US2281075A - Color photography - Google Patents

Description

APY 23, 1942. A. L.. MccoRMxcK ETAL 2,281,015 coLoR PHOTOGRAPHY Filed sept. 2, 1958 fm/2fgi@ ATTORNEY,

Patented Apr. 28, 1942 COLOR. PHOTOGRAPHY Allen L. McCormick, Chalmers C. Smith, and

l, Los Angeles, Calif., as- Incorporated, Los Angeles, Calif., a corporation of California Application September 2 1938, Serial No. 228,126

(Cl. Bit-16.2)

William T. Crespine signora to Cinecoior,

4Claims.

Our invention relates generally to the art of color photography, and more particularly to a novel and economical method for producing 16 mm. colored motion pictures with sound track thereon.

As is well-known, the standard motion picture film now used for theatrical work is 35 mm. in width, and most of the film used for amateur photography and various commercial purposes is 16 mm. in width, with some 8 mm. nlm being used. These three sizes have, over a period of years, become standardized and are manufactured by various film companies throughout the world. For the sake of simplicity, we will in the specification and claims speak of 35 mm. and 16 mm. films respectively, it being understood that by so doing, we refer to standard sizes, and if in the future these standard sizes should change, that Lthe words 35 mm. and 16 mm. whenever used throughout this. application are meant to include such changed sizes, so long as the general relationship between the standard sizes remains the same. Furthermore, it is to be understood that if in the future, the present standard film of 16 mm. is enlarged to 18 mm. or 19 mm. in width, whereby two 8 mm. films can be produced therefrom with an extra unused marginal strip as hereinafter set forth, that the term 35 mm. when used herein is meant to include such new type of film, and the term 16 mm. when used herein is meant to broadly include the relatively half-size films made therefrom.

In making colored photographs by the subtractive method, it is necessary to have a plurality of color-value or color-separation negatives, which are successively or simultaneously printed in register to a light sensitive film to produce a plurality of superposed positive color-value images therein, which images are subsequently selec tively colored with appropriate colors to give a resulting photograph which is the combination of the superposed part images with their respective colors. In producing subtractive color prints, it is of course necessary to have two r more printing negatives (depending upon whether the process is a two-color one, or three-color one), and in ordinary 35 mm. work where the films are provided with perforations along each edge, the problem of accurately registering the plurality of negatives during the printing operation, so that all of the printed images will be exactly superimposed, has been met generally by employing a pair of registering pins adapted to be inserted in opposite perforations of the nlm during the printing operation. When it is desired to print a sound track on 35 mm. film, a narrow space or strip is left along one side of the film between one row of perforations and the picture area, and a suitable sound track image is printed in this space.

The foregoing method offers relatively few difficulties now in the production of 35 mm. prints in color and sound, but it has been found that this procedure cannot be applied to the production of 16 mm. or 8 mm. sound prints in color, since it has been found necessary to dispense with one row of perforations in the small size films in order to provide space for the sound track. Ob-

yviously, it is impossible to accurately register a plurality of color-value negatives during the printing operation unless at least two perfora-` tions are available for the registering operation. Due to variations in the film shrinkage and other factors, it is virtually impossible to properly register the films by using different holes in the same row of perforations, and as a consequence thereof, it has heretofore been deemed impossible to produce satisfactory colored 16 mm. or 8 mm. films in sound, since they had but one row of perforations.

It is the major object ofl our invention to provide a simple and efficient method for producing highly satisfactory 16 mm. and 8 mm. prints in both color and sound, which process or method as will be hereinafter disclosed is very rapid and economical.

It is also an object of our invention to provide a special film. for use in our method, which greatly facilitates the operation thereof.

