HABER, Chairman

SYLVAN HARRIS
C. R. KEITH

Luncheon and Banquet

D. E. HYNDMAN, Chairman

J. A. HAMMOND

O. F. NEU

W. H. OFFENHAUSER, JR.

M. W. PALMER

205

P. A. McGuiRE
F. H. RICHARDSON

E. I. SPONABLE
J. H. SPRAY
R. O. STROCK
H. E. WHITE

MRS. M. R. BOYER
MRS. A. S. DICKINSON
MRS. J. FRANK, JR.
MRS. G. FRIEDL, JR.
MRS. P. C. GOLDMARK

F. CAHILL, JR.

T. H. CARPENTER
L. W. DAVEE

G. E. EDWARDS
J. K. ELDERKIN

Ladies Reception Committee

MRS. D. E. HYNDMAN, Hostess

MRS. H. GRIFFIN
MRS. J. A. HAMMOND
MRS. P. J. LARSEN
MRS. O. F. NEU
MRS. W. H. OFFENHAUSER,
JR.

MRS. P. D. RIES
MRS. E. I. SPONABLE
MRS. R. O. STROCK
MRS. H. E. WHITE
MRS. E. A. WILLIFORD

Projection Committee

H. F. HEIDEGGER, Chairman

W. W. HENNESSY
J. J. HOPKINS
C. F. HORSTMAN
L. B. ISAACS
A. L. RAVEN

F. H. RICHARDSON

P. D. RIES

J. E. ROBIN

H. RUBIN

R. O. WALKER

Officers and Members of New York Projectionists Local No. 306

HOTEL RESERVATIONS AND RATES

Hotel Rates. — The Hotel Pennsylvania extends to SMPE delegates and guests
the following special per diem rates, European plan :

Room with bath, one person $3 . 85-$7 . 70

Room with bath, two persons, double bed $5. 50-$8.80

Room with bath, two persons, twin beds $6.60-$9.90

Parlor suites: living room, bedroom, and bath $10.00, 11.00, 13.00,

and 18.00

Registration. — The registration headquarters will be located on the 18th floor
of the Hotel at the entrance of the Salic Moderne, where most of the technical

206 FALL MEETING [J. s. M. P. E.

sessions will be held. All members and guests attending the meeting are expected
to register and receive their badges and identification cards required for admission
to all sessions.

TECHNICAL SESSIONS

FIFTY-SECOND SEMI-ANNUAL BANQUET AND INFORMAL GET-TOGETHER

The usual Informal Get-Together Luncheon for members, their families, and
guests will be held in the Roof Garden of the Hotel on Tuesday, October 27th, at
12:30 P. M.

The Fifty-Second Semi- Annual Banquet and dance will be held in the Georgian
Room of the Hotel on Wednesday evening, October 28th, at 8:00 P. M. Pres-
entation of the Progress Medal and Journal Award will be made at the banquet,
and the officers-elect for 1943 will be introduced. The evening will conclude with
dancing.

LADIES' PROGRAM

MISCELLANEOUS

Motion Pictures. — The identification cards issued at the time of registering will
be honored at a number of New York de luxe motion picture theaters listed there-
on. Many entertainment attractions are available in New York to out-of-town
delegates and guests, information concerning which may be obtained at the Hotel
information desk or at the registration headquarters.

Golf. — Arrangements may be made at the registration desk for golfing at
several country clubs in the New York area.

Note: The dates of the 1942 Fall Meeting immediately precede those of the
meeting of the Optical Society of America at the Hotel Pennsylvania, New
York, N. Y., to be held on October 30th and 31st.

The Convention is subject to cancellation if later deemed advisable in the na-
tional interest.

Sept., 1942] FALL MEETING 207

TENTATIVE PROGRAM

Tuesday, Oct. 27

9 : 00 a.m. Hotel Roof; Registration.

10:00 a.m. Salle Moderne; Business and Technical Session.
12: 30 p.m. Roof Garden; SMPE Get-Together Luncheon for members, their
families, and guests. Introduction of officers-elect for 1943 and
addresses by prominent members of the motion picture industry
2:00 p.m. Radio City Music Hall Studio; Technical Session.
8:00 p.m. Museum of Modern Art Film Library; Technical Session.

Wednesday, Oct. 28

9 : 00 a.m. Hotel Roof; Registration.

9:30 a.m. Salle Moderne; Technical sessions.

12:30 p.m. Luncheon Period.

2: 00 p.m. Salle Moderne; Technical session.

8:00 p.m. Georgian Room; Fifty-Second Semi-Annual Banquet and Dance.

Thursday, Oct. 29

9:00 a.m. Hotel Roof; Registration.
10: 00 a.m. Salle Moderne; Technical Session.
12: 30 p.m. Luncheon Period.
2 : 00 p.m. Salle Moderne; Technical Session.
8:00 p.m. Salle Moderne; Technical Session and Convention adjournment.

Note: Any changes in the location of the technical sessions and schedules of
the meeting will be announced in later bulletins and in the final program.

W. C. KUNZMANN,
Convention Vice- President

SOCIETY ANNOUNCEMENTS

AMENDMENTS

At the meeting of the Board of Governors, held at Hollywood, May 3, 1942,
the amendments of the By-Laws and Constitution given below were proposed
and approved for submittal to the membership of the Society at one of the ses-
sions of the Hollywood Convention.

In view of the fact that a quorum was unobtainable at any of the sessions of the
Convention, the amendments were held over until the approaching Convention
to be held at New York, October 27th-29th, inclusive.

In accordance with the requirements of By-Law XII, relating to the method
cf acting upon proposed amendments, these amendments are published in an
issue of the JOURNAL prior to the meeting at which they are to be presented for
vote of the Society membership. These amendments provide for increasing
the number of members of the Board of Governors, and are as follows:

Proposed Amendment of Article V

The Board of Governors shall consist of the President, the Past-President,
the five Vice-Presidents, the Secretary, the Treasurer, the Section Charimen, and
ten elected Governors. Five of these Governors shall be resident in the area
operating under Pacific and Mountain Time, and five of the Governors shall be
resident in the area operating under Central and Eastern Time. Two of the
Governors from the western area, and three of the Governors trom the eastern
area shall be elected in the odd-numbered years, and three of the Governors from
the western area and two of the Governors from the eastern area shall be elected
in the even-numbered years. The term of office of all elected Governors shall
be two years.

Proposed Amendment of By-Law I/I, Sec. 2

Nine members of the Board of Governors shall constitute a quorum at all
meetings.

Proposed Amendment of By-Law III, Sec. 1

The Board of Governors shall transact the business of the Society between
members' meetings, and shall meet at the call of the President, with the proviso
that no meeting shall be called without at least seven (7) days' prior notice,
stating the purpose of the meeting, to all members of the Board, by letter or by
telegram.

208

SOCIETY ANNOUNCEMENT

209

ADMISSIONS COMMITTEE

At a recent meeting of the Admissions Committee, the following applicants
for membership were admitted into the Society in the Associate grade:

CORCORAN, J. P.
2213 Midvale Ave.,

West Los Angeles, Calif.
DONNELLEY, THORNE

Photographic Science Laboratory,

Anacostia, D. C.
GOLDBERG, H. E.

Eastman Kodak Company,

Rochester, N. Y.
HANSON, GEORGE
2960 Ettrick St.,

Los Angeles, Calif.
JOHNSTON, E. R.

742 Lakeview Blvd.,

Seattle, Wash.
KRAUSS, E. D.
1021 Chavez St.,
Burbank, Calif.

LEGRAND, C. C.

Mole-Richardson Co.
941 N. Sycamore Ave.,

Hollywood, Calif.
LOBALBO, C. F.
3202 Ampere Ave.,

Bronx, N. Y.
NAVE, F. A.
Rt. 2, Box 263,

Oakdale, Calif.
REEDY, W. A.

Weston Electrical Instrument Corp.

Newark, N. J.
SHERMAN, L. F., JR.
Calton Court,

New Rochelle, N. Y.
WILSON, W. G.
2411 East 15th St.,
Kansas City, Mo.

WOODWARD, H. L., JR.
Signal Photo Laboratories,
Army War College,
Washington. D. C.

In addition, the following applicants have been admitted to the Active grade:

BERTRAM, E. A.

DeLuxe Laboratories
441 West 55th St.,
New York, N. Y.
BARNET, STAN

333 West 57th St.,
New York, N. Y.

DEVRY, E. B.

1111 Armitage Ave.

Chicago, 111.
OSBORN, L. G.

Western Electric Co., Ltd.,
152, Coles Green Road,
London. N. W. 2, England

MEMBERS OF THE SOCIETY

LOST IN THE SERVICE OF

THEIR COUNTRY

FRANKLIN C. GILBERT

JOURNAL OF THE SOCIETY OF
MOTION PICTURE ENGINEERS

VOLUME XXXIX • • • OCTOBER, 1942

CONTENTS

PAGE

The Technique of Production Sound Recording

H. G. TASKER 213

Prescoring and Scoring B. B. Brown 228

A Study of Flicker in 16-Mm Picture Projection

E. E. MASTERSON AND E. W. KELLOGG 232

Developments in Time-Saving Process Projection

Equipment R. W. HENDERSON 245

Current Literature 258

Fifty-Second Semi-Annual Meeting, Hotel Pennsyl-
vania, New York, N. Y., October 27th-29th, Incl.
General Information 259

Abstracts of Papers 263

(The Society is not responsible for statements of authors.)

JOURNAL OF THE SOCIETY OF
MOTION PICTURE ENGINEERS

SYLVAN HARRIS, EDITOR

Board of Editors

ARTHUR C. DOWNES, Chairman

JOHN I. CRABTREE ALFRED N. GOLDSMITH EDWARD W. KELLOGG

CLYDE R. KEITH ALAN M. GUNDELFINGER CARLETON R. SAWYER

ARTHUR C. HARDY

Officers of the Society

*President: EMERY HUSE,

6706 Santa Monica Blvd., Hollywood, Calif.
* Past-President: E. ALLAN WILLIFORD,

30 E. 42nd St., New York, N. Y.
*Executive Vice-President: HERBERT GRIFFIN,

90 Gold St., New York, N. Y.
** Engineering Vice-President: DONALD E. HYNDMAN,

350 Madison Ave., New York, N. Y.
* Editorial Vice-President: ARTHUR C. DOWNES,

Box 6087, Cleveland, Ohio.
** Financial Vice-President: ARTHUR S. DICKINSON,

28 W. 44th St. , New York, N. Y.
* 'Convention Vice-President: WILLIAM C. KUNZMANN,

Box 6087, Cleveland, Ohio.
4 'Secretary: PAUL J. LARSEN,

1401 Sheridan St., N. W., Washington, D. C.
* Treasurer: GEORGE FRIEDL, JR.,

90 Gold St., New York, N. Y.

Governors

*MAX C. BATSEL, 501 N. LaSalle St., Indianapolis, Ind.
**FRANK E. CARLSON, Nela Park, Cleveland, Ohio.

*JOHN G. FRAYNE, 6601 Romaine St., Hollywood, Calif.

*ALFRED N. GOLDSMITH, 580 Fifth Ave., New York, N. Y.
**EDWARD M. HONAN, 6601 Romaine St., Hollywood, Calif.

*I. JACOBSEN, 177 N. State St., Chicago, 111.
**JOHN A. MAURER, 117 E. 24th St., New York, N. Y.

*LOREN L. RYDER, 5451 Marathon St., Hollywood, Calif.

* Term expires December 31, 1942.
** Term expires December 31, 1943.

Published monthly at Easton, Pa., by the Society of Motion Picture Engineers.

Publication Office, 20th & Northampton Sts., Easton, Pa.

General and Editorial Office, Hotel Pennsylvania, New York, N. Y.

Entered as second-class matter January 15, 1930, at the Post Office at Easton,

Pa., under the Act of March 3, 1879. Copyrighted, 1942, by the Society of Motion

Picture Engineers, Inc.

THE TECHNIQUE OF PRODUCTION SOUND RECORDING

HOMER G. TASKER**

Summary. — Although sound recording differs greatly from motion picture
photography, it involves many analogous techniques and some similar processes.
Sound recording requires special apparatus to transform sound into energy capable
of exposing motion picture film. Its reproduction from the film requires additional
transformations involving other specialized apparatus.

Good sound pick-up on the motion picture set involves acoustic conditioning quite
analogous to set lighting, camera angle selection, etc. The sound crew is provided with
flexible means for microphone placement and with controls and monitoring devices
for observation of the results obtained. The film recording machine is a specialized
mechanism requiring precision comparable to that of the motion picture camera.
Its operation entails skillful adjustments. The sound department cooperates with the
laboratory department in the establishment and interpretation of processing controls.

In discussing the aural or sound problems in the production of
motion pictures, three introductory tasks must be undertaken :

(1) To distinguish the problems of recording the aural elements of a motion
picture scene from those of recording the visual elements.

(2} To indicate the scope of production sound recording, as distinguished
from scoring and pre-scoring, and from re-recording or sound blending.

(5) To introduce, in elementary form, the recording and reproducing appa-
ratus common to all three of these recording activities.

(1) As entertainment media, the visual and aural elements of a
motion picture scene supplement each other in that sound contributes
many details of thought, action, or emotion not possible to the pic-
torial side and vice versa. As media to be recorded upon the motion
picture film, they differ in the extreme. The visual element, properly
illuminated, is capable of exposing the film directly through the
agency of the camera lens, but sound is quite as invisible to the
camera eye as it is to the human eye. Hence, it requires very con-
siderable transformations or translations before it can be photo-
graphed on the film, and again before it can be reproduced in the
theater in a form to be interpreted by the human ear.

* Presented at the 1942 Spring Meeting at Hollywood, Calif. ; received Aug.
20, 1942.

** Paramount Pictures, Inc., Hollywood, Calif.

213

214 H. G. TASKER U. s. M. p. E.

Further, the camera and the microphone differ, as do the eye and
the ear, in that off-stage objects are almost entirely ignored by the
camera, while off-stage sounds are almost as well recorded as the
wanted sounds from the scene itself. The limitations thus imposed
may be quite severe.

Although the visual and the aural elements both involve time as
the very essence of the entertainment values to be recorded, the
characteristics of the eye fortunately permit the simulation of con-
tinuous motion through the rapid succession of a large number of
still pictures, whereas sound requires absolute continuity of the re-
cording and of the subsequent reproduction. Fortunately, both these
requirements can be met with motion picture film.

Nevertheless, there are many motion picture processes common to
sight and sound, for the record of sound is photographic in character,
and there is basic similarity between the laboratory processes involved
in producing and multiplying these records and those employed for
the picture. Moreover, as they leave the studio for projection in
theaters throughout the world, they occupy, side by side, the same
piece of film.

(2) Production sound recording may be defined as the recording
of sound that takes place simultaneously with the photographing of
the scene. Ordinarily, this includes dialog and such incidental foot-
steps, door slams, and other noises as originate within the camera
angle.

Scoring is the subsequent recording of music to accompany the
scene. Pre-scoring is the prior recording of instrumental or vocal
music to be played back during the photographing of a scene to estab-
lish musical tempo to which the actors may synchronize their move-
ments.

Re-recording is the final blending together of the dialog, the pre-
or post-scored music, the "character" sound-effects such as crowd
murmurs and factory noises, and the effects separately recorded to
accompany scenes photographed without sound, etc.

(3) A great deal has been written about the design and character-
istics of sound recording and reproducing equipment but not so much
about the nature of the work to be accomplished with these tools or
about the techniques involved. The emphasis here will be on the
latter rather than on the former features. Details of the equipment
may be found in the appended bibliography.

For this reason the basic sound-recording and reproducing system

Oct., 1942]

PRODUCTION SOUND RECORDING

215

will be introduced here in quite elementary form. Subsequent
references will be made to specific characteristics of certain apparatus
as they bear on matters of technique.

Referring to Fig. 1 and beginning at the lower left of the diagram,
the essential elements of a sound-recording system are :

(a) Microphone (First Transformation). — Transforms sound
energy into electrical energy. Several different types1-2 are used de-
pending upon the requirements, but each is a high-quality device
responsive to the air pressure changes or air particle movements

MOTION PICTURE STUDIO

MODULATOR OPTICS

LIGHT SOURCE

SOUND NEGATIVE x
FILM

AMPLIFIER
VOLUME CONTROL

MICROPHONE

THEATER

OPTICS

LIGHT
SOURCE
POSITIVE
FILM

PHOTOCELL

VOLUME CONTROL
AMPLIFIER

L /

LOUD SPEAKER

FIG. 1. Elements of sound-recording and reproducing systems.

which characterize sound so that the result is an electrical copy of
whatever sound impinges upon the microphone.

(b) Amplifier. — Increases the above-mentioned electrical energy
to usable proportions. The output of the microphone is very feeble.
One milli-microwatt is typical, although this will vary with the type
of microphone and other circumstances from Viooo to nearly 1000
times that value. About one watt is needed for recording. Hence
the amplification must be very great and must also be of the highest
quality and controllable with precision.

(c) Electrooptical Modulator (Second Transformation).— Exposes
the sound negative motion picture film under control of the above-

216 H. G. TASKER [J. a M. P. E.

described amplified electrical energy. The motion picture industry
is about equally divided in the use of two types of modulators, both
of which employ a steady source of light plus electromagnetic means
for controlling the amount of this light that reaches the film. In the
"light- valve" type of modulator3 pairs of metallic ribbons surrounded
by a strong magnetic field alternately separate and converge to
control the passage of light in response to the amplified current from
the microphone. The system is usually so aligned as to expose the
sound-track uniformly across its full width but in varying degree
along its length, so as to produce the "variable-density" type of
sound-track. In the "galvanometer" type of modulator4 the same
purpose is served by the rotary oscillation of a small mirror mounted
on an electromagnetic structure in such a way as to be responsive
to electrical energy. The system is usually so arranged as to ex-
pose a fraction only of the width of the sound-track, the magnitude
of this fraction varying lengthwise of the film so as to produce the
"variable-area" type of sound-track.

(d) Film-Driving Mechanism. — Moves the film past the exposure
point with a very high degree of uniformity of speed.5-6 It has proved
useful to separate the sound recorder from the picture camera. The
necessary synchronism is maintained by one of several types of motor
systems including a-c interlock,7 d-c interlock,8 and synchronous.

(e) Auxiliary Apparatus. — This includes such necessary elements
as volume controls, fixed or variable equalizers, volume indicators,
monitoring equipment, power supplies, etc.

Subsequently to the necessary processing of the sound negative and
the making of positive prints the equipment necessary to reproduce
sound from this film in synchronism with the picture, whether for
studio purposes or for projection in theaters, is as follows :

(/) Film-Driving Mechanism. — Moves the sound-track past the
reproducing point with the required uniformity of speed and in
synchronism with the picture. In most studio processes the sound-
track and the picture are on separate films and the sound-reproducing
mechanism is driven by a-c interlock motors or by a "dual film
attachment"9 to the picture mechanism, as the requirements dictate.
When released in theaters a "composite print" is used in which
sound and picture are printed on adjacent areas of the same film.
In this case, the sound and picture mechanisms are combined, and
synchronism is afforded by locating a given picture frame twenty

Oct., 1942] PRODUCTION SOUND RECORDING 217

frames behind the corresponding sound modulation so that they will
appear in their respective "gates" of the mechanism simultaneously.

(g) Optics and Photocell (Third Transformation).* — Produces
electrical energy corresponding to the varying optical transmission of
the film record. A steady source of light is provided together with an
optical system so arranged that light passing through a narrow slit
(transversely of the sound-track) reaches the photoelectric cell. As
the sound-track moves through the mechanism, the variation in the
density or in width of the sound-track causes the required fluctuations
in the light falling upon the photoelectric cell.

(h) Amplifier. — Increases the electrical energy to useful propor-
tions. The photoelectric-cell output is very feeble under some condi-
tions. In good theater practice the amount of sound-modulated
electrical energy required to drive the loud speakers varies from 15 to
100 watts, depending upon the size of the theater, etc. Hence theater
amplifying systems must have not only considerable gain but also
quite high output levels with low distortions.

(i) Loud Speakers (Fourth Transformation). — In response to the
amplified electrical energy, the loud speakers reproduce in the theater
sound corresponding to that which originally appeared at the micro-
phone. Simple radio types of loud speakers, even though large in
scale, will not serve the requirements adequately. For good results,
special high-frequency speakers equipped with multicellular horns
are required to minimize high-frequency distortion and to afford uni-
form distribution of intelligibility throughout the theater. In order
to exercise proper judgment in scoring, re-recording, and reviewing
operations, similar equipment must be used in the studio.

THE TECHNIQUE OF SOUND PICK-UP

(4) To point a camera at an indoor object, turn on a light, and
snap the shutter is one thing. To produce photography having con-
sistent beauty and story-telling power is quite another. It is so with
sound. There must be acoustic "lighting" or "conditioning" to ob-
tain the best results. Microphone "placement," like camera
"angle," must be carefully worked out.

* The transformations referred to are those mentioned at the beginning as
being unique to sound recording and sound reproduction, as distinct from picture
photography; hence the film -processing transformations are not numbered among
them.

218 H. G. TASKER [j. s. M. p. E.

Consider first the problem of intelligibility vs. angle, as the actor is
photographed from various angles in a given scene. The voice is
directional in its frequency characteristic. Forward from the face it
is much more brilliant acoustically and carries more intelligibility
than toward the rear. Hence if two actors face each other and the
camera shoots over the shoulder of one into the face of the other, and
if the microphone takes the same view of the situation as the camera,
then the face-on voice will be good but the other will have a muffled
yet rather roomy or reverberant quality. Unfortunately, the micro-
phone exaggerates the effect over that observed by human ears in the
same location. But even in the absence of such exaggeration, the
effect would still be unwanted. A digression is in order to point out
why.

It is not the purpose of alternate angle shots over one shoulder of
one actor into the face of a second actor, and vice versa, to give an
audience the sensation of having been swung back and forth through
space to have a look first at one actor and then the other, nor yet
that the terra firma that supports the actors is performing similar
gyrations. On the contrary, if such a scene is well done in all tech-
nical respects, the audience should experience no such gyratory effect,
but only a snapping of attention from one actor to the other at the
instants of greatest interest or of greatest pertinence to the story.
The same considerations govern sound recording for such a scene, and
accordingly the microphone, though necessarily above the camera
angle, should always be in front of and facing the person speaking.
This requires extreme mobility of the microphone — mobility available
on the instant and accomplished without making noise, without
appearing in or casting a shadow on the scene. This demand has led
to the development of very excellent microphone booms which af-
ford great freedom of microphone movement and direction, con-
trollable from positions outside the camera angle. By their use the
microphone is manipulated into correct position from instant to
instant by the "boom" operator under the occasional guidance of the
chief sound man or "production sound mixer," who is also controlling
other portions of the system and observing the sound quality pro-
duced as discussed later.

The type of scene just described consumes a lot of Hollywood film
footage each year, but there are, of course, other cases in which the
audience should experience special orientation with respect to the
scene or should be made aware of such acoustic qualities of the scene

Oct., 1942] PRODUCTION SOUND RECORDING 219

as the reverberation of a cathedral, the hollowness of a cave, etc. In
other words, the character of the sound sought for by the mixer is
always governed by "good theater."

Such effects are rather easier to obtain when wanted than avoided
in scenes where they are inappropriate. The microphone is a "one-
eared" device, and tends to exaggerate the reflections from walls and
other surfaces that give rise to room effects so that the mixer's con-
stant struggle is to reduce them.

The case of strong short-path reflections encountered during close-
ups such as at lunch-counters or in other confined spaces is so typical
of the mixer's acoustic problems that a close look at this case will illus-
trate the tools and techniques employed by the mixer for nearly all
other cases as well.

. MICROPHONE

WAVES ARRIVING OUT OF PHASE

REFLECTING SURFACE

h DIRECT PATH — •{

\* REFLECTED P*TM — «j

FIG. 2. Interference due to short-path reflections.

The objectionable character of these short-path reflections lies in
the fact that they may arrive at the microphone with such strength,
due to their shortness of path, that they may nearly cancel the direct
sound at certain frequencies or objectionably overemphasize it at
other frequencies. As illustrated in Fig. 2, this is determined by the
relation of wavelength to difference of path between the direct and
the reflected portions.

Such reflections may be reduced during rehearsals by carefully
probing the available microphone space to find the spot least affected
by the reflections without suffering too much loss of voice brilliance
due to unfavorable angle as discussed earlier. The properties of
certain recently developed directional microphones1-1 may also be em-
ployed to discriminate somewhat in favor of the direct as against the

220 H. G. TASKER [j. S. M. P. E.

reflected sounds but with rather less benefit than might be expected.
Fig. 3 illustrates a microphone whose directional properties (see Fig.
4) are adjustable to embrace practically every directional character-
istic now attainable. A pressure-responsive unit which is essentially
non-directional (see Fig. 4D) is mounted in close association with a
velocity-responsive element whose polar directional diagram is a pair
of circles (see Fig. 4K) indicating full response in one axis and zero
response at right angles thereto. As may be seen in the intermediate
diagrams, these elements may be combined in varying degrees to

FIG. 3. Unidirectional microphone.

give a variety of response patterns of the general type known as
"cardioid."

If now the mixer attempts to use any one of these patterns to dis-
criminate between two sounds differing in angle by as little as thirty-
five degrees, as in the example of Fig. 2, then he must choose between
having the direct sound arrive at an angle of nearly maximum sensi-
tivity and let the reflected sound be scarcely attenuated, or let the
reflected sound arrive at an angle of nearly zero pick-up, which will
give excellent discrimination but will always find the direct sound
arriving at a point of much less than maximum sensitivity. In the
latter case, the major pick-up axis may enhance set noises or smaller
reflections from other surfaces to such an extent that these become
limiting factors.

Oct., 1942]

PRODUCTION SOUND RECORDING

221

The advantages of such microphones are not gained without some
penalty. Nearly all microphones are sufficiently bulky and heavy to
impair their mobility when swung at a radius of ten to eighteen feet
on the modern microphone boom. These "unidirectional" or multi-
duty microphones, consisting as they do of a pressure and a velocity
microphone combined in one case, always have greater weight and
bulk than other microphones of comparable sensitivity.

COMBINATION

DYNAMIC (D) IN V.
BIBBON (R)IN%

INDEX I

INDEX J

FIG. 4. Formation of directivity patterns by combinations of ribbon

and dynamic microphone elements.

/ Directivity \ T _ efficiency for sound of random incidence
\ Index / efficiency for sound of normal incidence

average efficiency for all angles of sound
incidence in rear hemisphere

average efficiency for all angles of sound
incidence in front hemisphere

It happens that the strong short-path reflections are most ..1>\ iotis
to the ear at frequencies below 1000 cycles. If the mixer has done his
best, with the cooperation of the boom operator, to locate a fuvorabK
position and orientation for the microphone and still finds himself
having reflection troubles, he may be able to effect an improvement
by adjusting his low-frequency equalizer or suppressor. If not, lu
may be able to find a spot favorable to reducing the low-f reqiu i u \
reflections at the cost of some brilliance, but he may be able to restore
some of the latter with his high-frequency equalizer. Sometime v
though seldom in this type of problem, he can introduce acoustic
absorbing material that will help.10

222 H. G. TASKER [J. s. M. P. E.

After fighting one of these ' 'lunch-counter" reflections for half a day
while the boy and girl finish their coffee and doughnuts, quarrel, kiss
and make up, and exhaust the sound crew's patience, the crew usually
go home resolved that if they ever become writers or producers or
executives, there will be no more lunch counter scenes!

The chances are that next day they may work in a well furnished
living-room set that gives no trouble at all; or in a bare tenement
bedroom having plenty of "cistern" effect but in which by laying a
rug on the floor (out of the camera angle) or by hanging a blanket or
two in some area that will not interfere with the lighting, the mixer
can get the "feel" of the set about right in his monitor. In general
the considerations of time-lag and intensity of reflection in the larger
spaces make proper sound pick-up a simpler problem. Of course,
when a large "exterior" set must be constructed inside a stage, the
stage-wall reflections must be held abnormally low if naturalness is to
be achieved. Most sound stages are treated on the inside with two
inches of rock wool furred out two or more inches from the solid con-
struction, with the result that the reflections11 are not objectionable
except in the case of exterior scenes. In such cases the sound man is
in contact with the job days in advance, learning the camera angles
to be used, studying the acoustic problems to be met, planning the
treatments necessary, etc. Nor does the sound department neglect to
develop the cooperation of the art department in shaping structures or
choosing material that will minimize the sound-reflection problem.10

We have seen then that the mixer's "acoustic lighting" problem is
primarily one of avoiding excessive reflections of three distinct types :

(a) Confined space or "barrel" reflections.
(6) Medium space or "roominess" reflections.
(c) Large space or "reverberant" reflections.

To any one of these reflection problems he may apply one or all of
the following controls :

(a) Proper choice of materials or designs, through cooperation with the art

department.
(&) Microphone placement.

(d) Blanketing to absorb reflections.

Noises occurring within the motion picture set are objectionable
except in rare instances when they are in keeping with the character
of the action. This is particularly true of such modern noises as

Oct., 1942] PRODUCTION SOUND RECORDING

traffic and machinery sounds when the scene being photographed be-
longs to an earlier period in history. To reduce the penetration of
traffic and other external noises, stage walls are heavily insulated,11
some having attenuations as high as 70 db. Mechanical noises arising
within the stage from cameras, wind machines, etc., are reduced by
careful design, by elimination of gears, and by the provision of good
insulating housings where necessary. 12'13-14 The relative effect of the
noises that remain, as compared to the wanted sounds arising from the
action, may be further reduced by taking advantage of the direc-
tional properties of microphones. Refer again to Fig. 4 for the
effectiveness of such microphones in reducing noises of random inci-
dence as compared to direct sounds.

ADDITIONAL QUALITY CONTROL MEASURES

(5) While acoustic considerations and microphone character-
istics are of utmost importance to successful sound recording for
theater projection, there must also be adequate control of volume.
In this respect also it is "good theater" that governs. In actual life a
dance band will produce more than ten million times the sound
energy of a quiet scene in a murder mystery. This is a 70-db dif-
ference, but if the murder scene were recorded 70 db lower in level
than a properly chosen dance band level, the dialog would be com-
pletely inaudible in the theater. We must, instead, enable the
persons in the back row of the theater to hear the quiet scene dis-
tinctly, even though softly, and for this purpose the original 70-db
difference in level must be reduced to about 25 db. Hence the mixer
must be constantly alert to make the proper volume adjustments of
the material he is recording. To this end he is provided with a "unit
volume control" for each microphone (normally one to as many as
four) plus an inclusive or master volume control. To help him gauge
the correct level, he is provided with a volume-indicator meter whose
deflections are an indication of the modulation reaching the film.
He is provided also with an audible monitoring system, usually a
headset of high quality,15 which enables him to listen critically to the
overall result of his work and to apply the judgment that his task
demands.

It is true that in the re-recording process some opportunity is
afforded for the refinement of the production mixer's work. However,
the signal-to-noise ratio of the film (of the order of 55 db) becomes a
limiting factor. If the production mixer records a "quiet" original

224 H. G. TASKER [J. s. M. p. E.

scene about 15 db lower than he should, then in attempting to correct
this error during re-recording, a very objectionable amount of film-
surface noise would be introduced. If, on the other hand, a dance
band were recorded 10 db too loud, the result would be severe dis-
tortions in the recording which could never be corrected. Hence, it
is necessary that the production mixer come as nearly as possible to
the correct level in the original recording.

Experience has indicated that there must also be considerable ad-
justment of frequency characteristic16 to secure proper theater pres-
entation. In some studios this step is reserved solely for the re-
recording process. In others, the production mixer makes a first-
order correction, leaving refinement to the re-recording mixer.

Having used the foregoing tools and methods in the control of
sound and quality to the best of his ability, the production sound
mixer must exercise the further control of suggestion and rejection.
The most successful mixers develop a high degree of tact and good
judgment, knowing just when a word of suggestion to the actor or
director will secure a more effective sound recording, and just when
sound imperfections are of such importance that he must request
additional takes which may cost anywhere from fifty to several
hundred dollars.

TECHNIQUE OF FILM RECORDING

(6) In the editing of a motion picture, great advantage is had if
the sound record is on a strip of film separate from the picture. It is
of further advantage if the sound-recording machine is separate from
the picture camera — a practice followed without exception in Holly-
wood. These two mechanisms must run in synchronism. In "proc-
ess" photography shots, a predetermined phase relationship between
the camera and the process projector is also involved, and for such
shots all studios use some form of a-c interlocking motor system.7
Several studios use this system for all studio operations and in some
cases even for location shooting. Other studios substitute salient-pole
synchronous motors for all production shooting except process
photography scenes. Neither of these systems is very economical of
electrical power and in location work, power-supply takes on consider-
able importance. For this reason, most studios employ some form
of d-c interlock for location work and especially for super-portables.8

The sound-film recorder, like the motion picture camera, is a
highly specialized and very precise piece of mechanism. The design

Oct., 1942] PRODUCTION SOUND RECORDING 225

requirements to secure the necessary uniformity of film motion are
adequately discussed in the literature;6- 8 so also are the requirements
and characteristics of the modulators by means of which exposure of
the film is produced corresponding to the sound impinging upon the
microphone.3-4 One such system is introduced schematically into
Fig. 5 to afford some idea of the operational problems involved.

In this illustration, the pole-pieces of the electromagnetic yoke are
cut away and the light-valve ribbons are much enlarged so that their
position and action may be clearly seen. Light from the lamp on the

'CONDENSER LENS

FIG. 5. Light-valve modulator system.

left is spread quite uniformly over the slit between the light-valve
ribbons by setting the condenser lens in a slightly out-of -focus posi-
tion. When a current passes through the ribbons from a to b, the
ribbons will separate allowing more light to pass between them, and
vice versa. The objective lens focuses this light into a thin, sharp line
on the motion picture film. If the film were at rest, the intensity of
this line would remain constant, but its thickness would vary exact 1\
in accordance with the spacing of the light- valve ribbons; but since
the film is moving at a uniform speed of 90 feet per minute, the effect
is to vary the exposure lengthwise of the film and hence produce
variable-density sound-track. The drum that carries the film is
mechanically filtered from the rest of the driving mechanism. Great

226 H. G. TASKER [J. s. M. p. E.

care is taken in the design of the mechanical filter, and in some types
the variation of speed or "flutter" is held to less than 0.05 per cent of
the designated uniform speed.

The light- valve ribbons weigh only two millionths of an ounce each,
are about six mils wide and half a mil thick, and must be spaced about
a mil apart and accurately parallel. The stringing and adjusting is
ordinarily done by a specialist, who also takes care of certain other
equipment requiring precise adjustment. In some studios, however,
each recordist (recording machine operator) strings and adjusts his
own light-valves as required.

During operation, these ribbons are "biased" electrically to a
spacing of about Vio of a mil to effect reduction of film grain-noise by
reducing the light reaching the negative. This results in darker ex-
posure of the positive, and hence less reproduced noise during intervals
of silence or of low sound level at the microphone.17' 18f 19 To make
the biasing adjustment properly, the recordist must carefully deter-
mine the sensitivity of the valve and then adjust the biasing current
to the proper amount. The accuracy required is approximately ten
millionths of an inch.

In the galvanometer type of modulator, comparable considerations
apply, except that in "type B" variable-area recording, as practiced
at one studio, no noise-reduction amplifiers are involved.

There are many other adjustments of the recording machine and
associated equipment that the recordist must make. In addition, he
usually starts and stops the entire system on signal from the stage and
applies "end strip" exposures for processing control, etc.

The sound department must participate actively in the establish-
ment of processing control limits and in the interpretation of the daily
results, and must provide the laboratory with most of the specially
exposed "strips" that are required. Sound quality controls for
processing of variable-density recordings always include sensitometer
strips for control of processing gamma. In the case of fine-grain
films, which afford considerable improvement in grain-noise and
distortion,20 it is also necessary to make occasional light- valve
gamma strips because of the failure of the photographic reciprocity
law and the fact that this failure is not uniform with conditions.
Most studios also use the newly developed technique of inter-modula-
tion measurement. This method affords a useful means of establish-
ing correct print density for given negative processing conditions.

Oct., 1942] PRODUCTION SOUND RECORDING 227

REFERENCES

(All references are to J. Soc. Mot. Pict. Eng.)

1 HOPPER> F- L': "Characteristics of Modern Microphones for Sound Record-
ing," XXXIII (Sept., 1939), p. 278.

1 LIVADARY, J. P., AND RETTINGER, M.: "Uni-Directional Microphone Tech-
nic," XXXII (Apr., 1939), p. 381.

8 FRAYNE, J. G., AND SILENT, H. C.: "Push-Pull Recording with the Light
Valve," XXXI (July, 1938), p. 46.

4 DIMMICK, G. L.: "The RCA Recording System and Its Adaptation to Vari-
ous Types of Sound-Track," XXXIX (Sept., 1942), p. 258.

6 KELLOGG, E. W.: "A Review of the Quest for Constant Speed," XXVHI
(Apr., 1937), p. 337.

• ALBERSHEIM, W. J., AND MACKENZIE, D.: "Analysis of Sound-Film Drives,"
XXXVII (Nov., 1941), p. 452.

7 TASKER, H. G.: "Improved Motor System for Self-Phasing of Process Pro-
jection Equipment," XXXVII (Aug., 1941), p. 187.

8 HOLCOMB, A. L.: "Multi-Duty Motor System," XXXTV (Jan., 1940), p. 103.

9 BORBERG, W., AND PINNER, E.: "The Simplex Double Film Attachment,"
XXXIV (Feb., 1940), p. 219.

10 THAYER, W. L. : "Solving Acoustic and Noise Problems Encountered in Re-
cording for Motion Pictures," XXXVH (Nov., 1941), p. 525.

11 LOYE, D. P.: "Acoustic Design Features of Studio, Stage, Monitor Rooms,
and Review Rooms," XXXVI (June, 1941), p. 593.

11 ROBBINS, J. E.: "Silent Variable-Speed Treadmill," XXXIV (June, 1940), p.
632.

13 ALBIN, F. G.: "Silent Wind Machine," XXXII (Apr., 1939), p. 430.

14 CLARKE, D. B., AND LAUBE, G.: "Twentieth Century Camera," XXVI
(Jan., 1941), p. 50.

u ANDERSON, J. L.: "High Fidelity Head Phones," XXXVH (Sept.. 1941), p.
319.

16 MORGAN, K. F., AND LOYE, D. P.: "Sound Picture Recording and Repro-
ducing Characteristics," XXXJI (June, 1939), p. 643.

17 SANDVIK, O., AND GRIMWOOD, W. K.: "An Investigation of the Influence of
Positive and Negative Materials on Ground Noise," XXV (Aug., 1940), p. 126.

M KELLOGG, E. W.: "Ground Noise Reduction Systems," XXXVI (Feb., 1941),
p. 137.

19 SCOVILLE, R. R., AND BELL, W. L.: "Design and Use of Noise Reduction
Bias Systems," XXXVIII (Feb., 1942), p. 125.

20 DAILY, C. R., AND CHAMBERS, I. M.: "Production and Release Applications
of Fine-Grain Films for Variable- Density Sound Recording," XXXVm (Jan..
1942), p. 45.

HOLCOMB, A. L. : "Motor Drive Systems for Motion Picture Production;"
presented at the 1942 Spring Meeting at Hollywood, Calif.; to be published in a
forthcoming issue of the JOURNAL.

PRESCORING AND SCORING*

BERNARD B. BROWN**

Summary. — A brief description of the procedure followed in the Hollywood
studios in scoring and prescoring motion picture productions. Scoring is the addi-
tion oj music and effects after the finish of the photographing; prescoring is the prep-
aration of musical or dance numbers before the photographing.

PRESCORING

The recording of music for motion pictures is divided into two
categories: prescoring and scoring. As the name implies, pre-
scoring means the recording of musical or dance numbers before the
numbers themselves are actually photographed. At first thought,
the idea of recording a sequence prior to photographing it may
seem strange; but in actuality there are two very logical reasons
for the sound director to do just that: (1) We prefer to make
these recordings on a stage that has been acoustically treated to
make it as perfect as possible for music recording. (2) By so doing,
we are able to achieve not only fidelity of tone, but also of tempo.

Our first reason is self-explanatory; our second is quickly explained.
If we were to record a musical number as the director photographs it,
we should be dealing with small sections of music, which when as-
sembled would not be smooth, for the director breaks the sequence up
into its component photographic parts, such as long shots, medium
shots, close-ups, and various camera angles. It is obviously im-
possible to play the music at exactly the same tempo each time
these short scenes are photographed. Therefore, to do the job cor-
rectly the musical number is first recorded on film and on a record,
thus insuring that an even tempo will be maintained. It is well to
point out that the artist, when making this recording, is free to make
all the grimaces and contortions he feels may be necessary to reach

* Presented at the 1942 Spring Meeting at Hollywood, Calif. ; received April
25, 1942.

** Universal Pictures Company, Inc., Universal City, Calif.
228

PRESCORING AND SCORING 229

the high notes and pronounce the words clearly, as he is not being
photographed while singing for this recording.

The record is then taken to the sound stage and played back to the
artist. Here the artist must look his (or her) best, which now is pos-
sible because he does not have to think of the singing but only of
looking well and synchronizing the lip movement to the record that
has already been niade. He only has to appear as if he were singing,
as the prescored record is used for the final film.

On the scoring stage is a small room, 10 X 10 X 10 feet in size, in
which the artist sings. A large window in one of the walls faces the
orchestra so that the artist and the musical director can see each
other. The singer can hear just enough of the orchestra to assist in
singing in tune, but the sound of the singer's voice does not penetrate
through to the stage, so the director uses ear-phones bridged into the
vocal channel. As soon as a piece has been sufficiently rehearsed,
all is ready for a take. The "quiet" signal is given, the stage man
signals the recordist to start his machine, the red light flashes, the
orchestra plays, the singer sings, and "Take Number One" is made.

The musical number is recorded on two or more separate films and
on a wax record which is played back so that the artist and others
may hear and criticize the recording. If everyone is satisfied, the
"take" is finished; if not, repeat recordings are made until a good one
results or until there are enough good parts of several takes to cut
together and make one good complete take.

The orchestra and artist may then be dismissed. If after assembling
the good parts of several takes the result is not entirely satisfactory,
the singer is called back to the scoring stage to re-make all or part of
the number. This is done by having the artist sing while listening
on a pair of headphones to the orchestra track that has already been
recorded. This process saves the studio thousands of dollars a year,
since the orchestra is not required for retakes.

When photographing dance numbers the recording that has been
pre-scored is played back and the dancers perform to it. If the
number is a tap dance the taps are recorded later on a special dance
floor on the recording stage. The dancers are brought in and the
picture of the dance that has been photographed is projected. The
performers then dance while listening to the music through head-
phones, and the taps are recorded. The picture has been cut ex-
actly the way it appears in the theater, and the taps match the picture
exactly.

2:iO B. B. BROWN [j. s. M. P. E.

SCORING

Scoring is sometimes called "underscoring," which means adding
music to the picture after it has been finished. The musical director
and his associates view the finished picture with the producer or
director, and decide where music can most effectively be used. While
the musical director is composing the themes his assistant is timing
the scenes, so as to know how much music to write and at what
points it must synchronize with the action.

Where it is necessary to time the music to several definite cues, a
"click track" is made, which when reproduced sounds like a metro-
nome. The "clicks" or beats range from one every sixteen frames to
as many as one to every four frames. The tempo is determined by
the tempo of the scene, and is produced by making a scratch or punch-
ing a hole in a piece of blank film at the points where the beats are to
occur.

The film is then run on a moviola, and along with the picture, and
on it are marked the cues in the picture to which the music must be
made to fit.

Now that the composer has the length of the scenes and the timing,
he composes the music for the picture. The compositions then must
be arranged, sometimes by the composer himself and sometimes by
professional ' ' arrangers. ' ' The arrangement is checked by a musician
called a proof-reader, who corrects any mistakes made by the com-
poser or arranger, and the score is given to copyists who copy on sepa-
rate sheets the music for the different instruments in the orchestra.
The proof-reader again checks what the copyists have done, and all is
now ready for recording.

The orchestra is seated in a semicircle in front of the director, who
stands upon a platform facing the screen and the musicians. The
orchestra is arranged in sections with a microphone in each section,
as follows, beginning at the left of the director: violins first, then
violas and cellos, woodwinds, piano, bass, guitar, and harp, with the
brass and the percussion instruments up in back on a separate plat-
form. There are two principal reasons for using this arrangement :
One is to provide good compositions and variety in the integrated
sounds, just as the cameraman in photographing resorts to long shots,
medium shots, and close-ups. The microphones used in the various
sections pick up sound from both sides. They are tilted so as to have
a close pick-up on one side and a long pick-up on the other side, and
thus give good definition, room tone, and scope to the orchestra.

Oct., 19421 PRESCORING AND SCORING

The other reason for using a microphone in each section is to penm t
the sound director to control the volume from each section by dials on
his mixing panel in the monitoring booth. The volume of any section
can be increased or decreased, so that if a section is too loud or too soft
corrections can be made during the recording and a retake avoided.
This saves much time, and time means money in the studio.

The musical director now rehearses the orchestra and at the same
time the sound director adjusts his levels on the mixing panel in the
monitor booth. When all is ready the recording room is signalled,
the picture is flashed on the screen, the orchestra plays, and the direc-
tor conducts the orchestra while listening to the click track or dialog
on a pair of headphones and looking at the picture on the screen be-
hind the orchestra. The process is repeated for each section of music
to be used with the picture.

This describes briefly the general processes of prescoring and scor-
ing. A thousand details have been omitted, and it must be em-
phasized that the processes are not matters of simple routine. Each
take has its own problems, and experience and experimentation are as
much parts of the work as the general routine that has been described.

A STUDY OF FLICKER IN 16-MM PICTURE PROJECTION*

E. E. MASTERSON AND E. W. KELLOGG**

Summary. — It seems to be generally accepted opinion that three-blade shutters
must be employed to control flicker properly in the projection of 16-mm pictures, even
though the machine is not required to operate at less than 24 pictures per second.
There is little complaint of the flicker in theater projection, where two-blade shutters
are practically universal. Why then should it be necessary to make a large sacrifice in
screen brightness by using three-blade shutters when projecting 16-mm pictures? Less
control of the conditions of projection is probably the most important of the valid ob-
jections. However, the opinion that two-blade shutters are not to be considered is based
in part upon misleading tests, and the writers hold that for many applications single-
speed machines should be given the benefit of the greater luminous efficiency possible
with two-blade shutters.

The paper discusses the various factors that bear on flicker, and reports a number of
experimental studies.