These and other objects and advantages of our invention will become apparent from the following 'description of a preferred form thereof, and from an inspection of the accompanying drawing, in which:

Fig.. l is a plan view of a section of ordinary 35 mm. lm with a developed image thereon,

Fig. 2 is a plan view of a section of one form of printing negative used in our invention,

Fig. 3 is a plan view of a section of our preferred form of positive film, showing schematically one form of printing,

Fig. 4 is a plan view of the positive film of Fig. 3, showing the final step of our system,

Fig. 5 is a plan view of a typical roller used in the film-treating equipment,

Fig. 6 is a plan view of a special type sprocket which may be used in our invention,

Fig. 7 is a diagrammatic view illustrating one way of printing a positive from two color-value negative films,

Fig. 8 is a plan view of a modified form of printing negatives, andA Fig. 9 shows the final step in the modified form of our invention utilizing the negative of Fig. 8. As the first step in our method, we produce a set of balanced color-value negatives by anysuitable process, such for instance as the well-known bi-pack system, wherein two films are run faceto-face through a camera, and are so constructed as to record substantially complementaryvfcolorthe beam-splitting 1 value images thereon; orby system, whereby the light is divided by appro-v priate means and the separate beams expose separate films to produce color-separation images; or by any other suitable process, by which it is possible to produce a set of' substantially complementary color-value negatives which can bey used for printing in a subtractive process. For example, itis possible to produce a lenticular negative or a screen-plate negative, and then by appropriate lmeans to produce a set of separate printing negatives from these single negatives, which printing negatives can subsequently be used in our process. The particular manner of obtaining the negatives forms no part of our invention, the onlyrequisite .being that they be color-separationnegatives'of proper range and quality.

In Fig. 1, we have illustrated one of a set of color-Value negatives produced ori-,35 mm. film with standard perforations. mm. negatives we preferably produce a setof 35 mm. printing negatives which have two parallel seriesy of negative images reduced from the 35 mm.

tor the 16 mm. size, it being understood of course that these dimensions refer films, and not the images. These printing negatives can be obtained by :any convenient means, such for example as making lavender prints of the original' negatives, and then making a pair oi' dupenegatives on one film yby reduction printing to produce the two series of 16 mm: pictures or if desired the reduction may; be accomplished during the printing of the lavender prints to give a set of lavender prints having two parallel series From this 4set of 35 type4 perfcrations I6 similar to the perforations I I first mentioned. Thus it will be seen that we have produced a printing negative having two parallel series of`duplicate 16 mm. type picture y I I of the printing negatives.

- to sound track areas I3 and n n The printing of the picture images f is preferably accomplished by. contact printing to `the Width 0f the of duplicate 16 mm. images thereon, which prints Y can subsequently `be usedV to produce printing negatives either by contact or optical printing.

In our preferred form of printing negatives, we "f ci 16 mm'. type 1perforaticns along e ci the stock'as indicated 2; ,f mentioned, two parael eficate have e position follows. One row of l"ations indicated by the numeral II is loea d in the usual manner for 16 mm. films, i. e., cicsely adjacent to the outer edge of the film. Adjoining this row of perforations is one series of 16 mm. picture images indicated by the nual I2. Inside of this row of images is a space ...ze images are produced on thisy large enough to receive a 16 mm. type sound track; said perforations, seriesof picture images, Y

sound track space occupying exactly 16 mm.'

ci' the width of saidfilm. Immediately adjacent v is a, blank strip I4v equal in Width to the strip occupied by-the perforations the sound track area I3 II. Ixmnediatelyfadjoining,this isla second series I5 of picture images of 16 film size. Ad-` jacent the other side of the picture strip I5 is a blank strip I1 equal in width to the strip I3,i. e., 16 mm. sound track width, the outer edge of this strip being exactly 32 mm. fromv the first-men- 3 mm.

tioned edge of the film. In the remaining strip on the edge of the film is a row of 16 mm.

images thereon with spaces left for a sound track for each series of picture images, there being a row of 16 mm. type perforations on each `edge ofthe film which can be used for registering in the printing operation.