The Problem. — For many years it has been the practice to project
35-mm pictures in theaters at 24 frames per second with two 90-
degree shutter blades, giving a 48-cycle flicker with equal dark and
light intervals. It is customary, on the other hand, to equip 16-mm
projectors with three-blade shutters, and this is at serious cost in
screen brightness. The gain in light from substituting a two-blade
for a three-blade shutter is shown in Table I. The gain depends
upon the blade width, which in turn depends upon the pull-down
time of the intermittent movement.

Shutter
Blade

TABLE I
Light on Screen
3 Blade 2 Blade

Ratio

45°

0.652

0.75

1.20

50°

0.585

0.72

1.22

60°

0.50

0.67

1.33

75°

0.375

0.585

1.56

90°

0.25

0.50

2.00

* Presented at the 1942 Spring Meeting at Hollywood, Calif. ; received May 4,
1942.

'* RCA Manufacturing Co., Indianapolis, Ind.
232

FLICKER IN 16-MM PICTURE PROJECTION

The requirement that the flicker rate be 72 cycles per second for
16-mm projection, whereas 48 cycles is considered satisfactory in
theaters, is the more surprising when we consider that in the projec-
tion of 16-mm pictures it has been common to use a pull-down that
operates over a smaller fraction of the picture cycle; for example,
about 60 degrees instead of the 90 degrees which is necessary with
the Geneva motion generally employed in 35-mm machines. It is
well known that the smaller the fraction of time that the screen is
dark, the less noticeable is the flicker. Thus, flicker would be less
with two 60-degree blades than with 90-degree blades. Therefore
48-cycle flicker should be less noticeable in 16-mm pictures than in
35-mm pictures.

The obvious explanation of the prevalence of three-blade shutters
in 16-mm projectors is that the machines are designed for projecting
pictures at either 16 or 24 frames per second. In view of the vast
number of silent 16-mm films, made at 16 frames per second, it seems
clear that general-purpose projectors for a long time to come will
have to meet this requirement and there seems to be no satisfactory
solution to the flicker problem at this picture frequency except to
use three blades. On the other hand, the increasing use of sound
pictures is unquestionably bringing a market for projectors that will
have to operate at only one speed. Under these conditions it becomes
a question of considerable importance whether it is necessary to
provide these projectors with three-blade shutters. The loss of
between a quarter and a third of the available light is serious if it is
not necessary. Tests have been made from time to time under
varying conditions, with the usual verdict that the 48-cycle flicker
is noticeable, whereas the three-blade shutter does away with flicker
entirely. The result has been the continued use of the three-blade
shutter. The anomaly that a projector with 48-cycle flicker is good
enough for a theater, even the best, but not for 16-mm projection,
has been a puzzle of long standing. The reluctance of many en-
gineers to accept this conclusion (which seems so illogical) appeared
to the writers to warrant a survey of the considerations applying to
the problem, and experimental checks of some of the factors.

Tests Using Screen without Picture or with Abnormally Bright Pic-
tures.— The first question that arises in attempting to make com-
parisons between flicker under 35-mm and 16-mm projection condi-
tions is, "What is the screen brightness at which the observations
were made?" The relations between screen brightness and flickrr

234

E. E. MASTERSON AND E. W. KELLOGG [J. S. M. P. E.

rate are shown in Fig. 1 which is reproduced from a paper by E. W.
Engstrom on television image characteristics.1

Screen brightness of the order of 10 foot-lamberts2 (without picture
but with shutter running) is recommended for satisfactory picture
projection, and is readily obtained with 16-mm projectors, provided

A. ONE FRAME CYCLE (96O°)
0. LIGHT OPENING

6 A

6RI6HTNCSJ IN FOOT LAM6CRT5
3 .6 .75 1.9 3 %9 6 7.ST I*

-JU.

0.5 f.O 2 3 ** 5 10 20

SCREEN ILLUMINATION IN FOOT CANDLES

FIG. 1. Relations between screen illumination, flicker frequency, and
blade angle for threshold flicker. (Curve 5 corresponds to two 90-degree
blades; Curve 6 to two 60-degree blades.)

the screen size is not abnormally large. When the question of
flicker is brought up the most natural way to make an observation
is simply to run the machine without a picture and decide whether
there is too much flicker. The result of such a test is almost invari-
ably that the 48-cycle flicker would be objectionable, but the test is
by no means a fair one. Theater practice is not based upon such a
test but upon the very practical test of experience while viewing the

Oct., 1942] FLICKER IN 16-MM PICTURE PROJECTION

2.35

pictures. When a picture is being projected the evidence of the
flicker is very much reduced by several causes. Measurements with
a number of typical pictures, including outdoor scenes, indicated
average or integrated screen brightnesses ranging from 8 to 28 per
cent of that of the blank screen, with an average of about 10 per
cent; and highlight or white object brightness ranging from 50 to
70 per cent. It might be thought that the tolerance for flicker would
be determined entirely by the highlight intensity, but tests indicate
that the area of the bright parts of the picture is also an important
factor. Fig. 2 shows the results of a number of observations of the

INCIDENT FOOT CANDL
FOR THRESHOLD FLICKC

H « M P ?

<M O «* O <J

•

•d

•

u-:

P* — ^^

VIEWING

X 3 * 8 • T
DISTANCE IN SCREEN WIDTHS

FIG. 2. Effect of angle subtended by illuminated
area upon flicker threshold (each form of symbol is for
one observer).

effect of viewing distance upon the value of screen brightness for
just-perceptible flicker, using a blank screen. The farther the ob-
server is from the screen, and therefore the smaller the angle sub-
tended by the screen from his viewpoint, the greater is the flicker
intensity that can be tolerated. It is a decidedly exceptional picture
in which a bright highlight occupies l/* of the screen area. Where
large areas of sky are shown, artistic photography would almost
invariably resort to breaking up the expanse of clear sky with clouds,
which means considerable darkening of much of the sky area.

Another effect of the presence of the picture is that attention
tends to be directed toward some center of interest. In viewing
a blank screen the eyes wander from one part of the area to another.
Flicker is much more noticeable with the eyes in motion than when
the observer looks steadily at one part of the area (see Table II).

236 E. E. MASTERSON AND E. W. KELLOGG [J. S. M. P. E.

In addition to the effects of the picture just mentioned, we must
recognize that picture jump is not completely eliminated, that there
is jerkiness in all motion, and that these and other imperfections
tend to mask what might otherwise be a perceptible flicker.

Part of our recent study was an effort to make a rough deter-
mination of the relation of flicker thresholds with and without pic-
tures. Two projectors were arranged side by side, one with a shutter
having three 70-degree blades and one with two 70-degree blades.
Removal of the reflector from the 48-cycle machine gave substantial
screen brightness balance. Loops of film showing the same subject
were put into the machines and a number of observers were asked

TABLE II

Effect of Picture upon Flicker Tolerance (Foot- Candles for Unobjectionable Flicker}

Still Blank Screen

Picture Moving Eyes Fixed Eyes

Observer Color* Picture* at Center Moving

RLH 11 10.5 2.0 1.5

LTS 9 13 4.8 2.0

EWF 10 10.5 3 2.0

HER 9 12 2.5 1.3

CC 14 8 4.2 2.0

HH 10 12 2.0 1.2

* Illumination adjusted for satisfactory flicker with picture in place and mea-
sured with picture removed. Screen reflectivity about 90 per cent. The angle
subtended by the picture width was 18 degrees for still pictures, and 22 degrees
for the motion pictures and blank screen tests, corresponding to observer dis-
tances of 3.1 and 2.6 screen widths, respectively.

to say whether they saw any more flicker in one than in the other,
after as many switchings back and forth as they wanted. The
distance of the screen from the projector was varied until the mini-
mum distance (maximum brightness) was found at which the ob-
server found no appreciable preference for the 72-cycle picture. The
film was then removed from the projector and the screen illumination
measured. Since the observer sat close beside the projectors, the
angle subtended by the picture was not altered by distance.

In another test a slide-projector was used with a shutter inter-
rupting the light-beam. The shutter had two 60-degree blades,
giving 48-cycle flicker. Numerous slides (in color) were introduced
and the distance of the screen from the projector changed until the
point was found at which flicker was not noticeable with the brightest

Oct., 1942] FLICKER IN 16-MM PICTURE PROJECTION 237

pictures. For comparison the screen illumination at which flicker
practically disappeared was measured with no picture, first with the
gaze directed continuously at the center of the screen and then with
the eyes moving. Table II shows the results of these tests.

The mean density of the slides was measured, using the Weston
illumination meter and a K-2 Wratten filter to simulate roughly the
color-sensitivity characteristic of the eye. These measurements
indicated about the same average or integrated light transmission as
the black-and-white 16-mm subjects, namely 28 per cent as a maxi-
mum, with most of the subjects in the region of 10 per cent.

The Committee on Non-Theatrical Equipment in its July, 1941,
report2 recognized the effect of the picture in reducing flicker, in
specifying 3 foot-lamberts for bare-screen flicker tests, whereas they
recommended 10 foot-lamberts as the desirable screen brightness
for picture projection conditions but with no film in the machine.

We have spoken of the misleading results of tests and demonstra-
tions with the bare screen, without making due allowance for the
effect of the picture. It is also easily possible for persons not too
well acquainted with projection problems to be mislead by observa-
tions with excessively bright pictures, especially if viewed from
nearby. Such excessive brightness is easily possible in individual
tests by projecting very small pictures. Beaded and metallized
screens3 may give bright spots having many times the luminous
intensity shown by a good matte screen. If the actual service for
which a projector is intended includes use with directive screens, a
three-blade shutter is obviously in order. Our purpose here is
simply to mention the fallacy of drawing conclusions from tests with
directive screens and applying these conclusions to the case of matte
screens.

Effect of Color of Light — Since theater pictures are projected with
arc lamps, and 16-mm pictures for the most part with incandescent
lamps, it occurred to the writers that the eye might be more sensitive-
to flicker near the red end of the spectrum than near the blue end.
The relations between color, brightness, and flicker have been the
subject of many investigations4- *• 6» 7 but not being completely
satisfied that the tests reported in the literature applied exactly to
the problem under consideration here, the authors carried out a
series of tests. In order to make any comparison it would be neces-
sary to establish the fact that the screen brightness was equal for
the two colors being compared. It was obviously not appropriate

238

E. E. MASTERSON AND E. W. KELLOGG U. S. M. P. E.

to make the measurement of brightness with a photocell or photronic
measuring device unless the spectral-sensitivity curve of the instru-
ment was the same as that of the eye. To test the relative flicker
sensitivity to lights of different color it was necessary, after selecting
the desired color-separation filters, to rate the light projected through
them in terms of its utility for visual purposes. In order that the
eye adaptation5' 6 might be representative of conditions during the
viewing of motion pictures, a small spot of colored light was pro-
jected on a test-object in the center of a rectangle which was illumi-
nated from the rear, to about normal screen brightness. The first
determinations of the illumination value of the light passing the
several filters were made by measuring the light-flux on a Weston

FIG. 3. Relative response of the eye to light of
various colors.

photronic cell required for bare visibility of a dark test-object of low
contrast. We then decided that it would be a better test of the
general utility of the light to bring up the intensity until a test-object
of extremely low contrast was just discernible. These readings gave
the ratio between the light as measured by the photronic cell and its
utility to the eye for visual purposes. The screen illumination at
which flicker became just discernible also was determined for the
same observers, and the ratio of measured illumination for threshold
flicker and threshold visibility was compared for the several colors.
The conclusion from these tests was that the sensitivity to flicker
is in direct proportion to the brightness which makes for visibility
and low-contrast discrimination. Since the photronic-meter mea-
surement was in each case used for comparing two effects of the light
of each color, the spectral sensitivity of the cell cancels out. As a

Oct., 1942] FLICKER IN 16-MM PICTURE PROJECTION 239

check, the visual density of the several color-filters was measured on
a Capstaff densitometer. The work just described checks the con-
clusions of various previous investigations. The well known flicker-
photometer, for example, evaluates lights of different color in terms
of the amount of flicker that they produce. Thus, when the flicker
of a green light cancels that of a red light they are regarded as equal.
In numerous investigations the results of flicker-photometer mea-
surements have been compared with those of other types of photo-
meter and the agreement has been found to be excellent. The well
known eye-sensitivity curve (Fig. 3) has been checked by the three
fundamental methods, judgment of brightness, flicker, and visibility,
with substantially identical results.4' 6>6»7

From the foregoing it is evident that if two screens are equally
satisfactorily illuminated but by light of slightly different color,
flicker will be no more noticeable in one than in the other. There is,
however, an error that may easily be made in comparing theater
screen brightness with 16-mm screen brightness. Although foot-
candle meters are designed to approximate eye-sensitivity, many
of them are relatively more sensitive to blue light than the eye. If
such a meter indicates an illumination of 10 foot-candles on a theater
screen and 10 foot-candles on a 16-mm screen, the latter would
actually look brighter to the eye. It is thus improper to compare
the flicker on the basis of equally measured screen brightness unless
the meter is corrected to match closely the spectral sensitivity of
the eye.

A psychological factor may enter into the judgment of screen
brigthness as seen in theaters and in 16-mm projection. We asso-
ciate high-intensity light-sources with very white or bluish light,
and may thus be inclined to estimate the brightness of an arc-lighted
screen as higher than that of an incandescent-lighted screen having
the same useful brightness. In addition to this, the better sup-
pression of stray light in the theater, of course, makes a given screen
intensity seem greater than it would in the presence of more stray
light.

Effect ofA-C Ripple.— During tests of the effect of speed of cutting
we were interested in the actual "wave-shape" of the illumination
curve. A cathode-ray tube was connected to the output of a photo-
cell. This showed that, in addition to the effects of the shutter,
the 120-cycle ripple in the lamp brightness was contributing to
flicker effects. We estimated that the light from the 750-watt

240

E. E. MASTERSON AND E. W. KELLOGG [J. S. M. P. E.

projection lamp fluctuated through a total range of about 5 per cent.
E. E. Masterson devised the method shown in Fig. 4 of illustrating
the effect of this upon flicker. In each x/24 second there are five
periods of higher and five of lower lamp brightness. The effect of
cutting off certain fractions of the cycle by the shutter-blades may
result in an unbalance which produces a small component of 24-
cycle flicker. The tolerance for flicker of this frequency is, of
course, very small. It appears also that there are certain blade-
widths that are better than others in reducing the 24-cycle compo-
nent to a minimum.

Effect of Blade Angle. — Fig. 1 summarizes in useful form the relation
between flicker frequency, screen illumination for flicker threshold,

I20~

FIG. 4. Unbalance of 120-cycle fluctuation in lamp
brightness, produced by shutter blades.

and ratio of bright to dark time. Screen illumination was measured
with the shutter running. The reflectivity of the test-screen was
given as 75 per cent, whence the brightness in foot-lamberts would
be 0.75 of the foot-candles read on the vertical scale. It will be
noted that narrowing the shutter-blades makes it possible to work
with greater screen brightness without observaole flicker. The
increased efficiency may be used in part for increasing screen bright-
ness and partly for reducing lamp wattage or simplifying the optics.
From Fig. 1 it is clear that we can not classify flickers in terms of the
frequency only but must specify the bright to dark ratio, or blade-
width, in addition to the number of blades and the mean screen
brightness. With two 60-degree blades, Fig. 1 indicates that 10
foot-candles, or 7.5 foot-lamberts would give threshold flicker on a

Oct., 1942] FLICKER IN 16-MM PICTURE PROJECTION 241

bare screen at 48 cycles. The observations upon which these curves
were based were with a 14 X 16-inch bare screen six feet from the
observer.

Effects of Speed Of Cutting. — It seems reasonable to expect that a
shutter system that maintained full brightness up to the last possible
instant, and then cut off quickly, would give less flicker than one
with which the screen was at its maximum brightness only during
the middle of the bright period. To test this, a projection system
was arranged with a large-diameter shutter that could be placed at
chosen positions in the light-beam and could be used either with its
axis fairly close to the optical axis or farther away, so that the blade
edges were moving faster. The light-beam was about 1 inch in
diameter at the largest and about 3/s inch in diameter at the smallest,
and the 24-rps shutter was used with from 2 to 4-inch active radius.
Within the range of these tests no noticeable difference was found
in the screen brightness for threshold. We do not consider that this
proves that the wave-form of the screen-brightness curve is immate-
rial, but it is safe to say that it does not affect the flicker radically
and there is every practical reason for maintaining the screen bright-
ness at full possible value for the longest possible time. It is of
course of even greater importance to cut the light off completely
during the time that the film is in motion.

Since the light-beam is at its smallest cross-section close to the
picture aperture, quick cutting is promoted by placing the shutter
close to the aperture. The gain, however, may not be quite in
proportion to the reduction in distance across the light-beam. With
a focal-plane shutter the entire picture is not obscured at the same
instant, and any portion that is not covered while the film is moving
is on the screen at full brilliance. The avoidance of travel-ghost
may therefore require more complete fulfillment of the requirement
of complete coverage during motion than seems to be necessary with
the shutter farther away where it acts to fade the entire picture in
and out.

Tests were made to determine whether there is any difference in
noticeable flicker with a focal-plane shutter as compared with a lens-
aperture shutter, the blade size being identical. No difference
could be noticed.

Shutters with Unequal Blades.— Trials have been made from time
to time of shutters with various arrangements of unequal blades in
the hope of finding an arrangement that would permit the necessary

242 E. E. MASTERSON AND E. W. KELLOGG [J. S. M. P. E.

blade-width to prevent travel-ghost and not intercept so much light
while the picture is stationary as the usual full- width extra blades.
In 1938 R. O. Drew conducted a series of experiments using a shutter
with one full-width and two narrower blades. The narrow blades
could be shifted in position. The optimal position was found (within
the limits of observations) to be that at which the shutter is also
mechanically balanced. If the light-intensity is plotted as a wave,
a Fourier analysis shows that the abovementioned condition results
in the fundamental component's becoming zero. In other words
there is no 24-cycle component of flicker. However, it is not beyond
possibility that the eye response is of such nature that the actual
optic nerve stimulation would have a component of fundamental
frequency even though the external stimulus did not have it. This
would be analogous to the well known reconstruction of fundamental
frequency due to the non-linear character of the ear. In these tests,
which were made with a blank screen, the observers judged the
flicker produced by the shutter with the three unequal blades to be
about as objectionable as the 48-cycle flicker from a balanced two-
blade shutter. In recent tests, however, the conclusions from a
fairly large number of observations was that when a picture is being
shown- the flicker from the unequal-blade shutter can, if the shutter
is properly designed, be substantially less than with a two-blade
shutter. The unbalanced shutter therefore represents a compromise
between the two- and three-blade shutters, and evidently has a place
in picture projection.

Conclusions. — Omitting from consideration the obvious necessity
of using a three-blade shutter if the same machine must also project
pictures at 16 pictures per second, the widely held opinion that three-
blacfe shutters are needed for 16-mm picture projection (at 24 frames
per second) whereas the two-blade shutters apparently give satis-
faction in theaters may be attributed to the following:

(1} Many of the comparisons have been made with no picture in the machine,
or with the screen so close to the machine that the picture was much brighter than
that corresponding to ordinary projection. '

(2} In comparing theater conditions with 16-mm projection conditions, it may
frequently have been considered that the screen brightnesses were equal, because
so indicated by a foot-candle meter, whereas from the visual standpoint the 16-mm
film was actually brighter. The better freedom from stray light and the whiter
character of the screen illumination probably gives theater patrons an impression
of abundant brightness whereas the same actual screen illumination under 16-mm
projector conditions would seem to be less bright.

(5) Although the only logical way of measuring screen brightness is in terms of

Oct., 1942] FLICKER IN 16-MM PICTURE PROJECTION 243

the reflected light (foot-lamberts), measurements of the incident light are com-
mon. The reflectivity of theater screens is cut down slightly by the perforations.
Therefore the actual brightness tends to be less, for the same illumination, in a
theater than in a 16-mm projecting system, assuming the screens to be of equal
quality.

(4) The 120-cycle fluctuation in lamp brightness may under some conditions
increase the flicker effect.

(5) The eye is more sensitive to flicker at the beginning of a period of watch-
ing motion pictures than after a few minutes of continuous viewing. Therefore
practically all tests for flicker threshold (and this includes our own tests recorded
here) give lower values of brightness for threshold flicker than those that would
correspond to freedom from noticeable flicker during most of the duration of a
film showing. The subject of flicker fatigue and adjustment to flicker was inter-
estingly discussed by P. A. Snell,8 in the May, 1933, JOURNAL.

(6) It is more than likely that if a comparison were arranged under theater
conditions with a two-blade shutter in one machine and a three-blade shutter in the
other and with the screen brightness equalized to normal level, the observers
would see a perceptible difference. In other words we probably tolerate per-
ceptible flicker in theaters. Owing to the ease with which tests and comparisons
can be made, we have become more critical in the 16-mm field.

(7) Screen brightness in the theater and viewing distances are the same from
day to day. The inability to control or predict conditions of use constitutes a
valid reason for providing against more severe conditions of showing in the case of
the 16-mm projectors.

The following items of interest in connection with flicker studies
have been brought out in our recent tests :

(1) Tolerance for flicker increases in marked degree after the first few minutes
of continuous viewing. Some of the tolerance is probably developed within a
few seconds, as is evidenced by the reduced sensitivity to flicker when the eyes do
not move.

(2) Color of the light may be a factor in creating a subjective impression (prob-
ably based upon association) of differences in screen brightness, but in terms of
visual utility the flicker threshold and useful brightness go together independ-
ently of the color of the light.

(3) When a picture is being projected the average screen brightness is a small
fraction of that of a blank screen, and even the bright portions are likely to be
little more than half the maximum possible brightness. This means that picture
projection will be satisfactory even though the illumination of the bare screen may
be three or four tunes flicker threshold.

(4) It is permissible to allow the screen brightness in small areas of the pro-
jected picture to exceed considerably the blank-screen flicker threshold. This is
because the viewing angle subtended by the bright area is a large factor.

(5) When viewing a large area, the sensitivity to flicker is much increased by
the motion of the eye.

. (6) The magnitude of the flicker is not materially affected by the location of
the shutter or the velocity of the edge of the blade, but the blade-width is im-
portant, and the narrower the blade the better.

244 E. E. MASTERSON AND E. W. KELLOGG

(7) The value of high blade-speed (or large radius) is that it will permit the
use of a narrower blade without travel-ghost.

The general conclusion from our studies is that the decision to
employ three-blade shutters for general-purpose 16-mm projectors
where the conditions of use can not be predicted, is entirely justified.
Projectors with three-blade shutters and with incandescent lamps
can, if provided with efficient optical systems, illuminate a 3 X 4-
foot screen with 10 foot-candles. Hence with screens of this size
or smaller, two-blade shutters can not be recommended as giving
any better picture. On the other hand, projectors that are designed
to be used for showings to fairly large audiences, where screens 5
feet or more wide are desirable in order to make the picture easily
seen from the remote seats, should (if they are not equipped with arc
lamps) preferably have two-blade shutters in order to obtain the
benefit of the brighter picture. Unless the screen brightness (with
no picture in the machine) considerably exceeds 10 foot-lamberts,
flicker should be no worse than it is in practically all theaters.

REFERENCES

1 ENGSTROM, E. W.: "A Study of Television Image Characteristics," Part II,
Proc. IRE (April, 1935) ; "Television," Vol. I, RCA Institutes, 1936.

2 Report of the Committee on Non-Theatrical Equipment, J. Soc. Mot. Pict.
Eng., XXXVII (July, 1941); (Recommended Screen Brightness, p. 31) (Flicker
Tests, p. 60).

3 Report of Committee on Non-Theatrical Equipment, /. Soc. Mot. Pict. Eng.,
XXXVII (July, 1941); (Optical Properties of Screens, p. 47).

JONES, L. A., AND FILLIUS, M. F.: "Reflection Characteristics of Projection
Screens," Trans. Soc. Mot. Pict. Eng., No. 11 (1930), p. 59.

JONES, L. A., AND TUTTLE, C.: "Reflection Characteristics of Projection
Screens," Trans. Soc. Mot. Pict. Eng., No. 28 (Feb., 1927), p. 183.

LITTLE, W. F.: "Tests of Motion Picture Screens," /. Soc. Mot. Pict. Eng.,
XVI (Jan., 1931), p. 31.

Report of the Projection Screens Committee, J. Soc. Mot. Pict. Eng., XVII
(Sept., 1931), p. 441.

LYMAN, D. F.: "Relation between Illumination and Screen Size for Non-
Theatrical Projection," /. Soc. Pict. Eng., XXV (Sept., 1935), p. 231.

4 Scientific Papers, Nos. 303 and 475, Nat. Bureau Standards.

6 HARDY, A. C., AND PERRIN, F. H. : "Principles of Optics," McGraw-Hill Book
Company, New York, Chapt. X.

6 SOUTHALL, J. P. C. : "Physiological Optics," Oxford University Press, Chapt.
X, p. 372.

7 IVES, H. E.: "Spectral Luminosity Curves by the Method of Critical Fre-
quency," Phil. Mag., 24 (1912), p. 352.

8 SNELL, P. A.: "An Introduction to the Experimental Study of Visual
Fatigue," /. Soc. Mot. Pict. Eng., XX (May, 1933). p. 367.

DEVELOPMENTS IN TIME-SAVING PROCESS PROTECTION

EQUIPMENT*

R. W. HENDERSON**

Summary. — The projection of a motion picture on a translucent screen for back-
ground purposes has become increasingly important in studio operations during the
past ten years. Many shots now made through the use of this process would have been
extremely costly and perhaps impossible if attempted by direct filming of the complete
action.

The sharp rise in production costs during the past few years, coupled with the cur-
tailment of foreign markets, demanded that every effort be expended to simplify pro-
duction methods.

With this in view, Paramount Pictures embarked upon a complete modernization
program of the Transparency department production equipment early in 1940. New
compact projection units, bases for the projectors, rewind tables, screen frames, screen
handling equipment, and light-bridges were designed and built. This equipment has
immeasurably simplified operations as well as improved quality beyond levels hereto-
fore achieved.

Descriptions of this equipment are presented, with emphasis upon a comparison of
the new with the old. The success of the equipment can be attributed largely to stand-
ardization of component parts. Complete inter changeability of essential units, coupled
with easy access to critical points, has gone far toward eliminating lost time and motion
in meeting unexpected emergencies.

The projection of a motion picture upon a translucent screen for
background purposes has become increasingly important in studio
operations during the past ten years. Directors and producers have
come to accept these backgrounds with confidence in the appearance
of the finished photographic illusion, where they once insisted
upon location shots. Through the cooperation of these men and
the efforts of the Transparency Division of Paramount's special photo-
graphic department, headed by Mr. Farciot Edouart, techniques
have been developed that permit the making of certain types of
scenes that would have been impossible without the use of projected
backgrounds. The importance of this work is more evident now

*Presented at the 1942 Spring Meeting at Hollywood, Calif. ; received April
13, 1942.

** Paramount Pictures, Inc., Hollywood, Calif.

L'4.r.

246 R. W. HENDERSON u. S. M. p. E.

than ever before, because of the increased costs entailed in sending a
shooting company on location.

One of the greatest advantages of background projection is that
of providing "cover" for a company that might otherwise be delayed
by some unforeseen difficulty that may arise in spite of careful plan-
ning. The most common of these is that of a company finishing a
day's scheduled shooting early in the afternoon, in which case the
cast would have to be dismissed on pay if it were not possible to move
into a transparency scene. Realizing this, the production depart-
ment attempts to maintain at least one transparency set as "cover"
for every shooting company.

The "stand-by" function of background projection set-ups de-
mands that all the equipment used be of a standardized, interchange-
able nature; flexible, efficient, easily handled by a minimum of
operating personnel; and so arranged that it can be assembled and
put into action in a few minutes.

With this aim in view, the Paramount Engineering department,
following a preliminary investigation period, commenced design work
early in 1940 on a complete modernization program embracing the
following major equipment used by the transparency department,
which will be described in the order named.

(I) Projection units
(2} Projector bases

(A) Single

(£) Triple
(5) Rewind tables

(4) Screen equipment

(A) Screen frames

(B) Screen jacks

(5) Light bridges

(1) PROJECTION UNITS

Customary studio practice during the last ten years has been to
have the projection machine permanently housed hi a large, cumber-
some, heavy booth which was awkward to move in and out of restricted
stage space. In addition, the extreme heat from the arc lamp,
cramped working space, excessive noise, and limited ventilation
provided poor operating conditions for the projectionist.

* Another objection to the booth was the difficulty of making high
shots. To accomplish such shots, the booth had to be taken to a
large hydraulic hoist on the lot, lifted, rolled off onto a caster base

Oct., 1942]

PROCESS PROJECTION EQUIPMENT

247

parallel, and pushed back upon the stage. This was not only time-
consuming but hazardous when negotiating the ramps outside the
stage doors.

To eliminate these objections, Paramount followed the lead set
by Selznick International Pictures in 1939 and embarked upon the
design of a comparatively light-weight, silent, projection unit that
could be used without a booth. In general, the specifications as
drawn up by the Process Projection Equipment Committee of the

FIG. 1. New type silent projector; operator's sidi

Research Council of the Academy of Motion Picture Arts & Sciences
were adopted.

To increase flexibility further, the projector was designed as a
complete unit in itself, comprised of a projection head, light-tube,
optical relay condenser system, lamp house, self-contained cooling
system, and a support housing that tied all these various elements
together into one completely independent assembly that could readily
be lifted on or off a separate base, as shown in Fig. 1.

The projection head was designed and built by the Mitchell
Camera Corporation in accordance with the suggestions of the Re-

248 R- W. HENDERSON [j. s. M. P. E.

search Council. To date eight of these heads have been built: one
for Selznick International Pictures, Inc., three for RKO, and four
for Paramount.

The projection-head mechanism is driven by a 1440-rpm distribu-
tor controlled, a-c interlock motor which is normally tied in with
a camera and a recording machine. To provide for all "sync" shots,
i. e., shots made without recording sound, a special variable -speed
d-c driving motor was built into the top of the projection-head.
When in use, this motor is connected through a magnetic clutch to
the head mechanism and to the rotor of the interlock motor. By
applying three-phase power from a common source to the stator
windings of both the interlock motor arid the camera motor, the
interlock motor becomes in effect a distributor interlocking the
camera to the projector.

For standard speed work the d-c motor operates at 1440 rpm,
controlled by a centrifugal governor. The variable-speed feature
was designed to provide for under1 and over-cranking between the
limits of 12 and 36 frames per second.

This system eliminates the necessity of having a sound crew stand-
ing by for the single purpose of operating the distributor in the re-
cording building, or the equally objectionable practice of having a
local distributor either on or just outside the stage. Another great
advantage of the reversible d-c drive system is that it provides a
rapid method of rewinding, particularly during line-up.

The light- tube serves as a support for the projection-head and also
as a housing for the relay condenser elements and fire-shutter. It
consists of cylindrical Mehanite casting to the outer end of which
the projection-head is fastened by a large-diameter clamping ring.
This ring is fitted with a tangent-screw adjustment which permits
rotation of the head about the optical axis for line-up purposes and
special effects. This feature is a particularly important time-saver
during the registration of superimposed pictures from several ma-
chines in multiple-head projection. The lamp house is a Mole-
Richardson type 250 designed in accordance with recommendations
of the Research Council.

The cooling unit consists of a motor, centrifugal pump, squirrel-
cage blower, and radiator, mounted on rubber as an isolated unit
under the lamp house. Its function is to supply cooling water to
the carbon -holding jaws in the lamp house and to the jacket sur-
rounding the distilled water in the water-cell of the optical system.

Oct., 1942] PROCESS PROJECTION EQUIPMENT

To 'increase the efficiency of the projection unit further, a talk-
back amplifier system was added, terminating with the cameraman
on the set in the form of a small combination microphone-speaker.
Paralleling this system is another combination microphone-speaker
mounted on a small portable desk just off the set which is normally
tended by the assistant cameraman whose duty it is to keep the
shooting log and print records. The desk is equipped with a remote-
control panel, making it possible to operate the projector from that

FIG. 2. Triple-head projection unit ; top view.

point for special shots. It also contains a group of signal push-
buttons for transmitting instructions to the projectionist without
the aid of the talk-back system.

High shots with the new equipment are normally made from
parallels. For certain shots, however, where restricted stage space
and the ability to make quick moves are the governing factors, the
equipment may be rolled onto the platform of a compact motor-
driven industrial stacker or telescoping elevator, the floor-space
required by the stacker being only slightly greater than that of the
projector and its associated equipment.

250

R. W. HENDERSON

U. S. M. P. E.

The performance of the unit can best be judged by the relatively
high average light output level of about 42,000 lumens, which has
been boosted to better than 50,000 lumens at times through careful
regulation and operation.

(A)

(2) PROJECTOR BASES

Single Projector Base. — The single projector base serves as

a mount for the projection unit and is a complete piece of equipment

FIG. 3. Key operator's station, triple-head projection unit.

in itself. Into it is built a panning mechanism permitting a 360-
degree rotation about a vertical axis, a tilt-mechanism allowing a
^20-degree tilt from the horizontal, and an elevating mechanism
capable of placing the optical axis anywhere between 4 feet 9 inches
and 6 feet 8 inches above the floor. The single bases built to date
are completely interchangeable with any of the four projection units,
thereby eliminating unnecessary confusion and delays that might
otherwise affect set-up time.

(B) Triple Projector Base. — With the advent of large-screen color
shots, the industry turned to multiple-head projection and super-

Oct., 1942] PROCESS PROJECTION EQUIPMENT 251

imposed pictures to increase the screen illumination. To provide
for this type of work, a base was designed upon which any three of
the four projectors could be mounted in approximately 45 minutes,
including the time required to collect and lift them from their indi-
vidual bases (Figs. 2 and 3). Built-in mechanisms in the base
provide for =*=5-degree pan and tilt with the possibility of increasing
this range through the auxiliary jacks used to tie off the base to the
floor. This new equipment has an average total light output level of

FIG. 4. New type projection unit, rewind stand, and working platform ;

front view.

about 126,000 lumens, replacing the old triple booth which had a total
light output of slightly less than one of the new single-projection
units.

Most of Paramount's large-screen shots are made in an outdoor
diffused area approximately 62 feet wide by 300 feet long. To
increase further the flexibility of the triple-head unit in this location,
the machine is placed on the floor of a semiportable elevator per-
mitting a maximum optical axis height of 19 feet 6 inches above the
floor. If the unit is required on any other stage, it can be rolled off

252

R. W. HENDERSON

[J. S. M. P. E.

the elevator, transported on its own wheels, and set up on its jacks
wherever desired.

The synchronized control of the triple-head motor system, neces-
sary for superposition of pictures, is accomplished through a central
control-panel permanently mounted on the base which gives the
key operator control of all three machines when running in interlock.
However, the individual projectionists can at will drop off the line
and run independently for line-up and rewind if they so desire. The

FIG. 5. New type 18' X 24' stressed-skin metal screen frame.

built-in talk-back system mentioned above as a part of the projection
unit serves in the same capacity in the triple set-up.

(3) REWIND TABLE

A necessary auxiliary to the projector is the rewind table, which
serves the dual purpose of a storage cabinet for film, lenses, and
operating equipment, as well as a work table for rewinding, cleaning,
and examining the film (Fig. 4).

This unit is of all steel construction and is normally mounted on a
rubber-tired caster-equipped dolly having a built-on folding work-

Oct., 1942]

PROCESS PROJECTION EQUIPMENT

253

platform on which the projectionist stands. The work-platform,
floor of the projector base, and floor of the rewind dolly are all at the
same level, thereby producing an unobstructed working area from
which the projectionist can reach either the table or the projector
controls merely by turning around.

The table top is equipped with standard manually operated re-
winds, a flush-surface opal-glass panel illuminated by fluorescent
light for scanning the film as it is rewound, and a folding- type flu-

FIG. 6. New metal light-bridge; minimum span and height.

orescent reflector for general illumination of the working area.

When it is necessary to operate the projector from high parallels
or on the elevator it would often be inconvenient to leave the rewind
table mounted on its dolly. For shots of this type the table is nor-
mally lifted off the dolly and used without the convenience of the
work platform.

With this new equipment, the operator has pleasant surroundings,
compact, orderly arrangement of all accessories, and no appreciable
mechanical noise, all of which is in marked contrast to the old system.

254

R. W. HENDERSON

(4) SCREEN EQUIPMENT

[J. S. M. P. E.

The primary objection to the conventional transparency-screen
frame and supporting structure has been its great bulk. Customary
practice has been to have the screen frame permanently hung inside
a portable bridge which served as a catwalk for the mounting of top
lights. This procedure necessitated moving the large units on and
off stages continually and was often complicated by the arrangement
of sets on the stage. In some cases the day's work on one stage

FIG. 7. New metal light-bridge; maximum span and height.

would require two or perhaps three screen sizes, which meant that
either a great deal of stage space was taken up by the units not in
use or the sets had to be so arranged as to leave easy access to the
door to permit exchanging the screens.

To minimize the handling problem, a system was devised that
incorporates a very light stressed-skin steel frame in which the screen
is mounted, portable elevating-type jacks which can be readily
attached to the ends of these frames for handling, and an independent
light-bridge of semistressed-skin construction from which the screen
frame can be hung if desired.

Oct., 1942] PROCESS PROJECTION EQUIPMENT 255

(A) Screen Frames. — Four standard-size screen frames were
designed using steel stressed-skin or the full Monocoque principle,
as it is sometimes called. In this type of construction, the loads
applied to the structure are carried principally by the thin sheet-
metal covering, eliminating the necessity of having a relatively heavy
internal structural framework, and thereby reducing the overall
weight of the unit. To date the studio has acquired four 1 1 feet X
14 feet, two 14 feet X 18 feet, two 16 feet X 21 feet, and four 18
feet X 24 feet screens (Fig. 5). The frames are remarkably light
and rigid, and can be used either on their own detachable jack sup-
ports or can be hung from the light-bridge structure.

One important feature of the frames is the minimum screen height,
which places the lower edge of the working area within three to four
inches of the floor. This feature permits building directly on the
floor certain sets that previously had to be built on parallels.

Some transparency shots can be made without heavy top-lighting,
so for these shots the light-bridge previously mentioned can be dis-
pensed with entirely. In the event that a small amount of overhead
lighting is required, but not enough to warrant the use of a light-
bridge, sockets have been provided along the top of the screen frames
to take the spindles of the light-bails. For protection of the screen
material during handling, light-weight plywood cover-panels of
sectionalized design are hung from the top of the frame. One man
can handle the largest panels, although two men usually work to-
gether.

An enclosed, moderately dust-tight storage shed with an overhead
monorail system was built for the protection of the screens and other
equipment when not in use. The monorail system makes it a simple
matter for the operating personnel to select any of the twelve screens
and move it out of the building. From that point it is transported
on its own jacks to any stage on the lot, the entire procedure requiring
only a few minutes.

(B) Screen Jacks. — The screen jacks are compact, easily handled,
caster-equipped elevators which engage built-in lugs on the ends of
the screen-frame. They are provided with a tow-bar, diagonal tie-
rods for bracing to the screen frame, and a folding leg with third
wheel for stabilizing the jack when not attached to the screen -frame.
The jacks have a maximum lift of six feet, permitting the making of
high shots without the expense of building special parallels for sup-
porting the screens.

256 R. W. HENDERSON [j. s. M. p. E.

When in the high position, the wheel-base of the jacks can be in-
creased by a built-in feature to provide all the necessary stability for
safe operation.

(5) LIGHT-BRIDGES

The light-bridge illustrated in Figs. 6 and 7 is of semistressed-
skin construction which gives it great load-carrying capacity in
proportion to its weight. The bridge structure is designed to tele-
scope in both directions. In the most compact position it has a net
clear rectangular opening of 13 feet 3 inches X 18 feet 3 inches,
which can be extended 13 feet 4 inches Vertically and 10 feet 0
inches horizontally to a maximum opening of 26 feet 7 inches X 28
feet 3 inches. This extended opening permits hanging an 18 feet X
24 feet screen six feet in the air. All smaller screens can be hung
wherever desired in the bridge opening. This construction is par-
ticularly useful when the arrangement of the props might require a
bridge that could completely straddle the set.

The first of three of these light-bridges has recently been put into
use. When the other two are completed it is planned to assign each
to a group of about four stages among which it can be shuttled as
required. This procedure should help considerably in minimizing
handling and set-up time.

The two remaining items included in the modernization program
are the construction of a stereopticon projector, the design of which
is substantially complete, and the design and construction of a high-
speed motion picture background projector.

The base for the high-speed projector will be identical to the other
four single-bases, and the general appearance of the projection unit
will be similar to that of the standard-speed machines. The differ-
ence will be mainly in the design of the motor system and the projec-
tion-head, which has been delayed by the war. It is intended that
this unit be capable of overcranking as high as 120 frames per second,
or five times normal speed, which is desirable for many types of
miniature work.

In addition to its primary high-speed function, it will be possible
to operate the unit at 24 frames per second, thereby giving the studio
a fifth-standard-speed projector if required during heavy shooting
schedules.

Stereo-projection is a potential source of considerable savings,
both in the shooting of the original plates as well as in processing.

Oct., 1942] PROCESS PROJECTION EQUIPMENT 257

The plates can be taken by a still photographer working without the
assistance of a staff of technicians, as contrasted to the procedure
necessary when shooting motion picture backgrounds. Here it is
necessary to send out a cameraman, an assistant, perhaps a camera
mechanic, and a considerable amount of miscellaneous operating
equipment that is particularly objectionable when travelling by air.
In addition, there is the cost of the negative, processing, and print
which must be met before the picture can be used. The resulting
cost differential makes it desirable to use still backgrounds wherever
possible.

Paramount has used the process frequently but has been limited
in recent years by design improvements and a higher standard of
quality that outmoded the equipment available. It is believed that
the new stereopticon that is about to be constructed will broaden
the field of application for this type of equipment and permit con-
siderable reductions in costs for still background work.

With the completion of this new equipment, it is felt that Para-
mount will be well equipped to cope with the changing production
technique and operating conditions that will inevitably follow as an
aftermath of the present world-wide conflict.

CURRENT LITERATURE OF INTEREST TO THE MOTION PICTURE

ENGINEER

The editors present for convenient reference a list of articles dealing with subjects
cognate to motion picture engineering published in a number of selected journals.
Photostatic copies may be obtained from the Library of Congress, Washington, D. C.
or from the New York Public Library, New York, N. Y. Micro copies of articles
in magazines that are available may be obtained from the Bibliofilm Service, Depart-
ment of Agriculture, Washington, D. C., at prevailing rates.

American Cinematographer

23 (Aug., 1942), No. 8

"Pre-Photographing" in 16-Mm as a Means of, Conserv-
ing Film (pp. 342-343, 382)

Animated Cartoon Production Today. Pt. V (pp. 344-
346, 380-382)

Make 16-Mm Business Movies That Help the War Effort
(pp. 347, 379-380)

Controlling Color in Lighting 16-Mm Kodachrome for
Professional Pictures (pp. 348-349, 377-379)

Diopters— for Distortion (pp. 358, 370-371)

Explaining "Montage" (pp. 359, 364-366)

Making Movies under Water (pp. 360, 370)

Why Not Try Making Third-Dimensional Movies? (pp.
362-363, 366-368)

Institute of Radio Engineers, Proceedings

30 (Aug., 1942), No. 8

Recording and Reproducing Standards (pp. 355-356)
The Zero-Beat Method of Frequency Discrimination (pp.

365-367)
Transients in Frequency Modulation (pp. 378-383)

Motion Picture Herald (Better Theaters Section)

148 (July 25, 1942), No. 4
Simple Method of Testing and Correcting the Projection

Light System (pp. 7-9, 19-20)
Luminous Screen Frame (pp. 10-11, 20)

L. GARMES
C. FALLBERG
W. G. Bosco

J. A. LARSEN, JR.
J. WALKER
L. G. DUNN
T. TUTWILER

P. TANNURA

L. C. SMEBY

C. F. SHEAFFER
H. SALINGER

C. E. SHULTZ

B. SCHLANGER

258

FIFTY-SECOND SEMI-ANNUAL MEETING

OF THE
SOCIETY OF MOTION PICTURE ENGINEERS

HOTEL PENNSYLVANIA, NEW YORK, N. Y.
OCTOBER 27th-29th, INCLUSIVE

OFFICERS AND COMMITTEES IN CHARGE

EMERY HUSE, President

E. ALLAN WILLIFORD, Past-President

HERBERT GRIFFIN, Executive V ice-President

W. C. KUNZMANN, Convention Vice-President

A. C. DOWNES, Editorial Vice-P resident

ALFRED N. GOLDSMITH, Chairman, Local Arrangements Committee

SYLVAN HARRIS, Chairman, Papers Committee

JULIUS HABER, Chairman, Publicity Committee

J. FRANK, JR., Chairman, Membership Committee

H. F. HEIDEGGER, Chairman, Convention Projection Committee

Reception and Local Arrangements

ALFRED N. GOLDSMITH, Chairman

R. B. AUSTRIAN
L. A. BONN
M. R. BOYER
J. C. BURNETT
F. E. CAHILL, JR.
A. S. DICKINSON
W. E. GREEN
J. A. HAMMOND
M. HOB ART

J. FRANK, JR.
G. FRIEDL, JR.

L. W. DAVEE
P. C. GOLDMARK
R. F. MITCHELL

C. F. HORSTMAN
L. B. ISAAC
E. W. KELLOGG

J. H. KURLANDER

P. J. LARSEN
J. A. MAURER
P. A. McGuiRE
O. F. NEU

J. A. NORLING

WM. H. OFFENHAUSBR, JR.

W. M. PALMER

H. RUBIN

V. B. SEASE

T. E. SHEA

E. I. SPONABLE

J. H. SPRAY

R. O. STROCK

H. E. WHITE

Registration and Information

W. C. KUNZMANN, Chairman
E. R. GEIB H. K. MCLEAN

F. HOHMEISTER

P. K. SLEEMAN

Hotel and Transportation
O. F. NEU, Chairman

W. M. PALMER
P. D. RIES
C. Ross

J. A. SCHBICK

F. C. SCHMID

E. S. SBBLBY

800

260

G. GIROUX
C. R. KEITH

FALL MEETING

Publicity Committee

JULIUS HABER, Chairman
SYLVAN HARRIS

[J. S. M. P. E.

P. A. McGuiRE
F. H. RICHARDSON

M. R. BOYER
J. C. BURNETT
P. C. GOLDMARK
ALFRED N. GOLDSMITH

MRS. M. R. BOYER
MRS. A. S. DICKINSON
MRS. J. FRANK, JR.
MRS. G. FRIEDL, JR.
MRS. P. C. GOLDMARK

F. CAHILL, JR.

T. H. CARPENTER
L. W. DAVEE

G. E. EDWARDS
J. K. ELDERKIN

Luncheon and Banquet

D. E. HYNDMAN, Chairman

J. A. HAMMOND

O. F. NEU

W. H. OFFENHAUSER, JR.

M. W. PALMER

E. I. SPONABLE
J. H. SPRAY
R. O. STROCK
H. E. WHITE

Ladies Reception Committee

MRS. D. E. HYNDMAN, Hostess

MRS. H. GRIFFIN

MRS. J. A. HAMMOND

MRS. P. J. LARSEN

MRS. O. F. NEU

MRS. W. H. OFFENHAUSER,

JR.

MRS. P. D. RIES
MRS. E. I. SPONABLE
MRS. R. O. STROCK
MRS. H. E. WHITE
MRS. E. A. WILLIFORD

Projection Committee

H. F. HEIDEGGER, Chairman

W. W. HENNESSY
J. J. HOPKINS
C. F. HORSTMAN
L. B. ISAACS
A. L. RAVEN

F. H. RICHARDSON

P. D. RIES

J. E. ROBIN

H. RUBIN

R. O. WALKER

Officers and Members of New York Projectionists Local No. 306

HOTEL RESERVATIONS AND RATES

Hotel Rates. — The Hotel Pennsylvania extends to SMPE delegates and guests
the following special per diem rates, European plan :
Room with bath, one person $3 . 85-$7 . 70

Room with bath, two persons, double bed $5. 50-$8. 80

Room with bath, two persons, twin beds $6 . 60-$9 . 90

Parlor suites : living room, bedroom, and bath $10 . 00, 1 1 . 00, 13 . 00,

and 18. 00

Reservations. — Early in September room-reservation cards were mailed to the
members of the Society. These cards should be returned to the hotel as promptly
as possible to be assured of desirable accommodations. Reservations are subject
to cancellation if it is later found impossible to attend the meeting.

Registration. — The registration headquarters will be located on the 18th floor
of the Hotel at the entrance of the Salle Moderne, where most of the technical

Oct., 1942] FALL MEETING 261

sessions will be held. All members and guests attending the meeting are expected
to register and receive their badges and identification cards required for admission
to all sessions.

TECHNICAL SESSIONS

Technical sessions will be held as indicated on the next page. The Papers
Committee is assembling an attractive program of technical papers and presen-
tations, the details of which will be given in a Tentative Program to be mailed
to the members of the Society about October 10th.

FIFTY-SECOND SEMI-ANNUAL BANQUET AND INFORMAL GET-TOGETHER

The usual Informal Get-Together Luncheon for members, their families, and
guests will be held in the Roof Garden of the Hotel on Tuesday, October 27th, at
12:30 P. M.

The Fifty-Second Semi-Annual Banquet and dance will be held in the Georgian
Room of the Hotel on Wednesday evening, October 28th, at 8:00 P. M. Pres-
entation of the Progress Medal and Journal Award will be made at the banquet,
and the officers-elect for 1943 will be introduced. The evening will conclude with
dancing.

LADIES' PROGRAM

MISCELLANEOUS

Motion Pictures. — The identification cards issued at the time of registering will
be honored at the Paramount Theater, the Roxy Theater, the Capitol Theater,
and Radio City Music Hall. Many entertainment attractions are available in
New York to out-of-town delegates and guests, information concerning which
may be obtained at the Hotel information desk or at the registration head-
quarters.

Golf. — Arrangements may be made at the registration desk for golfing at
several country clubs in the New York area.

Note: The dates of the 1942 Fajl Meeting immediately precede those of the
meeting of the Optical Society of America at the Hotel Pennsylvania, New
York, N. Y., to be held on October 30th and 31st.

The Convention is subject to cancellation if later deemed advisable in the na-
tional interest.

262

FALL MEETING

TENTATIVE PROGRAM

Tuesday, Oct. 27

9: 00 a.m. Hotel Roof; Registration.

10:00 a.m. Salle Moderne; Business and Technical Session.
12: 30 p.m. Roof Garden; SMPE Get-Together Luncheon for members, their
families, and guests. Introduction of officers-elect for 1943 and
addresses by prominent members of the motion picture industry
2:00 p.m. Radio City Music Hall Studio; Technical Session.
8:00 p.m. Museum of Modern Art Film Library; Technical Session.

Wednesday, Oct. 28

9 : 00 a.m. Hotel Roof; Registration.

9: 30 a.m. Salle Moderne; Technical sessions.

12:30 p.m. Luncheon Period.

2: 00 p.m. Salle Moderne; Technical session.

8 : 00 p.m. Georgian Room; Fifty-Second Semi- Annual Banquet and Dance.

Thursday, Oct. 29

9:00 a.m. Hotel Roof; Registration.
10: 00 a.m. Salle Moderne; Technical Session.
12:30 p.m. Luncheon Period.
2 : 00 p.m. Salle Moderne; Technical Session.
8:00 p.m. Salle Moderne; Technical Session and Convention adjournment.

Note: Any changes in the location of the technical sessions and schedules of
the meeting will be announced in later bulletins and in the final program.

W. C. KUNZMANN,
Convention Vice- President

IMPORTANT

Hotel room reservation cards must
be returned immediately; otherwise
the Hotel Pennsylvania can not guar-
entee satisfactory accommodations on
account of the recent large influx of
visitors to New York.

ABSTRACTS OF PAPERS

FOR THE
FIFTY-SECOND SEMI-ANNUAL MEETING

HOTEL PENNSYLVANIA

NEW YORK, N. Y.
OCTOBER 27-29, 1942

The Papers Committee submits for the consideration of the membership abstracts
of papers to be presented at the Fall Meeting that have been received thus far. It is
hoped that the publication of these abstracts will encourage attendance at the meeting
and facilitate discussion. The papers presented at Meetings constitute the bulk of the
material published in the Journal. The abstracts may therefore be used as convenient
reference until the papers are published.

A. C. DOWNES, Editorial Vice- President

S. HARRIS, Chairman, Papers Committee

C. R. SAWYER, Chairman, West Coast Papers Committee

J. L. FORREST

F. T. BOWDITCH C. R. KEITH W. H. OFPENHAUSER

G. A. CHAMBERS E. W. KELLOGG R. R. SCOVILLE
F. L. EICH P. J. LARSEN S. P. SOLOW

R. E. FARNHAM G. E. MATTHEWS W. V. WOLFE

Recent Laboratory Studies of Optical Reduction Printing; R. O. DREW AND
L. T. SACHTLEBEN, RCA Manufacturing Co., Indianapolis, Ind.

This paper reports recent laboratory work that has resulted in marked improve-
ments over previous 16-mm reduction print quality. Improvements in image
quality accrue from exposure of the print with ultraviolet light, and from the use
of reflection-reducing coatings on the lens surfaces, while speed variations are re-
duced by increasing printer speed to as much as twice the normal film speed.
These improvements involve only relatively simple changes in commercial reduc-
tion printers.

Precision Recording Instrument for Measuring Film Width; S. C. CORONITI
AND H. S. BALDWIN, Agfa Ansco, Binghamton, N. Y.

The film passes through a film gauge, one member of which is fixed and the other
movable. The latter is attached to one plate of an electrical condenser. Changes
of film width are translated into changes of capacitance. The electrical condenser
is connected to a parallel tuned circuit which acts as a load in the screen-grid cir-
cuit of a crystal oscillator. A 0 — 1 dc milliammeter is connected in series with the
screen grid. The circuit is tuned to some point off resonance. The dc screen-
grid current corresponding to this point operation is balanced out. Therefore,

264 ABSTRACTS OF PAPERS [J. S. M. p. E.

any changes of capacitance will vary the screen-grid current. For a width varia-
tion of 0.250 mm the relationship between screen-grid current and film width is
linear.

A continuous recording milliammeter is connected in the meter circuit. Its
chart velocity and film velocity are maintained at a fixed ratio. The accuracy of
the instrument is ±0.002 mm.

Some Characteristics of Ammonium Thiosulfate Fixing Baths; DONALD B.
ALNUTT, Mallinckrodt Chemical Works, St. Louis, Mo.

A brief description of the history and nature of ammonium thiosulfate is given.
Several practical formulas employing this agent are presented and their advan-
tages discussed. Some of the differences in characteristics between the am-
monium thiosulfate and sodium thiosulfate fixing baths are pointed out.

An explanation is offered to account for the apparent discrepancies in the effects
of concentration on clearing time reported by previous investigators. The speed
of fixation of ammonium thiosulfate is shown to be greater than that of sodium or
lithium thiosulfates and greater than that of mixtures of ammonium chloride
and sodium thiosulfate.

Motion Pictures in Aircraft Production; NORMAN MATHEWS, Bell Aircraft
Corp., Buffalo, N. Y.

The great numbers of aircraft needed in this war posed new problems in the
training of maintenance personnel in sufficient numbers ; every plane in the air re-
quires that there be three to twelve men on the ground for servicing. Each branch
of our armed forces was faced with the big job of training many men rapidly, not
only in the maintenance of aircraft, but in every phase of modern warfare. A
great share of this training job could be done by means of motion pictures.

Although the U. S. Army was producing an extensive series of training films
dealing with aircraft maintenance, the Bell Aircraft Corporation believed that it,
too, could help in this respect. Its service department had been in the field close
to the problems of maintaining one particular type of aircraft and it was from
their experience that material could be drawn for the production of training films
dealing with servicing the P-39, the Army Airacobra.

In April of this year the motion picture division of this company was organized
and production was begun on an extensive series of films, each dealing with a
specific service operation. All work was to be done in 16-mm and, with the ex-
ception of the laboratory, all phases of motion picture production were handled in
the division. Working closely with the service department, the details of the
various operations were carefully checked for accuracy and instructional value.
The small staff was organized into two crews, each alternating weekly in the
writing and shooting of scripts. All phases of production on a number of films
were kept moving simultaneously, with the added advantage from a working
point of view of having one crew follow a picture through from the initial script
stage to the final release.

Aside from being used by the Army these films were to be used by the company's
service department to train a rapidly expanding personnel and to help with serv-
ice training in the field. Service representatives throughout districts in the

<*t., 1^42] ABSTRACTS OF PAPERS 265

various war-fronts were equipped with small sound projectors and complete sets
of these films. A broader distribution was to be effected by the Army itself,
which is placing these films in all bases where these planes are in service.
The success of the films in aiding the training program is evidenced by their desig-
nation as official Army training films, and further by the results of a question-
naire aimed at an evaluation of them.

Pilot training is another subject being treated in film to tie in with the Army's
recently organized safety campaign. It is planned also that soon the work of the
motion picture division will be expanded to include industrial training, for which
there is an urgent need today in the aircraft industry with its rapid expansion
and the introduction of new methods of fabrication.

The Practical Side of Direct 16-Mm Laboratory Work; LLOYD THOMPSON, The
Com puny, Kansas City, Mo.

Laboratory practice for direct 16-mni production differs somewhat from 35-
mm methods. Thirty-five-mm laboratory practice as we know it is largely
confined to negative-positive, and 35-mm color is mostly done by special service
laboratories and not by the studio or release print laboratories.

Direct 16-mm production calls for the reversal type of processing, the negative-
positive method, and color developing. Some producers own laboratories for
doing the first two, but color is processed by the manufacturer. However, inde-
pendent laboratories are printing color. It is the purpose of this paper to ex-
plain how some of these processes are used in direct 16-mm production, especially
when the methods differ from conventional 35-mm practices. Some of the sub-
jects discussed are: processing originals, work prints, reversal printing, dupe
negatives, color printing, control methods, special laboratory equipment, etc.

Sixteen-Mm Editing and Photographic Embellishment; LARRY SHERWOOD,
The Calvin Company, Kansas City, Mo.

The paper will first discuss the essential equipment necessary to the editing of
16-mm film, with a detailed analysis of the types of commercial equipment avail-
able. Also will be included certain equipment that has been developed outside the
commercial field.

The second section will concern itself with the technique and methods that have
been developed and proved to be applicable to the editing of 16-mm film. This sec-
tion will take up the methods of identifying film ; of synchronization ; of matching
work print with original, both sound and photography, without edge-numbering;
and the technique of preparing film for the laboratory, with particular regard to the
methods employed in laying in mattes to produce dissolves, doubU- r\postin-s, trick
effects, etc.

The third section will concern itself with the importance of trick effects in indus-
trial and educational motion pictures; how trick effects might be utilized as an
integral part of the educational process; and examples will be given to show how
trick effects might be employed to eliminate footage, so essential to the produc-
tion of this type of film.

266 ABSTRACTS OF PAPERS [J. S. M. p. E.

Carbon Arc Projection of 16-Mm Film; W. C. KALB, National Carbon Co.,
Cleveland, Ohio.

This paper summarizes the characteristics of the high-intensity carbon arc as
applied to the projection of 16-mm film. It includes a description of the carbon
trim, color quality of the light, magnification, optical speed, and power require-
ments of the projection lamp. Intensity and distribution of screen light are dis-
cussed in relation to the operating characteristics of projectors commercially
available and the transmission characteristics of heat filters, shutters, and avail-
able types of lenses. Resulting screen illumination is interpreted in terms of
screen dimensions and audience capacity under conditions conforming to recom-
mended projection standards.

Laboratory Practice in Direct 16-Mm Sound-Film Production; W. H. OFFEN-
HAUSER, JR., Washington, D. C.

In a paper such as this, it is not uncommon to find minute detail of machinery
design and operation that is of little interest to any other than those who use the
machinery or its product. If, however, a motion picture film laboratory is de-
fined as but one of a series of tools necessary to accomplish the effective trans-
mission of intelligence by means of the 16-mm sound motion picture as a com-
munication medium, the laboratory takes on a new aspect — that of function.
It is with function that this paper deals, together with its inescapable results in
machinery and machinery operation.

Before our entry into the present World War, 16-mm films had been widely used
for advertising and ballyhoo purposes ; advertising seemed best able to supply the
largest sums for 16-mm production budgets. With our entry into the war, the
voices that had cried in the wilderness a decade ago for instructional and training
uses of film were finally heard; the death knell for the ballyhoo film occurred
"for the duration," and training films marched in to displace and overrun them.
This limitation of function was a blessing in disguise; the industry was per-
mitted for the first time to clear decks of non-essential frills and strip for action.

Direct 16-mm sound-films are generally of two kinds: black-and-white, and
color (usually Kodachrome). In both cases the original picture is developed by
the film manufacturer or his agents; the cost of development is included in the
price paid for the film.

The sound used is scored as a sound negative after the picture is edited; it is
from this stage onward that the commercial laboratory enters. In the case of
black-and-white, a fine-grain duplicate (intermediate) negative is made of the
picture, release prints being made from the original sound negative and the inter-
mediate picture negative. In Kodachrome, a black-and-white fine-grain positive
print is made of the sound, the Kodachrome duplicates being made from the origi-
nal Kodachrome picture and the black-and-white fine-grain sound-track print.

The paper deals with procedures, and presents some of the highlights of equip-
ment and operational techniques used in the volume production of high-quality
copies.

Oct.. 1942] ABSTRACTS OF PAPERS 267

Film Distortions and Their Effect on Projection Quality; E. K. CARVER, R. H.
TALBOT, AND H. A. LOOMIS, Eastman Kodak Co., Rochester, N. Y.

The three main types of film distortion are (2) Embossing due to differential
shrinkage or hardening of the emulsion caused by local absortion of heat in the
dense portions of the picture; (2} Fluted edges due either to stretching of the
edges or shrinkage of the center; (5) Short edges or buckle due to shrinkage of
the edges while in the roll.

Careful tests have failed to show any effect on the screen, such as in- and out-
of-focus effects, due to image embossing. Measurements of the magnitude of the
distortions show that these are ordinarily much less than the depth of focus of
the lens. Laboratory tests as well as field experience indicate that fluted edges
very rarely cause distortion of the image on the screen.

Short edges, however, produce a type of buckle which often shows in- and out-of-
focus effects. This is due to the fact that short edges leave a fullness in tin
center similar to the bottom of an oil can. Under some circumstances (his
fullness causes a movement back and forth in the projector gate causing in- and
out-of-focus movement. Short edges are commonly caused by loss of moisture
from the edges of the film when wound up in a roll immediately after processing.
When such films are placed in tin cans, the rate of loss is reduced so that moisture-
has time to diffuse from the center of the film to the edges and permit uniform
shrinkage. A scarcity of tin and substitution of cardboard boxes makes it de-
sirable to dry the film more thoroughly on the processing machines so as to avoid
this quick loss of moisture during the storage period before projection. Trouble-
can be avoided also by wrapping the film in moist ure-vaporproof envelopes before
packing in cardboard boxes or by the use of cardboard boxes of a highly imperme-
able type.

Effect of High Gate Temperatures on 35-Mm Film Projection; E. K. CARVI- K.
R. H. TALBOT, AND H. A. LOOMIS, Eastman Kodak Co., Rochester, N. Y.

In a study of the effects of high temperature arcs on 35-mm motion pictim
film in the projector gate, high-speed Cine Kodak pictures (1400-1500 frames per
second) were taken of the image of the 35-mm film on the projection screen. In
making these pictures an E-7 projector with a Macauley Hy-candescent lamp was
used and the image was sharply focused on the projection screen. A portion of
this image was used as a target for the high-speed Cine Kodak so that when this
Cine Kodak picture was projected one could observe the appearance of the 35-
mm image during various portions of each frame. The shutters of the 35-mm
projector were thrown slightly out of synchronism so that the appearance of the
image as it came to rest in the gate could be determined. When the high-speed
16-mm pictures were projected, it was observed that the 35-mm image was in
sharp focus during only a small part of its stay on the projection screen. After
the pull-down, the film comes into the gate out of focus, and slowly moves into
focus. As it moves into fdcus it always moves toward the lamp, as if the emulsion
were expanding, thus causing the film to curl away from the emulsion. In some
cases it does not come into sharp focus until after the flicker blade has passed.
The above phenomena occur during all normal projections but are more prominent

268 ABSTRACTS OF PAPERS [J. S. M .p. E.

at higher temperatures. The 35-mm projected pictures appear to be perfectly
sharp, even though the high-speed analysis shows them to be out of focus during
a large fraction of their stay on the screen. If the image is in focus during the last
fraction of a second before the next pull-down, it appears sharp to the eye regard-
less of the fact that it was out of focus during the first part of its stay on the screen.

Under certain definite circumstances, however, in- and out-of-focus effects are
observed on the 35-mm screen. When these are observed, the high-speed movies
indicate that the film comes into the gate out of focus, moves toward' the lamp
and, therefore, toward sharp focus, but before it reaches sharp focus a sudden
drift toward the lens occurs. Thus the film never reaches its position for sharp
focus and gives the in- and out-of-focus effect.

A further study of these effects was made by cutting away part of the projector
gate so that a high-speed Cine Kodak can be focused directly onto the film in the
gate. This study showed exactly the same effects as described above but, in some
respects, made them clearer.

The Use of High-Speed Photography in Analyzing Fast Action; E. M. WAT-
SON, Capt.t Ordnance Dept., Watervliet Arsenal, Watervliet, N. Y.

Various methods and devices may be used in studying action that is too fast for
unaided visual observation. In almost every set-up the following points must be
considered: (1) Means must be devised for placing the image (with necessary
sharpness and steadiness) on the medium where the exposure is to take place;
(2) Arrangements must be made for starting and stopping the exposure; (3)
Means must be devised for placing the subsequent exposures on recording ma-
terial at the proper time and location to obtain the desired results.

The principal methods for studying high-speed action are the shutter method and
the stroboscopic method. The former is used where subjects radiate light of them-
selves or reflect utility light not used to determine exposure time ; exposure time is
determined by the shutter. The stroboscope is used where other light does not
materially interfere with stroboscopic light; exposure time is determined by the
stroboscopic flash.

Whenever the subject being investigated does not repeat its motion at all or not
often enough to use a stroboscopic device, it is necessary to use some form of
photography for quickly recording the action for later study ; when complications
are not great, still cameras can be used. When a single picture is insufficient and
the motion occupies approximately the same area, causing multiple images to
overlap and be confused, one must resort to motion pictures. Motion pictures
taken at speeds moderately in excess of the regular projection speed can be taken
with an intermittent camera. When the film speeds up to about ninety miles per
hour it is necessary to use some kind of device for placing the image on the film
while the film is moving at a constant linear speed. If these additions are to be
exceeded it is then necessary mechanically to support the film in motion or allow
it to remain stationary and move the light which affects the exposure.

In any kind of high-speed photography, all the limitations of ordinary photog-
raphy are encountered plus some special restrictions imposed by the high speed.
As types of cameras are changed to obtain increased speed, compromises in image
quality and exposure must be made.

Oct., 1942] ABSTRACTS OF PAPERS

There is opportunity in high-speed photography for anyone having only modest
equipment, but many of the applications require very expensive equipment which
has little versatility.

Effect of Composition of Processing Solutions on Removal of Silver from
Photographic Materials; J. I. CRABTREE, G. T. EATON, AND L. E. MUKHLER,
Eastman Kodak Co., Rochester, N. Y.

To insure the permanence of the photographic negative or print it is necessary
to remove all residual hypo and silver. The effect of composition of the processing
solutions on hypo removal has been discussed in a previous paper. The factors
which govern the removal of residual silver are considered in the present paper.

The retention of silver in the photographic material gives rise to a yellowing of
the non-image area of the negative or print under adverse storage condition^, t IK
stain consisting of silver sulfide produced either by decomposition of complex
silver thiosulfates or the action of hydrogen sulfide present in the atmosphere on
the residual silver salts.

Present practice of using a single fixing bath to exhaustion except in th<»-i
cases where the concentration of silver is kept at a minimum by electrolysis does
not insure the complete removal of residual silver. With films the use of two
fixing baths is necessary but with prints intended for archival purposes three
fixing baths are required; preferably with a water rinse between baths. Two
fixing baths are sufficient for the normal processing of prints. Data on the
limiting concentrations of silver in the fixing baths and the photographic materials
are given.

The following factors affect the rate of removal of silver: (a) the pH of the
fixing baths and the wash water, (b) the nature of the hardener employed in the
fixing bath, and (c) the temperature of the wash water. Practical recommenda-
tions are given for the removal of silver to produce photographic negatives and
prints for (a) archival storage, and (b) normal keeping periods.

Copper and Sulfide in Developers; R. M. EVANS, W. T. HANSON, JR., AND
P. K. GLASOE, Eastman Kodak Co., Rochester, N. Y.

The formation of excessive fog by a developer containing copper or sulfide is
well known. However, no quantitative method for determining the concentration
of either copper or sulfide in a developer appears to have been published. In t hi-*
paper, polarographic methods of analysis for these substances are given together
with photographic determinations of the effect of concentration on fog, thus
demonstrating that the analyses are capable of determining the minimum amount
of copper or sulfide required to cause fog under the conditions used.

The fogging action of a developer which has accumulated sulfide by bacterial
action is shown to be the same as that produced by a fresh developer containing
the equivalent quantity of sodium sulfide.

Factors Affecting the Accumulation of Iodide in Used Photographic Developers;
R. M. EVANS, W. T. HANSON, JR., AND P. K. GLASOB, Eastman Kodak Co.,
Rochester, N. Y,

270 ABSTRACTS OF PAPERS

Development of uniformly flashed motion picture film has been carried out in
developers of varying composition and the amount of iodide, which remains in the
developer, determined by analysis. The amount of iodide in the developer was
found to increase under the following conditions:

(1) Development to a higher density.

(2) Increasing the footage of film for a given volume of developer.
(5) Increasing the time of development for the same density.

(4) Increasing the strength of the developer.

(5) Increasing the proportion of the surface covered by image.

These results are explained by a kinetic equilibrium between the rate of release
of iodide from the developing portion of the emulsion and the rate of removal
of iodide from the developer by the undeveloped silver halide.

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SOCIETY OF MOTION PICTURE ENGINEERS

HOTEL PENNSYLVANIA

NEW YORK, N. Y.

JOURNAL OF THE SOCIETY OF
MOTION PICTURE ENGINEERS

VOLUME XXXIX • • • NOVEMBER, 1942

CONTENTS

PAGE
Re-Recording Sound Motion Pictures

L. T. GOLDSMITH 277

The Cutting and Editing of Motion Picutres

F. Y. Smith 284

Progress in the Motion Picture Industry: Report of
the Progress Committee for 1940-11 294

The Photographing of 16-Mm Kodachrome Short Sub-
jects for Major Studio Release L. W. O'Connell 314

Elimination of Relative Spectral Energy Distortion in
Electronic Compressors B. F. MILLER 317

Current Literature 324

Society Announcements 327

(The Society is not responsible for statements oj authors.)

JOURNAL OF THE SOCIETY OF
MOTION PICTURE ENGINEERS

SYLVAN HARRIS, EDITOR

Board of Editors

ARTHUR C. DOWSES, Chairman

JOHN I. CRABTREE ALFRED N. GOLDSMITH EDWARD W. KELLOGG

CLYDE R. KEITH ALAN M. GUNDELFINGER CARLETON R. SAWYER

ARTHUR C. HARDY

Officers of the Society

*President: EMERY HUSE,

6706 Santa Monica Blvd., Hollywood, Calif.
* Past-President: E. ALLAN WILLIFORD,

30 E. 42nd St., New York, N. Y.
*Executive Vice-P resident: HERBERT GRIFFIN,

90 Gold St., New York, N. Y.
^Engineering Vice-President: DONALD E. HYNDMAN,

350 Madison Ave., New York, N. Y.
*Editorial Vice-President: ARTHUR C. DOWNES,

Box 6087, Cleveland, Ohio.
** Financial Vice-President: ARTHUR S. DICKINSON,

28 W. 44th St., New York, N. Y.

* Convention Vice-President: WILLIAM C. KUNZMANN,

Box 6087, Cleveland, Ohio.

* Secretary: PAUL J. LARSEN,

1401 Sheridan St., N. W., Washington, D. C.
^Treasurer: GEORGE FRIEDL, JR.,
90 Gold St., New York, N. Y.

Governors

*MAX C. BATSEL, 501 N. LaSalle St., Indianapolis, Ind.
**FRANK E. CARLSON, Nela Park, Cleveland, Ohio.

*JOHN G. FRAYNE, 6601 Romaine St., Hollywood, Calif.

*ALFRED N. GOLDSMITH, 580 Fifth Ave., New York, N. Y.
**EDWARD M. HONAN, 6601 Romaine St., Hollywood, Calif.

*I. JACOBSEN, 177 N. State St., Chicago, 111.
**JOHN A. MAURER, 117 E. 24th St., New York, N. Y.

*LOREN L. RYDER, 5451 Marathon St., Hollywood, Calif.

* Term expires December 31, 1942.
** Term expires December 31, 1943.

Published monthly at Easton, Pa., by the Society of Motion Picture Engineers.

Publication Office, 20th & Northampton Sts., Easton, Pa.

General and Editorial Office, Hotel Pennsylvania, New York, N. Y.

Entered as second-class matter January 15, 1930, at the Post Office at Easton,

Pa., under the Act of March 3, 1879. Copyrighted, 1942, by the Society of Motion

Picture Engineers, Inc.

RE-RECORDING SOUND MOTION PICTURES'
L. T. GOLDSMITH**

Summary. — The nature of re-recording as it applies to motion picture production
is described in some detail by showing what happens to a typical picture in the re-
recording department after shooting on the set has been completed and the picture has
been edited to the satisfaction of the producer.

Sound is added to those portions of the picture that have been photographed silent
because of the difficulty or impossibility of recording the corresponding sound at that
time, as for example, credit titles, montages, miniatures, stock shots, and scenes photo-
graphed silent to playbacks of pre-recorded sound. Music that has been especially
scored and recorded for the picture together with appropriate sound-effects is added
to heighten its dramatic presentation.

Improvements in dialog quality are made if required by employing electrical equal-
izers, although distortion is often purposely introduced where telephone, dictaphone,
radio, and similar types of quality must be simulated as required by the picture.

Proper balance of the relative volume of the dialog and accompanying music and
sound-effects is determined to the satisfaction of the re-recording supervisor. All
the sounds from as many as a dozen or more different sources are re-recorded to a
single composite sound-track which is afterward printed with the picture to make up
the final print to be projected in the theater.

The organization of the re-recording department is discussed and the duties of vari-
ous members of the personnel are outlined. Crews are so made up that an average of
from three to six pictures are in work at the same time.

A division of the sound department of every major film-producing
studio is known as the re-recording department, sometimes called the
dupe or dubbing department. In the days before sound pictures it
was common practice in the laboratory, to make duplicate picture
prints or "dupes," as they were called. Also, the special picture-
effects department would often add foregrounds or backgrounds to a
picture, a process termed "dubbing in" or "dubbing." So, in
general, the duplicating process, with the finishing touches added,
became known as duping or dubbing.

The sound-duplicating process, especially since it is not photo-
graphic but electrical duplicating, is more properly known as re-

* Presented at the 1942 Spring Meeting at Hollywood, Calif. ; received May
10, 1942.

** Warner Bros. Pictures, Inc., Burbank, Calif.

277

278 L. T. GOLDSMITH [J. S. M. P. E.

recording. As the name implies, sound originally recorded on film
in synchronism with the picture being shot on the set, is recorded
again from that film along with added sound-effects and music
recordings to a second film. This film is a composite of all the
desired sounds required for the picture. The composite sound-track
is then printed on the same film as the corresponding picture and
projected in the theaters.

Suppose we take a typical picture as an example, and follow its
progress through the re-recording department. After the shooting of
the picture on the set has been finished, the picture editor assembles
the daily prints of picture and sound:track in proper timing and
continuity. These two prints are known as the cutting picture and
cutting track. The producer who is responsible for this particular
production runs the picture in this form with the editor, and indicates
what changes he wishes made. When the picture is complete and
the corresponding original dialog sound-track is approved, the editor
delivers the picture to the re-recording supervisor.

The film is received as separate picture and sound-track reels,
which are close to 1000 feet long. The sound-track consists almost
entirely of dialog and any sound-effects that may have happened to
be recorded at the same time. The supervisor assigns the picture
to one of the re-recording crews who check it reel by reel.

The re-recording crew usually is made up of a re-recording mixer
who acts as the crew chief, two sound-track editors who edit the
music and further edit the dialog track, a sound-effects editor who
prepares appropriate sound-effects for the picture, and a projectionist.
The sound-track editors usually split up the reels between them, each
man taking every other reel. They check the reels for synchronism
and for words of the dialog that may have been cut off because of
picture cuts. These will require an overlapping of two sound-tracks
in re-recording.

As the reels are run one by one, the sound-effects editor makes
notes as to what kinds of sound-effects are required and where they
should go into the picture. Some sound-effects are recorded es-
pecially for the scene at the time the picture is shot. When such
effects are made, the production mixer sends a memorandum to the
re-recording department identifying by scene and take number, the
effects that have been recorded and noting where in the picture they
are to be used.

The sound-track editors then run the sound-track and picture in

Nov., 1942] RE-RECORDING SOUND PICTURES 279

a moviola and make notes in ink on the sound-track film, indicating
for the laboratory negative cutters which scenes are to be extended,
and what scenes and effects are to be removed. Additional prints
of the required scenes are ordered from the laboratory, which are
assembled into a secondary dialog track to allow some of the dialog
sentences to overlap when it is re-recorded. At the same time, the
sound -effects editor orders the required number of sound-effects
prints from the laboratory, both those made at the time the picture
was shot and those made from sound-effects negatives kept in the
sound-effects library.

The picture and sound-track are then sent to the laboratory, where
two composite sound-and-picture dupe prints are made. One of
these dupe prints is sent to the music department, where it is used
for checking the picture to determine where music must be scored.
The other dupe print is sent to the re-recording department. The
laboratory then cuts the original sound-track negative in accordance
with the edge-numbers and inked instructions on the cutting sound-
track, and makes a print. This may be called a primary dialog
print, and is the print used in the re-recording. It is necessary to
re-record from this new primary dialog track rather than from the
original cutting track because in the new track certain dialog se-
quences have been extended or removed at the laboratory to take
care of overlaps. Furthermore, the original track has become
scratched from the many runnings in the picture editor's moviola,
and the new track has been blooped at all splices. When the labo-
ratory delivers to the re-recording department the new primary
dialog track, the additional prints of portions of the dialog, the prints
of sound-effects, the composite dupe print, and the original picture
and sound-track prints, the sound-editors begin to prepare the reels
for re-recording.

The sound-track editors, using the original cutting picture and
cutting track as guides, prepare the secondary dialog track which
will cover the overlaps in conjunction with the primary dialog track.
At the same time, the sound-effects editor, using the dupe-picture
print as a guide, cuts his sound-effects prints into reels to match the
picture action. He may have the sound-effects on several reels
because often more than one effect is required at one time. In
addition, there are usually several loops of sound-effects which run
all the time during the re-recording of the reel and can be mixed in
as required. The loops are numbered and catalogued and consist

280 L. T. GOLDSMITH [J. S. M. p. E.

of the more frequently used sound-effects such as laughter, applause,
crowd noise, street noise, etc.

If the music recordings or "takes" are now available, the sound-
track editor prepares the music tracks for re-recording, using the
cutting-picture as a guide and following the footage notes prepared
for him by the music department as to what the music selections are
and where they go into the reel. Several music tracks are often
required, and here again additional prints may have to be ordered to
take care of overlaps in the music. As soon as a reel has been pre-
pared either with or without all the music and effects tracks, it is run
once to check for synchronism, overlaps, effects, etc. If no music
has been received for that particular reel, the sound-track editors
then set it aside and prepare another reel.

The sound-track editors prepare a cue sheet for the re-recording
mixer to use during the re-recording of each reel to indicate to him
where the secondary dialog and music tracks come in and go out.
A similar cue sheet is prepared by the sound-effects editor for his
own use when he assists the mixer in re-recording the reel. These cue
sheets must be corrected as changes are made during re-recording
rehearsals, so that after the re-recording is made and the sheets are
filed, they will be accurate if at some later time they are used again.

When all the tracks are prepared, the re-recording mixer and the
sound-effects editor, acting as an assistant mixer, proceed to rehearse
the reel for re-recording. The mixer usually handles the dialog and
music, and the assistant mixer handles the effects tracks. All the
tracks, usually eight to twelve in number, are threaded on re-recording
machines by machine-room attendants, and the speech circuits
patched to the desired mixer controls on the mixer console. The
projectionist who has the cutting or dupe picture to project on the
screen as a guide to the mixer threads his print on a silent projector.
In addition to the picture screen for watching the action, the mixers
have an illuminated footage indicator similar to a veedor counter,
which is used with the picture for cueing the various sound-tracks.
A peak-reading neon volume indicator and theater-type loud speaker
behind the screen serve as guides to the mixers as to the volume and
balance of the dialog, music, and sound-effects tracks.

After a number of rehearsals, depending upon the complexity of
the reel, the re-recording supervisor is asked to approve a rehearsal.
If he approves, a recording or "take" is made of the combined tracks
on a film-recording machine. The film is sent to the laboratory as

Nov., 1942] RE-RECORDING SOUND PICTURES 281

the re-recording crew proceeds to the next reel. (It might be men-
tioned here that a picture is not always re-recorded reel by reel con-
secutively, because some reels may take longer to prepare for duping
than others.)

The following morning a checking print made from the sound
negative is delivered by the laboratory to the sound department.
This is run by the sound director in a review room with the cutting
picture. It is carefully checked for synchronism, volume, quality,
balance of sounds, and quietness. If the re-recording is judged
faulty in some respect, the entire reel or part of it is ordered re-
recorded again. Usually the reel is satisfactory and the laboratory
is notified that a composite picture and sound print of it can now be
made. The laboratory first cuts the original picture negative in
accordance with the cutting picture print edge-numbers, and then
makes the composite print from this and the re-recorded sound
negative. When all the reels have been re-recorded and a com-
posite print made of each, the picture is previewed in a neighboring
theater.

If there are changes to be made after the preview, the picture
editor makes the required changes in the cutting picture and sound-
track, and again delivers the affected reels to the re-recording depart-
ment. Sometimes the changes are such that the previously re-
recorded sound-track negative need only be cut to match the picture
cut, but more often a re-recording has to be made of the sections
affected, usually one or more small sections of reels, sometimes entire
reels. A checking print of the new sections or reels is approved by
the sound director, and the picture is either previewed a second tum-
or is approved for making composite release prints.

In the meantime, the re-recording crew has usually received another
picture and begun its preparation for re-recording in the same way.
The re-recording department has several such crews so that a number
of pictures can be in various stages of re-recording at any one time.

In addition to the re-recording crews that work directly on the
picture there are the machine-room personnel who thread up the
re-recording machines, and a man who is responsible for the recording
and operation of the recording machines. Often several machine-
room men and a single recordist are sufficient to handle the equip-
ment for three or four re-recording crews. A transmission engineer,
or maintenance man who sometimes is also the recordist, maintains
all the electrical equipment. The mechanical equipment is usually

282 L. T. GOLDSMITH [j. s. M. p. E.

maintained by men who care for the rest of the equipment in the
sound department as well. A representative of the music department
is often assigned permanently to the re-recording department who is
responsible for the music cutting, and acts as contact between the two
departments. A film clerk receives all incoming and outgoing film
and acts as general secretary to the department.

In connection with the re-recording of a picture the re-recording
department is called upon for a variety of duties other than those
mentioned. Pre-recordings may be required for timing the photo-
graphed action on the set to a previously recorded song or dance
number. Frequently the music recording for this has been made in
sections. Perhaps a separate choir track of voices, an orchestra
track, or even added tracks of trumpets, drum beats, or other effects
may be needed. To permit the chorus and dancers to perform in
proper tempo while they are being photographed without sound, a
composite sound-track is played back to them on the set through
loud speakers for timing. This track is made in the re-recording
department by editing the various music tracks or parts of tracks,
and re-recording them to the playback film or disk.

Timing or "tick" disks are similarly prepared for the use of the
orchestra in music scoring. The ticks are made in a special machine
and so spaced that when played back to the members of the orchestra
through headphones the musicians will be in tempo with each other
and with the action of the picture.

The re-recording department is equipped to record acetate disks
at either 33l/s or 78 rpm, as in some cases songs and musical numbers
are re-recorded from film to disk for talent rehearsals at home or for
music-publisher auditions. Microphone pick-up facilities are avail-
able for recording sound-effects and wild lines of dialog. These can
be timed by watching the picture on a screen or by following the
dialog played back through headphones.

Many kinds of circuit equalizers are used to distort the quality
of speech or music purposely to simulate radio, telephone, dictophone,
or other types of sounds. An "echo chamber" is available to simu-
late voice sounds in large halls, caves, etc., and to add reverberation
and life to some kinds of music. Sound-tracks are often run at
variable speeds to achieve special effects, particularly in cartoons.

No description has been given of the actual equipment, both
electrical and mechanical, that is used in re-recording. There are
many kinds of machines used for special purposes, and an adequate

Nov., 1942] RE-RECORDING SOUND PICTURES 283

description of them would cover many pages. For this reason, the
reader is referred to the following bibliography, which lists publica-
tions describing the equipment.

BIBLIOGRAPHY

LOOTENS, C. L., BLOOMBERG, D. J., AND RETTINGER, M.: "A Motion Picture
Dubbing and Scoring Stage," J. Soc. Mot. Pict. Eng., XXXII (April, 1939), p. 357.

MORGAN, K. F., AND LOVE, D. P.: "Sound Picture Recording and Reproducing
Characteristics," /. Soc. Mot. Pict. Eng., XXXIII (July, 1939), p. 107.

REISKIND, H. I.: "A Single-Channel Recording and Re-Recording System,"
J. Soc. Mot. Pict. Eng., XXVIII (May, 1937), p. 498.

LOYE, D. P.: "Acoustic Design Features of Studio Stages, Monitor Rooms,
and Review Rooms," /. Soc. Mot. Pict. Eng., XXXVI (June, 1941), p. 593.

MUELLER, W. A.: "Audience Noise as a Limitation to the Permissible Volume
Range of Dialog in Sound Motion Pictures," /. Soc. Mot. Pict. Eng., XXXV (July,
1940), p. 48.

AALBERG, J. O., AND STEWART, J. G. : "Applications of Non-Linear Volume Char-
acteristics to Dialog Recording," /. Soc. Mot. Pict. Eng., XXXI (Sept., 1938), p.
248.

MUELLER, W. A.: "A Device for Automatically Controlling the Balance be-
tween Recorded Sounds," /. Soc. Mot. Pict. Eng., XXV (July, 1935), p. 79.

CRANE, G. R. : "Variable Matte Control (Squeeze-Track) for Variable- Density
Recording," /. Soc. Mot. Pict. Eng., XXXI (Nov., 1938), p. 531.

HOPPER, F. L. : "Electrical Networks for Sound Recording," /. Soc. Mot. Pict.
Eng., XXXI (Nov., 1938), p. 443.

"How Motion Pictures Are Made," /. Soc. Mot. Pict. Eng., XXIX (Oct., 1937).
p. 349.

KIMBALL, H. R. : "Application of Electrical Networks to Sound Recording and
Reproducing," /. Soc. Mot. Pict. Eng., XXXI (Oct., 1938), p. 358.

WILLIAMS, F. D.: "Methods of Blooping," /. Soc. Mot. Pict. Eng., XXX (Jan.,
1938), p. 105.

OFFENHAUSER, W. H., JR.: "Current Practices in Blooping Sound-Film," /.
Soc. Mot. Pict. Eng., XXXV (Aug., 1940), p. 165.

STROCK, R. O.: "Some Practical Accessories for Motion Picture Recording,"
J. Soc. Mot. Pict. Eng., XXXII (Feb., 1939), p. 188.

LAMBERT, K. B.: "An Improved Mixer Potentiometer," J. Soc. Mot. Pict.
Eng., XXXVII (Sept., 1941), p. 283.

READ, S., JR: "A Neon-Type Volume Indicator," /. Soc. Mot. Pict. Eng.,
XXVIII (June, 1937), p. 633.

THE CUTTING AND EDITING OF MOTION PICTURES*

FREDRICK Y. SMITH**

The Physical Aspect

Summary. — The first part of this paper deals with the physical aspect of cutting
and editing motion pictures — that is, the manner in which the film is physically
handled in the process of assembling the various "dailies," "rushes," and other forms
of film up to the time of release.

The second part of the paper deals with the editorial aspect — that is, the assembling
of the various shots of the picture and the importance of the proper arrangement of
these shots in producing the desired dramatic effects.

Questions usually asked by visitors to a studio Cutting Room are,
"What is a film editor?" "What does he do?" "Is a cutter a film
editor?" In fact, questions like these are asked not only by laymen,
but also quite often by workers of other crafts in the industry. No
one thinks of asking, "What is a director, a cameraman, or a writer?"
Their professions were known before motion pictures existed. There-
fore, it seems to follow that whatever the skills and artistic accom-
plishments of the film editor — or cutter — they are specific for this
medium of expression, and have grown out of motion pictures.

Webster's New International Dictionary gives the following de-
finitions :

Cutter: One who cuts ; as a stone cutter ; specif. : (1) one who cuts out garments ;
(2) one whose work it is to cut a (specified) thing (in a specified way), as in:
amethyst cutter, machine cutter, disc cutter, gravestone cutter, timber cutter, film cutter.

Editor: One who produces or exhibits. One who prepares the work of another
for publication ; one who revises, corrects, arranges, or annotates a text, document,
or book.

Substituting the word exhibition for publication, and film for text,
document, or book, we have a fairly simple yet accurate definition of a
Film Editor.

This title appearing on the technical credit card of most motion pic-
tures produced today refers to the person who assembles the scenes

* Presented at the 1942 Spring Meeting at Hollywood, Calif. ; received May
30, 1942.

** Metro-Goldwyn-Mayer Studios, Culver City, Calif; President, Society of
Motion Picture Film Editors, 1941-42.
284

CUTTING AND EDITING PICTURES 285

after they are photographed and who is invariably referred to in the
industry as the cutter. Whereas the term film editor is more indica-
tive of the creative nature of the work, the term cutter seems to imply
that the process is the work of a technician who performs his duties
according to the standards and regulations of this profession.

This creator-technician position, as we know it now, was a child of
necessity. Mass production of motion pictures demanded a person
who would keep the film assembled so that when the last scenes of the
picture were photographed the producer could expect an early projec-
tion of the final total results.

With the advent of sound, film cutting became a much more in-
volved process than it was in the era of silent pictures. In those days
it may have been possible to edit a picture with a work-bench, a set
of rewinds, a pair of scissors, film cement, a viewing device, and a
receptacle for the film.

Since the introduction of sound, film cutting has become much more
technical; and before considering the artistic phase of editing, we
must first become acquainted with the mechanical side of the business.
This necessitates a description of the materials with which the editor
works, the tools at his disposal, and the application of these tools to
the materials at hand. The tools of the cutting room consist of
reels, rewinds, flanges, synchronizers, scissors, film cans, bins, racks, a
splicing machine and a viewing machine (moviola) .

When the positive film comes from the laboratory to the cutting
room, the first operation, unless it has been done already in the lab-
oratory, is the synchronizing of the "rushes," or "dailies," which are
the terms given to the scenes taken by a producing unit the previous
day. A set of synchronizing leaders is prepared, and attached
to the right-hand rewind apparatus. Identification marks are placed
on these "sync" leaders, giving the number of the reel and stating
whether it is picture or sound-track. These sync leaders are 16 feet
long, the first four feet being required for threading the projector,
and the next 12 feet being necessary to permit the projector to get up
to full speed before showing the picture on the screen and reproducing
the sound. Four feet from the beginning of each leader a frame is
marked off on both picture and sound-track for the "starting mark."
The frames thus marked are placed directly opposite each other on
the wheels of the synchronizer and locked in position. The cutter
then now winds through the remaining 12 feet of leader, and marks
off both pieces on the frame line of the synchronizer.

286 F. Y. SMITH [j. s. M. P. E.

The closing of the "clappers" on the picture film and the sharp
modulations on the sound-track recording the noise of the clappers
provide the synchronizing cue. The picture reel is unrolled to the
point of the first scene, where the synchronizing clappers are seen to
come together, and the frame is marked. The point of the correspond-
ing modulation on the sound-track film is also marked, and the two
films are then placed in synchronism on the synchronizer and wound
back to the start of the scene, where the films are cut. They are then
fastened, by means of paper clips, to the leaders and wound on to their
respective reels. The markings are made on the emulsion side of the
film with red grease pencil, which can be easily wiped off with a clean,
dry cloth without damaging the film. The use of carbon tetrachloride
will greatly help the cleaning.

Sometimes the clapper marks occur at the end of the scene, usually
under the following circumstances :

(1) When the position of the camera on the opening shot is such that it would
be inconvenient to use the clappers.

(2} When it is necessary to avoid frightening the subject or impairing his acting
ability by any sudden shock or noise (e.g., an infant, or an animal).

The synchronizing of scenes when the clappers occur at the end is
accomplished in the same way as described before. The clapper
marks are framed ; a foot of identifying slate footage is retained after
the marked frame; and then the scene is wound back to the begin-
ning of the scene and cut at the light flash. Where an interlocked
start is used, or a synchronized fog mark is made, the procedure is the
same, the fog marks being substituted for the clapper marks.

When all the scenes of one day's shooting have been thus syn-
chronized and all the splices have been made, the "dailies" are pro-
jected for the approval of the producer, director, cameraman, and
editor, after which they are sent to the numbering room. Here the
film is put through a numbering machine similar to the machine that
prints the key numbers on the negative. The sound-track and pic-
ture films are threaded on machines so that the number 000 will be
printed at the "start" marks and every foot of film is thereafter num-
bered consecutively. The numbers are printed along the clear edge
of the film on the side opposite the negative key numbers.

After the film has been numbered it is delivered to the continuity
room where typists make up the continuity sheets giving scene number,
description of angle and action, and the exact dialog. From the con-

Nov., 1942] CUTTING AND EDITING PICTURES 287

tinuity department the "dailies" are returned to the cutting room,
where the first and last negative key numbers of each scene, both pic-
ture and track, are written on cards which are later filed in index form.
This procedure enables the assistant editor promptly to locate the
trims of scenes after they are cut and filed away.

The "dailies" are now ready to be broken down. This process is
accomplished with the aid of a disk or flange. The disk is placed on
the rewind to the right of the operator, while the reel of action or sound
to be broken down is placed on the left rewind. A ground-glass plate
lighted from below is between the rewinds, so that the film may be
viewed easily. The film is broken at the end of the scene, and the
roll of film that has been wound upon the disk is removed from the
spindle.

The film is now ready for cutting by the film editor, or it may be
filed away in tins, marked with the scene number in racks or in lock-
ers until such time as a sequence is completed and ready for a first
assembly.

Omitting the editorial functions, we come to the final mechanical
stages of cutting, which include the preparation and synchronization
of music and additional sound-effects. These multiple sound-tracks
consist of off -scene dialog, dictaphone dialog, echo or reverberant
dialog, etc., sounds of water lapping on a shore, croaking of frogs,
chirping of crickets, motorboat sounds, etc. These must all be in
synchronism with the picture, and built for the purpose of "dubbing"
or re-recording. The splices in the sound-track are painted over
with photoblack or covered with scotch tape in the form of triangles
or crescents, to eliminate the noise that would otherwise occur when
the sound-track is reproduced in the theater.

When the picture has been finally re-recorded and is ready for
negative cutting, it is necessary for the Editor, or his assistant, to
make a final check of the film, attach new standard leaders, fill in the
picture with black frames and mark all negative jump-cuts unless
specifically desired, and check the synchronizing numbers of each
scene to the sprocket-hole code number opposite code number. All
cuts not clearly obvious to the negative cutters are plainly marked,
either by pen and ink, or by scratching the film with a stylus.

This, in brief, constitutes the physical handling of film, but obvi-
ously has omitted the creative aspect of the film editing.

288 F. Y. SMITH [J. S. M. P. E.

The Editorial Aspect

Paul Rotha says, in part, "From the first days of film production
until the present, most story -film technique to have emanated from
Western studios has been based upon the fact that the camera could
reproduce phenomena photographically onto sensitized celluloid,
and that from the resulting negative a print could be taken and
thrown in enlarged size by a projector onto a screen. In consequence,
we find that more consideration is accorded the actors, scenery, and
plot than the method by which they are given screen presence, a sys-
tem of manufacture that admirably suits the departmental organiza-
tion of the modern film studio. Thus the products of the scenario,
together with the accommodating movements of the camera and
microphone, are numerous lengths of celluloid, which merely require
trimming and joining in correct sequence, according to the original
scenario, for the result to be something in the nature of a film. Occa-
sionally, where words and sounds fail to give the required lapses of
time and changes of scene, ingenious camera and sound devices are
introduced. It is not, of course, quite so simple as this but, in essen-
tials, the completed film is believed to assume life and breath and
meaning by the transference of acting to the screen and words to the
loud speaker.

"The skill of the artist, therefore, lies in the treatment of the story,
the guidance of the actors in speech and gesture, the composition of
the separate scenes within the picture-frame, movements of the
cameras, and the suitability of the settings ; in all of which he is as-
sisted by dialog- writers, cameramen, art-directors, make-up experts,
sound-recordists, and the actors themselves, while the finished scenes
are assembled in their correct order by the editing department.

"Within these limits, the story-film has followed closely in the
theatrical tradition for its subject-matter; converting, as time went
on, stage forms into film forms, and stage acting into film acting, ac-
cording to the exacting demands of the reproducing camera and micro-
phone.

"The opposite group of thought, however, while accepting the
same elementary functions of the camera, microphone, and projector,
proceeds from the belief that nothing photographed, or recorded on
celluloid has meaning until it comes to the cutting bench; that the
primary task of film creation lies in the physical and mental stimuli
that can be produced by the factor of editing. The way in which the
camera is used, its many movements and angles of vision in relation

Nov., 1942] CUTTING AND EDITING PICTURES 289

to the objects being photographed, the speed with which it repro-
duces actions, and the very appearance of persons and things before
it are governed by the manner in which the editing is fulfilled."

To understand these words fully, let us go back to the beginning
of the motion picture. Edwin S. Porter was working for the Edison
Company in 1896 when that concern imported some pictures made
by George Melies, a Frenchman. Porter studied these pictures very
carefully and became aware of the tremendous effect such simple
pictures had upon audiences. As a result an idea came to Porter
that contained all the elements of motion picture making as we know
it today, an idea that created a new art-form, a new mode of expres-
sion, working with new tools. It was the first process of using me-
chanical means to create emotional values. The idea was to try to
tell a story with the new film medium by combining several shots or
scenes in successive order, the story to be told not only through the
action in a given scene, but also by the relation of that scene to the
preceding and the following scenes, thus giving a coherent meaning to
the whole.

Porter's first motion picture telling a story was The Life of an
American Fireman. He found some stock material about fires and fire
brigades and then staged such additional scenes as his plot demanded.
These scenes, together with the stock shots, he assembled into a
dramatic continuity that has become the pattern for all motion pic-
ture action stories since.

The very same method which Porter used in his The Life of an
American Fireman is frequently used today. It is not uncommon for
a studio having a good deal of stock material of some exciting event to
assign a producer, writer, and film editor to build a story around this
material. This pertains particularly to the cheaper action pictures.
A picture was released last year that contained about 3000 feet of
stock scenes, and the entire length was only 7200 feet.

Exactly what did Porter achieve? He discovered that real oc-
currences can be made dramatic by means of editing, that the art of
the motion picture depends not upon the shots alone, but upon the
continuity of shots. He discovered that the combination of shots
into scenes gives a meaning that is not in the individual shots; and
that a scene need not be taken in one shot. A long period of time in
actual life can be shown on the screen in a short period of time, and
vice versa.

The Life of an American Fireman contained a very significant in-

290 F. Y. SMITH tf. S. M. P. E.

novation, namely, the close-up. The second scene of the picture is a
close-up of a New York fire-alarm box. This was at least five years
before D. W. Griffith established the close-up as an integral part of
motion picture technique. Porter discovered that a film story can be
made from the sum of a number of individual scenes, but D. W.
Griffith developed the new technique and applied it not only to story,
but also to sequence, scene, and individual shot. He found that
editing enables the dramatization of the moment, that it gives per-
spective and interpretation. He became aware of the fact that mood
and tempo could be created by the proper arrangement of scenes.
He found a new technique by composing his scenes with a number of
shots, each shot and scene being kept on the screen only long enough
to portray the essential piece of business in its dramatic height.
Without waiting for the end of a scene, he cut to the next, thus giving
the whole a continuous flow and rhythm. The result, to quote from
Lewis Jacobs, is that, "Not connected by time, separated in space,
shots are now unified if affected by the theme. The basis of film
expression has become editing, the unit of editing the shot and not
the scene."

Thus the invention of editing had a great effect upon story con-
tent. The world was open, the sky the limit. Events of the moment
could be put into relation to the dim past. The hero of the drama
could travel to China and to the North Pole. New themes rapidly
found their way onto the screen.

In The Thread of Destiny Griffith found another use for shots. For
the first time he shot scenes not called for in the script, scenes with-
out action, to give atmosphere and background, thus underlining the
narrative and action of the story and establishing mood and motive.
He introduced the extreme long shot, giving the feeling of wide space
and, when the story required it, he cut to an extreme close-up, achiev-
ing a singular dramatic effect by the contrast.

In the final analysis, motion pictures are movement. Story, drama,
moods, and thoughts are expressed in movement. The action is
movement, the camera moves. Cutting is movement, forcing the
eye of the spectator to move from one scene, one object, from one
angle to another. In cutting shorter and shorter, trimming the in-
dividual shots down to the last of one essential fact, the rhythm of
the movement is accelerated and the tension is led to its highest point.

To sum up Griffith's contribution to the making of motion pic-
tures and thus to editing, Lewis Jacobs may again be quoted: "It is

Nov., 1942] CUTTING AND EDITING PICTURES 291

that the primary tools of the screen medium are the camera and the
film, rather than the actor; that the subject matter must be con-
ceived in terms of the camera's eye and film cutting; that the unit of
the film art is the shot; that manipulation of the shots builds the
scene ; that the continuity of scenes builds the sequence ; and that the
progression of sequences composes the totality of the production.
Upon the composition of this interplay of shots, scenes, and se-
quences depend the clarity and vigor of the story." Pudovkin, the
famous Russian director, states: "Editing is the foundation of film
art, the process of physical integration of scenes and sequences by
which the film becomes a unified entity." It follows therefore that
editing becomes all important. The camera, in spite of its obvious im-
portance, becomes subordinate to the cutting process. If necessary, a
film can be made from still pictures transposed to film and assembled
in changing rhythm.

The camera now has the function of an observer; an observer,
however, who can see an object or an occurrence from all and every
side, angle, and distance. The aim of the editing is to show the de-
velopment of the scene, drawing the attention of the spectator to the
details and occurrences that best represent and form the meaning
one wishes to give to the scene. In doing this, the dramatic tensions
are created, reinforced, or re-directed. One might compare the proc-
ess to the job of an announcer at a football game. He observes the
game from the most advantageous point. He does not give a de-
tailed account of all the things happening on the field ; or rather, he
chooses those events that give meaning to the occasion. If the action
is fast and exciting, he will hurry in his commentary, speaking in fast,
short sentences that give close-up impressions. If the game is slow
and uneventful, he will describe the general atmosphere, giving long-
shot impressions. Just as a good announcer, by selecting the out-
standing happenings — the highlights of the event — can give his
listeners the impression of the entire game, so the film editor, by
proper choice of his material, by using the right angles for the right
piece of action, will convey to his audience the strongest dramatic
interpretation of the material.

This leads to the subject of rhythm. It has been said that rhythm
is the skeleton of the motion picture art, to be filled out with the flesh
of content. How is rhythm built in a picture ? The tempo of the ac-
tion can be accelerated or slowed down in the canu-ra, and camera
movements can have rhythmic values that become apparent aitn
editing. The rhythmic effect is formed either by the footage — that

292 F. Y. SMITH [J. S. M. P. E.

is, by the number of frames of each shot in a sequence; by the se-
quence or changes of angle; by the changes in direction of move-
ment— left to right against right to left, top to bottom against bot-
tom to top, etc., by the changes of size — long shot against close shot,
etc.; or finally by any combination of these devices.

Ten years ago the Russian technique of cutting influenced motion
picture production and turned attention to the importance of form and
structure through editing. Directors, writers, and producers be-
came montage-conscious — it was recognized that certain very strong
dramatic effects could be achieved through editing and through
montages . What is montage ?

Montage, as the term is used in Hollywood, is a condensation of all
the various ways of cutting, as mentioned before. The cutting is
done partly or entirely in the optical printer, making it possible to
show several scenes simultaneously. Condensation is here used not
only in the technical, but also in the dramatic sense. A montage is a
sequence in the abstract. It is the strongest form of dramatic expres-
sion motion pictures can give. It should, therefore, be used only
when the dramatic content of the story demands it, and not, as un-
fortunately is often the case, when the writer does not know how to
get over a lapse of time in the story.

Another important discovery was that editing releases the latent
suggestive powers of an audience, thus making a series of pictures
impressive, eloquent, and significant. In 1921, Kuleschov, a Soviet
film director, proved this point with the following experiment. He
took a medium close shot of a young man who was looking down at
something. He intercut this shot once with a scene of a plate of food.
While running this little sequence it was quite obvious that the young
man was hungry. Then Kuleschov intercut the same scene with a
shot of a dead man. Now our young man appeared afraid and seemed
to have a guilty conscience. The audience was convinced that he had
killed the man. Finally, the scene of the young man was intercut
with a shot of a nude woman lying on a bed. Now it became apparent
that the young man had strictly dishonorable intentions. The very
same shot, used in three different ways, had three different mean-
ings— a practical film demonstration of the power of suggestion.

By the same manner of suggestion, motion pictures actually have
created their own symbolism and sign language, a language as vivid
and changing as slang. The funnel of an ocean liner and the wake of a
boat are sufficient to tell that the hero has crossed the ocean; the
gavel of the judge indicates that the court is in session ; a few shots of

Nov., 1942] CUTTING AND EDITING PICTURES 293

a radio tower convince us that the news has spread to the four cor-
ners of the universe.

And now a few words about the relationship of the editor to the
members of the other crafts in the industry. In the early days the
editing was done by the cameraman, the director, writer, or super-
visor, or any combination of them. Next to the director, and often
more than he, the writer took the most prominent part in the cutting
of a picture. The reason for this is quite easy to understand if one re-
members that titles had to be composed to fit the material and that
they had to be spaced correctly.

As pictures became longer and more elaborate, as more separate
angles were shot, and as camera technique and optics improved, film
editing became a specialized job. First, the cutter merely relieved
the director of the tiresome job of sorting out and splicing film. But
the front office soon wanted to see the assembled picture as quickly as
possible. The cutter was entrusted with the first rough cut. It was
soon recognized that the editor's ability to evaluate a scene was an
important faculty that directors often lacked.

Eventually the editor gave the picture its final form, strengthening
continuity, progression, and logic; tightening story and plot; cover-
ing up technical mistakes and bad acting. The technical knowledge
of what actually can be done by arranging various pieces of film de-
veloped into a creative ability. In the old days, a personal creative
relationship existed between editor and director and writer, but as the
process of motion picture making became industrialized, this rela-
tionship disintegrated. Today, in most cases, a director seldom
chooses his own film editor and the editor has scant opportunity to
confer with the director and practically no chance to discuss story
points with the writer.

In conclusion, it will be appropriate to quote from Frank Capra,
one of the foremost directors of the present time and former President
of the Screen Directors Guild: "The motion picture, as a creative
art, peculiarly has need for many contributors, of whom the film
editor is of foremost importance. Without his sympathetic under-
standing of theme, his sensitive appreciation for mood, his instinct
for dramatic effect, and his sense of timing for comedy, every motion
picture would suffer immeasurably."

The writer wishes to thank two members of the Society of Motion
Picture Film Editors, Herman J. Kleinhenz and Walter Stern, for
their cooperation and for their permission to use some of their ma-
terial in this paper.

PROGRESS IN MOTION PICTURE INDUSTRY*
REPORT OF THE PROGRESS COMMITTEE, 1940-41

Summary. — No report of the Progress Committee has been presented to the Society
since that covering the year 1939, which was published in the JOURNAL in May, 1940.
Accordingly, the present report covers the years 1940-41. This report, like previous
ones, includes the following classifications: (I) Cinematography: (A) Professional,
(B) Substandard; (II) Sound Recording; (III) Sound and Picture Reproduction;
(IV) Television; ( F) Publications and New Books.

The period covered by this report ends with the entrance of the
United States into World War II, and during these two years the
facilities of the equipment manufacturers have been gradually turned
to production for the war effort. As a result there is little to report in
the way of new equipment. Specialized instruments and methods
developed for war photography in England have been the subject of
a number of papers, particularly in the Photographic Journal, and a
list of these is included in the final section of this report.

The Committee wishes to acknowledge especially the contributions
of the following individuals and organizations: Drs. W. B. Rayton
and A. F. Turner of the Bausch & Lomb Optical Company, Robert
E. Shelby of the National Broadcasting Co., Inc., H. Barnett of the
International Projector Corp., and Charles W. Handley of the Na-
tional Carbon Co. Because of the war there have been no reports
available from members abroad.

G. A. CHAMBERS, Chairman

F. T. BOWDITCH M. S. LESHING

G. L. DIMMICK G. E. MATTHEWS
J. A. DUBRAY D. R. WHITE

SUBJECT CLASSIFICATION

(I) Cinematography

(A) Professional

(1) Emulsions

(2) Cameras and Accessories

(3) Lenses and Surface Treatments

(4) Studio Lighting

(5) Color

* Received August 15, 1941.
294

PROGRESS IN MOTION PICTURE INDUSTRY 295

(5) Substandard

(1) Films

(2) Cameras and Accessories
(5) Projectors and Accessories

(//) Sound Recording

(1) General
(2} Equipment

(///) Sound and Picture Reproduction
(IV) Television
(V) Publications and New Books

(I) CINEMATOGRAPHY

(A) Professional

A short time prior to the last Progress Report the advances in mo-
tion picture films had been chiefly in the field of negative emulsions
where increased speed had been combined with suitable contrast and
grain characteristics. Minor additional changes and adjustments
have been made in this field during the past two years but the main
progress has been in the realm of positive materials which had been
essentially unchanged for a considerable period of time.

(1) Emulsions. — Progress in this field started in sound recording
work where fine-grain stocks were tested experimentally. Pictorial
tests were made with some of these stocks which showed that the
field of their usefulness was not limited to sound recording but that
they could be used also for release work with an overall improve-
ment of quality. The status of the work in this field is summarized
to the fall of 1939 in a paper by Daily published in the JOURNAL in
January, 1940. l

Following these first steps, improvements were made and new
fine-grain sound and positive stocks were introduced both by DuPont
and Eastman. The DuPont Company introduced the 226 type which
was first used for background projection work and sound recording,
and then, as further advances were possible, introduced the 225 type,
fine-grain release positive, and the 230 type, a low-contrast fine-grain
sound recording stock particularly designed for variable-density
recording. The 228 type, master positive, carried these emulsions
into this field of work. The Eastman fine-grain release positive, type
1302, was introduced in the fall of 1940, being followed by a fine-grain
sound negative for variable-density recording, carrying the code
number 1370. This latter film was first marketed in May, 1941.

296 PROGRESS IN MOTION PICTURE INDUSTRY [j. S. M. P. E.

The speed of these new fine-grain release positive films is about one-
quarter that of the older type of positive. The new emulsions are
characterized by high resolving power and image sharpness. Proc-
essing techniques and conditions have been discussed by Shaner2 and
by Wilkinson and Eich.3 Daily and Chambers4 have discussed the
application of fine-grain films to variable -density recording.

An advance in the coating of a protective layer over the emulsion
following the normal photographic processing operations was out-
lined by Talbot.5 Unlike earlier coatings, this particular one is re-
movable in an alkaline solution and the film can then be recoated,
thus greatly extending the life of the film during which the emulsion
itself can be kept free from scratches and abrasions.

(2) Cameras and Accessories. — Additional units of the Twentieth
Century camera described in earlier reports have been manufactured
and are in use. Details regarding the camera are given in the JOURNAL
by Clarke and Laube.6

Several new, very compact slating devices have been described.
These units, usually attached to the camera, provide translucent data
which are photographed through the camera lens. The Twentieth
Century camera includes such a device, and another has been de-
scribed by Gilbert.7

A novel method of obtaining great depth of field has been proposed
by Goldsmith.8 In this increased range (IK) system a method of
regional lighting of the set in synchronism with differential focusing
during each frame exposure is employed. Another attack on this
same problem is made in the Electroplane camera9 which incorporates
an oscillating element in the lens. This element is driven electrically
over a total distance of 0.3 mm many times during the exposure
of each frame.

(3) Lenses. — The use of surface-treated lenses to increase speed
and contrast has become rather widespread in the two-year period,
1940-41. Firms that have either announced the provision of surface
treatment in certain optics of their own manufacture, or have solicited
work to be surface-treated are the following: Bausch & Lomb Optical
Co., Rochester, N. Y.; General Electric Co., Schenectady, N. Y.;
National Research Corp., Brookline, Mass.; RCA Manufacturing
Co., Indianapolis, Ind.; Yard Mechanical Laboratories, Pasadena,
Calif.

The surface treatment of lenses is carried out commercially in one
of the following ways : (a) by chemical means in which some constitu-

Nov., 1942] PROGRESS IN MOTION PICTURE INDUSTRY 297

ents of the glass are leached out to a certain depth below the sur-
face, and (b) by physically applying a film of material of low refrac-
tive index to the glass surface. Frank L. Jones10 describes chemical
methods for optical glasses and F. H. Nicoll11 announces anew chemi-
cal method using hydrofluoric acid. In the second method (b) films
are applied in high vacuum, for instance, as described in U. S. Patent
2,207,656 (July 9, 1940). Both W. C. Miller12 and RCA claim im-
provements in the evaporation process to increase the durability of
the films. The method of surface treatment using films built up of
monomolecular layers of metallic soaps described by K. B. Blodgett1*
does not appear to have been adopted commercially.

The action of films in increasing transmission by reducing surface
reflection loss is discussed popularly by A. F. Turner.14 W. B. Ray-
ton15 describes the application of films in projection optics and C. H.
Cartwright16 gives data on a treated camera objective. Charles G.
Clarke17 and Gregg Toland18 relate experiences in shooting with
treated camera optics.

(4) Studio Lighting. — The high-intensity carbon arc continues to
be the principal light-source for color photography19 and is being
used also to an increasing degree in monochrome, where it is reported
to bring out textural values and to permit the use of smaller aper-
tures as required by increased-depth technique.20 A number of re-
finements in the design of the carbon arc lamps used for set illumina-
tion have been made during the period under review, although none
involves basic changes in the nature of this equipment. An important
advance in this connection is the elimination of objectionable lamp
noise through rubber mounting of the feed-motors, the use of an im-
proved negative carbon, and a sound-proofing treatment of the lamp-
house.21 The use of a triple-head projector22 has expanded the scope
of background process photography for both color and black-and-
white, and a new 16-mm super-high-intensity studio positive carbon
capable of burning at currents as high as 225 amperes is finding con-
siderable use in this type of work!23 New lamp equipment19 for use
with process projection makes possible the transition from one car-
bon size to another with only momentary delay, as positive carbons
are positioned through an automatic photronic control. This lamp
will accommodate carbons from 13.6 to 16 and 18 mm in diameter
with their various negative carbons. The positive feed is water-
cooled. An increased amount of process slide projection is being done
with the larger size biplane filament tungsten lamps made available
for this'purpose.19- 23

298 PROGRESS IN MOTION PICTURE INDUSTRY [j. s. M. P. E.

A trend is also reported toward the increased use of properly cor-
rected incandescent lighting for color photography where smaller
units are required, on certain types of close-ups and on small sets.20
Daylight fluorescent lamps were also introduced to studio technique21
where the high diffusion and freedom from glare is suited to general
lighting not requiring projection.

An item of particular interest in special fields of photographic il-
lumination is the use of the Edgerton high-speed mercury lamp,19
which is capable of photographing a single frame in a time-interval
of only Viso.ooo second and is thus adapted to "slow-motion" photog-
raphy at a frame rate determined primarily by the mechanical limita-
tions of film movement.

(5) Color. — Experimental work looking toward the use of a 35-mm
monopack-type film for original exposure has been in progress. That
considerable success is being achieved was demonstrated by results
shown at the Spring meeting of the Society in 1942 by the Techni-
color Motion Picture Corporation.

Considerable work has been done also on the problem of producing
35-mm three-color prints from 16-mm Kodachrome originals. Sev-
eral shorts produced by this method using Technicolor for the 35-mm
imbibition prints have been released by Warner Bros.

(B) Substandard

(1) Films. — Agfa introduced two new emulsions in this field during
the period — a 16-mm high-resolving sound recording film and twin-8-
mm Triple-5 Pan. The 16-mm sound recording film was designed
primarily to improve the available quality of variable-area records
but, of course, can be used for other purposes by proper selection of
processing conditions. The twin-8 mm Triple-5 Pan is a high-speed
film for use in black-and-white photography in the 8-mm field.

In 1940 DuPont improved the 16-mm films that it sold by the
introduction of the 321 -type which continued to carry the name of
regular panchromatic reversal, and the 302-type superior panchro-
matic reversal.

In 1941 the advances which had been made in fine-grain positive
stocks were made available in the 16-mm field by the introduction of
the 605-type, fine-grain positive by DuPont and type 5302 fine-grain
positive by Eastman.

The quality of Kodachrome images was improved by a new method
of processing, as reported by Mees at the 1940 Christmas Lectures at

Nov., 1942] PROGRESS IN MOTION PICTURE INDUSTRY 299

the Franklin Institute (Philadelphia). The older method required
three separate color developments on three machines, with a drying
after each development. Continuous processing on one machine is
possible by the improved procedure. The assigning of the three dyes
to their correct layers depends upon the sensitivity of the three emul-
sions rather than the position of the layers in the depth of the film.

The sequence of the processing operations is as follows: (1) de-
velopment to a negative; (2) exposure through the base side to red
light; (3) development of a cyan image in the lower emulsion layer;
(4) exposure from the top side to blue light; (5) development of a
yellow dye image in the top emulsion layer; (6) development of a
magenta dye image in the middle layer; (7) removal of the silver
from all three layers; (8) fix; (9) wash; (10) dry.

Two sizes of color prints (2x and 5jc) from miniature Kodachrome
transparencies were announced in August, 1941. These were made
on an opaque safety support and were exposed and processed by the
Eastman Kodak Company. Commercial color enlargements for
advertising or lobby display purposes were introduced at the same
time. A similar type of support was used but improved color cor-
rection resulted from the use of a special black-and-white mask printed
on panchromatic film from the original sheet Kodachrome. These
enlargements, known as Kotavachrome, were supplied in several
sizes to a maximum of 30 X 40 inches.

A new still process of color photography was announced in Decem-
ber, 1941, under the name "Kodacolor." It uses roll film which is
exposed in the camera in the usual way. After development by the
manufacturer, negatives are produced which have colors complemen-
tary to those of the original subject, and from these negatives, color
prints are made on paper. The film has three light-sensitive layers,
in each of which are suspended minute particles of organic compounds
in which the couplers are dissolved. After exposure, the film is de-
veloped and the oxidation product of the developer penetrates the par-
ticles and reacts with the couplers, each in its own layer, to form a dye
image. The printing material is coated with a similar set of emul-
sions. Prints are made by projection and are of the same width,
27/s inches, regardless of the size of film used.24

(2) Cameras and Accessories— -The magazine-loading principle
was extended to the 8-mm camera field in the Cine^Kodak Eight,
model 90, announced in July, 1940. The magazine contains 16-mm
film which is slit after processing. The magazine is suitably marked

300 PROGRESS IN MOTION PICTURE INDUSTRY [J. s. M. P. E.

so that the user can expose it properly, running the film through the
camera once, reversing the magazine in the camera, and subsequently
exposing the second side.

A professional type 16-mm camera incorporating pilot-pin regis-
tration was produced by Bell & Howell.20 While only one unit was
manufactured, it has been used for commercial production. The
manufacture of additional units must necessarily await available ma-
terials after the war. This camera is in every way a miniature of the
well known Bell & Howell 35-mm camera.

A review of the problems related to lens design for sub-standard
cameras, together with a description of various commercial lenses
available, has been given by Kingslake.25

(3) Projectors and Accessories. — A non-intermittent 16-mm motion
picture projector was designed by F. Ehrenhaft and F. H. Back.26
Optical compensation is effected by means of a rotating glass prism
placed between the film and the projection lens. The prism has twelve
faces and the distance between opposite faces is 41 .5 mm. The relation
between image displacement and rotational angle of the prism is sub-
stantially linear. To prevent misalignment of the prism faces with
respect to the film frames during the rotation of the prism, it is driven
by the film itself.

A new line of 16-mm sound projectors identified as F, FB, FB-25,
FS-10, and FB-40 were introduced by Eastman Kodak Company.27
The first three models operate on alternating or direct current while
the last two operate only on a 50 to 60- cycle 100 to 125-volt supply.
On all models, a governor of the electrical vibrating-reed type main-
tains constant sound speed of 24 frames per second. Fast rewind for
all sizes of reels up to and including the 1600-ft. is provided on all
models through the use of a clutch, rewind lever, and the main drive
motor. Uniform speed of the film at the scanning point is assured by
the use of a specially designed oil-damped, film-driven flywheel.
Models F, FB, and FS-10 provide 10 watts of undistorted power.
Model FB-25 has an output of 25 watts and model FB-40 provides
40 watts. Projection lamps from 300 up to 750 watts are recom-
mended.

An extensive study has been made of procedure and equipment
specifications for 16-mm projection by a Committee of the Society.28
This Non-Theatrical Equipment Committee recommends that pro-
jectors be selected to provide, in conjunction with the screen used, pic-
ture brightness not greater than 20 ft-lamberts and not less than 5

Nov., 1942] PROGRESS IN MOTION PICTURE INDUSTRY 301

ft-lamberts. When screens larger than eight or nine feet wide are
used, the incandescent projectors conventionally employed with
smaller screens are incapable of furnishing the amount of light recom-
mended and an arc-lamp type of machine should be employed. A
new high-intensity carbon trim has been made available for this pur-
pose.29 The light from this combination of carbons has been modi-
fied to give a spectral quality suitable for use with colorfilm processed
primarily for projection with incandescent lamps. These carbons,
used in lamps especially developed for them, provide approximately
three times as much light as was hitherto available for 16-mm pro-
jection.

(II) SOUND RECORDING

(1) General. — During 1940 and 1941 much attention was directed
to the problems of recording and printing multiple sound-tracks on
film. Control tracks of various types were developed in the labora-
tories and were tested in the studios under production conditions.
Stereophonic recording on film was accomplished and was successfully
demonstrated.

The trend toward fine-grain film continued during the past two
years. The speed of fine-grain film was increased and the objection-
able brown color was eliminated. Although work continued on the
high-pressure mercury-vapor lamp for exposing fine-grain film, there
was a growing desire to use incandescent lamps for original recording.
The increased efficiency obtained by coating the recording optics to
reduce reflections greatly relieved the exposure problem.

The effect of ultraviolet light on variable-density recording and
printing was studied in the laboratory.30 An ultraviolet variable-
density recording system utilizing quartz lenses31 was built and tested
under studio production conditions. These tests showed an improve-
ment in both wave-shape and frequency response. The noise level
from the film was not affected by the wavelength of the exposing
light.

A careful study of the noise-reduction amplifier was made,11' M and
the desired characteristics were expressed in terms of promptness of
opening and closing, peak reading ability, and filtering. Many cir-
cuits were analyzed and the requirements for variable-area and vari-
able-density were compared. '

(2) Recording Equipment. — A line-type microphone for speech
pick-up was developed by RCA.14 It has a pick-up angle of approxi-

302 ' PROGRESS IN MOTION PICTURE INDUSTRY [J. S. M. P. E.

mately 30 degrees at medium and high frequencies and approxi-
mately 60 degrees at low frequencies. The frequency response is rea-
sonably flat between 150 and 5000 cps. A model was sent to Holly-
wood for test.

ERPI developed a multiduty motor system35 for use in (1) original
recording on a studio stage, (2} original recording on location, (3) re-
recording, and (4) background projection. The new system provides
more power for camera motors without increase in size, more accu-
rate interlock, and a number of accessory features which add to the
convenience and reliability of operation.

RCA developed a three-layer dichroic reflector for use in photocell
monitoring systems.36 It has a transmission of 95 per cent at 4400^4
and a reflectivity of 65 per cent at 7340^4 . When placed in the light
path of a recording optical system the new reflector transmits the
actinic rays and reflects the rays to which a caesium photocell is
most sensitive.

A new noise-reduction unit designated as RA-1124 was introduced
by ERPI.37 This unit delivers sufficient bias current to give closure
to any Western Electric light-valve circuit and will also operate the
Western Electric variable-area shutter. Peak-type operation is em-
ployed and the timing is easily changed for standard or push-pull
variable-area or variable-density records. (Photo, p. 144, Feb.,
1942.)

A precision direct-reading densitometer was developed by Afga
Ansco.38 It utilizes a simple electronic arrangement designed to give
a uniform scale over a density range of 0 to 3.0. The color-response
represents a compromise between the response of the eye and that of
positive film. The scale is calibrated to read visual diffuse density.
(Photo, p. 167, Feb., 1942.)

Headphones having high-fidelity characteristics were offered by
RCA.39 These phones combine high sensitivity and low distortion
with a good frequency response. They are comfortable to wear and
are readily serviced. (Photo, p. 322, Sept., 1941.)

ERPI developed an amplifier (RA-1111-A) for the application of
stabilized feed-back to the RA-1061 and other ERPI light- valves.40
The amplifier is used to obtain controlled damping of the mechanical
resonance without distortion and temperature variations inherent in
mechanical damping methods. Light- valves that are tuned to 10,000
cps will now produce uniform response from 40 to 8000 cps. (Photo,
p. 248, March, 1942.)

Nov., 1942] PROGRESS IN MOTION PICTURE INDUSTRY 303

The Canady Sound Appliance Company announced a new profes-
sional-type 16-mm recorder41 built to meet the requirements of the
commercial producer of 16-mm films. The recorder is provided with
a rotary stabilizer of the dry type which is not affected by climatic
conditions. A gaseous discharge lamp is used as a light-modulator
and the output is focused on the film by an optical unit of high re-
solving power. Frequencies from 30 to 9000 cps have been recorded
on a standard recording emulsion. (Photo, p. 208, Aug., 1940.)

OH) SOUND AND PICTURE REPRODUCTION

(1) General. — Limitations of the single-channel reproducing system
were generally recognized and several methods were developed for
increasing the volume range and the acoustic spread of the sound in
the theater.42- 43 Walt Disney's Fantasia** was an outstanding ex-
ample of the added realism accomplished through the use of a three-
channel reproducing system. This system employed four double-
width sound-tracks. Three of these were used for music and dialog
and one was a control-track for regulating the volume of each of the
three reproducing channels. The special sound reproducer and other
units of the equipment were developed by RCA in cooperation with
Disney engineers.

The Bell Telephone Laboratories developed a system for stereo-
phonic reproduction45 from film, and successfully demonstrated it in
New York and Hollywood. The system employed four variable-area
sound- tracks,46 one of which was used for controlling the volume from
the other three. The three program tracks were separately recorded
from three microphones spaced across the stage. Separate reproduc-
ing channels carried the output of the sound-tracks to three loud
speakers having the same relative positions as the microphones. The
frequency response of the complete system extended from 50 to 15,000
cps. By compressing the original recording and expanding it in re-
production, a volume range of 100 db was realized.

A sprocket-hole control-track system was developed by RCA Manu-
facturing Co., Inc., for switching on additional speakers for
music and for regulating the volume from a multiple-speaker repro-
ducing system. One advantage of this system is that the release
print is interchangeable with standard release prints. The sprocket-
hole control-track also eliminates the necessity for changing existing
film standards and the obsolescence of reproducer equipment. Warner

304 PROGRESS IN MOTION PICTURE INDUSTRY [j. s. M. p. E.

Bros, studio has applied this system to a number of pictures43 and are
testing it in three large theaters.

ERPI developed a reproducing system utilizing a 5-mil control-
track located between the sound-track and the picture. One or more
variable-frequency tones are recorded on the narrow track for the
purpose of regulating the volume of the sound and for switching the
side speakers on and off. The advantages of this system are that it
can be made to perform several functions, and the control can be
operated very fast.

Projection lenses with coated glass surfaces continued to gain in
popularity during 1940 and 1941. The increase in light transmission
due to the surface treatment varied from 15 to 30 per cent depending
upon the number of elements in the lens. Improved contrast ap-
peared to be as important as the gain in light. New coated projec-
tion lenses were offered for sale by the Bausch & Lomb Optical Com-
pany. Also a service for coating used projection lenses was offered by
RCA Manufacturing Co. Inc., Indianapolis; Vard Mechanical Labo-
ratory, Pasadena, Calif.; and the National Research Corporation,
Brookline, Mass.

Continued improvement in light-sources for the projection of 35-
mm motion picture film was characterized by the appearance of a
series of improved carbons giving more and cheaper light, new
lamps, particularly in the "One Kilowatt" classification, adapted to
supply economical white light to the smaller theaters, and a renewed
interest in automatic control mechanisms for accurately maintaining
carbon position.

The "One Kilowatt" direct-current lamps employ a 7-mm copper-
coated positive carbon burned at 27.5 volts and 40 amperes, the
low voltage being made possible through the development of a special
negative carbon47 which permits the use of a very short arc length
without the development of the carbide tip obtained when earlier
types of negative carbons are so operated. An a-c type of "One
Kilowatt" arc also was made available,48 operating on 96-cycle al-
ternating current delivered by a special generator. The choice of this
frequency was determined by the fact that one full cycle occurs during
each 90-degree shutter opening of a standard 24-ftame-per-second
projector, so that the flicker ordinarily considered characteristic of
alternating current arcs is eliminated.

A new 8-mm copper-coated positive carbon49 was introduced, char-
acterized by a 60 per cent increase in crushing strength, giving added

Nov., 1942] PROGRESS IN MOTION PICTURE INDUSTRY 305

resistance to the action of carbon clamping devices, a burning life ap-
proximately 20 per cent longer, and an increased current-carrying
capacity giving 25 per cent more maximum light than that of its
predecessor.

For the inclined-trim condenser-type lamps, a new regular 13.6-
mm positive carbon was introduced,60 having 50 per cent longer life
with the same light as the carbon it replaced, plus a higher current
capacity resulting in more light at 150 amperes than was available
from the old super 13.6-mm carbon at 180 amperes. As an aid to the
largest theaters, a new super 13.5-mm carbon for operation at 170
amperes has very recently been introduced,61 giving almost 25 per cent
more light than the old super at 180 amperes, and 15 per cent more
than the new regular just described at its maximum current of 150
amperes.

An increased consciousness of the importance of the spectral qual-
ity of projector light-sources as they determine the color of the screen
image is evidenced by the Society's participation in the activities of
the Inter-Society Color Council62 and by the interest shown in screen
light color determinations.63

Development work with methods of arc control employing photo-
electric cells and bimetallic thermostats54 has demonstrated that
automatic devices of simple construction are capable of maintaining
constant the intensity, distribution, and color of the light on the pro-
jection screen. The more efficient the optical system becomes, the
less the tolerance of the carbon position, so that it is anticipated that
the commercial development of control devices of this type will per-
mit a considerable advance in projection efficiency as realized in the
average theater.

(2) New Equipment. — The International Projector Corporation
introduced a Simplex double-film attachment.65 This unit was de-
signed for use with the Simplex 4-Star sound system where separate
picture and sound prints are run for reviewing purposes in studios or
for showing pre-release prints in theaters. For double-film operation
the lower magazine provides space for three 1000-ft reels. For ordi-
nary sound and picture projection there is ample space in the lower
magazine for a 2000-f t reel.

A 35-mm motion picture projector with improved mechanism
was offered by the Century Projector Corp.6* Greater accuracy in
projection, increased operating efficiency, low maintainance, and
longer life are claimed as the result of accurate design and precision

306 PROGRESS IN MOTION PICTURE INDUSTRY tf. s. M. P. E.

workmanship. Sealed-for-life ball-bearings are used for the high-
speed shafts and oil-less sleeve bearings for the low-speed shafts. The
projector is equipped with a double-shutter mechanism having 67-
degree blades running in opposite directions.

A coin-operated 16-mm sound movie projector was developed for
the Mills Novelty Company under the trade name of Panoram. In
a large cabinet are housed a type RCA-PG-170 16-mm sound-picture
projector and a 25- watt amplifier which drives six cone speakers.
Forced draft ventilation is used for cooling the projector as well as the
amplifier. The 16-mm prints, which are treated to prevent sticking,
are spliced into an endless loop and are kept in a special continuous-
feed type magazine. The picture portion of these prints is obtained
by optically reducing 35-mm negatives, whereas the sound-track is
contact printed from directly recorded 16-mm sound negatives.
Rear projection is used to permit viewing the picture on a translucent
screen incorporated in the cabinet.

(TV) TELEVISION

In an order dated May 3, 1941, the Federal Communications
Commission authorized commercial television broadcasting to become
effective July 1, 1941. On that date one station, WNBT, started
commercial service in the New York area; a second station, WCBW,
began regular program service under a commercial construction per-
mit ; and several others in various cities inaugurated regular program
operation under existing experimental licenses. Subsequently to
that date, television broadcast service on either a commercial or ex-
perimental basis has been provided in the Philadelphia, Schenectady,
Chicago, and Los Angeles areas in addition to New York City. The
FCC Rules and Regulations require a minimum of fifteen program
hours per week for commercial operation, and specify technical stand-
ards essentially as recommended by the National Television Systems
Committee, and industry group set up jointly in 1940 by the Radio
Manufacturers Association and the Federal Communications Com-
mission to study the problems of technical standards. These stand-
ards were given in detail in a report by the Television Committee of
the Society in the July, 1941, issue of the JOURNAL.

In spite of the serious handicap caused by shortages of essential
materials for both receivers and transmitting equipment, commer-
cial television has made notable progress. It is hoped that it will be
able to continue in spite of the war, at least on a modest scale, so that

Nov., 1942] PROGRESS IN MOTION PICTURE INDUSTRY 307

it may be expanded rapidly when the war is over. This is in contrast
to the situation in England where television was shut down com-
pletely, for the duration, on the first day of the war.

Television broadcasting is aiding in various ways in the nation's
civilian defense effort. In New York City, for example, it is being
utilized by the police department as a medium for giving official
training to the air-raid wardens in that area, as well as to the thou-
sands of persons viewing these official lessons on home receivers.
These training programs from station WENT are being re-broadcast
by station WPTZ in Philadelphia and station WRGB in Schenectady
for the benefit of air-raid wardens and the public in those areas.
Television receivers have been installed in all precinct police stations
in New York City for the training of air-raid wardens and police
personnel.

At the present time, it is estimated that there are approximately
five thousand television receivers in the New York Metropolitan
area, four hundred in the Philadelphia area, one hundred in the Chi-
cago area, one hundred fifty in the Schenectady area, and four hundred
fifty in the Los Angeles area. Since the last report of this Committee,
several notable improvements in television receiver design have been
made, including the demonstration of a projection- type receiver for
home use producing a picture of good brilliance on a translucent
screen, IS1/* inches X 18 inches. Substantial progress has been
made in circuit engineering of receivers, and prices have been reduced
from the levels at which receivers were first introduced to the public.
Very few receivers have been available for retail sale for six months
or more, however.

Progress in television broadcasting has been highlighted by im-
proved studio techniques and facilities and by extension of the scope
of outside pick-ups. The latter has been made possible primarily by
the development of the orthicon camera for television pick-up under
adverse light conditions. With this camera it is possible to televise
most public events (boxing and wrestling bouts, baseball games,
track meets, etc.), using only the lighting provided for the benefit of
the spectators who are present, and programs of this sort are now an
important part of the regular television schedule. New compact
television camera and pick-up equipment has been developed and
described in the literature by both the Dumont and RCA Manu-
facturing Companies, that of the latter company utilizing orthicon
camera tubes. New television studio plants have recently been put

308 PROGRESS IN MOTION PICTURE INDUSTRY [j. s. M. P. E.

in operation by the General Electric Company in Schenectady and
the Don Lee Company in Los Angeles, and new facilities are under
construction by Philco in Philadelphia.

Television network operation has become a reality with the regular
re- transmission of programs from the NBC station WNBT in New
York, by station WPTZ of the Philco Radio & Television Corpora-
tion in Philadelphia. Earlier experiments in the re-transmission of
WNBT programs by the General Electric station WRGB in Schenec-
tady have also been resumed.

Two developments were announced leading toward possible solu-
tions of the problem of providing a more comprehensive television
network service. One of these was the experimental work by the Bell
Telephone Laboratories on the transmission of television signals over
800 miles of coaxial cable, looped back and forth between Minneapolis
and Stevens Point. The second was the experimentation by RCA
Communications on the relaying of television signals by means of
500-megacycle modulated radio repeater stations. For television
transmission over shorter distances (within a single city), consider-
able use is now being made of regular twisted-pair telephone cable
circuits with special equalization.

Further progress was made in the development of large-screen
television for theater use, and on May 9, 1941, a demonstration was
given by RCA in the New Yorker Theater in New York to an audience
of twelve hundred people. A 15 X 20-ft picture was shown, having
a screen brightness within the range considered acceptable by the
Society for motion picture theater screens. Commercialization of
this development has been halted temporarily, however, by the war.

During the past year and a half there has been considerable increase
of interest in color television by the method that employs mechani-
cally rotated color-filters at the transmitter and receiver. Reports
on work done by the Columbia Broadcasting System using this
method have been made to the Society. Considerable experimenta-
tion has been carried on by several organizations in this country and
abroad, but it is generally felt that the work on color television has
not yet progressed to a point where commercial standards can be
recommended.

The standards set up by the FCC on May 3, 1941, allowed for sev-
eral alternative methods of transmitting synchronizing signals to the
receivers, with the stipulation that the various alternatives used must
give adequate performance for standard receivers. This was done to

Nov., 1942] PROGRESS IN MOTION PICTURE INDUSTRY 309

allow further study of the several alternative methods before final
adoption of a single standard. The National Television System Com-
mittee of the Radio Manufacturers' Association accordingly has been
carrying on tests and investigations on various proposed methods
of synchronization, but at the time of writing of this report, final
recommendations have not been announced.

A bibliography of important publications in the field of television
during 1940-41 is given in the following section of this report.

(V) PUBLICATIONS AND NEW BOOKS

Shipment of periodicals and books from Europe to this country
was slowed up considerably during 1940-41 by the war abroad and
ceased entirely with the entry of the United States into the conflict,
in December, 1941. Most of the English periodicals continued to be
printed with good regularity.

The more notable books which have been published since the April.
1940, report of this Committee are the following:

CO The Cinema Today; D. A. Spencer and H. D. Waley (Oxford University Press,
London) .

(2) Motion Picture Projection and Sound Pictures; J. R. Cameron (Cameron

Publishing Co., Woodmont, Conn.}, 8th ed.

(3) Chemistry for Photographers; A. R. Greenleaf (American Photographic Pub-

lishing Co., Boston).

(4) Movie Making for the Beginner; H. C. McKay (Ziff -Davis Publishing Co.,

Chicago) .

(5) Color Movies for the Beginner; H. B. Tuttle (Ziff -Davis Publishing Co.,

Chicago} .

(6) How to Make Good Movies (Eastman Kodak Co., Rochester, N. Y.).

(7) Kodachrome and How to Use It; I. Dmitri (Simon and Schuster, New York).

(8) Photographing in Color; P. Outerbridge (Random House, New York).

Yearbooks were issued by the following publishers:

Quigley Publishing Co., New York.

Film Daily, New York.

Kinematograph Publications, Ltd., London.

Amateur Cinema League, New York.

Abridgments, dictionaries, and compilations were issued as fol-
lows:
Abridged Scientific Publications of the Kodak Research Laboratories, 21 (1939),

and 22 (1940) (Eastman Kodak Company, Rochester, N. Y.).
A Dictionary of Applied Chemistry; T. E. Thorpe and M. A. Whitely. 4th ed.,
2 (1938) (Longmans, Green, Ltd., London). Contains a section on Film Manu-
facture by W. Clark under "Cellulose."

310 PROGRESS IN MOTION PICTURE INDUSTRY [j. s. M. P. E.

The Complete Photographer; edited by W. D. Morgan (National Educational
Alliance, Inc., Chicago}. A photographic encyclopedia containing about two
thousand articles by authorities in various fields of photography, including
motion pictures. Ten volumes, or about four thousand pages, when com-
pletely issued.

Fortschritte der Photographic, 2; E. Stenger and H. Staude (Akad. Verlag.,
Leipzig}.

American Cinematographer Handbook and Reference Guide; J. J. Rose (Ameri-
can Society of Cinematographer s, Hollywood}, 4th ed.

Television Bibliography

(1} Streiby, M. E., and Wentz., J. F.: "Television Transmission Over Wire

Lines," Bell Syst. Tech. J., 20 (Jan., 1941), p. 62.
(2} "Groundwork Laid for Commercial Television," Electronics, 14 (April, 1941),

p. 66.

(5) "NTSC Proposes Television Standards," Electronics, 14 (April, 1941), p. 18.
(4} Fink, D. C.: "Photographic Analysis of Television Images," Electronics, 15

(Aug., 1941), p. 24.

(5) Fink, D. C.: "Brightness Distortion in Television," Proc. IRE, 29 (June,

1941), p. 310.

(6) Sarnoff, D.: "A New Era in Television," RCA Rev., 6 (July 1941), p. 3.

(7) Maloff, I. G., and Tolson, W. A.,: "A Resume of the Technical Aspects of

RCA Theater Television," RCA Rev., 6 (July, 1941), p. 5.
(8} "Television Committee Report," /. Soc. Mot. Pict. Eng., XXXV (Dec. 1940),

p. 569.

(9} Hanson, O. B.: "RCA-NBC Television Presents a Political Convention as
First Long Distance Pick-Up," RCA Rev., 5 (Jan., 1941), p. 267.

(10} "Columbia Colour Television," Electronics and Television and Short Wave
World, 13 (Nov. 1940), p. 488.

(11} "Television Experiments on Coaxial Cable," Bell Lab. Rec., 19 (June, 1941),
p. 315.

(12} Kroger, F. H., Trevor, B., and Smith, J. E.: "A 500-Megacycle Radio Re-
lay Distribution System for Television," RCA Rev., 5 (July, 1940), p. 31.

Progress Reports

The Photographic Journal annually prints a number of reports
covering advances in many fields of photography. The following is
a list of those relating to the period 1940-41, a number of which are of
great interest as to the application of photography to the war effort
in England:

April, 1941

Mortimer, F. J. : "Photography's Part in the War."

Duncan, C. J., "Cine Camera Guns in Service with the R.A.F."

Spencer, D. A.: "Photography Applied to Engineering."

Matthews, Glenn E.: "Photographic Progress during 1940."

Nov., 1942] PROGRESS IN MOTION PICTURE INDUSTRY 311

Cartwright, H. Mills: "Photo-Engraving in 1940."

Saunders, John E.: "Progress in Apparatus."

Yule, W. H. Drury: "Colour Photography in 1940."

Cricks, R. Howard: "Technical Progress in Kinematography."

Sewell, G. H.: "Sub-Standard Kinematography in 1940."

April, 1942

Mortimer, F. J.: "More about Photography's Part in the War."

Cartwright, H. Mills: "Photo-Engraving in 1941."

Cricks, R. H. : "Wartime Progress in the Film Industry."

Sewell, G. H. : "Sub-Standard Kinematography in 1941."

June, 1942

Matthews, Glenn E.: "Photographic Progress during 1941."

REFERENCES

1 DAILY, C. R. : "Improvement in Sound and Picture Release through the
Use of Fine-Grain Film," /. Soc, Mot. Pict. Eng., XXXIV (Jan., 1940), p. 12.

2 SHANER, V. C.: "A Note on the Processing of Eastman 1302 Fine-Grain Re-
lease Positive in Hollywood," /. Soc. Mot. Pict. Eng., XXXVIII (Jan., 1942), p.
66.

3 WILKINSON, J. R., AND EICH, F. L.: "Laboratory Modification and Proce-
dure in Connection with Fine-Grain Release Printing," /. Soc. Mot. Pict. Eng.,
XXXVIH (Jan., 1942), p. 56.

4 DAILY, C. R., AND CHAMBERS, I. M.: "Production and Release Applications
of Fine-Grain Films for Variable-Density Sound-Recording," J. Soc. Mot. Pict.
Eng., XXXVIII (Jan., 1942), p. 45.

6 TALBOT, R. H. : "A New Treatment for the Prevention of Film Abrasion and
Oil Mottle," /. Soc. Mot. Pict. Eng., XXXVI (Feb., 1941), p. 191; U. S. Pat.
No. 2, 259,009.

6 CLARKE, D. B., AND LAUBE, G.: "Twentieth Century Camera and Accesso-
ries," /. Soc. Mot. Pict. Eng., XXXVI (Jan., 1941), p. 50.

7 GILBERT, F. C.: "Scene-Slating Attachment for Motion Picture Cameras,"
J. Soc. Mot. Pict. Eng., XXXVI (Apr., 1941), p. 355.

8 GOLDSMITH, ALFRED N.: "The IR System: An Optical Method for Increas-
ing Depth of Field," J. Soc. Mot. Pict. Eng., XXXVIH (Jan., 1942), p. 3.

9 HOLDEN, EDWARD P., JR.: "The Electroplane Camera," Amer. Cinemat., 23
(Feb., 1942), p. 56.

10 JONES, F. L.: "Some Properties of Polished Glass Surfaces," /. Soc. Mot.
Pict. Eng., XXXVII (Sept., 1941), p. 256.

11 NICOLL, F. H.: "A New Chemical Method of Reducing the Reflectance of
Glass," RCA Review, 6 (Jan., 1942), p. 287.

15 MILLER, W. C.: "Recent Improvements in Non-Reflective Lens Coating,"
/. Soc. Mot. Pict. Eng., XXXVH (Sept., 1941), p. 265.

» BLODGETT, K. B.: Phys. Rev., 55 (Feb. 15, 1939), p. 391.

14 TURNER, A. F. : Bausch & Lomb Educational Focus, 12, Spring 1941. p. 4.

16 RAYTON, W. B.: "New Lenses for Projecting Motion Pictures," /. Soc. Mot.
Pict. Eng., XXXV (July, 1940), p. 89.

312 PROGRESS IN MOTION PICTURE INDUSTRY [J. S. M. P. E.

16 CARTWRIGHT, C. HAWLEY: "Treatment of Camera Lenses with Low-Reflect-
ing Films," /. Opt. Soc. Amer., 30 (March, 1940), p. 110.

17 CLARKE, CHARLES G. : "Are We Afraid of Coated Lenses?" Amer. Cinemat.,
22 (April, 1941), p. 161.

18 TOLAND, GREGG: Popular Photography, 8 (June, 1941), p. 55.

19 Report of the Studio Lighting Committee, J. Soc. Mot. Pict. Eng., XXXV
(Dec., 1940), p. 607.

20 "Technical Progress in 1941," Amer. Cinemat., 23 (Jan., 1942), p. 6.

21 ACAD. MOT. PICT. ARTS AND SCIENCES: "Report on Arc Lamp Noise Tests,"
J. Soc. Mot. Pict. Eng., XXXVI (May, 1941), p. 252.

22 HASKIN, BYRON: "The Development and Practical Application of the
Triple-Head Background Projector," J. Soc. Mot. Pict. Eng., XXXIV (March,
1940), p. 252.

23 Report of the Studio Lighting Committee, J. Soc. Mot. Pict. Eng., XXXV
(July, 1940), p. 86.

24 MEES, C. E. K.: "Direct Process for Making Photographic Prints in Color,"
/. Franklin Institute, 233 (Jan., 1942), p. 41.

26 KINGSLAKE, R. : "Lenses for Amateur Motion Picture Equipment," J. Soc.
Mot. Pict. Eng., XXXIV (Jan., 1940), p. 76.

26 EHRENHAFT, F., AND BACK, F. G.: "A Non-Intermittent Motion Picture
Projector," J. Soc. Mot. Pict. Eng., XXXIV (Feb., 1940), p. 223.

27 MERRIMAN, W. E., AND WELLMAN, H. C.: "Five New Models of 16-Mm
Sound Kodascope," /. Soc. Mot. Pict. Eng., XXXVII (Sept., 1941), p. 313.

28 A REPORT OF THE COMMITTEE ON NON-THEATRICAL EQUIPMENT: "Recom-
mended Procedure and Equipment Specifications for Educational 16-Mm Pro-
jection," /. Soc. Mot. Pict. Eng., XXXVII (July, 1941), p. 22.

29 LOZIER, W. W., AND JOY, D. B.: "A Carbon Arc for the Projection of 16-
Mm Film," /. Soc. Mot. Pict. Eng., XXXTV (June, 1940), p. 575.

30 FRAYNE, J. G., AND PAGLIARULO, V.: "The Effects of Ultraviolet Light on
Variable-Density Recording and Printing," J. Soc. Mot. Pict. Eng., XXXIV (June,
1940), p. 614.

31 DUPY, O. L., AND HILLIARD, JOHN K. : "A Monochromatic Variable-Density
Recording System," J. Soc. Mot. Pict. Eng., XXXVI (April, 1941), p. 367.

32 KELLOGG, E. W.: "Ground Noise Reduction Systems," J. Soc. Mot. Pict.
Eng., XXXVI (Feb., 1941), p. 137.

33 SCOVILLE, R. R., AND BELL, W. L. : "Design and Use of Noise-Reduction
Bias Systems," /. Soc. Mot. Pict. Eng., XXXVIII (Feb., 1942), p. 125.

34 OLSON, HARRY F.: "Line Microphones," J. Soc. Mot. Pict. Eng., XXXVI
(March, 1941), p. 302.

^HOLCOMB, A. L.: "A Multiduty Motor System," J. Soc. Mot. Pict. Eng.,
XXXIV (Jan., 1940), p. 103.

36 DIMMICK, G. L. : "A New Dichroic Reflector and Its Application to Photo-
cell Monitoring Systems," /. Soc. Mot. Pict. Eng., XXXVIII (Jan., 1942), p. 36.
,37 SCOVILLE, R. R., AND BELL, W. L.: loc. cit.

38 SWEET, M. H.: "A Precision Direct-Reading Densitometer," /. Soc. Mot.
Pict. Eng., XXXVHI (Feb., 1942), p. 148.

39 ANDERSON, L. J.: "High-Fidelity Headphones," J. Soc. Mot. Pict. Eng.,
XXXVH (Sept., 1941), p. 319.

Nov., 1942] PROGRESS IN MOTION PICTURE INDUSTRY 313

40 ALBERSHEIM, W. J., AND BROWN, L. F.: "Stabilized Feedback Light-Valve,"
J. Soc. Mot. Pict. Eng., XXXVIH (March, 1942), p. 240.

41 CANADY, D.: "Professional 16-Mm Recording Equipment," /. Soc. Mot.
Pict. Eng., XXXV (Aug., 1940), p. 207.

"REISKIND, H. I.: "Multiple Speaker Reproducing Systems," /. Soc. Mot.
Pict. Eng., XXXVH (Aug., 1941), p. 154.

48 LEVINSON, N., AND GOLDSMITH, L. T.: "Vitasound," /. Soc. Mot. Pict. Eng.,
XXXVH (Aug., 1941), p. 147.

4*GARiTY, W. E., AND HAWKINS, J. N. A.: "Fantasound," /. Soc. Mot. Pict.
Eng., XXXVII (Aug., 1941), p. 127.

46 FLETCHER, H.: "The Stereophonic Sound-Film System," /. Soc. Mot. Pict.
Eng., XXXVH (Oct., 1941), p. 331.

46 WENTE, E. C., BIDDULPH, R., ELMER, L. A., AND ANDERSON, A. B.: "Me-
chanical and Optical Equipment for the Stereophonic Sound-Film System," J.
Soc. Mot. Pict. Eng., XXXVH (Oct., 1941), p. 353.

47 LOZIER, W. W., JOY, D. B., AND SIMON, R. W. : "A New Negative Carbon for
Low-Amperage High Intensity Trims," /. Soc. Mot. Pict. Eng., XXXV (Oct., 1940),
p. 349.

48 KALB, W. C.: "Progress in Projection Lighting," /. Soc. Mot. Pict. Eng.,

XXXV (July, 1940), p. 17.

49 LOZIER, W. W., CRANCH, G. E., AND JOY, D. B.: "Recent Developments in
8-Mm Copper-Coated High-Intensity Positive Carbons," /. Soc. Mot. Pict. Eng.,

XXXVI (Feb., 1941), p. 198.

60 JONES, M. T., LOZIER, W. W., AND JOY, D. B.: "New 13.6-Mra High-Inten-
sity Projector Carbon," /. Soc. Mot. Pict. Eng., XXXVTI (Nov., 1941), p. 539.

61 JONES, M. T., LOZIER, W. W., AND JOY, D. B.: "New 13.6-Mm Carbons for
Increased Screen Light," /. Soc. Mot. Pict. Eng., XXXVHI (March, 1942), p. 229.

" GAGE, H. P.: "Color Theories and the Inter-Society Color Council," /. Soc.
Mot. Pict. Eng., XXXV (Oct., 1940), p. 361.

63 NULL, M. R., LOZIER, W. W., AND JOY, D. B.: "The Color of Light on the
Projection Screen," J. Soc. Mot. Pict. Eng., XXXVHI (March, 1942), p. 219.

64 ZAFFARANO, D. J., LOZIER, W. W., AND JOY, D. B.: "Improved Methods of
Controlling Carbon Arc Position," /. Soc. Mot. Pict. Eng., XXXVH (Nov., 1941).
p. 485.

w BORBERG, W., AND PiRNER, E. : "Simplex Double-Film Attachment," /.
Soc. Mot. Pict. Eng., XXXIV (Feb., 1940), p. 219.

M BOECKING, E., AND DAVES, L. W.: "Recent Developments in Projection
Mechanism Design," J. Soc. Mot. Pict. Eng., XXXVIH (March, 1942), p. 262.

THE PHOTOGRAPHING OF 16-MM KODACHROME SHORT
SUBJECTS FOR MAJOR STUDIO RELEASE*

L. WILLIAM O'CONNELL**

Summary. — A method is described of photographing professional short subject
pictures on 16-mm Kodachrome film having edge numbers and enlarging on standard
35-mm black-and-white film for the purpose of cutting, editing, and viewing in
standard 35-mm studio equipment. The edited black-and-white film is used as a
pilot film for cutting the original 16-mm Kodachrome for color separation negatives
and the subsequent 35-mm Technicolor release prints.

In practically all recent photographic publications whose readers
are either professional or amateur, there have been many articles
showing increasing interest in the possibilities of 16-mm Kodachrome
film with regard to its application and success in making pictures
comparable to those made on 35-mm film. Proof that comparable
pictures can be produced lies in the fact that some major producing
companies have already accepted a number of such short subjects
made in 16-mm for release in 35-mm.

Progress in any field of endeavor, whether in sports, entertain-
ment, manufacturing of automobiles, aeroplanes, radios, or motion
pictures, is based upon the research experimentation, and achieve-
ments in the various parts of the field, which, when brought together,
establish the present state of the art.

Thanks to manufacturers of 16-mm equipment and film, light
weight, portable, and dependable equipment has done much toward
producing 35-mm color shorts on reasonable budgets.

In the search for enhancement of the black-and-white short sub-
ject release, especially "Sport Shorts," an attempt was made to
produce them in color, using the familiar bipack 35-mm camera and
two-color release prints. As this added considerable additional
cost, it was decided to attempt to use 16-mm Kodachrome, which
since has proved highly satisfactory both as to color rendition arid

* Presented at the 1942 Spring Meeting at Hollywood, Calif.; received
May 4, 1942.

** Warner Bros. First National Studios, Burbank, Calif.
314

16-MM KODACHROME SHORT SUBJECTS 315

as to cost. Furthermore, it provided for the professional camera-
man and director great advantages in portability, and flexibility
in making angle shots — in fact, angles that are impracticable with
standard 35-mm equipment can be made with this lighter equipment,
helping to remove some of the restrictions under which the picture
director works in planning his angle shots.

The following describes the procedure originated by Del Frazier,
of the Warner Brothers Studios, for using camera equipment and
Kodachrome film in the production of short subject features to be
released as standard 35-mm Technicolor prints

The Cine Kodak Special, equipped with 15-mm, 25-mm, and 50-
mm lenses has served every purpose required and has not been found
lacking in any respect. A large field professional viewfinder has
been added to the left side of the camera, giving more speed and
accuracy of operation and eliminating horizontal parallax.

A normal camera speed of 24 frames per second is used when
recording sound in synchronism with the photography. A speed
of 32 frames per second is used for photographing sport action shots
to be presented with narration. For slow-motion or shots of pro-
longed interest, such as fast swimming, diving, and golf action, etc.,
a Bell & Howell Golf Speed camera operating at 128 frames per sec-
ond is used. A third camera is carried as a cover for action while
reloading magazines; an Eastman Model K camera with a 15-mm
fixed-focus lens carried in a convenient side pocket. Precautions
should be taken in selecting group cameras with regard to the rela-
tion between sprocket-holes and frame lines, which should be held
to close tolerances so as to avoid frame shift when splicing and during
subsequent projection.

A sturdy tripod should aways be used whenever possible, but in
many instances work can be accomplished without one, giving more
freedom of action. This is especially true in shots close to the
ground or taken from tree-tops, or perhaps from a step-ladder. Scenes
taken from fast-moving cars or motorboats can be completed in the
length of time it would take to fasten down a bulky 35-mm camera.
But then again one must be very careful, always holding the camera
firmly against the body, and breathing very lightly.

As in all other operations pertaining to the photography of 16-mm
pictures, great attention must be given to exposure, for the reason
that an under- or overexposure shifts the color of the scene. In
addition, it is possible that a slight loss in rendition might occur in

316 L. W. O'CONNELL

the Technicolor print as compared to the original Kodachrome,
but this is negligible inasmuch as an audience is not in a position to
make a direct comparison. A Weston reading of 8 is used in most
instances, but wherever there is a great percentage of deep colors,
blue sky, or heavy shadows, a slight overexposure (Weston 6) gives
more latitude in making separations.

An important lesson that we learned was not to work with the
16-mm film immediately after processing. When the soft-surfaced
emulsion is enlarged to 35-mm size and then enlarged further to
the size of a theater screen, all the scratches and finger marks become
sadly obvious.

The principal advantages of editing a 16-mm film enlarged to
35-mm black-and-white are, first, the original Kodachrome needs
no handling other than that required in printing the 35-mm negative
and in cutting to match the 35-mm black-and-white pilot print.
Second, the editor can work much faster, and with the same confi-
dence as in regular 35-mm production; the projection of his work
can be seen in any available viewing room. To cut the original
Kodachrome in the orthodox manner would entail endless splicing
troubles, and the required handling of the film would ruin its value
for reproduction.

The enlargement of the 16-mm Kodachrome to 35-mm black-
and-white is accomplished in a specially constructed optical printer
in which a Bell & Howell movement is modified to take the 16-mm
film, and the aperture is opened on the edge-numbered side to in-
clude the full edge figures. The image is projected through a 3-
inch copying lens to the modified aperture of a Mitchell camera
which gives a picture size of approximately 0.600 X 0.825 inch,
comparable to the sound-film projector aperture. The edge-numbers
are approximately in the position of the normal sound-track, and,
of course, are not projected. The Hanovia type AH4 mercury-
sodium lamp is used as a printing light, and the 35-mm negative is
produced on Eastman Background X negative stock and developed
to a gamma of 0.6. Subsequent prints are remarkably free from
graininess and possess a very high fidelity to the original Koda-
chrome pictures, having been mistaken at times, for original black-
and-white productions.

ELIMINATION OF RELATIVE SPECTRAL ENERGY DIS-
TORTION IN ELECTRONIC COMPRESSORS*

BURTON F. MILLER**

Summary. — The exaggeration of sibilant speech-sounds produced when electronic
volume compression is employed in sound-recording channels is shown to be a form
of amplitude-selective frequency distortion, which is generated by virtue of the normal
mode of operation of the compressor. The practical elimination of this form of dis-
tortion is accomplished by equalization of the compressor control-rectifier input circuit,
the amount of equalization employed being proportional to the inverse average relation-
ship between rms speech-pressure per cycle and speech component frequency.

Prior to the development of sound systems capable of faithfully
recording and reproducing signals having a volume range in excess of
35 or 40 db, it was rather generally believed that the dramatic value
of sound pictures was definitely limited by the restricted volume
range of the recording medium. Later, following the development
of systems inherently capable of recording and satisfactorily repro-
ducing a range of signal intensity comparable with that of dramatic
dialog, it was discovered that theater reaction to such recordings was,
in general, surprisingly unfavorable.

The results of a study made to determine the cause of this situation
have been previously reported in this JOURNAL by W. A. Mueller,1 in
which it was concluded that the general theater auditorium noise
level sets a definite lower sound level limit for the intelligible repro-
duction of sound, while the comfort of the theater patron appears to
establish a corresponding upper sound level limit. The normal
acceptable range of reproduced sound intensity levels for general
dialog recording has, by these studies, been set at approximately 25
db.

In general, two basically different methods may be employed to
limit satisfactorily the volume range of dialog recordings. The first
of these depends upon manually controlling the relative signal levels

* Presented at the 1942 Spring Meeting at Hollywood, Calif. ; received
May 4, 1942.

** Warner Bros. Pictures, Inc., Burbank, Calif.

317

318 B. F. MILLER [j. s. M. P. E.

during recording and re-recording of the sound-track to a suitable
overall volume range. The second method, which provides almost
instantaneous control of signal levels and repeatedly duplicates its
action on signals of equivalent energy levels, is provided by the elec-
tronic type of compressor-amplifier. A third method is obviously
afforded by combining the two basic forms of control, and represents
a fair example of modern recording technique.

Following the installation of electronic compressor units in all the
recording and re-recording channels at Warner Bros, studios, it was
consistently noted that sibilant speech sounds were reproduced with
unusual prominence, occasionally being exaggerated to the point of
being reproduced as harsh whistling tones when these sounds were
stressed in the original speech. For a. time this effect was attributed
to the residual high-frequency distortion in the recording and re-
producing channels, and numerous circuit developments were studied
and employed to minimize such distortion. Meanwhile, the process
of re-recording was severely hampered, since it was found impossible
to remove the objectionable sibilance merely by introducing a suit-
able value of high-frequency equalization in the re-recording channel
without, at the same time, producing a finished sound-track that was
definitely lacking in high-frequency signal energy content.

It was found necessary, therefore, to reduce the energy content of
the numerous exaggerated sibilants in each reel of sound-track prior
to re-recording by manually applying a layer of semi-opaque ink over
each of the offending sections of the record. This process, needless
to say, was both time-consuming and costly, since it was necessary to
reproduce each reel of the master re-recording print several times to
permit locating the objectionable sibilants with reference to the
sound-start mark, and then to "paint-out" manually the corre-
sponding sections of track. On the average, from thirty to fifty such
spots would appear in each reel of dialog track, requiring approxi-
mately two hours of work for the location and "painting-out" of
these sections.

It soon became evident that all attempts to reduce the excessive
prominence of recorded sibilants through reduction of high-frequency
channel distortion were accomplishing almost nothing, and that the
cause of the difficulty being experienced was likely due to some factor
that had thus far been completely ignored.

In consequence of the above conclusion, attention was directed to
the results of the several statistical studies of the spectral distribution

Nov., 1942]

SPECTRAL ENERGY DISTORTION

319

of speech energy. Notable among these is the paper by Dunn and
White,2 outlining the results of recent studies on this subject at the
Bell Telephone Laboratories. The curves and data presented in the
Dunn and White paper indicate that while no single curve can be
taken as universally representative of the distribution of speech
energy throughout the audio-frequency band, it is nevertheless
possible to arrive at statistical averages of speech-energy distribution
that can, in any event, be employed to determine the probable energy

M
Of
3-10

.500 IOOO 1C

FREQUENCY IN C.PS.

FIG. 1.

Average relation between rms speech-pressure per
cycle and speech component frequency.

relationships existing between different portions of the normal band
of speech frequencies.

The curve in Fig. 1 represents a "smoothed-over" relationship
between root-mean-square speech-pressure per cycle, and frequency,
which has been prepared from data taken from the Dunn and White
paper. The averaging process employed in obtaining this curve
ignores the normal differences in energy distribution between male
and female voices, as well as the departures from a smooth curve that
actual measurements of speech-energy distribution indicate. In
view of the use that is to be made of the above curve, however, this
averaging process is believed legitimate.

320 B. F. MILLER [J. S. M. P. E.

Assuming this curve to be representative of the relative pressure
distribution with frequency for the various frequency components of
each spoken work, it may, in general, be observed that the pressures
corresponding to the lower-frequency vowel sounds of speech are
many times higher than those corresponding to the higher-frequency
sibilant sounds. Correspondingly, the low-frequency components of
speech signal voltage in the recording channel will normally be many
times greater in amplitude than the high-frequency components. If
the total amplification of the recording channel is made an inverse
function of the instantaneous signal voltage at some point of the
recording circuit, as is done when electronic compression is employed,
the channel amplification may be expected to be notably higher when
speech sibilants are being recorded than when vowel sounds are tra-
versing the recording system. Such a condition gives rise to a form
of amplitude-selective frequency distortion, which will be incapable
of correction by any straightforward process of signal-frequency
equalization during reproduction of the sound record.

This situation may, perhaps, be clarified somewhat by a simple
analytical treatment of the several factors involved. In a normal
amplifier system the overall amplification may be defined as the
ratio of the amplifier output voltage E0 to the amplifier input voltage
E0. This ratio may be a function of signal frequency, but throughout
the working range of signal input levels, is independent of signal
voltage. Presuming the amplification to be made independent of
frequency as well, the ratio of amplifier output to input voltages may
be expressed as

I - * «)

where ua is a constant.

In the case of the electronic compressor, however, the amplification
obtained is purposely made a function of a tube electrode control-
voltage ec. This control- voltage is normally derived by rectifying a
portion of the compressor output voltage, which is then so applied to
the amplifier tubes that the expression for amplification through the
compressor generally takes the form

EC _ Ue Uc (2)

Et (*)*

where uc and ki are constants, and where the exponent m varies from
approximately zero at low values of E0 to a positive limiting value
approached as E0 assumes progressively higher values.

Nov., 1942]

SPECTRAL ENERGY DISTORTION

321

Solving eq. 2 for the ratio £</£, in terms of the input voltage Eit

E»

^ = «.(£.-)" (3)

where ue is a constant, and n — — m/(m + 1). A curve showing the
actual relationship between compressor amplification and input
signal level at constant frequency for the compressors employed at
Warner Bros, studio is shown in Fig. 2, the amplification being ex-
pressed in decibels rather than in the arithmetical ratio employed in
eq. 3. It will be noted that throughout the greater portion of the

-52 -46

COMPRESSOR

I. -40 -36 -32

INPUT LEVEL IN DB.

FIG. 2. Relation between compressor amplification and
compressor input signal level. Reference level employed is 6

mw.

compression range of input signal levels, the exponent n employed in
eq. 3 would correspond to approximately —0.5.

Returning to consideration of the expression for compressor ampli-
fication, let it first be noted that the compressor input voltage corre-
sponding to a speech signal may be written as

Ei = A*(f) (4)

where A is a constant for any single word, and where the function
<r(f) expresses the relationship between probable speech-pressure per
cycle and frequency as given by the curve of Fig. 1.

Combining eq. 3 and eq. 4, the compressor output voltage is given
by

E. - «.(£<)»+l -

322 B. F. MILLER [J. s. M. P. E.

In this equation the factor An^'1 indicates that the amplitude of the
compressor output signal is a non-linear function of the input signal
amplitude, and is indicative of the fact that amplitude compression
may be obtained. On the other hand, it is also evident that the
normal spectral distribution function v(f) has been distorted to the
new distribution function [0-(/)]n+1. It is this latter distortion of the
compressed signal that is, in general, responsible for the excessive
prominence of speech-signal sibilants in the recorded signal. A
simple example may serve to indicate the relative magnitude of this
distortion.

Assume that the word say is to be recorded. If the predominant
frequency3 of the sibilant 5 is assumed to be approximately 6000 cps,
while that of the vowel q is taken as approximately 500 cps, reference
to Fig. 1 and eq. 4 indicates that the probable amplitude of the signal
delivered to the compressor input terminals which corresponds to the
s sound will be approximately 15.5 db lower than that corresponding
to the a sound. Assuming a value n = —0.5 for the exponent in the
compressor output- voltage equation (eq. 5), the signal corresponding
to the 5 sound at the compressor output terminals will be only 7.75
db lower in amplitude than that corresponding to the a sound. In
other words, the 5 sound has been exaggerated 7.75 db relative to
the a sound.

A clue to the method of correcting the distortion just described is
offered by the form of eq. 2. Let it be assumed that before the com-
pressor output voltage is delivered to the compressor control rectifier,
the portion of the output voltage employed for control purposes is
equalized to the form

E.' = *(f)E. (6)

where the form of the function i/>(/) is as yet unspecified. Sub-
stituting eq. 6 for E0 in the right-hand member of eq. 2, and solving
for the ratio E0/Eit one obtains

Substituting eq. 4 in eq. 7,
If, then, we set

Eo
Ei

Nov., 1942]

SPECTRAL ENERGY DISTORTION

k being a constant, the right-hand member of eq. 8 is independent of
the normal frequency distribution of speech energy.

Electrically, the correction implied by eq. 9 is obtained by inserting
an equalizer between the compressor output terminals and the control-
rectifier input circuit, the loss-characteristic of this equalizer being
designed to vary with frequency according to the inverse of the
pressure-frequency distribution curve of Fig. 1. A schematic dia-
gram of the modified compressor circuit is shown in Fig. 3.

FIG. 3. Schematic diagram of modified compressor
circuit.

In conclusion, it may be stated that recordings made with the
modified form of compressor are singularly free of any tendency
toward exaggerated sibilance, yet exhibit a normal brilliance equiva-
lent to that obtained during reproduction of normal uncompressed
recordings.

REFERENCES

1 MUELLER, W. A.: "Audience Noise as a Limitation to the Permissible
Volume Range of Dialog in Sound Motion Pictures," /. Soc. Mot. Pict. Eng.,
XXXV (July, 1940), p. 48.

8 DUNN AND WHITE: "Statistical Measurements on Conversational Speech,"
J. Acoust. Soc. Amer., 11 (Jan., 1940), p. 278.

» FLETCHER, H..: "Speech and Hearing," D. Van Nostrand Co. (New York)
1929, pp. 56-62.

CURRENT LITERATURE OF INTEREST TO THE MOTION PICTURE

ENGINEER

Acoustical Society of America, Journal
14 (July, 1942), No. 1

An Absolute Pressure Generator and Its Applica-
tion to the Free-Field Calibration of a Micro-
phone (pp. 19-23)

Sound Power Density Fields (pp. 24-31)

Perturbation of Sound Waves in Irregular Rooms
(pp. 65-73)

Experiments with the Noise Analysis Method of
Loudspeaker Measurement (pp. 79-83)

American Standard Acoustical Terminology (pp.
84-101)

American Standard for Noise Measurement (pp.
102-110)

American Cinematographer

23 (Sept., 1942), No. 9
More Realism from "Rationed" Sets? (pp. 390-

391, 430)
Sound-Recording Methods for Professional 16-

Mm Production (pp. 392-393, 427)
Film Conservation and Substandard Film (p. 407)

23 (Oct., 1942), No. 10
16-Mm Gains in Studio Use (pp. 442-443)
Shooting Action Movies from a Gunstock Mount
(pp. 444, 453)

British Kinematograph Society, Journal

5 (July, 1942), No. 3

The Soviet Film in Peace and War (pp. 65-76)
The Optical Printer and Its Applications (pp. 77-

86)
324

W. J. KENNEDY AND C. P.

BONER
J. H. ENNS AND F. A.

FIRESTONE

R. H. BOLT, H. FESHBACH
AND A. M. CLOGSTON

B. OLNEY

P. FERGUSON
J. A. LARSEN, JR.

W. STULL

K. O. HEZZELWOOD

I. MONTAGU
T. HOWARD

CURRENT LITERATURE 325

The Combined Services Film Studio (pp. 87-90)

Educational Screen

21 (Sept., 1942), No. 7

Motion Pictures — Not for Theaters (pp. 259-261,
264), Pt. 39 A. E. KROWS

Electronic Engineering

15 (Aug., 1942), No. 174
Colour and Stereoscopic Television (pp. 96-97)

Electronics

15 (Sept., 1942), No. 9
Amplitude, Frequency and Phase: Modulation

Relations (pp. 48-54) A. HUND

An Auxiliary Circuit for C-R Photography (pp.

59-60, 144) H. C. ROBERTS

Communications

22 (Aug. 1942), No. 8
Recording Standards (p. 20)

International Photographer

14 (Sept., 1942), No. 8
Night Shots in Daylight (p. 10)

14 (Oct., 1942), No. 9

A Lab on Wheels (pp. 3^) D. WOOD

Cinecolor Enlargement from 16-Mm Kodachrome

(pp. 10-11) W. T. CRESPINEL

Conservation of Film (pp. 12, 16, 18)

International Projectionist

17 (Aug., 1942), No. 8
Educational Activities of the Toronto Projection

Society (pp. 7-8) A. MILLIGAN

Projection Lenses with Treated Surfaces (pp. 9,

21) A. F. TURNER

Role of Projectionists in the U. S. Navy (pp. 10-

11)
Amplifier Breakdowns Averted by Use of Pilot

Lamps as Fuses (pp. 11, 17) W. DUNKBLBBRGBR

Underwriters Code as It Effects Projection

Rooms (pp. 14-15, 18), Pt. IV

17 (Sept., 1942), No. 9

Innovation Ends Buckling of Film (pp. 7-8) L. CHADBOURNB

Review of Projection Fundamentals. Pt. V,

Necessary Formulas (pp. 11, 18-21)
Underwriters Code as It Effects Projection

Rooms (p. 16), Pt. V

326

CURRENT LITERATURE

Motion Picture Herald

148 (Aug. 29, 1942), No. 9

British Educational Film Expanding Despite
War (p. 43)

Motion Picture Herald (Better Theaters Section)

148 (Aug. 22, 1942), No. 8

Simplified Tests for Determining Efficiency of
Projector Shutters (pp. 20-23)

RCA Review

6 (Apr. 1942), No. 4

Low-Frequency Characteristics of the Coupling
Circuits of Single and Multi-Stage Video Am-
plifiers (pp. 416-433)

A Discussion of Several Factors Contributing to
Good Recording (pp. 463-472)

A. FLANAGAN

C. E. SHULTZ

H. L. DONLEVY AND D.
EPSTEIN

R. A. LYNN

SOCIETY ANNOUNCEMENTS
ADMISSIONS COMMITTEE

At a recent meeting of the Admissions Committee, the following applicants for
membership were admitted into the Society in the Associate grade:

BROWNING, ARTHUR KBLLOCK, ALAN

190 William St., Union Carbide & Carbon Corp.,

Alexandria, Va. 30 East 42nd St.,

CARLTON F. HAYDEN New York, N. Y.

n,;' LAUPMAN.A.L.

Ogden Utah 1274 E. 83rd St..

r^ : ,n Cleveland. Ohio

U. S. Signal Corps,

Photographic Center, MONTAGUE, H. B.

35-11, 35th Ave., 3327 "A" Locust St.,

Long Island City, N. Y. St. Louis, Mo.

RAMANNA, B.
"Padmalaya,"

1792 Sampiga Rd.,
Malleswaram P. O.,
Bangalore, India

In addition, the following applicants have been admitted to the Active grade

DOUDEN, W. L. KNIGHT, J. B., JR.

2011 Poplar St., U. S. Navy Underwater Sound Lab.,

Philadelphia, Pa. Fort Trumbull,

New London, Conn.

O'GRADY, F. T.

33-64, 164th St.,

Flushing, L. I., N. Y.

The following applicant was admitted to the Student Membership grade :

WHITMER, MARVIN
417 Marion St.,
Boone, Iowa

817

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SOCIETY SUPPLIES

The following are available from the General Office of the Society, at the prices
noted. Orders should be accompanied by remittances.

Aims and Accomplishments. — An index of the Transactions from October,
1916, to December, 1929, containing summaries of all articles, and author and
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Journal Index. — An index of the JOURNAL from January, 1930, to December,
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JOURNAL OF THE SOCIETY OF
MOTION PICTURE ENGINEERS

VOLUME XXXIX • • • DECEMBER, 1942

CONTENTS

PAGE

The Navy's Utilization of Film for Training Purposes

W. EXTON, JR. 333
The Underground Motion Picture Industry in China

T. Y. Lo 341
Wright Field Training Film Production Laboratory

H. C. BRECHA 348
The Documentary, Scientific, and Military Films of the

Soviet Union " G. I. IRSKY 353

A One-Ray System for Designing Spherical Condensers

L. T. SACHTLEBEN 358

Light-Scattering and the Graininess of Photographic

Emulsions A. GOETZ AND F. W. BROWN 375

Some Engineering Aspects of Portable Television
Pick-Ups H. R. LUBCKE

Current Literature

The 1942 Fall Meeting of the Society at New York,
October 27-29, 1942

Program of the Meeting
Highlights of the Meeting
Society Announcements

Index of the Journal, Vol. XXXIX (June- December,
1942)

Author Index

Classified Index !|1('

(The Society is not responsible for statements of authors,)

JOURNAL OF THE SOCIETY OF
MOTION PICTURE ENGINEERS

SYLVAN HARRIS, EDITOR

Board of Editors

ARTHUR C. DOWNES, Chairman

JOHN I. CRABTREE ALFRED N. GOLDSMITH EDWARD W. KELLOGG

CLYDE R. KEITH ALAN M. GUNDELFINGER CARLETON R. SAWYER

ARTHUR C. HARDY

Officers of the Society

*President: EMERY HUSE,

6706 Santa Monica Blvd., Hollywood, Calif.
*Past-President: E. ALLAN WILLIFORD,

30 E. 42nd St., New York, N. Y.
*Executive Vice-President: HERBERT GRIFFIN,

90 Gold St.. New York, N. Y.
^Engineering Vice-President: DONALD E. HYNDMAN,

350 Madison Ave., New York, N. Y.
^Editorial Vice-President: ARTHUR C. DOWNES,

Box 6087, Cleveland, Ohio.
**Financial Vice-President: ARTHUR S. DICKINSON,

28 W. 44th St., New York, N. Y.
^Convention Vice-President: WILLIAM C. KUNZMANN,

Box 6087, Cleveland, Ohio.
^Secretary: PAUL J. LARSEN,

1401 Sheridan St., N. W., Washington, D. C.
* Treasurer: GEORGE FRIEDL, JR.,

90 Gold St., New York, N. Y.

Governors

*MAX C. BATSEL, 501 N. LaSalle St., Indianapolis, Ind.
**FRANK E. CARLSON, Nela Park, Cleveland, Ohio.

*JOHN G. FRAYNE, 6601 Romaine St., Hollywood, Calif.

*ALFRED N. GOLDSMITH, 580 Fifth Ave., New York, N. Y.
**EDWARD M. HONAN, 6601 Romaine St., Hollywood, Calif.

*I. JACOBSEN, 177 N. State St., Chicago, 111.
**JOHN A. MAURER, 117 E. 24th St., New York, N. Y.

*LOREN L. RYDER, 5451 Marathon St., Hollywood, Calif.

* Term expires December 31, 1942.
** Term expires December 31, 1943.

Published monthly at Easton, Pa., by the Society of Motion Picture Engineers.

Publication Office, 20th & Northampton Sts., Easton, Pa.

General and Editorial Office, Hotel Pennsylvania, New York, N. Y.

Entered as second-class matter January 15, 1930, at the Post Office at Easton,

Pa., under the Act of March 3, 1879. Copyrighted, 1942, by the Society of Motion

Picture Engineers, Inc.

THE NAVY'S UTILIZATION OF FILM FOR TRAINING
PURPOSES*

WILLIAM EXXON, JR**

Summary. — The use of training films automatically achieves standardization of
instruction, and helps to take the place of many men, formerly instructors, who are
now needed at sea.

The production of such training films requires thorough understanding of the
subject matter of the films, and its application in practice. Furthermore, one must be
acquainted with the kind of men to be taught by the films and the facilities available
for teaching them.

The development and use of such films in the Navy has advanced greatly during the
past six months, and has covered a vast variety of subjects.

When I had the pleasure of addressing this organization in Holly-
wood last May, I told you something of the part that the motion
picture was beginning to play in the training of men for the navy.
The situation at that time was briefly this : The navy was, and still
is, faced with an enormous expansion program, requiring that hun-
dreds of thousands of men be converted almost overnight from land-
lubber civilians to man-o-war's men, mechanics, and technicians, for
our rapidly growing fleet, air arm, and other naval activities. A
large proportion of these men had to be given special skills so that
they can handle the complicated and exacting apparatus and equip-
ment of our modern ships and planes.

All this training must be done when the number of officers and
skilled men who are available for instruction purposes is reduced to
an absolute minimum by the needs of our fleet for all possible skilled
personnel. Further, all this instruction must be carried out as
hundreds of separate, individual activities, with consequent danger
that the differences in the teaching at each activity may result in

* Presented at the 1942 Fall Meeting at New York, N. Y.; received October
27, 1942.

** Lt., U.SJST.R., Bureau of Navigation, Navy Dept.. Washington. D. C.

333

334 W. EXTON, JR. Lf. s. M. P. E.

considerable lack of efficiency when the men are assembled for duty
at sea. Adding to these difficulties is the fact that modern war,
being almost entirely technological, involves changes and develop-
ments in techniques to such an extent that an instructor who may be
fully up to date at any given moment is likely to be behind the times
shortly thereafter.

The motion picture training film, under these circumstances, offers
many of the essential advantages required to solve these problems.
The films can be produced under the supervision of experts in each
subject, so that the highest and most recent standard of information
is included in each film. The use of the same films at all activities
concerned automatically effects standardization of instruction.
Furthermore, to the extent that these films supplement personal in-
struction, they take the place of many valuable men, at present
instructing, who are required at sea; and the films should thus
provide a necessary supplementation for the teaching staff that is
available. The training films could be utilized also to keep all tech-
niques up to date, and to correct or adjust techniques as changes are
made through experience and development.

You will note that we are concerned with a training program that
was and still is an emergency rather than a routine program ; and that
the training film offers special advantages in the overcoming of the
adverse factors of this great emergency.

The last time I spoke to you there was a great deal of excellent
work already being done in the use of motion pictures for training
purposes. At the beginning comparatively few films had been pro-
duced specifically for naval training purposes, and comparatively
few training activities had become habituated to the use of motion
pictures for training purposes and accustomed to using films in their
training.

It is nearly six months since that time. The development and use
of motion pictures for training purposes in the navy has advanced
mightily during these past six months. I spent a part of this time at
sea aboard a destroyer and was myself surprised at the advances
made, even though I had participated in planning many of them.
Many more films have become available for training purposes.
Many training activities, and many officers concerned with training,
have become aware of the possibilities in the use of training films and
have adapted them to their purposes and needs. I am informed
that we now distribute about 2000 separate titles, to more than one

Dec., 1942] NAVY TRAINING FlLMS 335

thousand activities. It is the rule rather than the exception today
that officers given command of ships, not yet in commission, are
urgently requesting that they be provided as soon as possible with tin-
training films and projectors with which to prepare their crews i'..i
the duties to come. The medium of the motion picture training
film has thoroughly sold itself and is well established in its usage in
the navy.

Thousands of people are now familiar with the application of motion
pictures for training or educational purposes who never dreamed of
this until the war brought it into general use. You will recall that I
predicted last May that the educational functions of motion pictures
would some day exceed in importance and value their entertainment
function. I can reiterate that prediction today with a great deal of
support; for outstanding educators have said to me earnestly and
with an intensity approximating that of the ancient mariner, that the
Navy's development of training films will have repercussions in
civilian life after the war that no one today can estimate.

Responsible and leading educators predict that the introduction of
the motion picture to the extent now achieved will undoubtedly have
a profound effect upon education in the future. The Navy is in-
terested, of course, only in developing motion pictures for its own
special purposes. The fact that such a development may, however,
have its influence upon other developments for other purposes can
not be denied, and it is not unfitting that this should be examined
at this time.

Some of you may recall that I took considerable pains to point out
that the use of the motion picture for training purposes had in com-
mon with the use of the motion picture for entertainment purposes
only the fact that both are made with cameras, on film ; and are pro-
jected on screens in the same manner. I am firmly of the opinion
that the arbitrary introduction into the training film of the para-
phernalia of the entertainment motion picture — such as the use of
introductory and incidental music and other entertainment devices —
results in distraction and frustrates the purpose of the training film.
This has all too often been done merely because of habits developed
in the making of entertainment film, and results in inclusion of
material that has no proper place in a film intended to impart under-
standing to persons with a-serious interest in the subject. I labored
this point at some length because at that time there was very link
appreciation of the principles expounded. Since that time, I am

336 W. EXTON, JR. [J. S. M. P. K

very happy to say, there has been a much wider realization of the
fact that the training film is a training film and not an entertainment
film. Where once it was common to see a training film intended to
teach the workings of a lathe, or riveting machine, for instance, open
and close with music and have a musical background for the an-
nouncer's voice, that is now exceptional, and is generally the earmark
of the newcomer in the field of the training film. It is not that the
training film scorns the devices of the entertainment film, but rather
that any such device must be utilized only functionally — that is, when
it is useful for a training purpose, and not merely when it is entertain-
ing, and therefore distracting.

The Navy — and along with the Navy, the many companies that
are producing films for us — is learning a great deal about the develop-
ment of this medium for training purposes. One of the important
developments within the Navy itself is the assignment to the many
training activities of officers who are specialists in the utilization of
motion pictures. These experts in visual aids guide instructors so
that they may get the best results from the use of the many visual
aids increasingly being made available.

One of the most interesting things about the development of the
training film and in envisioning the future of this development, is the
concept of the changing, indeed, the ever rising, standards. There
are standards for the training film existing today in the minds of
certain individuals that are considerably higher than any actual
attainments to date. There are officers of the armed services who
have spent literally thousands of hours looking at training films
collected from many different sources. They have seen English,
German, Russian, Japanese, Canadian, and other training films as
well as those of our own Armed Forces and many developed by
educational organizations and by private industry. They have been
faced with numerous problems involving the development of visual
aids for specific purposes. They have seen these individual projects
developed, and they have viewed the final products. They have
evaluated these products in terms of actual use for the purposes in-
tended. They have seen many efforts to produce training films made
by persons who had distinguished themselves in the production of
motion pictures for entertainment. And they have been able to see
the obvious shortcomings, for the purposes intended, of many of
these efforts. They have listened to innumerable ideas, theories,
and proposals from many sources. As a result of all this there has

Dec., 1942] NAVY TRAINING FlLMS 337

been built up a very definite consciousness on the part of many of
those now connected with the armed services, of what is required in
a general way and frequently in a specific way, if a film is actually to
succeed in serving a valuable purpose. In connection with any
given training problem in the solution of which films are to play a
part, we have learned the necessity of organizing the material for
maximum assimilability. We have learned the need of exploring in
its every aspect the function to be performed by those who are to be
trained. We have been conscious of the fact that we must often
provide for the pedagogical effect of repetition — not necessarily for
repetition within the film itself, but the film must sometimes be
planned so that it can profitably be repeated. No element in it must
seem to deteriorate on repetition. The successful training film must
be a very skillful and effective blend of intelligent pedagogy (which
applies the teaching methods proper to the presentation of the sub-
ject), of technical knowledge (which insures that the subject-matter
presented is accurate and effective), and of good production (so that
the film will do complete justice to both the pedagogical and tech-
nical elements).

Generally speaking, in planning a film it is necessary to have a
pretty fair idea of the subject to be taught. It is just as necessary
to have a good understanding of the application of that subject to
the service for which it is intended. Then one must have a knowledge
of the kind of men who are to be taught, and the facilities that will be
available for teaching them; that is, the general conditions under
which the film is to be utilized. On the basis of an appreciation of
these four factors, it should be possible to plan the production of a
training film that will be accurate in content; designed to be under-
stood by the men for whom it is intended; and convey to them in a
manner justifying the use of the medium, the information that it is
necessary that they should have.

The fault in many of the training films that have already been
produced too often lies in the omission or abuse of one or more of
these factors. A film may be technically correct but badly pro-
duced; or its pedagogy may be effective for the more intelligent
person but poor for those who have not had much education. There
may be excellent pedagogy but poor technology, or excellent tech-
nology with poor pedagogy. In a few cases good pedagogy plus
good technology have been ruined by bad production. In the pro-
duction of films there are often several elements of production. For

338 W. EXTON, JR. [J. S. M. P. E.

instance, many of our training films are composed partly of animation
and partly straight photography. In some cases the animation is
excellent but the photography fails in its purpose. In others the
photography is excellent but the animation does not do all that
might be expected of it. Sometimes much footage is wasted on a
sequence that could be handled as well or better by the use of film
strips.

The use of the commentator — the monologue of explanation — is
extremely common. It is possible that great advances will be made
in the effective use of the voice of the commentator, and in the tech-
nique of such comment. There is little appreciation of the part
this element plays in the total effect.

The use of acting, of dialogue, for training purposes has, of course,
been highly developed. When well done and when done with an
understanding of the purpose, it can be invaluable. There is, how-
ever, a tendency, especially on the part of those who have made film
for entertainment, to abuse this element by overemphasis, thus in-
troducing all sorts of distracting elements.

When we speak of training films we mean films covering a very
large variety of subjects and also even of interests. We usually,
among ourselves, specify the major purpose of the film, indicating
whether it is a film of purely technical instruction, such as Forming
Sheet Metal, or whether it is an indoctrinal film intended to provide
general familiarity with a subject rather than specific knowledge to
be utilized. It may be specific visual education, such as the many
films that have been made on identification of ships and planes ; or it
may be a film that is shown for its general effect, such as some of the
inspirational short subjects that have been produced for general
popular distribution.

The production of each kind of training film involves, of course,
problems that the other types may not present. Individuals who
may be eminently fitted to produce a film of one kind may not do
very well with another. There is a growing tendency for persons
who are charged with the production of films for technical training
to attempt to include a psychological or inspirational introduction,
showing the importance of the job to be learned and its place in the
total war effort. There is much logic in this; for instance, a man
who must be instructed in the duties of a lookout should be impressed
with the importance of his function. However, a person skilled in
technical presentations may not do as well with the less tangible

Dec., 1942] NAVY TRAINING FlLMS 339

subjects, and this is, perhaps, another example of the need for in-
tegrated collaboration.

In general it may be said that the production of a training film
requires a coordination of essential creative elements that is rather
difficult to attain. It is rarely that all these elements can be found
in one person. Lacking such an unusual individual, it is necessary
that these elements be found in several persons, who can cooperate
effectively and successfully. Lacking such cooperation, the film
produced will be deficient, and will to a greater or lesser extent fail in
its purpose.

One of the most interesting of creative developments occurs in the
kind of cooperation that various individuals have been giving one
another in the production of training films. As this type of co-
operation is developed and as those who are outstandingly capable
of contributing certain essential elements come more and more to
realize the necessity for simultaneous contribution by other persons
in the interests of achieving best ultimate results, we may look for-
ward to the realization of many of the standards now merely visual-
ized. The realization of these standards will constitute the blazing
of a trail which should have an invaluable effect upon the production
of training and educational films for civilian purposes. In addition,
many films being produced for the Armed Forces have application
to civilian purposes, and plans are afoot to make such of them avail-
able as need not be withheld for reasons of security. As these films
come to be widely shown, it is likely that they will have the effect of
stimulating civilian demand for the production of such films.

The many commercial producers now working with the Navy will
have had invaluable experience that may enable some of them to
help fill this demand satisfactorily. There is no question in my mind
that we are actually dealing with the early stages of development of
an educational medium that will truly revolutionize life. When
every crossroads school can have the benefit of the direct application
of educational materials and methods, and even actual instruction
created by the best qualified talent instead of relying entirely upon
the local teacher, there will undoubtedly be effected a change in
the effectiveness of education, the results of which can not be
foreseen.

It is possible and even probable that the educational film will be
used to condition children in early life to conduct themselves aim mi;
their fellows and their elders in such a way as to pmlisposr t IK-HI for

340 W. EXXON, JR.

successful and effective living in the kind of democracy whose future
we are defending.

The technology of the motion picture, the engineering aspects, the
physics, chemistry, and even the economics of the motion picture,
are already well advanced. The motion picture has been able to
dominate the field of entertainment, a universal and important field
previously reserved for a comparatively few talented individuals as
to performance, and for a comparatively few urban centers as to en-
joyment. But the application of the motion picture to the inculca-
tion and dissemination of ideas and to the imparting of specific knowl-
edge and techniques is in its early infancy. The Armed Forces
have, through force of circumstance, the privilege of bringing its
development to a much higher point than any previously attained.
Their contribution to the development of this medium may well be
regarded in the future as one of the important results of the war.

THE UNDERGROUND MOTION PICTURE INDUSTRY
IN CHINA*

T. Y. LO**

Summary. — Motion picture production carries on in China under the most
hazardous conditions of war. The industry has literally had to go underground.
As protection against the Japanese bombings the laboratories and editing and storage
compartments are built in tunnels as deep as thirty feet below the surface. At the
alarm the equipment and portions of the sets and props are carried into the dugouts.
Actors and directors go on with their rehearsing, while editors and cutters continue
with their work to the hum of the approaching raiders. Thus production today in
valiant China.

The motion picture industry today in China is carried on in dug-
outs. The motion picture industry is a modern industry, and bomb-
proof dugouts are even more modern. But before we look at the
modern aspect of the Chinese motion picture industry, first let us go
back two thousand years.

Those were the days before electric lights. In the market square
after sundown, someone had put up a screen of white cloth stretched
across two bamboo poles. Behind it, a bright oil lantern burned,
throwing its light upon the screen. A crowd began to gather to
watch the spectacle. Music started, and on the screen shadows
appeared — shadows of puppets, images of scholars, warriors, and
women. A play was enacted. The puppets were skillfully manipu-
lated by hand, and because they were made of translucent colored
material, they looked very lifelike and real.

That was the ancient Chinese "screen show." Today we may
well regard such a show as good enough only for children, but in those
days and for the succeeding centuries up to the beginning of the
Twentieth, these shadow shows, together with the stage plays, held

* Presented at the 1942 Fall Meeting at New York, N. Y.; received October
27, 1942.

** Deputy Chief, Film Section, Political Department, Military Affairs Commis-
sion, Government of the Republic of China.

341

342 T. Y. Lo [J. S. M. P. E.

the field of popular entertainment in China. The ancient Chinese
were very proud of this all-action-dialogue-singing-dancing-music-
and-color screen show. Two thousand years later, we moderns are
still struggling with the problems that our forefathers imagined
were completely solved.

Now, we take a gigantic leap from 100 B.C. to the first decade of
the Twentieth Century. The first cinema theater in Shanghai was
opened by a Spanish showman in 1909. The moving picture novelty
took China by storm. The Chinese called the shadow show "lantern
shadows." Now, by substituting an electrical contraption for the
oil lantern, we introduce the fascinating motion picture. So, in
the image-suggesting language for which we Chinese are famous,
we call the modern motion picture the "electric shadows" — tien
ying — which is still the Chinese name for present-day motion
pictures.

From 1931 to 1936, China was in a period of transition. The
struggle for independence and for freedom from the shackles that the
train of unequal treaties since the Opium War had put on the Chinese
nation was still in progress. But above the horizon, another menace
was rising. Japan, jealous of China's natural resources and her
growing unity and power, had decided to carry out her plan of conti-
nental and world conquest. In 1931, sheliad occupied Manchuria.
Stimulated by this unwarranted attack, Chinese nationalism rose to
immense proportions. Reverberations were sounded in the motion
picture world. Film stories produced in China during that period
mostly reflected the spirit of the Chinese people, who fought against
aggression on the one hand, and sought to rebuild the country into a
new nation on the other.

Two films stood out during that period — The Fisherman's Song,
directed by Mr. Tsai Chosheng, and The Road to Life, directed by
Mr. Sun Yu. Both were imbued with the spirit of protest against
oppression, and everywhere in the country they were greeted with
rousing welcome. They were shown continuously for two months in
Shanghai and broke all box-office records both for Chinese and im-
ported films.

More and more films have been brought into China, including
Soviet films. Two schools of critics arose with regard to American
and Soviet films. One maintained that the Soviet film, with its
serious theme, treated in a powerful style, is the height of cinematic
art; while the other argued that since the movies are primarily for

•

Dec., 1942] MOTION PICTURE INDUSTRY IN CHINA 343

entertainment, the American films, with their gaiety, liveliness, and
forwardness in style, are more universal in appeal.

Before the advent of the talkies there were about twenty motion
picture companies in China. With the introduction of the sound
picture a process of absorption and amalgamation began, until
finally only five held the field, with a number of independent pro-
ducers attaching to one or another of these. By 1933, the govern-
ment had also set up several studios — the Central Studio, The
Educational Film Studio, and the China Film Studio; the last to
become later the China Motion Picture Corporation. A Visual Edu-
cation Committee was also organized by the Ministry of Education
to promote popular education through the medium of the cinema.

Prior to the outbreak of war in 1937, there were 375 cinema theaters
in China, mostly concentrated in cities along the coast. This figure
includes nearly a hundred theaters opened farther inland between
1936 and 1937, during which period there developed a tendency for
the cinema to spread to the interior. At the same time, the Visual
Education Committee of the Ministry of Education began to put the
16-mm silent films to extensive use. Two hundred IG-mm projection
units were set up at various places throughout the country. The
Political Department of the Military Affairs Commission organized
mobile cinema units, showing films not only to the troops, but to the
people in the villages and towns where the troops were garrisoned.

For the production of films, the companies imported foreign-made
cameras, mostly from the United States, but small machines and
equipment, such as lighting equipment, rewinders, splicers, and
printers, were sometimes made in the studio workshops and other
machine shops. In 1931, a recording machine was invented called
the tien tung, and later another machine came into use, called the
chunghua tung. In both, the variable-density system with the glow-
lamp was used. The whole idea is to make the machine into an
easily portable one. In 1935, an engineer in the Central Studio com-
pleted a machine for developing films. Besides these, many factories
and machine shops in some coastal cities also made amplifiers and
spare parts for sound projectors. The China Film Studio in Hankow
built sound stages based on the latest models. It is reported that
the Japanese have now turned these sound studios into stables.

Now we pass to the next stage in the history of the Chinese movie
industry. At the end of 1937 the Chinese Army, having withstood
for three months the violent onslaught of the Japanese invading

344 T. Y. Lo

forces, started to withdraw from Shanghai. With that withdrawal
began one of the greatest migrations in all history. Slowly but
steadily, the human stream moved west, first to Nanking, then to
Wuhu and Hankow. Amidst this great migration were fifteen
hundred people of the motion picture industry of Shanghai. These
included producers, scenarists, directors, actors, actresses, technicians,
and studio hands.

These people joined the government studios, one of which, the
China Film Studio, moved to Hankow where it organized film pro-
duction shock units devoted exclusively to war films. In four months
these shock units completed eleven features and over forty short
subjects. Another government studio, the Central Studio, was less
fortunate. In its hasty withdrawal from Wuhu, which was very
near Nanking, a large amount of its equipment was lost; so it was
compelled to travel to Chungking where it could be safe from enemy
bombings, and settled down for rehabilitation.

In the fall of 1938, Hankow itself was threatened and the last stage
of the migration began. Three months before, preparations were
already underway in the China Film Studio for the removal of all
equipment to Chungking. Systematically, everything that could
be carried away was transported up the river Yangtze, either by
steamer or on barges. It was winter and water was low in the
Yangtze. Wherever the currents ran too swiftly, the studio staff
had to go ashore and help the boatmen drag the barges upstream by
ropes.

It was in Chungking that the Chinese movie industry entered the
dugouts. Although we are movie people, we had not gone to the
length of building this subterranean show simply for the romantic
ring of its name. It was done of necessity. All the headaches,
heartaches, and backaches would have been for naught if within the
hour the savage mass bombings of the brutal Japanese had reduced
everything to ruins.

Now let us see this strangely located industry in action. Of
course, not all the work is done in the dugouts. The sound stages, for
example, are on the ground surface. But the laboratories, and editing
and storage compartments are built in the tunnels which in some
parts reach as far as thirty feet below ground. As soon as an air-
raid alarm is sounded, things start to move. Studio lights, cameras,
sound equipment, even portions of studio sets and important "props,"
are carried down into the dugouts. Once there, work is resumed.

FIG. 1. A "long shot" scene taken from Chinese "Lantern Shadow."
For the convenience of photographing, the "moving sticks" and "sup-
porting stick" are not shown.

FIG. 2. Actors, actresses, and extras studying and rehearsing their
parts in the tunnel during an air-raid.

FIG. 3. One of China Film Studio's sound stages located in Hankow
and designed by Mr. T. Y. Lo in 1936. The Japanese have turned it
into a stable.

FIG. 4. Miss Lily Lee (Mrs. T. Y. Lo, standing in center) in Storm
over the Border. Miss Lee spent a year in Inner Mongolia with a crew to
get the real background for the picture.

MOTION PICTURE INDUSTRY IN CHINA :;i :•

Directors confer with scenarists on scripts, actors and actresses study
and rehearse their parts, editors work at their benches, cutting and
splicing furiously to the horrible hum of approaching enemy raiders.

One of our great worries is the possible destruction of stages or
studio sets by Japanese bombs. The worst problem, however, is the
destruction of the water mains. The China Film Studio is situated
at the highest point in Chungking. When electric supply is cut off,
we can still use our own generators as a makeshift. But when the
water supply is cut off, as it was in 1939, we are compelled to carry
water from the river at the foot of the hill up to the studio, and by
this painful means fill a reservoir made specially for the purpose.
About two hundred people were needed for this task alone.

I remember an interesting incident that happened in -June, 1939.
We were at that time producing a film called The Light of East Asia,
with a large Japanese cast. These Japanese were originally war
captives who, after spending two years in the Chinese internment
camp, became aware of the fact that they had been fooled by the
Japanese militarists. They sent a petition to the Chinese govern-
ment for permission to form a "JaPanese Anti-War Federation in
China." It was some of these Federation members who played in
this film, The Light of East Asia.

One day, these Japanese were working on one of our back lots,
quite a distance away from the studio dugouts. An air raid came.
In the hurry, an amplifier was forgotten. When that was discovered,
enemy planes were already above Chungking. One of the Japanese,
Takahashi by name, volunteered to fetch the amplifier. But before
he got out of the dugout, bombs fell thick and fast. The blast sent
Takahashi rolling down the steps at the entrance of the tunnel.

The amplifier was destroyed after all. The wrecked sets could be
put up again in two days, but the amplifier was quite another matter.
Furthermore, we had at that time only one portable recording ma-
chine. But a resourceful recording engineer confidently told the
director that he could have everything fixed up for use in two days.
Promptly on time, he produced his amplifier for the shooting. It
was made out of the parts of a 7-tube d-c radio receiver.

There are at present three film studios in Chun^kin^. namely, the
China Film Studio, the Central Studio, and the Educational Film
Studio, all under various government departments. The China Film
Studio has a working staff of 700 people. I ts work is chiefly connected
with military training. All three studios together produce annually

346 T. Y. Lo U. S. M. P. E.

about 20 features and 80 short subjects and training films. For ex-
ample, there are story films like Good Husband, about military service ;
Victory Symphony, about the well known victory at Changsha, both
directed by China's famous- director, Mr. T. S. Shih; Storm over the
Border played by the writer's wile, Miss Lily Lee, which is her 21st
picture; and films like Anti-Tank Methods, to show how the civilians
close to the battle front can play their part to stop the advance of
Japanese tanks. The production of films is greatly affected by the
transportation problem, since all film has to be imported from
America.

I have mentioned other migrant factories. Naturally, these
factories devote themselves to the production of arms and other
needs more directly connected with the war. The making of spare
parts and small machines for the movie industry is thus handicapped.
But we can still obtain the cooperation of these factories, which are
themselves built in the dugouts. For example, they make sprockets
to supply our mobile units and lights for use in the studios. In 1940,
one of the arms factories made for the China Film Studio a five-plane
cartoon photographing machine. In a dugout of the China Film
Studio, there is a repair shop, which also produces tripods and
camera dollies. An unusual achievement of this repair shop was the
transformation of an old-model Bell & Howell silent camera into a
sound camera. The shutter and some gears of the old machine
were removed but the center axle was retained. The result was a
purely noiseless sound camera. We are compelled to make all these
improvisations because to obtain a priority on the supply and trans-
port of movie equipment from the United States is very much of a
happy dream.

The question may be asked as to what we do with the films we
produce. In Free China, we have 112 theaters as against the pre-
war figure of 375. These theaters also have their own dugouts to
store away their projectors during an air raid. Some of them install
generators to supply the current against a sudden cut-off as a result
of bombing. The generators use charcoal or vegetable oil for fuel.
In addition to our own productions, these theaters also show Ameri-
can and Soviet films.

Apart from the theaters, the mobile cinema units of the Political
Department, under the Military Affairs Commission, do some ex-
cellent work. There are ten of these units, first organized by Mr.
Y. C. Cheng, of the China Film Studio. Each unit has a captain,

Dec., 1942] MOTION PICTURE INDUSTRY IN CHINA 347

two projectionists, two electricians, and four carriers. Sometimes
they have to tour parts of Free China where there are even no roads.
They visit villages near the front, showing films to soldiers and
farmers. The generator alone weighs 150 pounds. Due to the
shortage of gasoline, alcohol is used.

According to the report sent in by the captain of one of the units,
during a period of seven months beginning January, 1940, his unit
made a journey of three thousand miles from Chungking to Inner
Mongolia, showing films to audiences totaling one and a half million
people. They travelled by trucks or on camels. Sometimes they
could obtain only two mules to carry the generator, so they them-
selves had to travel on foot. Once, they lost their way in the desert,
and managed to get out of it only by tracking the trail of another
caravan.

But the labor and hardships that these men had to go through were
duly rewarded. In Inner Mongolia, they showed films to people who
had never seen motion pictures before, and these people were so
elated over the fascinating spectacle that they made up a song, set it
to Mongolian music, and dedicated it to this unit. The song was
named, Down with the Little Japs.

Although suffering from a shortage of equipment and raw film, these
units have done some wonderful work. For instance, the Seventh
Mobile Unit went right behind the Japanese lines and showed films
to Chinese people in villages in an area that the Japanese believed
was under their control. On the wall of the China Film Studio hangs
a slogan that represents the spirit of these mobile units. It reads as
follows: Remember — One Foot of Film Properly Used Is as Deadly as
a Bullet Fired against the Enemy.

This is the simple story of the Chinese motion picture industry of
the present day. Compared with the great American motion picture
industry, we are but a toddling infant. We have yet to grow and to
learn. But we share with you the belief that the motion picture is a
very effective educational and cultural force. More than that, it is
an indispensable means of promoting international understanding
and good- will.

Today, our one great concern is to win this war. Let us never
forget that in the motion picture the United Nations have a powerful
weapon that will make a vital contribution toward a glorious victory
for justice and democracy.

WRIGHT FIELD TRAINING FILM PRODUCTION
LABORATORY*

H. C. BRECHA*

Summary. — The Army must train more than 2,000,000 men for the world's air
fronts as quickly as possible. This requires, in addition to instructors, a streamlined
program of visual education by means of training films. The Wright Field Training
Film Laboratory is a most modern establishment, and is manned by the most capable
and experienced producers, writers, directors, and technicians.

Some of the features described are the portable sound-truck, animation, special
effects facilities, the film processing plant, and some of the equipment used at the Field.

The U. S. Army Air Forces must train more than two million men
for the air fronts of the world, as soon as possible. These men will
not all be pilots — there will be bombardiers, gunners, radiomen,
navigators, and observers — and vitally important — the maintenance
crews: mechanics, armorers, radio repairmen, on all of whom the
Air Forces depend to "Keep 'Em Flying."

To prepare this tremendous and diverse body of men requires more
than instructors, more than the standard teaching aids now em-
ployed. It requires a new and completely streamlined program of
visual education which can be accomplished only through the power-
ful medium of motion pictures.

And that's where training films come in. By closely coordinating
its program with the courses taught at the various Air Forces Schools,
the Signal Corps Training Film Laboratory at Wright Field is pro-
viding training films that have cut weeks from current courses, at a
time when every minute counts.

Of -course, this is not an overnight development. Long before
most of the United States was aware we might be drawn into war,
the Army Air Forces and Signal Corps planned and created a Train-
ing Film Production Laboratory at Wright Field to streamline and
standardize visual education for aviation personnel. The Signal

* Presented at the 1942 Fall Meeting at New York, N. Y.; received October
27, 1942.

** Wright Field, Dayton, Ohio.

348

WRIGHT FIELD LABORATORY 349

Corps assigned an outstanding motion picture expert, Colonel Freder-
ick W. Hoorn, to do the job. Colonel Hoorn, who came to Wright
Field in 1939 with one civilian assistant, now heads a laboratory
consisting of several hundred persons, including officers and civilians.

These people are putting forth their extreme effort in expediting
the production of these training films, thus enabling the Army Air
Forces, in turn, to speed up their vital training courses.

Training films require a different technique from the motion pic-
tures you are accustomed to seeing Saturday night at your favorite
theater. Instruction — not entertainment — is sought, and the "star"
of the training film may be a mechanic or the airport weatherman.
Tempo of action varies from the careful unscrewing of nuts and bolts
to the flash of P-40s and Japanese Zeros locked in aerial battle. But
regardless of the tempo of the picture, every moment of it is planned
to prepare our pilots and mechanics to do their jobs more thoroughly
and with greater understanding. Throughout the making of the
picture, the producers, writers, and directors have the collaboration
and advice of the "Number One" specialists in the Air Forces.

Colonel Hoorn has assembled as his staff a capable group of officers
and civilians who are old hands at making motion pictures. The
Executive Department, headed by Lt. Colonel H. W. Mixson, assists
Colonel Hoorn in long-range planning, procurement of personnel and
administration.

There are three other major departments that supervise the mak-
ing of training films — the scenario, production, and editing depart-
ments.

Director of scenarios is Captain Robert Kissack, whose job is to see
that the Air Forces' ideas for films are translated into finished work-
ing scripts. Captain Kissack was formerly head of the department
of visual education at the University of Minnesota.

Production Manager is Lt. Hiram Brown, who correlates all phases
of production and keeps the plant running smoothly. Lt. Brown was
formerly an executive producer at Republic Pictures.

The Editorial Department is headed by Major Bertram Kalisch
who makes it his responsibility to smooth out the picture by effective
editing. He is also in charge of scoring the narration and synchro-
nizing it with the picture. Major Kalisch was for many years Assis-
tant Editor of Paihe News, and News of the Day, and also wrote and
supervised the production of many theatrical, educational, and
propaganda shorts.

350 H. C. BRECHA Lf. s. M. P. E.

Each of these men is assisted by competent aides who have had
wide experience in the making of motion pictures. A partial list
includes Assistant Editor Captain Jack Bradford, formerly with the
March of Time; and Lt. Richard D. Goldstone, formerly executive
producer of MGM shorts.

So much for the executive staff of the organization. Let us look
over the activities of the skilled craftsmen who direct the pictures,
make the sets, expose the films, put on the sound-track and perform
other highly specialized duties. From Hollywood, New York,
Detroit, Chicago, and even from foreign lands, the Laboratory has
recruited the best talent available. There are seven producers who
supervise the various production groups of directors and writers.

It is the writer's job to translate to teaching film the knowledge
that the foremost Army Air Force authorities wish to inculcate in
the thousands of up-and-coming pilots, bombardiers, and other
aviation students. In order to transfer this knowledge to film most
effectively, the writer himself must become familiar with the subject.
He has frequent conferences with the Army Air Force advisers who
oversee the script throughout its preparation.

The director who receives the script after it has been approved by
the proper Army Air Force authorities and by Captain Kissack's
scenario department prepares to shoot the picture. He often has
extensive conferences with the writer who can give him invaluable aid.

The director is perhaps the closest to a training film, because once
he takes charge of it, it is his responsibility during the rest of its pro-
duction. He has at his command the services of all the craftsmen
in the Laboratory. He is responsible more than anyone else for the
quality.

Let us take a look at the various departments whose services a
director often uses. The Camera Department is composed of twelve
ace cameramen, most of whom are leaders in the field of cinematog-
raphy. All types and makes of camera are used. B&H, Eyemo,
and Mitchell cameras are used extensively. As for the lenses, the
stock is most complete; thus both long and short focus lenses are in
general use.

The Sound Department is being built up rapidly, and is provided
at the present time with three truck channels, a fixed channel, and a
re-recording channel. New equipment will permit handling five
sound-tracks simultaneously; e. g., narration, synchronous dialogue,
music, and two types of sound-effects. Variable-area recording

Dec., 1942] WRIGHT FIELD LABORATORY 351

apparatus is used and most of the narration that accompanies the
pictorial part of the film is non-synchronous. A studio has been set
up and most of the films being made at the present time are scored here.

A portable sound-truck goes on location in cases where direct
sound recording is desired, while a library of sound-effects for dubbing
purposes is being augmented daily.

Animation is more than the stuff Donald Duck is made of. At the
Training Film Production Laboratory, animation drawings are deadly
serious work. Educators have found that they provide the best
means of teaching, and they are used by the Laboratory whenever a
point is to be driven home that can not be shown pictorially. Some
pictures are nearly one hundred per cent animation. A staff of 80
animators keeps things moving night and day !

Special effects, like animation, is a trick way of getting across a
point. In the special-effects department at the Training Film Pro-
duction Laboratory, such dangerous scenes as a forced landing or
a wrecked oil depot are realistically photographed in miniature with
a special type of camera. Naturally, this is an old art to Hollywood,
and so, many of the special-effects staff have been drawn from the
film capital. Samples of the work of the special-effects staff may be
found in almost every picture.

A developing and printing plant has recently been installed. By
virtue of its completion the Training Film Production Laboratory is
now entirely self-contained. The new film-processing laboratory
occupies 2500 sq. ft. of floor space. First tests have proved successful
and production will go into high gear within the next few days. The
laboratory is the Army's most modern film-processing unit.

Designed and installed by Consolidated Film Laboratory's En-
gineering Department, the machines use variable-speed torque
motors whose speed varies as the tension on the film increases or
decreases, as the case may be. A million feet of film per month is a
possible output, but actual production will be proportional, of course,
to the varying demand. The new laboratory, which, incidentally, is
completely sprocketless, is headed by Lt. Ted Hirsch, formerly of
Consolidated.

It is a straight-line processing unit in which the exposed film is fed*
into the developing machine; comes out completely developed, fixed,
washed, and dried; then goes to the negative breakdown assembly,
into timing, cleaning and printing, projection inspection; and finally
into the finishing room for possible additional prints.

352 H. C. BRECHA

The completed laboratory will include special rooms for developing
(wet and dry sections) ; timing ; negative cleaning ; printing ; sensi-
tometry and control; stock vaults; loading; test projection;
optical printing; and finishing. Facilities are also provided for
chemical mixing, circulation, storage, laboratory control, and silver
reclamation.

The spirit of the Laboratory — something that can not be defined
easily — is high. Cooperation exists throughout the whole structure
of the organization, and each person likes to feel that he is contribut-
ing in some small way to victory.

THE DOCUMENTARY, SCIENTIFIC, AND MILITARY FILMS
OF THE SOVIET UNION*

GREGORY L. IRSKY**

Summary.— The documentary, scientific, and military films produced in the
studios of USSR have one basic, main purpose — to show the Soviet people themselves,
and the rest of the world as well, how the Soviet citizen is living and fighting; how.
as a result of the war, factories and plants have been established in new localities;
how the tempo of production has increased; and how the people have contributed and
sacrificed to hasten the defeat of the enemy. And, despite the exigencies and demands
of war, cultural, educational, and scientific films continue to be produced in greater
numbers than before. The war has not hindered or stopped the cultural growth of the
country.

As I reported to you at the Hollywood Convention last spring,
during the war period Soviet Cinematography has been able to re-
organize its resources to meet the demands of the times. All docu-
mentary, scientific, and military films that are produced by our
studios have one basic idea, one main purpose — to show not only to
the Soviet people themselves, but to the whole world, how the
Soviet citizen is living and fighting ; how the people, at short notice,
have reestablished their factories and plants in new localities; how
they have increased their tempo of production; and how they have
sacrificed themselves in every way to strike blow after blow at the
bloodthirsty Fascists. These pictures are very valuable in ac-
quainting the Red Army and the Soviet people with the modern
technique that is helping us to crush our common enemy.

Our documentary films and newsreels, which are being released
regularly, are especially outstanding in this respect — the directors
and cameramen risk their very lives to make these films under the
fire of battle, working side by side with the soldiers, to give the world
the true picture of the present war. These films show the terror and
atrocities brought by the Hitlerite despots. These films show how

* Presented at the 1942 Falf Meeting at New York, N. Y.; received October
27, 1942.

** Cinema Committee of the U.S.S.R., Washington, D. C.

353

354 G. L. IRSKY [j. s. M. P. E.

the Soviet people are heroically and valiantly defending not only the
liberty of their own country, but that of the entire world as well.
Despite grave dangers and great difficulties our cameramen film the
most vivid episodes in the heroic struggles of our Red Army against
the Hitlerites. Flying with the bombers, they film aerial bombings
of enemy troops and parachute landings, while on the battlefield they
film the actual operations of our tank units, infantry, cavalry, and
artillery. Behind the enemies' lines they find excellent subjects in
the activities of our people's fearless avengers — the guerrillas, both
men and women.

A few of our documentary films as, for instance, Our Russian Front,
Moscow Strikes Back, and others, have already been shown here in
the United States. Their reception by the American people and the
American press has been excellent and very gratifying.

The subject-matter of our documentary films is very diversified,
portraying the intensity and the strenuousness of our lives. Aside
from the more recent military aspect of these films, the majority of
them deal with our industrial achievements and our scientific prog-
ress. They also reveal the intense research of our laboratories.
They show the great experiments being conducted in our leading
factories and on our collective farm fields, where our peasants, using
modern methods, have successfully surmounted many obstacles and
are supplying the towns with their products.

Our Soviet people know only too well how much success on the
front lines is dependent upon the home front. More than a million
feet of documentary film has been taken by our cameramen from the
time the Hitlerite hordes suddenly attacked our country. Years
will pass, and these historical films will be a permanent record, form-
ing a perfect tribute to our heroes. They will show our future genera-
tions how heroically and valiantly their forefathers fought for liberty,
suffered profoundly, and died nobly to insure the future happiness
of their children. These films will ever stand as an example of the
great heroism of the millions of people in the present war, who have
never faltered or surrendered their right to liberty. These films will
inspire our future youth also to hold high the banner of liberty and
independence.

Let us consider now what we are doing along scientific and edu-
cational lines. Undoubtedly you all know what great attention we
give in our young country to the matter of educational films, since
the law gives every youth the right to an education. We have a

Dec., 1942] FILMS OF THE SOVIET UNION 355

great many high schools. We have special technical schools where
the people can listen to lectures by the various specialists in order to
improve the quality and increase the quantity of their production.
We have many institutes, universities, and colleges with students
representing all the nationalities of the Soviet Union. All the peoples
of our country start on an equal basis and enjoy equally the inherent
right to study and pursue their respective studies.

Before the war, there were approximately 700,000 students en-
rolled in the country's 800 institutes. Among the 600,000 graduated
from these institutes are to be found engineers, doctors, teachers,
leading scientists, artists, architects, design engineers, famous Red
Army commanders, and leading experts in industries and trans-
portation. In wartime the Soviet institutes continue their work,
revising their schedules and programs of study to meet the basic re-
quirements and demands of the times. By increasing the number of
study hours in the week and shortening the holiday periods without
lowering our standards of education, we have been successful in
accelerating the graduation of students with such favorable results
that in the year 1941-42 the institutes gave the country 170,000
trained specialists, which is almost double the number normally
turned out. The institutes and colleges that have been moved to
safer localities from the territories temporarily occupied by the
enemy, continue to function normally. Upon arrival in the new
towns, professors and students rapidly establish their laboratories
and classrooms and begin working. Odessa and Kharkov's uni-
versities are functioning very well in their new homes and the Kiev
industrial institute now in Tashkent has already graduated 200
engineers. The above re'sume' shows us that the war has not hindered
or stopped the progress of the educational and scientific life of our
country. Therefore, the role of scientific cinematography remains
on a very high level as a vitally important factor in the training of our
personnel.

During the years 1940-42 as many as 450 scientific and educa-
tional films containing 1559 reels and 1,500,000 feet were made.
These films cover various subjects, such as geography, history, tech-
nology, agriculture, and military tactics. In other words, the topics
or the subject-matter of the films are closely interrelated with those
studied in the programs of our schools and colleges.

The Peoples Commissariat of Education has a cinema department
that has approximately 20,000 16-mm projectors, which are furnished

356 G. L. IRSKY [j. s. M. p. E.

for lectures to the high schools upon request. Many of our technical
and educational films are so effective that they enable us to teach our
people without the actual presence of a teacher. Under the direction
of Academician Choudakov, a cinema film entitled The Automobile,
containing 90 reels, was produced. With the assistance of this film,
several hundred thousand drivers of cars, trucks, tractors, tanks,
and motorcycles received instructions in the correct methods of
driving, and were well trained.

If some collective farm needs skilled drivers for tractors, this film is
sent and a group of prospective drivers study the principles of the
motor and other parts of the tractors and receive the consultations of
an adviser. After reviewing the film they have actual practice in
driving. Then they are qualified Nto drive.

When Moscow's famous turner Goudov invented a new method of
increasing the tempo of production, we made a special film showing
this method. This gave us the opportunity of utilizing Goudov's
method in many factories throughout our country. Several pictures
were made of the great work of our Academician Tsisin in growing a
new kind of grain for Siberia. This film helped us to explain simply
to our collective farmers this excellent experiment and, as a result, in
many barren lands where farmers had never grown any wheat before
there now appeared a harvest of wheat.

Pictures were made also for the medical profession and for students,
medical institutes, and scientists. In the Institute for Medical Re-
search and Experimentation there was conducted a great experiment
in the revitalization of organisms. In order to familiarize our
medical circles with this great experiment, we made a film under the
title of The Experience in Revitalizing (by Director lashin). This
film shows how the separate parts of an organism, the heart, for in-
stance, after having been taken out and put into a special receptacle
continued to function for a certain period.

A very good reception was given to a film taken on the sea bottom,
directed by Mr. Zgurydi. In this film the director and cameraman,
very completely and entertainingly, show the colorful life on the
bottom of the sea. For the filming 'of this picture, Soviet engineers
designed a special camera and cabin in which the cameraman dived to
the bottom of the water. Very complicated work in the field of film-
ing scientific biological films was made under the direction of Pro-
fessor Lebedev, who also designed special equipment for taking pic-
tures of microbes.

Dec., 1942] FILMS OF THE SOVIET UNION 357

In producing scientific and educational films, we have always paid
particular attention to the military aspect. These training and in-
structional films have not only helped our fighters to familiarize
themselves with tactics and the principles of operation of military
equipment, but also with the methods of proper upkeep and servicing.

Naturally, the war has required more consideration of the filming of
military pictures, and in order to meet the demand during recent
years, our studios have had to make many military films which are
successfully utilized in our military schools and camps on the battle-
fronts. In illustration, a few such pictures may be mentioned :

Hand to Hand Fighting: In this film are shown the methods of hand
to hand fighting under various conditions.

The Training of Ski Troops: The Red Army fighters are enabled to
study quickly the technique of using skis in combat, in reconnaissance
and marching.

Defense in Tank Warfare: In this film the director and cameraman
very successfully depict existing methods of defense against the on-
slaught of tanks under various conditions in open fields, forests, and
the like.

Marksmanship: This film teaches the soldiers and civilians the
minute details of good marksmanship so that they will at all times be
ready to defend their native land from the enemy.

Camouflage in Winter: This film was made on the basis of much
experience gained when our Red Army fought the Hitlerite invaders
in the winter time and is a very good subject for training new fighters.

Mine Control: Emphasizes the caution that must be exercised in
regard to the mines planted by our enemies and demonstrates the
modern methods of mine sweeping.

Training of Parachute Troops: This film shows the jump of the
parachutist under various conditions and illustrates methods of
training parachute troops.

The Anti-Tank Rifle: Shows the principles and action of the anti-
tank rifle designed by Soviet inventors. This particular rifle has
had exceptional success in the struggle against Nazi tanks, and the
film makes possible the training of masses of our fighters.

The great experience gained in producing documentary and sci-
entific films will enable us to utilize our resources to the utmost
advantage in the future for the purposes of reconstruction, further
progress, and the assurance of a happy life, after we have finally
crushed the destructive forces of mankind.

A ONE-RAY SYSTEM FOR DESIGNING SPHERICAL
CONDENSERS*

L. T. SACHTLEBEN**

Summary. — A spherical condenser is a simple lens of relatively large aperture.
The outer portions of such a lens focus the rays much nearer to the lens than do the
center portions. As a result the lens as a whole fails to produce a sharp image. This
defect of the lens is known as spherical aberration.

While in the case of spherical aberration no sharp image is produced, an image-
like region of best focus does exist. This is- known as the disk of least confusion. Its
diameter may be minimized by shaping the lens so as to minimize spherical aberration.
It is with this disk of least confusion and its required location that the designer of a
spherical condenser must deal.

Without a knowledge of the properties of the disk of least confusion a designer might
compute rays through a large number of trial lenses until, by an extensive and costly
trial-and-error process, a condenser, having the correct shape for minimal spherical
aberration and the disk of least confusion at the required location, is obtained.

The present paper examines some simple properties of the disk of least confusion.
In consequence it shows how, by computing the course of a single ray through the pro-
posed lens, a spherical condenser will result having the correct shape for minimizing
spherical aberration, and the correct center thickness for its assumed diameter and edge
thickness; and for which, finally, the location of the disk of least confusion is known.
The method is applicable to condensers comprising more than one lens, and leads to
the required design with a minimum of relatively simple trials.

Optical condensers are an important part of the motion picture
engineer's equipment. They are essential in optical systems for the
recording and reproduction of sound, and only by means of them
can the motion picture itself be adequately and efficiently illuminated.
In simplest terms, a condenser is the optical means by which the area
of a light-source is virtually increased manyfold, in order that a spe-
cific point or area may be illuminated more strongly than is possible
with the naked light-source alone.

Condensers are of various forms and types. The reflecting con-
denser of ellipsoidal form is widely used in picture projectors; aspheri-
cal-glass refracting condensers of the parabolic type are used in pic-

* Presented at the 1942 Spring Meeting at Hollywood, Calif. ; received April
14, 1942.

** RCA Manufacturing Co., Indianapolis, Ind.
358

ONE-RAY SYSTEM FOR CONDENSERS 359

ture projectors, and in sound reproducing optical systems. Simpler
and cheaper, if less efficient, spherical-glass refracting condensers
are widely used in all types of motion picture equipment employing
optical condensers, and it is to the problem of their design that at-
tention is directed in the present paper. The author does not claim
to have made an exhaustive study of the problem ; the purpose here
is to indicate the direction in which the solution has been found to lie
during the course of designing several condenser systems. The sub-
ject does not seem to have been treated systematically in any pub-
lished work of which the author is aware, and the problem is worthy
of considerable further study and elaboration.

In what follows the author has endeavored to adhere to the sign
and symbol conventions (see Appendix I) established by Professor
A. E. Conrady in his treatise on "Applied Optics and Optical De-

FIG. 1. A simple lens.

sign."1 The interested reader is urged to consult that work, if he is
not already familiar with it, as a practically unfailing aid in the un-
derstanding and solution of many optical problems.

INTRODUCTION

The conjugate axial object and image points, A and B, of the sim-
ple spherical lens shown in Fig. 1, have their positions related to each
other by the simple formula

where /' is the equivalent focal length of the lens, and / and /' are
measured from the first and second principal planes of the lens, // and
H' , respectively. This relation holds true for any position of the ob-
ject point A along the axis, but it is mathematically true only for the
so-called paraxial rays, which lie infinitely close to the axis of the
system. In a practical sense it is true for rays inclined as much as

360

L. T. SACHTLEBEN

Q. S. M. P. E.

2 degrees to the axis or to the incidence normals to the spherical
surfaces of the lens.2 (The incidence normal is the normal to the re-
fracting surface that passes through the point of intersection of the
ray with the surface.)

If in Fig. 2 a cone of rays of large angle originating at A and entering
the lens at height Yz from the axis be considered, it will be found upon
computing its course through the system that it fails to focus at the
point B, but comes to focus on the axis at a point somewhat nearer
the lens, say Bz' ' , at distance Lz' from the second principal plane of
the lens. The focal error, BZB = I' — Lz', is known as the spherical
aberration of the lens for the zone of radius Yz, and may be included
in the above formula, which then becomes

L.' + Bt'B I f
for rays at any inclination to the axis.

FIG. 2. Spherical aberration in a simple lens.

It is not possible to formulate an exact algebraic expression for the
spherical aberration in terms of /, Yz, and the radii and refractive in-
dex of the lens, for the law of refraction is itself trigonometric or
transcendental in nature. Frequently the spherical aberration is
expressed as a series in Yz, the constants of which must be evaluated
for the particular case under consideration. This series takes the form

B.'B =

there being no constant term and no odd powers of the variable Yz in
the expression.3 The successive terms of the series are said to express
the primary, secondary, tertiary, etc., spherical aberrations of the
system. (In general, YI may be any reasonable measure of the aper-
ture of the lens, and need not be restricted to the height of the point
of incidence above the axis. In the practical part of this paper Yz will
be taken as the tangent of the inclination angle Uz, between the ray
and the axis.3)

Dec., 1942] ONE-RAY SYSTEM FOR CONDENSERS 361

In view of the above-given statement that the simple lens formula
holds true, practically, only for rays having inclinations or incidences
up to 2 degrees, it is obvious that it can not be relied upon when de-
signing a condenser for which these angles may be as large as 20
degrees or more. Evidently the presence of spherical aberration must
be considered.

THE CONDENSER DESIGN PROBLEM

It is the function of a condenser ordinarily to direct all the light
from an illuminated object into a lens that is to project an image of
the object. Except in certain special cases a condenser is not required
to be aberration free, but it is usually required to be of quite large
aperture and frequently must be designed so that the brightest, or
most concentrated part of the beam emerging from it falls in the plane
of a lens or other aperture. In general, condensers are simple lenses
of large aperture required to cover a relatively small field. As such
they may be studied by considering only the images of object points
lying on the axis.

Since a high degree of freedom from spherical aberration is usually
not one of the conditions of condenser design, it will suffice to assume
that the actual aberrations of the condenser obey the law of primary
spherical aberration

B.'B = a2F.»

For simple condensers up to a speed off/2, this equation represents
the spherical aberration to a sufficiently good approximation if Oi is
evaluated by computing BZ'B for an edge or marginal ray, and divid-
ing that value by the square of the effective semi-aperture of the lens.

Professor Conrady proves4 that when the focal errors of a lens
system obey the law of primary spherical aberration, the best focus
occurs three-fourths of the way from the focus for the center of the
lens, to the focus for the edge of the lens. (The proof is corollary to a
proof4 that the disk of least confusion occurs "at the point of inter-
section of the arriving rays from the half -aperture, with the produced
marginal rays.") This constricted region in the emerging beam of
light represents the nearest possible approach to a true image in the
presence of primary spherical aberration, and is known as the disk of
least confusion. It is with this disk of least confusion, and its location
on the axis of the system, that the designer of spherical condensers is
concerned; rather than with the image point Bt which exists only for
rays having inclinations and incidences of 2 degrees or less.

362 L. T. SACHTLEBEN [j. S; M. p. E.

FUNDAMENTAL CONDITIONS OF THE SOLUTION

If the spherical aberration of any zone of the lens of Fig. 2 is ex-
pressed as

B.'B = a2Yt*

and the spherical aberration of the margin of the lens as

Bm'B = «2 Fw2
then by division

B*'B _ V2/V 2

Bm'B ~ Ys/Ym

Remembering that for the point Bzt corresponding to the position
of the disk of least confusion

Bm'B

it is seen that for this point the corresponding Yz is given by

That is, the zone through which the rays must pass, if they are to
come to focus at a point Bz' corresponding to the position of the disk
of least confusion, has an aperture which is V 3/4 = 0.8660 X the full
effective aperture of the lens. This zone of the lens, which is thus as-
sociated with this important point, shall be called the "square-root-of-
three-fourths-zone" ; written simply as the " v 3/4 zone." The deter-
minate diameter of this zone is the fundamental fact upon which the
present solution of the condenser problem is based. It is thus clear
that only the rays from the object-point A that enter the lens at an
aperture equal to v3/^ times the full effective aperture of the first
surface of the lens need be considered. And since all such rays form
an axial cone or pencil of rays, which are all refracted exactly alike,
it becomes necessary to consider only one ray as the key to the solu-
tion of the problem.

In Professor Conrady's proof referred to above, it is shown that the
diameter of the disk of least confusion is proportional both to the
spherical aberration Bm'B of the rays from the margin of the lens, and
to the tangent of the angle Um' which they make with the axis at their
focus. It is desirable in any condenser system that this diameter shall

Dec., 1942] ONE-RAY SYSTEM FOR CONDENSERS 363

be kept as small as conveniently possible, and since both these quan-
tities vary in the same sense, the diameter of the disk will be smallest
when the spherical aberration of the marginal ray is smallest. It is
well known that a simple lens has minimal spherical aberration when
its shape is such that the change in direction, or deviation of the edge
ray, is the same at both surfaces. It shall here be prescribed that the
deviation of the V*74 zone ray, rather than the edge ray, shall be
equally divided between the two surfaces. This will give the lens a
shape slightly different from that necessary to divide the total devia-
tion of the edge ray equally between the two surfaces. But since for
that shape the total deviation of the edge ray is a minimum, the pre-
scribed small departure from it will change the total deviation of the
edge ray by a negligible amount. If the condenser is to have four or
more glass-air surfaces the total deviation of the Vy^ zone ray shall
be divided equally among all of the surfaces. The component lenses
will thus all have approximately the same power; they will each have
very nearly the correct shape for minimal spherical aberration; and
as will be seen, this equal apportionment of the deviation among the
surfaces makes it possible to calculate all lens thicknesses, and the
curvature of every surface after the first, by means of a very simple
formula.

SOLUTION OF THE CONDENSER DESIGN PROBLEM

Having determined the fundamental conditions that the finished
condenser must fulfill, it is possible to proceed with the actual prob-
lem of its design. The problem can not well be put into a general
form, for each design becomes a problem of itself, depending upon the
particular combination of requirements that must be fulfilled, and
upon which of the variables are left to be determined by the conven-
ience of the designer. In general the designer begins with some in-
formation regarding certain of the following: magnification of the
system; speed or diameter of the system; distance from system to
source or image ; separation of source and image ; allowable thickness
of system ; allowable cost of system ; etc. The problem may thus pre-
sent itself in innumerable ways. Frequently certain assumptions or
estimates must be made, and trial designs based upon them until a
design is found that meets the stated requirements. In such cases the
assumptions are based upoti actual designing experience.

The initial inclination of the ray that will traverse the v*/4 zone of
the lens may be readily calculated from that of the edge ray, which

364 L. T. SACHTLEBEN fj. S. M. P. E.

may be known or readily determined from the general requirements
of the proposed condenser system. Thus, if the initial inclination of
the edge ray is Um, then the initial inclinaton of the V 3/4 zone ray is

U, = tan"1 v/3~A tan Um (1}

Occasionally Uz must be estimated, and the design approached
through a succession of such estimates.

It is usual for a condenser to be designed to work at some specified
magnification, say, M, in which case

sin Ut = M sin final Us'
or

final UM' = sin-1 ^jp (2)

If M is not given, a trial estimate of it may also be necessary. Thus
the total deviation of the ray becomes simply

-U. + final UM' (5)

If, further, I— I' = 6 is the deviation of the ray at each surface,
and Q is the number of individual lens elements comprising the pro-
posed condenser, then

2<2 X 6 = - U, + final U,'
or

e = ~ U. +^final U.' (4}

After choosing the glass from which the condenser is to be made
(usually some variety of Crown), the initial angle of incidence /, of
the ray, may be calculated. SnelTs Law of Refraction is expressed
in terms of the sines of the angles of incidence and refraction, 7 and
I', respectively, and the corresponding indexes, N and Nf, of the first
and second mediums, thus:

N sin / = N' sin /'

But where there are given only the indexes and the deviation / — I' =
6, as in the present case, then from Snell's Law, by Appendix II,

I = cotan-i -jp\ (5)

Dec., 1942] ONE-RAY SYSTEM FOR CONDENSERS 365

Having computed Uz, and / by equations 1 and 5 above, it is finally
necessary to choose the distance LI from the object-point A to the
first surface of the condenser, if it is not already given; after which
the radius of curvature r\ of the first surface may be computed by the
formula, derived in Appendix III

Following this, the remaining curvatures and thicknesses of the
system may be rapidly computed by alternate application of the
standard trigonometric computing formulas7' *• 9 (see Appendix IV)
and a simple algebraic formula to be deduced in Appendix V. (The
Standard trigonometric computing formulas are a group of simple
trigonometric equations by which the coordinates of a ray, after re-
fraction at a spherical surface, are computed from its coordinates be-
fore refraction.)

The work is continued by introducing LI, U\ = Un, and TI into the
standard trigonometric-ray tracing formulas and computing L\ and
Ui' for the v*/* zone ray in the second medium, after refraction at the
first surface. This computation automatically yields the angles /i
and /i', whose difference I\ — Ii should be equal to 6 above. For the
second surface of the lens Lz = L/ — di't where d\ is the center thick-
ness of the lens (as yet undetermined).

The assumption of equal deviation of the ray at each surface now
leads, by Appendix V, to the important algebraic formula relating
La, and the second radius of curvature r2, thus :

(7)

L2 Li' - di' 2ri - V

From equation 7 it is seen that the ratio of r* to La is a constant which
may be evaluated in terms of the now known data r\ and L\ for the
first surface. Equation 7 makes possible a slide-rule computation of
rz, upon the assumption of any trial value of d\, from which the edge
thickness of the lens at its assumed or required diameter may be com-
puted (see Appendix VI). When a value of d\ has been found that
will yield a satisfactory edge thickness the corresponding value of
ra is accurately computed. The values of Lj, U\t and fj are then in-
troduced into the standard ray-tracing formulas, and the new L»' and
U2' computed trigonometrically for the Vyi zone ray after its refrac-
tion at the second surface. The difference /t - /t' should again be
computed and seen to be equal to 0.

366 L. T. SACHTLEBEN [j. s. M. P. E.

Equation 7 may now be rewritten with suffixes increased by unity,

- L2f ' va)

and applied as before to compute the third radius of curvature. This
is allowable, for the relation expressed by equation 7 is purely geo-
metrical and unrelated to the laws of optics. Ordinarily, the second
and third surfaces of the lens are separated by an air-space d2 ' of
nominal length, say 0.5 mm. As there can be no question of edge
thickness at the air-space for lenses of this form, since such spaces
have negative curvature, it is permissible to assume a nominal thick-
ness for the air-space and immediately compute r3.

FIG. 3. Form and proportions of a lens designed by the
one-ray method, showing the course of the \/M zone ray.

It is now evident that completion of the design of the condenser is
only a matter of repeating the procedure, outlined above for the
second and third surfaces of the lens, until all the radii and thick-
nesses of the originally assumed number of component lenses have
been computed.

EXAMPLE

In Appendix VII, an actual design is carried through in detail, the
condenser having a speed of about//!, and a magnification of M =
— 4.5 X- Fig. 3 illustrates the form and proportions of the resulting
lens, and shows the course of the V 3/4 zone ray through it.

Fig. 4 illustrates the distribution of the rays in the vicinity of the
focus. The focus of the V 3/4 zone ray is seen to lie very near the disk
of least confusion, which, due to the presence of the higher-order aber-
rations, is itself displaced toward the lens from the originally assumed
theoretical position. The fact that the focus B of Fig. 4, computed
by the simple lens formula, lies nearly 2l/t inches beyond the disk

Dec., 1942] ONE-RAY SYSTEM FOR CONDENSERS 367

illustrates the futility of using the simple lens formula when designing
lenses of this type.

The computations of Appendix VII would normally represent about
three hours' work, and in actual practice two to four trials may be re-
quired to produce a condenser fulfilling all the requirements of a de-
sign.

APPENDIX

(I) SIGN AND SYMBOL CONVENTIONS*

A ray is completely designated with respect to a given spherical refracting sur-
face if its point of intersection with the chosen axis of that surface and its angle
of inclination to the axis are given. Professor Conrady chooses to apply the nega-

FIG. 4. Distribution of rays in the vicinity of the focus
of the lens of Fig. 3. Computed rays: (a) marginal ray;
(6) x/Ji zone ray; (c) half -aperture ray; (d) estimated
ray (not computed). B represents the location of the
image as computed by the simple lens formula. Vertical
scale increased 5X for clarity.

tive sign to all intersection-lengths lying to the left of a surface, and the positive
sign to all those to the right. The radius of curvature of a surface is treated as the
intersection-length of any normal to that surface, and is therefore negative
if the center of curvature lies to the left of the surface, and positive if it lies to the
right. He chooses to measure the inclination of a ray by the acute angle that the
ray makes with the axis, calling the angle negative if it is generated by a counter-
clockwise rotation from the direction of the axis into that of the ray, and positive
if generated by a clockwise rotation. Accordingly the angles of incidence and re-
fraction are positive if generated by a clockwise rotation from the direction of the
ray to the direction of the radius or incidence normal. The axis of a single spheri-
cal surface may be any straight line through the center of curvature, but in a
system of two or more spherical refracting surfaces, the centers of curvature of all
the surfaces are made to lie on the same straight line, which is then regarded as
their common axis.

Inclination angles for rays actually in the medium to the left of a refracting sur-
face are designated by a plain vowel, as U; and in the medium to the right by a

368

L. T. SACHTLEBEN

LT. S. M. P. E.

primed vowel, as U'. Intersection-lengths for rays actually in the medium to the
left of a surface are designated by a plain consonant, as L; and in the medium to
the right by a primed consonant, as L'. In like manner / and I' designate the
angles of incidence for rays actually in the mediums to left and right of a surface,
respectively. Capital letters designate the data of rays at finite angles to the
axis, and small letters the data of rays lying indefinitely close to the axis.

N and N' designate the indexes of refraction of the mediums to the left and
right of a surface, respectively; d and d', which are always positive in the usual
left-to-right computation, designate the axial thicknesses of elements to the left
and right of a surface, respectively.

Numerical subscripts refer the above symbols to particular surfaces that are
numbered successively from left to right, beginning with 1.

(II) THE ANGLE OF INCIDENCE
The relation between the angles of incidence and refraction, / and /', and the

FIG. 5.

corresponding indexes of refraction, N and N', is known as Snell's Law of Refrac-
tion and is stated thus:

N sin / = N' sin /'
The change hi the direction of the ray or its deviation upon refraction is equal to

/ - /' = 6

By transposition and substitution Snell's Law becomes
N sin / = N' sin (/ - 0)
Upon expansion of the right hand term

N sin I = N' (sin / cos 6 — cos / sin 0)
and upon dividing this equation by sin /, and transposing

= cotan i

sin0

Dec., 1942] ONE-RAY SYSTEM FOR CONDENSERS 369

(in) THE FIRST RADIUS

Professor Conrady proves' (see Fig. 5) that if a ray at inclination U intersects
the axis of a spherical surface of radius r at a point Bt which is separated a distance
L from the vertex A of the surface, and meets the surface at an angle of incidence
/, then the length of the chord connecting the point of incidence P with the vertex
A may be written

PA - L sin U sec

But since also

then by substitution and transposition

r = — sin U sec — -^

17 I + U

cosec — —

(6)

FIG. 6.

(IV) STANDARD TRIGONOMETRIC COMPUTING FORMULAS'

If the axial intersection length L, and the inclination £7 of a ray are given, and if
the refractive indexes N and N' of the first and second mediums, respectively, are
given, and if, furthermore, the radius of curvature r of the spherical refracting
surface is known, then the new intersection length L' and new inclination V of
the ray after refraction may be computed by the following formulas:1' •

The angle of incidence / in the first medium of index N is given by

sin / = sin
The angle of incidence /' in the second medium of index N' is given by

sin /' - p sin / (B)

The inclination U' of the ray after refraction is given by

U' - U + / - /' (O

370 L. T. SACHTLEBEN [j. s. M. P. E.

The intersection-length L' of the ray after refraction is given by

Where d' is the axial distance to the next succeeding surface, the new L for that
surface becomes L' — d', and the new U is obviously equal to U'.

(V) ANY RADIUS AFTER THE FIRST

Given two spherical surfaces of radii r\ and r2, separated a distance d\ (Fig. 6).
Consider any line PP' which connects the two surfaces, and whose extension
intersects the axis of the two surfaces in the point A' at a, distance L\ from the
vertex of the surface of radius r\. In general the line PP' will make an angle I\'
with the radius CiP of the surface of radius rit and an angle 72 with the radius
CzP' of the surface of radius r2. The line PP' will be inclined at an angle £/i' = Z7*
to the axis of the two surfaces.

From the triangle A'C\P, for the first suface

7- /

Li\ T\ T\

sin h' = ihTTV
and from the triangle A'CzP', for the second surface

=
sin Iz sin Uz

By division of the second equation by the first

Li — r2 sin // _ r2 sin U\
Li — r\ sin Iz f\ sin Uz

By imposing the condition that I\ = —Iz and, at the same time, noting that
Uir = Uz, and I* = L\ — di, there results the simple algebraic equation

from which

rJL - r<l ri (7\

L2 L^'-di' 2rl-L1'

a purely geometrical relationship.

(VI) RADIUS, SEMICHORD, AND SAGITTA OF AN ARC

The radius r, semichord d, and sagitta h of the circular arc A CB (Fig. 7) are
related by the formula

_ h* + d2
~~2h~

This may be written as

Dec., 1942]

ONE-RAY SYSTEM FOR CONDENSERS

371

By allowing h/r to assume an appropriate series of values from 0 to 2, a correspond-
ing series of values of d/r may be computed, and plotted against h/r as abscissas.
From this curve d may be readily deter-
mined when h and r are given, or h may be
obtained when d and r are given.

By dividing each member of the series
of computed values of d/r by the corre-
sponding values of h/r, a likewise corre-
sponding series of values of d/h is obtained.
When these values are plotted against h/r
as abscissas the resulting curve easily
yields d when h and r are given, or yields r
when d and h are given.

The two curves thus obtained are in-
valuable in quickly solving problems in-
volving the center and edge thicknesses,
radii, and diameters of lenses. They
quickly repay the trouble spent in comput-
ing and plotting them.

pIG 7

(VII) EXAMPLE

The lens to be designed will have a speed of about //I, and will work at a mag-
nification M = — 4.5 X. The inclination UM of the edge ray arriving from the
source will be taken as —25 degrees, and the distance LI from the source to the
first refracting surface will be taken as — 1 inch. It is assumed that the lens will
be made of glass having an index Nif = 1.5230. The lens will comprise two ele-
ments, as the speed of any individual element should not exceed //2.

By equation 1

U,(= Ui) = tan~l 0.866 tan -25° = - 22° (very nearly)

By equation 2

Assuming, upon the basis of experience, that the distance L* from the last sur-
face of the lens to the image will be 5 inches, the estimated diameter of the lens
is calculated as

Diameter - i-^ tan 4°47' - 0.96 inch

U . oOO

(It will be convenient to take the diameter as 1 inch, and compute the center
thicknesses upon an assumed edge thickness of 0.1 inch.)
By equation 3

-U, + final U.' - 26°47'

and by equation 4

26°47/
2X2

- 6°41'45'«? - 2 elements)

log sin / =

9.51498

colog Nf =

9.81730

log sin /' =

9.33228

I =

19-06-24

/' =

-12-24-39

372 L. T. SACHTLEBEN [J. s. M. P. E.

By equation 5, / is computed as follows10'11

log cos e = 9.99703 = log 0.993185

colog -N' = 9.81730- = log -0.656599
log (cos 0-^) = 9.52710 = log 0.336586

colog sin e = 0.93331
logcotan/ = 0.46041 = log cotan 19-06-24

(The more convenient method of writing angles as 19-06-24, instead of the usual
19°6'24", will be used beyond this point.)

A check of the last computation is most conveniently made by computing /'
from Snell's Law. Thus sin /' = sin I/N'.

log sin 12-24-39

B = 6-41-45

It will be well to precede the computation of r\ by tabulation of the relevant
data as required by equation 6.

L! = -1 l/z(I - U,) = 20-33-12

U. = -22-00-00 l/*(I + U.) = -1-26-48

/ = 19-06-24

By equation 6, r\ is computed as follows

log Li = 0.00000-

colog2 = 9.69897

log sin U. = 9.57358-

colog cos V2(7 - U,} = 0.02856

colog sin V2(7 + U.) = 1.59780-

log ri = 0.89891- = log -7.92337

From the now known values of LI, Ui and r\ a computation7 by the Standard
trigonometric computing formulas yields

Li' = -1.47163, and US = U2 = -15-18-15

By equation 7, rz/L2 is computed as follows (assuming di = 0)

logn = 0.89891-
colog (2fi - Li7) = 8.84239-

logr2/L2 = 9.74130 = log 0.551 188

Dec., 1942] ONE-RAY SYSTEM FOR CONDENSERS 373

A few trial values of di' show that an edge thickness of 0.1 inch will result from
a center thickness d\ — 0.230 inch.

By equation 7, r2 is computed as

r2 = (Li' - <*/) £

log (L,' - di') - 0.23087- (- logL,)
Iogr2/Lj - 9.74130

Iogr2 = 9.97217- = log -0.93793

From the known values of Z,2, Ut, and r«, the standard computing formulas
yield

IV = -2.98889, and US = U> = -8-36-32

The third radius may be immediately computed upon assumption of d\ »•
0.020 inch.

By equation 7, r, is computed as follows

log (ZV - d2') = 0.47841- (= log Z,)

Iogr2 = 9.97217-
colog (2r2 - ZV) = 9.95349

log r3 = 0.40407 = log 2.53554

From the known values of £3, Us, and r, the standard computing formulas
yield

ZV = -13.7880, and £78' = C74 = -1-54-57

If, as is advisable, a scale drawing is made as the design progresses, to show the
course of the ray through the system, it will be apparent that the first element
must be made about 1.062 inches in diameter and the second element must be
made about 1.125 inches in diameter to accommodate the edge ray. With this in
mind, the final radius r4 may be computed.

By equation 7a, r4/Lt is computed as follows (assuming d* = 0)

Iogr3 = 0.40407
colog (2r8 - Z,3') = 8.72448

log f4 = 9.12855 = log 0.134447
L*

It is seen that L\ is very much larger than any probable value which d\ may as-
sume, and that as a result the value of r4 will be only slightly different from the
value obtained on the assumption that d\ = 0. With this in mind it is quickly
found that the edge thickness of the second lens (diameter — new value of 1.125
niches) will be very nearly 0.1 inch when the center thickness is 0.250 inch.

By equation 7a, r4 is computed -as

374 L. T. SACHTLEBEN

log (V - <V) = 1.14731- (= log Z,4)
logr4/Z,4 = 9.12855

Iogr4 = 0.27586- = log -1.88738

From the known values of Z,4, U4, and r4 the standard computing formulas
yield

L/ = 5.52255, and E74' = 4-46-56
The height of the point of incidence at the last surface is

F4 = r4sin (U, + 74)12

The free aperture of the last surface is thus 2F4/0.866, and is computed to be
1.080 inches.

Thus the lens is specified as follows:

N' = 1 5230

n = -7. 923 inches dir = 0.230 inch. Diameter = 1 . 062 inches

r2 = -0.938 inch

d2r = 0.020 inch (air-space)

ra = +2.536 inches d3' = 0.250 inch. Diameter = 1.125 inches

r4 = —1.887 inch

Free aperture of first component = 1.030 inches.
Free aperture of second component = 1.080 inches.

REFERENCES'

1 CONRADY, A. E.: "Applied Optics and Optical Design," Part One, Oxford
University Press, London (1929).

2 Ibid., p. 37.

3 Ibid., p. 101.

4 Ibid., pp. 120-122.

6 Ibid., pp. 4-6.

• Ibid., pp. 25-26.

7 Ibid., pp. 6-18.

8 MARTIN, L. C. : "An Introduction to Applied Optics," Vol. I, Sir Isaac Pit-
man and Sons, Ltd., London (1930), pp. 16-20.

9 HARDY, A. C., AND PERRIN, F. H.: "The Principles of Optics," 1st ed.,
McGraw-Hill Book Co., New York (1932), pp. 34-41.

10 In optical calculations it is common practice to write the characteristic of a
logarithm as 9 ( = 10-1), in place of 1, to avoid the use of negative characteristics.

11 Logarithms of negative natural numbers are followed by a minus (— ) sign.
The result of a logarithmic computation is positive if an even number of such signs
is involved, and is negative if an odd number is involved.

12 CONRADY, A. E. : "Applied Optics and Optical Design," Part One, p. 29.

LIGHT-SCATTERING AND THE GRAININESS OF
PHOTOGRAPHIC EMULSIONS*

A. GOETZ AND F. W. BROWN**

Summary. — The factors upon which the optical scattering power of a photo-
graphic emulsion depend and the relationship of the former to the graininess are
investigated by a method that consists in determining the ratio of two average trans-
parencies (7yr2) of a moving emulsion sample of uniform density with a micro-
photometric device integrating simultaneously over a large (Ti) and a small (Tt)
section of the sample. The variation of the scattering power (defined as T\/T^ with
the density is determined (a) for negative emulsions: the finer grain has the larger
Ti/Ts; (6) for a positive emulsion directly exposed and printed through various
types of negative emulsions: Ti/T2 is independent of the resulting graininess; (c)
for positive emulsions printed with white and ultraviolet light: T\/T\ is not affected
by the wavelength of the printing light; (d) for a positive emulsion with varying
gamma (0.44 to 2.5): no influence upon T\/Ti by gamma is observed.

(I) INTRODUCTION

Previously the senior author with his collaborators1- 2i 3> 4 has
published an approach to the absolute determination of the graininess
of photographic emulsions based upon the statistical distribution of
the relative transparency fluctuations in terms of the Gaussian
probability function :

) f%-
Jo

« = x)

The graininess coefficient G has been found to be an accurate and
universal representation of the graininess realization by the subject i v</
optical as well as the sound observer, if certain factors such as the
"discrimination factor" are considered.

An instrument has been designed and described4 which by means
of an automatic microphotometric analysis of a small area of the
emulsion, exposed and developed to a known uniform density D
permits the evaluation of the graininess coefficient G by a relatively
simple manipulation. This graininess meter has been used for a

* Presented at the 1942 Spring Meeting at Hollywood, Calif. ; received May
24, 1942.

** California Institute of Technology, Pasadena, Calif.

375

376

A. GOETZ AND F. W. BROWN

LT. S. M. P. E.

number of years in the research laboratories of a large industrial
producer of emulsions and a great deal of data have been thus accu-
mulated, in particular with reference to the variation of G with D.
The evaluation of this particular function brings forth a factor that
has a major influence upon the subjective as well as the objective
realization of the graininess, that is, the light-scattering power
(Callier effect) of the emulsion. In order to clarify the relationship
between this effect and other factors contributing to the evaluation

FIG. 1. Apparatus for measuring scattering in photo-
graphic emulsions: Lt tungsten arc lamp; D, rotating
shutter with adjustable sectors; E, emulsion sample on
rotating stage; MI, transparent mirror; C-l, C-2, bound-
ary layer photocells (Lange) ; S, double-pole double-throw
switch; G, galvanometer.

of G, an experimental study of the causes of the light-scattering power
under the particular conditions under which the graininess of an
emulsion is measured was undertaken.

(II) THE METHOD

The method employed is similar to the optical system in the graini-
ness meter of Goetz, Gould, and Dember;1- 4 it differs only in the
elimination of mechanical parts not essential to the determination of
the scattering power.

Fig. 1 gives a schematic view : The tungsten arc lamp L illuminates

Dec., 1942] PHOTOGRAPHIC EMULSIONS 377

through an achromatic condenser of large aperture the emulsion E
mounted upon the rotary stage of a microscope. The intensity of
the illumination can be varied by a rotating disk D which carries a
large number of equal-sized sectors which can be obscured individ-
ually. The speed of rotation of D was adjusted to be far above the
mechanical frequency of any of the instruments used — hence the
spectral distribution of the light-source as well as the aperture of the
incident beam were always constant.

The rotary stage (not shown in the diagram) upon which the emul-
sion sample was mounted was driven by motor at 30 rpm, and was
adjusted so that its center was several millimeters off of the optical
axis of the condenser and objective. In this manner, the transpar-
ency was averaged over an annular section of the emulsion and local
irregularities were avoided. The microscopic objective was a 20X
apochromat with a numerical aperture of //0.60. Above it the beam
was split by a clear thin glass plate MI deflecting a fraction of the
light transmitted through the objective into a horizontal direction
upon a very sensitive photoelectric layer cell (Lange), C-l. The
vertical beam projected through the tube M into an ocular (15X
compensation) and from there through a camera. In the image plane
a second photoelectric cell C-2 was mounted. The difference be-
tween the positions of C-l and C-2 effected thus, by scanning, an
integration of the transmitted light over a large area of the emulsion
in the former, and over a very small area in the latter cell. The
ratio of the field diameters was approximately 70:1.

The photoelectric currents were measured with a mirror galva-
nometer G (Fig. 1) in alternate connection with each of the photo-
electric cells through a double-throw switch 5. The intensity of the
light entering the objective was kept approximately independent of
the density of the emulsion sample in order to obtain commensurable
galvanometer readings, i. e., by the adjustment of the sectors on D.

For the calibration of this instrument first a clear glass plate or
film base (representative of a "non-scattering" object) was mounted
upon the stage and the photo currents of the lower and the upper cell
were determined and expressed as the ratio I\/Ii — /o. Obviously
/o is an instrument factor depending only upon the optical configu-
ration and the geometry of the device. If a scattering object is
placed on the stage, a change of the light distribution takes place and
the ratio ///V = / > 70 is observed. 7//8 represents thus the
scattering power of the object in arbitrary units.

378

A. GOETZ AND F. W. BROWN

[J. S. M. P. E.

The density D of the emulsion samples was measured with a gray
wedge densitometer (Eastman).

(HI) RESULTS

(a) Various Emulsions. — Fig. 2 represents a typical variation of
the scattering power 5 with the density D for two different negative
emulsions varying largely in grain size (A having rough, D having
fine grain). The measurements were taken from sensitometric
strips. The straight line in Fig. 2 indicates an approximately linear

1.3

1.0

SCATTERING RATIO
NEGATIVE FILM

OANEO • D NEG

.6
DENSITY

1.0

FIG. 2. S-D diagram: variation of scattering ratio I/Io with
density, for two different negative emulsions (A rough grain, D fine
grain).

relationship between ,S and D for D > 0.1. The scattering for a
given value of D is the larger, the smaller the grain of the emulsion.

(b) Positive Prints. — Fig. 3 represents measurements of the S(D)
function for a positive emulsion exposed directly and exposed
(printed) through three different types of negative emulsions. It is
well known that the graininess of a print is under most conditions
larger than the graininess of the negative; hence the negative emul-
sions were chosen to vary considerably as far as their graininess is
concerned. Some of these positive prints thus showed variations
seen easily with the unaided eye. The observations nevertheless
indicated that the scattering power of the prints is within the experi-
mental error the same as for the directly exposed positive film. This

Dec., 1942]

PHOTOGRAPHIC EMULSIONS

879

proves that the scattering power is independent of the graininess, i. e.t
size and the distribution of the statistical fluctuations of the grain.

(c) Printing Method. — It is well known that the wavelength of
the printing light influences the graininess considerably, ultraviolet
being considerably more favorable, probably due to its being more
scattered in the negative emulsion. In order to study the effect of
this type of printing upon the scattering power of the positive film,
prints from the rough and fine-grain negative emulsions (shown in
Fig. 2) were made, once with white and once with ultraviolet light.

1.4

1.0

X *

SCATTEF

RING RATIC

)

S^°

POSITIVE FILM

OPOSITIVE FILM
• PRINT OF FAST PAN NEC
CPRINT OF MEO PAN NEC

•x<

1.0

246
DENSITY

FIG. 3. S-Z) diagram: variation of scattering ratio 7//o for the
same positive emulsion exposed directly and printed through emul-
sions of various grain sizes.

The results are plotted in Fig. 4, showing no systematic deviation of
the scattering power for either the nature of the printing light or the
graininess of the negative material.

(d) Dependence upon Gamma. — A set of sensitometric strips of
positive film were exposed and developed within a gamma range
varying from 0.44 to 2.50 and their scattering power measured at a
density of approximately D = 0.5. The 5-values were found to be
identical within the experimental error; *'. «., within 2.5 per cent.
It can thus be concluded that in spite of the large effect that gamma
has upon the graininess, it does not influence the scattering power of
the emulsion.

380

A. GOETZ AND F. W. BROWN

[J. S. M. P. E.

(IV) DISCUSSION OF RESULTS

From the results described above, it is evident that the statistical
fluctuations of the grain configuration in an emulsion, that is, the
factors that cause the chief limitation in the optical resolving power
as well as produce the noise level on a sound-track and the discon-
tinuity of a visually realized photographic image, do not influence the
scattering power; but that the latter is dependent chiefly upon the
size of the individual grain, i. e., granularity. Thus neither the
contrast (gamma) of a negative nor the color of the printing (not the
illuminating) light-source was found to affect the scattering power of
the positive print within the density range studied.

1.5

~°L4

<
gU

1.0

SCATTERING RATIO
POSITIVE FILM

CD POS-UV o o POS-W

1.0

1.2

.2 4 .6

DENSITY

FIG. 4. 5-Z> diagram: variation of scattering ratio ///o for the
same positive emulsion exposed with white and ultraviolet printing
light through a rough-grain and a fine-grain negative emulsion.

The fact that the scattering power shows an inverse relationship to
the grain size is in qualitative agreement with observations of various
previous observers.5-6 The approximately linear relationship be-
tween scattering power and density, however, is not only at variance
with the density dependence of the graininess but also with previously
published results. Narath7 observed in the density range between 0
and 1 a behavior so widely varying among different emulsions that
one may suspect secondary influences (such as scattering irregulari-
ties in the emulsion and the base). As this author does not scan
the sample, his observations are restricted necessarily to a small area
of the emulsion, where accidental faults mav influence the results.

Dec., 1942]

PHOTOGRAPHIC EMULSIONS

381

Though Narath's optical arrangement was considerably different
from the one used here, it is not plausible to explain the difference of
the density function by the difference in the optical method.

The difference between the density functions of the scattering
power and the graininess seem worthy of a brief discussion : Fig. 5

FIG. 5. G-D diagram: typical variation of graini-
ness of two different emulsions with the density, where
Git Gi is based upon relative (&T/Tm) and G»\t Gt\ upon
absolute transparency fluctuations.

shows the graininess density function of two different emulsions,4
measured with the graininess meter, i. e., under optical conditions
identical with those used for the measurement of the scattering
power, G\t £2 are determined from relative transparency fluctuations,
while Gsi, GS2 are determined from absolute transparency fluctuations,
both from the same pair of emulsions. A comparison between, e. g.,

382 A. GOETZ AND F. W. BROWN [j. s. M. p. E.

Figs. 3 and 4, and Fig. 5 shows the obvious difference between the
scattering power and the graininess. This difference results in a
peculiar mutual relationship between graininess and scattering power
when both are realized under optical conditions closely similar to
those employed for image and sound reproduction. If the graininess
G is defined in terms of LT/Tm, i. e., as relative transparency
fluctuations, realized by determining the amplitude and frequency of
fluctuations with constant field brightness (constant transmitted
light), the scattering effect renders the absolute magnitude of AT",
depending upon the size of the field to which the (constant) field
brightness (^> Tm) is adjusted. In a small field such as is scanned by
the upper cell in Fig. 1, an emulsion with a large scattering power
requires a large total field brightness while an emulsion of equal
density but small scattering power needs less light; similarly, if a
large field, such as the lower cell in Fig. 1, is referred to for the ad-
justment for the field brightness, an emulsion with a large scattering
power will register a smaller AT" at the upper cell than a sample
causing only little scattering. In the first case the scattering power
will cause the observation of a graininess larger than in the second
instant, though the grain configuration will be identical. At the
same field brightness a large field will consequently show less apparent
graininess for an emulsion with a large than with a small scattering
power, a small field produces, cet. par., the opposite effect. Certain
differences in the realization of the graininess of identical emulsions
on large and small fields, such as in picture and sound projection, are
likely to be due to this relationship.

Since the relative influence of both factors, graininess and scatter-
ing, varies with the density, the resulting effect is predictable only if
both functions are known for the emulsion in question.

The authors wish to express their appreciation for considerable
technical assistance received from Agfa Ansco, Binghampton, and
Agfa Raw Film Corporation, Los Angeles.

REFERENCES

1 GOETZ, A., AND GOULD, W. O. : "The Objective Quantitative Determination
of the Graininess of Photographic Emulsions," /. Soc. Mot. Pict. Eng., XXIX
(Nov., 1937), p. 510.

2 GOULD, W. O., GOETZ, A., AND DEMBER, A. : "An Instrument for the Objec-
tive and Quantitative Determination of Photographic Graininess," Phys. Rev., 54
(1938), p. 240.

Dec., 1942] PHOTOGRAPHIC EMULSIONS 383

8 GOBTZ, A., GOULD, W. (X, AND DEMBBR, A.: "An Instrument for the Abso-
lute Measurement of the Graininess of Photographic Emulsions," /. Soc. Mot.
Pict. Eng., XXXIH (Oct., 1939), p. 469.

4 GOBTZ, A., GOULD, W. O., AND DEMBER, A.: "The Objective Measurement
of the. Graininess of Photographic Emulsions," /. Soc. Mot. Pict. Eng., XXXIV
(March, 1940), p. 279.

• THRBADGOLD, S. D.: Phot. Ind., 72 (1932), p. 348.

• EGGBRT, J., AND KUBSTER, A. : Veroeff. Agfa, m (1933), p. 93 ; IV (1935), p.
49; H. Brandes, Ibid., IV (1935), p. 57.

7 NARATH, A.: Kinotcchnik, XVI (1934), pp. 255, 287.

SOME ENGINEERING ASPECTS OF PORTABLE TELE-
VISION PICK-UPS*

HARRY R. LUBCKE**

Summary. — The routine oj portable television programing may be termed "ap-
plied" television engineering. The preceding is hardly more than a byplay of words,
but is intended to convey the impression of an engineering technique evolved to put a
program across regardless of extenuating circumstances. The emphasis is not on
engineering, but on the program, with engineering as one of the tools used in accom-
plishing the program.

The essentials of the technique are set forth. Proper preparation requires constant
servicing of equipment when the latter and staff are available. A pre-program test
several hours before program time is essential to consistent performance and allows
reasonable time for correcting installation or transportation-caused faults . A suitable
equipment "warm-up" period precedes the program. Service failures during the
program are usually unpredictable but must be met by prompt diagnosis and repair.
A thorough knowledge of the many circuits, normal and abnormal operational charac-
teristics thereof, and the "knack" of finding trouble are requisites of this aspect.

Experience in the technique eliminates certain difficulties by methodical prepara-
tion. The television engineering attributes of a program location are tested and re-
corded prior to the arrival of equipment. Voltmeter, dummy load, photometer, field
glasses, and photographic camera comprise the preliminary test equipment.

Significant experiences in televising 140 separate portable programs of the Don Lee
Television Station, W6XAO, Hollywood, are recited.

"How many minutes until program time?" "Sorry, we were
delayed; the space for our truck was filled with locked parked cars."
"What did you do? It doubled the signal strength!" "Switch over
to camera No. 1 direct, I've got a fire in master control!"

Such phrases are a part of portable television broadcasting. The
emphasis is on the program. The action is applied engineering.
The goal is an uninterrupted succession of perfect pictures.

A portable television pick-up staff has somewhat the problem of
the young parent, of inducing the offspring to perform correctly at
the proper time. The public never knows what may have occurred
before program time, nor what happens after it, and it cares less.

* Presented at the 1942 Spring Meeting at Hollywood, Calif.; received April
15, 1942.

** Don Lee Broadcasting System, Hollywood, Calif.
384

PORTABLE TELEVISION PICK-UPS

886

All activities are directed toward establishing the best insurance
designed to accomplish peak technical performance during the pro-
gram period.

Several factors contribute to the desired end: methodical prepara-
tion, adequate time for preparation, careful testing, an experienced
crew having the "feel" of the equipment, technical-programing

FIG. 1. The Mt. Lee television installation
of the Don Lee Broadcasting System, Hollywood.
This is the receiving location for all portable
pick-ups where the incoming image on 324 mega-
cycles is rebroadcast by station W6XAO. The
tower is 2000 feet above sea level and the build-
ing houses all television operations.

coordination, adequate policing to prevent damage to equipment
during the program, and "luck." These factors will be treated in
turn.

The basis of methodical preparation lies in the formulation and
use of suitable lists and forms. At the start of our portable pick-up
endeavors a list of necessary items was formulated, down to pieces
of rope, masking tape, screws, nails, and a hammer. Upon starting
on a job, the equipment is checked off against the list. Experience

386 H. R. LUBCKE [J. S. M. P. E.

dictates changes, and the lists are frequently revised. Large metal
tool cases have been found convenient to carry parts, tools, and
lenses; one case for each classification.

The principal form employed has been our "Mobile Television
Pick-Up Work Sheet," which tabulates the information required
for the pick-up. It is desirable to describe the television require-
ments to the manager and his electrician on the premises where the
event occurs. The head of the portable television department
surveys the site, getting the major portion of the information for
the form by inspection and by asking questions.

Many questions are answered in consultation at the site. How-
ever, as regards important technical factors, the criterion of not
taking anything for granted unearths difficulties at an early date
when they are relatively harmless. Thus, the television engineer
may include two heavy-current electric heaters and an a-c voltmeter
among his equipment. Placing them on the line removes all doubts
as to the regulation of the voltage and the ability of the fuses to
carry the thirty-ampere load. Should this test not be performed
at this time, it is then performed at the preliminary or propagation
test, or finally, at the very start of operations as many hours before
program time as possible.

Equipment always carried by the survey engineer comprises a
photometer (or Weston brightness meter), field-glasses, and a photo-
graphic camera. The former is used to test the installed illumination,
as at a prize fighting ring, or the effect of grandstand shadows. The
field-glasses are used to determine whether a line-of-sight path exists
from the program site to the home television station. Beam tele-
vision transmitting and receiving equipment operating on a fre-
quency of 324 megacycles, as used by the Don Lee Broadcasting
System, requires substantially a line-of-sight transmission path.
The camera is used to take photographs of the premises pertinent
to the scene of action, the proposed points of installation, and as an
additional check on the illumination of the scene. It is not difficult
to calibrate a given film and camera to the sensitivity of the television
system, and the photographs thus obtained are a definite guide and
aid in evaluating existing conditions and in suggesting changes.

After the initial survey, which may be a week or even a month in
advance of a new program or series of programs, "adequate time for
preparation" and "careful testing" call for a propagation test if the
relay distance is greater than five miles. This entails installing

Dec., 1942] PORTABLE TELEVISION PlCK-UPS 387

the portable transmitter and an antenna at the program site and
sending a "dummy picture" back to the home station. The latter
is comprised of a group of vertical black and white bars, and is
produced by a small self-contained portable oscillator operating on
a frequency of 94,500 cycles. Six white and six black bars are
produced. By noting the evenness of the boundary from black
to white the amount of "noise" on the relay propagation channel
Is indicated. Unevenness is caused by interference bursts occur-
ring near the time of the high-frequency synchronizing pulse of
sufficient amplitude to desynchronize the receiver scanning os-
cillator.

With relay equipment of given power and sensitivity the only
method of increasing the signal-to-noise ratio on a pick-up is to vary
the placement and the type of transmitting and receiving antennae.
The rapidity and effectiveness with which a desirable combination
can be effected may be regarded as half the requisite skill of portable
pick-up work.

After a few years' work, an organization usually comes to rely
upon a few types of antennae. In the Don Lee organization these
have reduced to a "pitchfork" type for transmitting and either a
pitchfork or F-antenna for receiving. The merit of the former lies
in portability, ease of erection, and signal-strength performance,
while the merit of the latter lies in extreme sensitivity or gain. A
pitchfork antenna consists of sixteen half-wave elements arranged in
four groups spaced vertically one-half wavelength and horizontally
one-fourth wavelength. Eight elements are driven, and eight ele-
ments form parasitic reflectors spaced one-fourth wavelength away.
A F-antenna consists of two wires ten wavelengths long forming
a V with a central angle of 30 degrees and the open ends terminated
in a small inductance, a 50-ohm resistor, and a vertical half-wave
element "ground," while the closed end comprises a 300-ohm, two-
wire transmission line which conveys energy to the receiver.

As important as the antenna itself is its placement in space. I
am impelled to mention an experience recently related to me, of the
National Broadcasting Company with the Empire State Building
installation. This experience emphasizes the importance of antenna
placement and also shows that the problems and technique of this
work are not unique to one organization, but are common to all in
the field.

A pre-program test was in progress at the New York station with

388 H. R. LUBCKE tf. S. M. P. E.

not too encouraging results. The signal-to-noise ratio was not as
high as desirable. Suddenly it doubled for apparently no reason
whatever. Investigation soon revealed that a routine window washer
had just raised the window frame on which was attached the ultra-
high-frequency receiving antenna, raising it vertically about three
feet! The effect of this increment in relation to the 1200-ft antenna
height requires little further comment on the importance of antenna
placement.

The experience of the Don Lee organization has shown that in-
creased elevation of antennae, even above purely wooden roofs,
invariably increases the signal-to-noise ratio. Roughly, considering
the placement of the transmitting antenna particularly, and in the
range of from ten to fifty feet above a building structure, doubling
the height of the antenna above the structure will double the signal-
to-noise ratio. This holds whether the propagation path is line-of-
sight or not, whether there is a clear sweep in front of the building
toward the receiving station, and whether the building is ten or a
hundred feet high.

It is important to note that this occurs in spite of the reverse
effect of increased feeder loss with increased length. The above
statements include this countereffect, which latter may double for
each doubling of height if the transmitter is located at the base of
the antenna mast. This performance is all the more surprising when
it is recalled that feeder losses at 324 megacycles are large. We
invariably use a two-inch-spaced number-twelve two-wire feeder,
Victron insulated.

Horizontal positions are equally important. The antenna is kept
as far as possible from all objects, metallic or non-metallic, but the
combined effect of several objects in the neighborhood can not be
known until experimentally determined. Proper technique requires
that all reasonable displacements be made during the propagation-
test period.

F-antennae must be oriented to the transmitter in order to achieve
maximum response, and besides properly locating the antenna in
azimuth the vertical clearance above ground and the geometry of
the V must be adjusted. The vertical angle of maximum receptivity
decreases with vertical clearance. Particularly when the receiving
location is a few thousand feet above the program location on the
plain below, as at Mt. Lee, Hollywood, the V must be at least five
wavelengths above ground. Alteration of the central angle of the V

Dec., 1942] PORTABLE TELEVISION PlCK-UPS

three degrees either side of the theoretical often results in reasonable
signal increases, thereby compensating for some local idiosyncrasy.

The last phase, allowing adequate time for preparation, is con-
cerned with the day of the telecast. Circumstances permitting, tin-
portable crew is dispatched eight working hours before the scheduled
conclusion of the telecast. A crew of two engineers and an assistant
are then able to drive the equipment truck to the location, establish
necessary connections, place the cameras in position, install sound
equipment, and make a complete test of facilities two to four hours
before program time on a pick-up of fixed format, such as a baseball
game or a boxing or wrestling match.

On more involved pick-ups, such as a soap-box derby, held in the
hills and necessitating a portable gasoline-driven power truck, antenna
erected in a field, cameras established on hillsides, telephone lines
extended, and conditions of self-sufficiency met as would become a
military expedition, a crew of six men dispatched ten hours before
conclusion of the program is required.

On Easter Sunrise pick-ups from the Hollywood Bowl it has been
our practice to start installation Saturday afternoon, make tests
with the failing light of evening, and then with the artificial light
installed, work until nine o'clock Saturday night and then return at
four A. M. Sunday morning. Electric heaters are kept on the equip-
ment all through the night in order to prevent the infiltration of
dampness, which lengthens the warm-up period considerably.

On the other hand, we have occasionally televised two portable
pick-up programs in one day from locations several miles apart, with
one set of equipment and one crew. With a trained crew of six men
the equipment can be in operation one hour after arriving at a
location.

Careful testing and complete familiarity of the crew with the
equipment are the best forms of program insurance. Capable port-
able pick-up television engineers must carefully scrutinize the equip-
ment performance under all sorts of conditions. The manner in
which equipment begins and ceases to function upon being switched
on or off provides a definite indication of any probable surge-provoked
failure. If a condenser, resistor, or other component fails it does so
usually during an "on" or "off" operation. The seriousness of a
failure caused by shutting off the equipment at the end of a success-
ful pre-program test will be appreciated. Engineers are instructed
to observe carefully the "die-down" behavior of the equipment;

390 H. R. LUBCKE

such as the manner in which the images leave the monitor cathode-
ray tubes, the rapidity with which transmitter meters return to zero,
a crackle, a minute spark, and, of course, any odor of burning insula-
tion. The behavior of properly functioning equipment is invariably
uniform. Anything unusual is a danger signal.

In addition, the functioning of the equipment during the pre-
program test tells an experienced operator whether everything is
normal, or whether the unusual operation of one or more controls
indicates a forthcoming failure. An engineer with a keen perception
of these many operating indications has the "feel" of the equipment.

Technical-programing coordination is important in preventing
avoidable disasters. The technical and production heads witness
a performance, or the sequence and locale of events are described on
the location by a qualified executive associated with the event. De-
cisions from artistic and technologic viewpoints are reached, and
departures therefrom involving general movement of the equipment
just prior to program time are not allowed.

Adequate policing is important to prevent damage to the television
equipment. At one Easter Sunrise service our portable transmitter
was taken off the air for a few minutes at the close of the program
by a young man utilizing the power cable as a rope for climbing a
steep hillside in the Hollywood Bowl. Our operator at the top of the
hill saw the cable move, engaged in a tug-of-war with the unknown
climber and a large plug was pulled from its socket in the equipment.
The next year the cable was firmly tied to a stout stake driven in
the ground, and a safety loop of cable was interposed between the
stake and the socket.

In general, one or more policemen, Boy Scouts, or uniformed
officials should be detailed to guard the cables and equipment of an
installation.

No consideration of portable television operations would be com-
plete without mention of the unpredictable combinations of circum-
stances and consequences briefly described as "luck." It is futile
to attempt to enumerate the countless happenings that occur in
such operations. The requirements of portability preclude duplicate
channels of equipment, the vagaries of weather and natural illu-
mination are factors beyond human control, and the newness of
television instrumentalities does not provide the reliability to be
found in other arts and acquired through years of experience. How-
ever, a conscious alertness of staff tends to minimize the consequences
of "bad luck" and enhances the opportunities for "good luck."

CURRENT LITERATURE OF INTEREST TO THE MOTION PICTURE

ENGINEER

The editors present for convenient reference a list of articles dealing with subjects
cognate to motion picture engineering published in a number of selected journals
Photostatic copies may be obtained from the Library of Congress, Washington, D. C.
or from the New York Public Library, New York, N. Y. Micro copies of article •*
in magazines that are available may be obtained from the Bibliofilm Service, Depart-
ment of Agriculture, Washington, D. C., at prevailing rates.

American Cinematographer

23 (Nov., 1942), No. 11
A Portable Developing-Machine for Field Service with the

Army (pp. 473, 489)

The First Real Combat Camera (pp. 474-475, 489-490)
"Post-Recording" Dialog for Educational and Training

Films (pp. 477, 500)

A Professional Sunshade for the Eastman Special (pp. 485,
492)

British Kinematograph Society, Journal

5 (Oct., 1942), No. 4

The Electron Multiplier and Its Application to Sound Re-
production (pp. 102-110)

The Post-War Organization of Scientific Films (pp. 111-

113)
High-Speed Photography and Its Application to Industrial

Problems (pp. 114-127)

Educational Screen

21 (Oct., 1942), No. 8

Motion Pictures— Not for Theaters (pp. 302-304, 306),
Pt. 40

Electronics

15 (Nov., 1942), No. 11

Recording Machinery Noise Characteristics (pp. 46-51,
164-165)

Motion Picture Herald (Better Theaters Section)

149 (Oct. 17, 1942), N.>

How Viewing Angles Determine tin BUMI- Fnrin «>f tlu-
Auditorium (pp. 8-9, 22)

W. STULL
W. STULL

J. A. LARSEN, JR.
C. MURRAY

F. J. G. VAN DEN
BOSCH

H. D. WALBY
E. D. EYLBS

A. E. KROWS

H. D. BRAILSPORD

H. SCH I AN.. I K

392

CURRENT LITERATURE

Photographische Industrie

40 (Jan. 20, 1942), No. 3/4

Zeitraffung und Zeitdehnung (Time-Lapse and Slow Mo-
tion) (pp. 22-23)

40 (Feb. 4, 1942), No. 5/6
Stereophonic mit Dynamikerweiterung (Stereophonic

Sound with Wider Dynamic Range) (pp. 34-36) P. HATSCHEK

40 (Feb. 17, 1942), No. 7/8

Bin neuer franzosisches Verfahren fur plastische Kino-
pro jektion (A New French Method for Stereoscopic
Motion Picture Projection) (p. 47) LUSCHER

40 (March 3, 1942), No. 9/10

30 Jahre plastischer Farbentonfilm (30 Years of Stereo-
scopic Color Sound Film) (pp. 71-72) W. SELLE

40 (March 31, 1942), No. 13/14

Die Widerstandsfahigkeit des Film Behalters gegen Feuer
(Resistance of the Film Container to Fire) (pp. 98-100)

40 (Apr. 14, 1942), No. 15/16

Neuzeitliche Lichtgebung in Filmtheatern (Modern Light-
ing in Motion Picture Theaters) (pp. 108-111) H. WINKLER

40 (Apr. 28, 1942), No. 17/18

Neuer Normblattentwurf. DIN ENTWURF 15632 Film
16-mm Aufnahmespulen (DIN Standard 15632. 16-
Mm Film Take-Up Spool) (p. 123)

40 (May 12, 1942), No. 19/20

Das Auflosungsvermogen bei der photographiscen Auf-
nahme (The Resolving Power of the Photographic Emul-
sion). Pt. I (pp. 128-130)

Optische Kopiermaschine statt Filmtrick (The Optical
Printer Instead of Film Tricks) (pp. 135-136)
40 (May 26, 1942), No. 21/22

Das Auflosungsvermogen bei der photographiscen Auf-
nahme (The Resolving Power of the Photographic Emul-
sion). Pt. II (pp. 139-140)

Filmentwicklungsmaschine ohne Zahntrommeln (Film
Developing Machine without Sprockets) (pp. 146-148)

40 (June 9, 1942), No. 23/24

Kohlenachschub bei H. I. Spiegelbogenlampen (Carbon
Feeding in High Intensity Reflector Arc Lamps) (pp.
158-160)

40 (June 23, 1942), No. 25/26
GerauscharmerTonfilm (Low Noise Level Sound Film)

(pp. 170-172) P. HATSCHEK

H. ROEDER AND

G. HANSEN
C. EMMERMAN

H. ROEDER AND
G. HANSEN

W. NAUCK

PROGRAM OF THE 1942 FALL MEETING*

OCTOBER 27th-29th, HOTEL PENNSYLVANIA, NEW YORK, N. Y.

TUESDAY, OCTOBER 27, 1942

Morning Session: General Session; A. C. Dowries, Chairman

Report of the Convention Vice-President, W. C. Kunzmann.

Report of the Financial Vice-President, A. S. Dickinson.

Report of the Engineering Vice-President, D. E. Hyndnian.

Welcome by the Past-President, E. Allan Williford.

Election of Officers and Governors for 1943.

"Wright Field Training Film Laboratory;" H. C. Brecha, Dayton, Ohio.

"The Navy's Utilization of Film for Training Purposes;" Wm. Exton, Jr .
Lt. U.S.N.R., Bureau of Navigation, Navy Department, Washington, D. C.

"The Documentary, Scientific, and Military Films of the Soviet Union;" Greg-
ory L. Irsky, Cinema Committee of the U.S.R.R., Washington, D. C.

"The Underground Motion Picture Industry in China;" T. Y. Lo, Deputy
Chief, Film Section, Military Affairs Commission, Government 6f the Re-
public of China.

Noon: Informal Get-Together Luncheon; E. Allan Williford, Presiding.

Introduction of Officers-Elect for 1943.

Addresses by:

Mr. Claude Lee, Director of Public Relations, Paramount Pictures, Inc., New
York, N. Y.

Colonel M. E. Gillette, Commanding Officer, U. S. Army Signal Corps Photo-
graphic Center, Astoria, L. I., N. Y.

Colonel Montgomery Schuyler, Assistant Director of Disaster Relief. New
York Chapter, American Red Cross.

Afternoon Session: Radio City Music Hall Tour; Sylvan Harris, Chairman.
An extensive tour of the technical facilities of the Radio City Music Hall.
front-stage and back-stage; arranged by courtesy of Mr. G. S, Eysscll.
president and managing director of Radio City Music Hall; Mr. Fred L.
Lynch, publicity director; and Mr. Harry Braun, sound director.

Evening Session: Museum of Modern Art Film Library; E. F. Kerns (Technical
Director, Film Library), Chairman.

Address on the development of the motion picture by Miss Iris Barry, accom-
panied by a showing of pictures selected for their importance in the develop-
ment of the art.

"Motion Pictures and the War KtTort;" by Captain John G. Bradley. National
Archives, Washington, D. C.

* As actually followed at the sessions.

394 PROGRAM OF THE FALL MEETING [j. s. M. p. E.

WEDNESDAY, OCTOBER 28, 1942

Morning Session: General Session; D. E. Hyndman, Chairman.

"Sound Control in the Theater Comes of Age;" H. Burris-Meyer, Stevens In-
stitute of Technology, Hoboken, N. J.

"Recent Developments in Sound-Tracks;" Edward M. Honan and Clyde R.
Keith, Electrical Research Products Division of Western Electric Co.,
Hollywood, Calif.

Society Business

Report of the Theater Engineering Committee; Alfred N. Goldsmith, Chair-
man.

"Effect of High Gate Temperatures on 35-Mm Film Projection;" E. K.
Carver, R. H. Talbot, and H. A. Loomis, Eastman Kodak Co., Rochester,
N. Y.

"Film Distortions and Their Effect on Projection Quality;" E. K. Carver,
R. H. Talbot, and H. A. Loomis, Eastman Kodak Co., Rochester N. Y.

Afternoon Session: General Session; J. A. Maurer, Chairman.

"Recent Laboratory Studies of Optical Reduction Printing;" R. O. Drew and

L. T. Sachtleben, RCA Manufacturing Co., Inc., Indianapolis, Ind.
"Some Characteristics of Ammonium Thiosulfate Fixing Baths;" Donald B.

Alnutt, Mallinckrodt Chemical Works, St. Louis, Mo.
"Copper and Sulfide in Developers;" R. M. Evans, W. T. Hanson, Jr., and

P. K. Glasoe, Eastman Kodak Co., Rochester, N. Y.

"Factors Affecting the Accumulation of Iodide in Used Photographic Develop-
ers;" R. M. Evans, W. T. Hanson, Jr., and P. K. Glasoe, Eastman Kodak

Co., Rochester, N. Y.
"Effect of Composition of Processing Solutions on Removal of Silver from

Photographic Materials;" J. I. Crabtree, G. T. Eaton, and L. E. Muehler,

Eastman Kodak Co., Rochester, N. Y.
"A Precision Recording Instrument for Measuring Film Width;" S. C. Coroniti

and H. S. Baldwin, Agfa Ansco, Binghamton, N. Y.

Evening Session: Fifty-Second Semi- Annual Banquet and Dance.
Introduction of Officers-Elect for 1943.
SMPE Journal Award.

THURSDAY, OCTOBER 29, 1942

Morning Session: Symposium on the Production of 16-Mm Motion Pictures;
Ralph E. Farnham, Chairman.

Introduction by John A. Maurer, Chairman of the Committee on Non-Theatri-
cal Equipment.

"Sixteen-Mm Production Planning;" Russell C. Holslag, J. A. Maurer, Inc.,
New York, N. Y.

"The Practical Side of Direct 16-Mm Laboratory Work;" Lloyd Thompson,
The Calvin Co., Kansas City, Mo.

"Sixteen-Mm Laboratory Practice;" Wm. H. Offenhauser, Jr., Washington,
D. C.

Dec.. 1942] PROGRAM OF THE FALL MEETING 395

Afternoon Session: Symposium on the Production of 16-Mm Motion Picture!

(Continued); Frank E. Carlson, Chairman.
"Sixteen-Mm Sound Recording;" John A. Maurer, J. A. Maurer. Inc., New

York, N. Y.
"Sixteen-Mm Editing and Photographic Embellishment;" Larry Sherwood.

The Calvin Co., Kansas City, Mo.
"Sixteen-Mm Screen Illumination;" Frank E. Carlson, General Electric Co.,

Cleveland, Ohio.
'^Carbon Arc Projection of 16-Mm Film;" W. C. Kolb, National Carbon Co.,

Cleveland, Ohio.
"Application and Distribution of 16-Mm Motion Pictures;" F. W. Bright. The

Aetna Casualty and Surety Co., Hartford, Conn.
"Improvement in Motion Picture Printer Illumination Efficiency;" C. J.

Kunz, H. Goldberg, and C. E. Ives, Eastman Kodak Co., Rochester, N. Y.

Evening Session: U. S. Army Signal Corps Photographic Center; General Ses-
sion; E. Allan Williford, Chairman.

Welcome by Colonel M. E. Gillette, Commanding.

"Analysis of Fast Action by Motion Pictures;" E. M. Watson, Capt., Ord-
nance Dept., Watervliet Arsenal, Watervliet, N. Y.

"Sixteen-Mm Motion Pictures and the War EiTort ;" Michael S. David, General
Motors Corp., Detroit, Mich.

"Motion Pictures in Aircraft Production;" Norman Matthews, Bell Aircraft
Co., Buffalo, N. Y.

Exhibition of Army Training Films produced by the U. S. Army Signal Corps.
and conducted tour of the Photographic Center, U. S. Signal Corps.

HIGHLIGHTS OF THE FALL MEETING

HOTEL PENNSYLVANIA

NEW YORK
OCTOBER 27-29, 1942

The 1942 Fall Meeting of the Society, recently concluded at New York, re-
flected very strongly the state of the times. The program included seven pres-
entations dealing directly with the uses and applications of motion pictures in
the prosecution of the war, and a number of other papers on industrial applica-
tions of motion pictures in the war industries.

The sessions were remarkably well attended, as well as the sessions of any
previous Meeting, far beyond expectations in view of the pressure under which
the members of the motion picture industry are laboring in these troublous times.
The interest of the Armed Services of the nation in our semi-annual meetings is
also very gratifying; the Army, the Navy, and the Air Forces are all represented
on the program, and an outstanding feature of the three- day conclave was the
session held at the Photographic Center of the U. S. Army Signal Corps at Astoria,
Long Island.

An innovation of the Meeting was the holding of three of the sessions away
from the Hotel headquarters: one at the Museum of Modern Art Film Library,
another at the Radio City Music Hall, and the third, as mentioned, at the Army
Signal Corps Photographic Center. These sessions provided interesting and
profitable relief from the routine, and sometimes arduous, regular papers sessions.

After the usual reports of the Officers of the Society, the Tuesday (October
27th) morning session opened with a description by H. C. Brecha of the new
Army Air Forces Laboratory at Wright Field and an account of the production of
training films for the Air Forces. This was followed by a discussion by Lt. Win.
Exton, Jr., of the Navy's program in the utilization of training films. Of especial
interest were the papers by Gregory L. Irsky and T. Y. Lo, describing the progress
of the motion picture industries in the U.S.S.R. and in China under the diffi-
culties of actual warfare. Motion pictures play an exceedingly important role on
the Russian front, not only in helping to maintain the morale of the fighting
forces and the civilian population in the fighting areas, but also in training the
soldiers actually at the front. In China, Mr. Lo reported, the motion picture
studios actually had to move from place to place to avoid the Japanese bombings,
and, in fact, eventually had to construct laboratories and other facilities below
ground.

At the informal luncheon held at noon in the Roof Garden of the Hotel Mr. E.
A. Williford, presiding in the absence of the Mr. Emery Huse, president of the
Society, announced the results of the elections for 1943. The successful candi-
dates were as follows:

President: Herbert Griffin
Executive Vice-President: Loren L. Ryder
Editorial Vice-President: Arthur C. Downes
Convention Vice-President: William C. Kunzmann
396

HIGHLIGHTS OF THE FALL MEETING 397

Secretary: E. Allan Williford
Treasurer: M. R. Boyer
Governors: W. A. Mueller

H. W. Remersheid

Mr. Emery Huse continues as a member of the Board in the capacity of Past-
President. Terms of office of those listed above are for two years, except for the
Secretary and Treasurer, who held office for one year.

Additional members of the Board of Governors are Dr. Alfred N. Goldsmith,
who was reflected Chairman of the Atlantic Coast Section, and Charles W.
Handley, elected Chairman of the Pacific Coast Section. At the business meeting
of the Society, held on the morning of Wednesday, October 28th, amendments of
the Constitution and By-Laws were adopted providing for five additional Board
members. Those appointed to fill the vacancies created by the establishment of
these new Board members were H. D. Bradbury, J. H. Spray, R. O. Strode,
A. M. Gundelfinger, and H. W. Moyse. The amendments referred to were pub-
lished in the September issue of the JOURNAL, p. 208.

Following the announcements by Mr. Williford, the principal speaker at the
luncheon was Mr. Claude Lee, Director of Public Relations of Paramount Pic-
tures, Inc., New York. Seated also at the speakers' table were Col. M. E.
Gillette of the U. S. Army Signal Corps, and Col. Montgomery Schuyler, Assis-
tant Director of Disaster Relief of the New York Chapter of the American Red
Cross.

In the afternoon the members of the Society were the guests of the Radio City
Music Hall. Through the courtesy of Mr. G. S. Eyssell, president and managing
director of the Music Hall, Mr. Fred L. Lynch, publicity director, and Mr. Harry
Braun, sound director, a special tour of the technical facilities of the Music Hall,
both front-stage and back-stage, was provided. The tour included practically
all the departments of the organization concerned with putting on the show:
projection room, sound department, wardrobe department, power plant, refriger-
ating plant, stage equipment, music department, etc. The Society extends its
thanks to Messrs. Eyssell, Lynch, and Braun for this interesting contribution to
our sessions.

The evening session of Tuesday was held in the auditorium of the Museum of
Modern Art, presided over by Mr. E. F. Kerns, of the Film Library staff. A
series of early motion pictures, especially selected for their importance in the
development of the cinematic art, were projected, and preceding each selection
Miss Iris Barry, of the Museum, discussed the relation of the picture to the
motion picture art as we know it today. Acknowledgment is due to Miss Barry
and Mr. Kerns, and to Mr. John Abbott, curator of the Film Library, for their
kindness in arranging this session.

The morning session of Wednesday, October 28th, opened with a paper by
Harold Burns-Meyer on special applications of sound under the title, "Sound
Control in the Theater Comes of Age." This was followed by an interesting
paper by Messrs. E. M. Honan-and C. R. Keith, of ERPI, discussing the various
types of sound-tracks used by the motion picture industry. A feature of the
session was the report of the Theater Engineering Committee of the Society. Dr.
Alfred N. Goldsmith, Chairman, which included reports from the sub-committees

398 HIGHLIGHTS OF THE FALL MEETING (J. S. M. P. E.

on Projection Practice and on Civilian Defense in Theaters. The latter sub-
committee has only recently been established, and its studies of the problems of
air-raids and black-outs, etc., are expected to be noteworthy contributions to the
industry. The report of the Projection Practice Sub-Committee included an
extremely valuable discussion of the problems involved in various mechanical
systems that have recently been proposed for conserving motion picture film.

Other papers of the Wednesday morning session were two by Messrs. E. K.
Carver, R. H. Talbot, and H. A. Loomis, of the Eastman Kodak Company,
on the effect of high gate temperatures in 35-mm projection and on the effect of
film distortion upon the quality of projection. These two papers provide very
valuable studies of some serious problems that have been facing the industry.

The afternoon of Wednesday was devoted principally to processing and labo-
ratory problems. R. O. Drew and L. T. Sachtleben, of RCA, presented some
recent laboratory studies of optical reduction printing, followed by a paper by
D. B. Alnutt, of the Mallinckrodt Chemical Works on "Some Characteristics of
Ammonium Thiosulfate Fixing Baths." Other papers, by Messrs. Evans,
Hanson, and Glasoe, and Messrs. Crabtree, Eaton, and Muehler, all of the
Eastman Kodak Company, dealt with the questions of copper and sulfide in
developers, tHe accumulation of iodide in developers, and the effect of the com-
position of processing solutions upon the removal of silver from photographic
materials. The session concluded with a paper by S. C. Coroniti and H. S.
Baldwin, of Agfa, describing a precision recording instrument for measuring film
width.

The Fifty-Second Semi-Annual Banquet and Dance of the Society was held
in the Georgian Room of the Hotel in the evening (Wednesday, October 28th),
Mr. Williford presiding. The officers and governors-elect for 1943 were intro-
duced, followed by the presentation of the 1941 Journal Award certificates to Mr.
W. J. Albersheim and Donald MacKenzie for their paper entitled "Analysis
of Sound-Film Drives," published in the July, 1941, issue of the JOURNAL.

Both morning and afternoon sessions of Thursday, October 29th, were devoted
to a symposium on the production of 16-mm motion pictures, and included papers
on practically all phases of this important branch of the industry. The morning
session, presided over by Mr. Ralph E. Farnham, opened with an introduction
by John A. Maurer, followed by papers on production planning, direct 16-mm
laboratory work, and general 16-mm laboratory practice, by Messrs. R. C. Hoi-
slag, Lloyd Thompson, and Wm. H. Offenhauser.

In the afternoon, with Mr. Frank E. Carlson presiding, papers were presented
dealing with 16-mm recording, 16-mm editing and photographic embellishment,
carbon arc projection of 16-mm film, 16-mm screen illumination, and on applica-
tions and distribution problems of 16-mm pictures — by Messrs. J. A. Maurer,
L. Sherwood, F. E. Carlson, W. C. Kalb, and F. W. Bright. This symposium of
nine papers on 16-mm motion picture production is a valuable companion to the
symposium on 35-mm production held at the Hollywood Convention last Spring.

The closing session of the three-day meeting was held at the U. S. Army Signal
Corps Photographic Center at Astoria, Long Island, by courtesy of Col. M. E.
Gillette, commanding. The evening opened with a paper by Capt. E. M.
Watson, of Watervliet Arsenal, on the analysis of fast motion by means of motion
pictures. Interesting slides and motion pictures taken at very high speed supple-

Dec., 1942] HIGHLIGHTS OF THE FALL MEETING

mented the paper. Following this, papers were presented by M. S. David, of the
General Motors Corp., and Norman Matthews, of Bell Aircraft Corp., on addi-
tional applications of motion pictures in wartime training of industrial employees
and men in the Service.

After a showing of some films that had been shot in the Astoria studio years ago
by Paramount, long before the studio had been taken over and revamped by the
Signal Corps, the evening concluded with a conducted tour through all the facili-
ties of the studio.

The Society wishes to acknowledge its gratitude to the large number of persons
and companies who collaborated in providing the various facilities for the Meet-
ing. Acknowledgment is due also to the Capitol Theater, the Radio City Music
Hall, the Roxy Theater, Warner's Strand Theater, and the Paramount Theater
for the passes issued to SMPE delegates during the dates of the Meeting.

SOCIETY ANNOUNCEMENTS

OFFICERS AND GOVERNORS FOR 1943

As a result of the elections held at the recent Fifty-Second Semi-Annual Meet-
ing at the Hotel Pennsylvania, New York. October 27th to 29th, the following will
be the list of officers and governors of the Society beginning January 1st:

** President: HERBERT GRIFFIN
** Past-President: EMERY HUSE
** Executive Vice-P resident: LOREN L. RYDER

* Engineering Vice-President: DONALD E. HYNDMAN
** Editorial Vice-President: ARTHUR C. DOWNES

* Financial Vice-President: ARTHUR S. DICKINSON
** Convention Vice-President: WILLIAM C. KUNZMANN

* Secretary: E. ALLAN WILLIFORD

* Treasurer: M. R. BOYER
Governors: * H. D. BRADBURY

* FRANK E. CARLSON

* A. M. GUNDELFINGER

* EDWARD M. HONAN

* JOHN A. MAURER

** WILLIAM A. MUELLER

* HOLLIS W. MOYSE
** H. W. REMERSHIED
** JOSEPH H. SPRAY
** REEVE O. STROCK

Additional members of the Board of Governors are the Chairmen of the three
Local Sections of the Society:

* Atlantic Coast Section: ALFRED N. GOLDSMITH

* Pacific Coast Section : CHARLES W. HANDLEY

Election results for the Mid- West Section will be available shortly.

ADMISSIONS COMMITTEE

At a recent meeting of the Admissions Committee, the following applicants for
membership were admitted into the Society in the Associate grade:
CULL, R. A. GOETZ, ALEXANDER

5743 Irving Park Rd., Rare Metals Institute,

Chicago, 111. Calif. Institute of Technology,

Pasadena, Calif.

* Term expires December 31, 1943.
** Term expires December 31, 1944.

400

SOCIETY ANNOUNCEMENTS 401

HOMSANY, EMIL F. KNOWLES, GERALD L.

1405— 8th Ave.. 1041 1 Oletha Lane,

Brooklyn, N. Y West Los Angeles, Calif.

ROSEN, NORMAN
28-17 38th Ave.,

Long Island City, N. Y.

In addition, the following applicants have been admitted to the Active grade:

ASHCRAFT, C S. CASPAR, BELA

47-31 35th St., 1050 Cahuenga Blvd.,

Long Island City, N. Y. Hollywood, Calif.

BENNETT, M. F. PULMAN, ROBERT

Warner Bros. Pictures, Inc., 12-A Brunswick Rd.,

321 West 44th St., Sutton, Surrey, England
New York, N. Y.

TELLING, MARTINUS
Camp-N

Sherbrooke, Quebec,
Canada

The following applicant was admitted to the Student Membership grade:

HUFFORD, ROBERT GRAY
Clemson A. & M. College,
Clemson, S. C.

The following members were transferred from Associate to Active grade:

BACH, WALTER THOMPSON, LLOYD

E. M. Berndt Corp., The Calvin Company,

5515 Sunset Blvd., 26th & Jefferson Sts..

Hollywood, Calif. Kansas City, Mo.

JOURNAL

OF THE SOCIETY OF

MOTION PICTURE ENGINEERS

AUTHOR AND CLASSIFIED
INDEXES

VOLUME XXXVIII
JULY-DECEMBER, 1042

AUTHOR INDEX, VOLUME XXXIX

JULY TO DECEMBER, 1942

Author
BAUMBACH, H. L.

BECKER, L. S.

BOYLE, J. W.

BRECHA, H. C.

BROWN, B. B.

BROWN, F. W.
(and A. GOETZ)

CAMPBELL, R. L.

(and KESSLER, R. E., and
RUTHERFORD, R. E., and
LANDSBERG, K. V.)

CLARKE, C. G.

EXXON, W., JR.

FULLER, R. B.

(and RHODES, L. S.)
GARITY, W. E.

(and JONES, WATSON)
GOETZ, A. (and BROWN,

F. W.)

GlTTERMAN, HENRY

GOLDSMITH, L. T.
HENDERSON, R. W.

HOCH, W.
IRSKY, G. L.

JONES, WATSON

(and GARITY, W. E.)
KELLOGG, E. W.

(and MASTERSON, E. E.)
404

Issue Page

Continuous Replenishment and Chem-
ical Control of Motion Picture De-
veloping Solutions July 55
Technology in the Art of Producing

Motion Pictures Aug. 109

Black-and-White Cinematography Aug. 83

Wright Field Training Film Laboratory Dec. 348

Prescoring and Scoring Oct. 228
Light-Scattering by Graininess of

Photographic Emulsions Dec. 375

Mobile Television Equipment July 22

Putting Clouds into Exterior Scenes Aug. 92

The Navy's Utilization of Film for
Training Purposes Dec. 333

Production of 16-Mm Motion Pictures

for Television Projection Sept. 195

Experiences in Road-Showing Walt

Disney's Fantasia July 6

Light-Scattering by Graininess of

Photographic Emulsions Dec. 375

A New Electrostatic Air-Cleaner and
Its Application to the Motion Pic-
ture Industry July 70

Re-Recording Sound Motion Pictures Nov. 277

Developments in Time-Saving Process

Projection Equipment Oct. 245

Technicolor Cinematography Aug. 96

The Documentary, Scientific, and Mili-
tary Films of the Soviet Union Dec. 353

Experiences in Road-Showing Walt Dis-
ney's Fantasia July 6

A Study of Flicker in 16-Mm Picture

Projection Oct. 232

INDI-X

405

Author

KESSLER, R. E.

(and CAMPBELL, R. L.,
and RUTHERFORD, R. E.,
and LANDSBERG, K. V.)

LANDSBERG, K. V.,
(and CAMPBELL, R. L.,
and KESSLER, R. E.,
and RUTHERFORD, R. E.)

Lo, T. Y.

LUBCKE, H. R.

MASTERSON, E. E.

(and KELLOGG, E. W.)
MILLER, B. F.

O'CONNELL, L. W.

OFFENHAUSER, W. H., JR.

PLUMB, EDWARD H.

RETTINGER, M.

RHODES, L. S.

(and FULLER, R. B.)

RUTHERFORD, R. E.
(and CAMPBELL, R. L.,
and KESSLER, R. E.,
and LANDSBERG, K. V.)

SACHTLEBEN, L. T.

SlLVERTOOTH, E. W.

SMITH, F. Y.
STOTT, JOHN G.
TASKER, H. G.
THOMPSON, L.

WILKINSON, J. R.
WILLIFORD, E. A.

Wrrr. H. A.

Issue Page
Mobile Television Kquipment July 22

Mobile Television Equipment July 22

The Underground Motion Picture In-
dustry in China Dec. -t J I

The Engineering Aspect of Portable

Television Pick-Ups. Dec. 384

A Study of Flicker in 16-Mm Picture

Projection Oct. 232

Elimination of Relative Spectral En-
ergy Distortion in Electronic Com-
pressors Nov. :<17

The Photographing of 16-Mm Koda-
chrome Short Subjects for Major
Studio Release Nov. :H4

A Review of the Question of 16-Mm

Emulsion Position Aug. 123

The Future of Fantasound July lf>

A Modern Music Recording Studio Sept. 18T»

Production of 16-Mm Motion Pictures

for Television Projection Sept. 195

Mobile Television Equipment July 22

A One-Ray System for Designing

Spherical Condensers Dec

Stop Calibration of Photographic Ob-
jectives Aug. 1 19

The Cutting and Editing of Motion

Pictures Nov. 2»4

The Application of Potent iomvtr it-
Methods to Developer Analysis July

The Technique of Production Sound

Recording Oct. LM.'i

The Production of Industrial Motion

Pictures Aug. 135

Motion Picture Laboratory Practices Sept. 166

The Carbon Situation and Copper

Conservation July 3

The Practical Aspect of Edge- Number-
ing 16-Mm Film July

CLASSIFIED INDEX, VOLUME XXXIX

JULY TO DECEMBER 1942

Air Cleaners

A New Electrostatic Air-Cleaner and Its Application to the Motion Picture
Industry, Henry Gitterman, No. 1 (July), p. 70.

Apparatus

A New Electrostatic Air-Cleaner and Its Application to the Motion Picture

Industry, Henry Gitterman, No. 1 (July), p. 70.

Developments in Time-Saving Process Projection Equipment, R. W. Hender-
son, No. 4 (Oct.), p. 245.

Arcs

The Carbon Situation and Copper Conservation, E. A. Williford, No. 1 (July),
p. 3.

Army, U. S.

Wright Field Training Film Laboratory, H. C. Brecha, No. 6 (Dec.), p. 348.

Atlantic Coast Section

The Carbon Situation and Copper Conservation, E. A. Williford, No. 1 (July),
p. 3.

Cameras

Stop Calibration of Photographic Objectives, E. W. Silvertooth, No. 2 (Aug.),
p. 119.

Carbons

The Carbon Situation and Copper Conservation, E. A. Williford, No. 1 (July),
p. 3.

Cartoons

Experiences in Road-Showing Walt Disney's Fantasia, W. E. Garity and Wat-
son Jones, No. 1 (July), p. 6.
The Future of Fantasound, Edward H. Plumb, No. 1 (July), p. 16.

China, Motion Pictures in

The Underground Motion Picture Industry in China, T. Y. Lo, No. 6 (Dec.),
p. 341.

Cinematography

Black-and-White Cinematography, J. W. Boyle, No. 2 (Aug.), p. 83.
Putting Clouds into Exterior Scenes, C. G. Clarke, No. 2 (Aug.), p. 92.
Technicolor Cinematography, W. Hoch, No. 2 (Aug.), p. 96.
Stop Calibration of Photographic Objectives, E, W. Silvertooth, No. 2 (Aug.),
p. 119.

406

INDEX 407

The Photographing of 16-Mm Kodachrome Short Subjects for Major Studio
Release, L. W. O'Connell, No. 5 (Nov.), p. 31 I

Color Cinematography

Technicolor Cinematography, W. Hoch, No. 2 (Aug.), p. 96.
The Photographing of 16-Mm Kodachrome Short Subjects for Major Studio
Release, L. W. O'Connell, No. 5 (Nov.), p. 314.

Committee Reports

Projection Practice, No. 4 (Sept.), p. 149.
Progress, No. 5 (Nov.), p. 3.

Compressors, Electronic

Elimination of Relative Spectral Energy Distortion in Electronic Compressors,
B. F. Miller, No. 5 (Nov.), p. 317.

Condensers, Optical

A One-Ray System for Designing Spherical Condensers, L. T. Sachtleben, No.
6 (Dec.), P. 358.

Conservation

The Carbon Situation and Copper Conservation, E. A. Williford, No. 1 (July).
p. 3.

Control
(See Processing, Control of.)

Copper

The Carbon Situation and Copper Conservation, E. A. Williford, No. 1 (July),
p. 3.

Cutting Motion Pictures
The Cutting and Editing of Motion Pictures, F. Y. Smith, No. 5 (Nov.), p. 284.

Developers
The Application of Potentiometric Methods to Developer Analysis, John G.

Stott, No. 1 (July), p. 37.

Continuous Replenishment and Chemical Control of Motion Picture Develop-
ing Solutions, H. L. Baumbach, No. 1 (July), p. 65.

Distortion, Sound

Elimination of Relative Spectral Energy Distortion in Electronic Compressors.
B. F. Miller, No. 5 (Nov.), p. 317.

Editing Motion Pictures

The Cutting and Editing of Motion Pictures, F. Y. Smith, No. 5 (Nov.), p. 284.

Edge-Numbering

The Practical Aspect of Edge-Numbering 16-Mm Film, H. A. Witt. No. 1

(July), p. 67.

408 INDEX [j. s. M. P. E.

Educational Motion Pictures

The Navy's Utilization of Film for Training Purposes, Wm. Exton, Jr., No. 6

(Dec.), p. 333.
The Underground Motion Picture Industry in China, T. Y. Lo, No. 6 (Dec.),

p. 341.

Wright Field Training Film Laboratory, H. C. Brecha, No. 6 (Dec.), p. 348.
The Documentary, Scientific, and Military Films of the Soviet Union, Gregory

L. Irsky, No. 6 (Dec.), p. 353.

Emulsions

Light-Scattering by Graininess of Photographic Emulsions, Alexander Goetz
and F. W. Brown, No. 6 (Dec.), p. 375.

Fantasia

Experiences in Road-Showing Walt Disney's Fantasia, W. E. Garity and Wat-
son Jones, No. 1 (July), p. 6.

Fantasound

Experiences in Road-Showing Walt Disney's Fantasia, W. E. Garity and Wat-
son Jones, No. 1 (July), p. 6.
The Future of Fantasound, Edward H. Plumb, No. 1 (July), p. 16.

Flicker

A Study of Flicker in 16-Mm Picture Projection, E. E. Masterson and E. W.
Kellogg, No. 5 (Oct.), p. 232.

General

The Future of Fantasound, Edward H. Plumb, No. 1 (July), p. 16.
Technology in the Art of Producing Motion Pictures, L. S. Becker, No. 2 (Aug.),

p. 109.
The Navy's Utilization of Film for Training Purposes, William Exton, Jr., No. 6

(Dec.), p. 333.
The Underground Motion Picture Industry in China, T. Y. Lo, No. 6 (Dec.), p.

341.

Wright Field Training Film Laboratory, H. C. Brecha, No. 6 (Dec.), p. 348.
The Documentary, Scientific, and Military Films of the Soviet Union, Gregory

L. Irsky, No. 6 (Dec.), p. 353.

Historical

Progress in the Motion Picture Industry: Report of the Progress Committee
for 1940-41, No. 5 (Nov.), p. 294.

Index

Author: July-December, 1942, No. 6 (Dec.), p. 404.
Classified: July-December, 1942, No. 6 (Dec.), p. 406.

Industrial Motion Pictures

The Production of Industrial Motion Pictures, L. Thompson, No. 2 (Aug.), p.
135.

Kodachrome

The Photographing of 16-Mm Kodachrome Short Subjects for Major Studio
Release, L. W. O'Connell, No. 5 (Nov.), p. 314.

Dec., 1942] INDEX .„,,,

Laboratory Practice

Motion Picture Laboratory Practices, J. R. Wilkinson, No. 3 (Sept.), p. 160.

Light-Scattering

Light-Scattering by Graininess of Photographic Emulsions, Alexander Goctz
and F. W. Brown, No. 6 (Dec.), p. 375.

Navy, U. S.

The Navy's Utilization of Film for Training Purposes. William Exton, Jr., No.
6 (Dec.), p. 333.

Non-Theatrical Motion Pictures
( See Sixteen- Millimeter. )

Optics

Stop Calibration of Photographic Objectives, E. W. Silvertooth, No. 2 (Aug.),

p. 119.
A One-Ray System for Designing Spherical Condensers, L. T. Sachtleben, No.

6 (Dec.), p. 358.

Portable Equipment

Experiences in Road-Showing Walt Disney's Fantasia, W. E. Garity and Wat-
son Jones, No. 1 (July), p. 6.
The Engineering Aspect of Portable Television Pick-Ups, H. R. Lubcke, No. 6

(Dec.), p. 384.

Prescoring

Prescoring and Scoring, B. B. Brown, No. 4 (Oct.), p. 228.

Process Projection

Developments in Time-Saving Process Projection Equipment, R. W. Hender-
son, No. 4 (Oct.), p. 245.

Processing

Motion Picture Laboratory Practices, J. R. Wilkinson, No. 3 (Sept.). p. 168.

Processing, Control of

The Application of Potent iometric Methods to Developer Analysts. John C.

Stott, No. 1 (July), p. 37.

Continuous Replenishment and Chemical Control of Motion Picture Develop-
ing Solutions, H. L. Baumbach, No. 1 (July), p. 65.

Production

The Production of Industrial Motion Pictures, L. Thompson. No. 2 (Aug.).

p. 135.
Production of 16-Mm Motion Pictures for Television Projection. R. B. Fuller

and L. S. Rhodes, No. 3 (Sept.), p. 195.

Progress

Progress in the Motion Picture Industry: Report of the Progress Commit tcr
for 1940-41, No. 5 (Nov.), p. 294.

410 INDEX [J. S. M. P. E.

Projection

The Carbon Situation and Copper Conservation, E. A. Williford, No. 1 (July),
p. 3.

Report of the Projection Practice Sub-Committee of the Theater Engineering
Committee: Projection Room Plans, No. 3 (Sept. ), p. 149.

A Study of Flicker in 16-Mm Picture Projection, E. E. Masterson and E. W.
Kellogg, No. 4 (Oct.), p. 232.

Developments in Time-Saving Process Projection Equipment, R. W. Hender-
son, No. 4 (Oct.), p. 245.

Projection Practice

The Carbon Situation and Copper Conservation, E. A. Williford, No. 1 (July),

p. 3.
Report of the Projection Practice Sub- Committee of the Theater Engineering

Committee: Projection Room Plans, No. 3 (Sept.), p. 149.

Recording Stages

A Modern Music Recording Studio, M. Rettinger, No. 3 (Sept.), p. 186.

Re-Recording

Re-Recording Sound Motion Pictures, L. T. Goldsmith, No. 5 (Nov.), p. 277.

Replenishment

Continuous Replenishment and Chemical Control of Motion Picture Develop-
ing Solutions, H. L. Baumbach, No. 1 (July), p. 55.

Scoring

Prescoring and Scoring, B. B. Brown, No. 4 (Oct.), p. 228.

Sixteen-Millimeter

The Practical Aspect of Edge-Numbering 16-Mm Film, H. A. Witt, No. 1

(July), p. 67.
A Review of the Question of 16-Mm Emulsion Position, W. H. Offenhauser,

Jr., No. 2 (Aug.), p. 123.
The Production of Industrial Motion Pictures, L. Thompson, No. 2 (Aug.), p.

135.
Production of 16-Mm Motion Pictures for Television Projection, R. B. Fuller

and L. S. Rhodes, No. 3 (Sept.), p. 195.
A Study of Flicker in 16-Mm Picture Projection, E. E. Masterson and E. W.

Kellogg, No. 4 (Oct.), p. 232.
The Photographing of 16-Mm Kodachrome Short Subjects for Major Studio

Release, L. W. O'Connell, No. 5 (Nov.), p. 314.

Sound Reproduction

Experiences in Road-Showing Walt Disney's Fantasia, W. E. Garity and Wat-
son Jones, No. 1 (July), p. 6.

The Future of Fantasound, Edward H. Plumb, No. 1 (July), p. 16.

A Modern Music Recording Studio, M. Rettinger, No. 3 (Sept.), p. 186.

The Technique of Production Sound Recording, H. G. Tasker, No. 4 (Oct.), p.
213.

Prescoring and Scoring, B. B. Brown, No. 4 (Oct.), p. 228.

Dec., 1942] INDEX 411

Re-Recording Sound Motion Pictures, L. T. Goldsmith, No. 5 (Nov.). p. 277.
Elimination of Relative Spectral Energy Distortion in Electronic Compressors,
B. F. Miller, No. 5 (Nov.), p. 317.

Special Effects Cinematography

Black-and-White Cinematography, J. W. Boyle, No. 2 (Aug.), p. 83.
Putting Clouds into Exterior Scenes, C. G. Clarke, No. 2 (Aug.), p. 92.
Technicolor Cinematography, W. Hoch, No. 2 (Aug.), p. 96.

Standardization

The Practical Aspect of Edge-Numbering 16-Mm Film, H. A. Witt, No. 1 (July),

p. 67.
A Review of the Question of 16-Mm Emulsion Position, Wm. H. OfTcnhauscr,

Jr., No. 2 (Aug.), p. 123.
Report of the Projection Practice Sub-Committee of the Theater Engineering

Committee: Projection Room Plans, No. 3 (Sept.), p. 149.
Production of 16-Mm Motion Pictures for Television Projection, R. B. Fuller

and L. S. Rhodes, No. 3 (Sept.), p. 195.

Studio Practice

Black-and-White Cinematography, J. W. Boyle, No. 2 (Aug.), p. 83.

Putting Clouds into Exterior Scenes, C. G. Clarke, No. 2 (Aug.), p. 92.

Technicolor Cinematography, W. Hoch, No. 2 (Aug.), p. 96.

Technology in the Art of Producing Motion Pictures, L. S. Becker. No. 2 (Aug.),
p. 109.

Stop Calibration of Photographic Objectives, E. W. Silvertooth, No. 2 (Aug.),
p. 119.

A Review of the Question of 16-Mm Emulsion Position, W. H. Offnehauser, Jr..
No. 2 (Aug.), p. 123.

A Modern Music Recording Studio, M. Rettinger, No. 3 (Sept.), p. 186.

The Technique of Production Sound Recording, H. G. Tasker, No. 4 (Oct.), p.
213.

Prescoring and Scoring, B. B. Brown, No. 4 (Oct.), p. 228.

Developments in Time-Saving Process Projection Equipment, R. W. Hender-
son, No. 4 (Oct.), p. 245.

Re-Recording Sound Motion Pictures, L. T. Goldsmith, No. 5 (Nov.). p. 277

The Cutting and Editing of Motion Pictures, F. Y. Smith, No. 5 (Nov.), p. 284.

Technicolor

Technicolor Cinematography, W. Hoch, No. 2 (Aug.), p. 96.

Technology of Motion Pictures

Technology in the Art of Producing Motion Pictures, L. S. Becker, No. 2 (Aug.).
p. 109.

Television

Mobile Television Equipment, -R. L. Campbell, R. E. Kessler, R. E. Rutherford.

and K. V. Landsberg, No. 1 (July), p. 22.
Production of 16-Mm Motion Pictures for Television Projection. R. B. Fuller

and L. S. Rhodes, No. 3 (Sept.), p. 195.

412 INDEX

The Engineering Aspect of Portable Television Pick-Ups, H. R. Lubcke, No. 6
(Dec.), P. 384.

Theater Engineering Committee

Report of the Projection Practice Sub-Committee of the Theater Engineering
Committee: Projection Room Plans, No. 3 (Sept.), p. 149.

Training Films

The Navy's Utilization of Film for Training Purposes, William Exton, Jr., No. 6

(Dec.), p. 333.

Wright Field Training Film Laboratory, H. C. Brecha, No. 6 (Dec.), p. 348.
The Documentary, Scientific, and Military Films of the Soviet Union, Gregory

L. Irsky, No. 6 (Dec.), p. 353.

Trick Photography

Putting Clouds into Exterior Scenes, C. G. Clarke, No. 2 (Aug.), p. 92.
Developments in Time-Saving Process Projection Equipment, R. W. Hender-
son, No. 4 (Oct.), p. 245.

U.S.S.R., Motion Pictures in

The Documentary, Scientific, and Military Films of the Soviet Union, Gregory
L. Irsky, No. 6 (Dec.), p. 353.

MEMBERS OF THE SOCIETY

LOST IN THE SERVICE OF

THEIR COUNTRY

FRANKLIN C. GILBERT
ISRAEL H. TILLES

BACK NUMBERS OF THE TRANSACTIONS AND JOURNALS

1924

1925

No.
19
20
21
22
2:*
24

Price
$1.25
1.25
.125
125
1.25
1.25

1920

1927

No. Price
25 $1.25
20 ] 25
1 25
I 25

.25
.25

1923

1929

No.
33

34
35
30
37
38

Price
$2.50
2.50
2.50
2.50
3.00
3.00

SOCIETY SUPPLIES

The following are available from the General Office of the Society, at the prices
noted. Orders should be accompanied by remittances.

Aims and Accomplishments. — An index of the Transactions from October,
1916, to December, 1920, containing summaries of all articles, and author and
classified indexes. One dollar each.

Journal Index. — An index of the JOURNAL from January, 1930, to December.
1935, containing author and classified indexes. One dollar each.

Motion Picture Standards. — Reprints of the American Standards and Recom-
mended Practices as published in the March. 1941, issue of the JOURNAL; 50 cents
each.

Membership Certificates. — Engrossed, for framing, containing member's name,
grade of membership, and date of admission. One dollar each.

Test-Films. — See advertisement in this issue of the JOURNAL.

OC 1 1 1943

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