Referring now to Fig. 3, wherein is illustrated a'strip of positive film adapted to receive the images-fromthe negatives ofFig. 2, the numeral 20 indicates a space along one edge corresponding in size to strip II)l of the printing negatives, andprovided with a series cf 16 mm, type perforations 2I, corresponding to the perforations The positive film is preferably also provided with a series of perforations 24 in a s trip area corresponding to strip I4 of the printing negatives, and a series of perforations `26 along its other edge, corresponding lwith perforations I6 ofthe printing negatives, the

being of thesamel ksize Aand spaced the same as thev perforations'in The images carried by the printing negatives are printed onto their appropriate perforations in the positive the negatives.

picture areas I2'` and 25 on the positive stock corresponding to the areas I2 and I5 yofthe negaf track is printed tives,`.and an appropriate sound in the areas 23 and 21 which correspond inwidth I1 ofthe printing negatives.

with an over-sized aperture suchas indicated by, numeral I8, which, as will successive yframes in each row of picture images, thatis to say, during each printing light ex` posure, two consecutive frames of each series of n negatives are printed at the same time, thus` doubling thevordin'ary speed of printing, and

since two separate 16mm. prints are made simultaneously,

so that our method of printingis four times as fast as conventional methods.' `It is to be under.-v stood, of course, that we may having an emulsion layer on one or both'sides for producing the colored prints, the printing operation being'the same in either case.

The vpicture and soundtrack images may then be developed and the picture images colored in any suitable' manner, it being understood 1 of course that the order ofy steps employed forms no part of our invention, and that it is irnmaterial whetherthesound tracks or the pictures are printedjfirst, or whether both picture images are printed at the y tively. Likewise, the sound tracks may be colored or left black and white as desired. In other words,` our invention contemplates theuse ,of` of color processes, and may yreadily 2 any of them, so long as the ultivarious types be adapted to mate result is `two duplicate or substantially duplicate parallel series of 16mm. picture images incolor, each accompanied by a` sound track of pictures .in-.

suitablenature, these two series of cluding their sound tracks occupying 32 mm. of the v35 mm. strip of vfilm, leavinga 3 mm. pro-` tective strip along one edge of the may carry the perforations 26 therein.

vIn Fig.' 7, wer have illustrated diagrammatically one means of printing a positive film lfrom a set of printing negatives. Thenumerals 9a and 9b indicate the. printingk negatives, and the numeral I9 be seen, is double. length so asto simultaneously accommodate two the speed of printing is again doubled,

use positive stock.'

same time or consecu`- nim which indicates the positive stock receiving the prints from the printing negatives. A pair of lamp houses 3D and 3| are shown as being oppositely disposed, so as to simultaneously print the negatives 9a and 9b to the positive stock I9. It is to be understood of course that -this is merely illustrative of one suitable method of performing the printing operation.

In Fig. 4, we show a strip of finished film carrying two series of developed and colored 16 mm. picture images each with its own sound track, the various film areas being`indicated by numerals as in Fig. 3. For example: strip 20 is provided with a series of perforations 2| adjacent to picture area 22 which has sound track 23 on its other side. Next comes the strip carrying perforations 24 adjacent to' picture 25 with its corresponding sound track 21, these various elements all together again occupying 32 mm. of the film width. The 3 mm. strip left on the other edge of the film carries a row of perforations 26 as before. Fig. 4 illustrates the nal step in our system which comprises removing the 3 mm. strip 26 with its perforations and then slitting the remaining 32 mm. film down the middle bee tween sound track 23 and the perforations 24 to give two separate and complete 16 mm. positive prints in color and sound, it being noted that the two prints are duplicates of eachother. It will be understood of course that the sequence of operations-in the final step of our process is immaterial, it making no'difference whether the film is slit between the track 23 and perforations 24 before, after, or during the slitting or removal of the strip 26.

In Fig. 5, we have illustrated a typical film roller used in cameras and film treating machines comprising a spool portion 32 with raised shoulders 33 and 34 on each end thereof, each shoulderl being provided with a flange 33a and 34a as indicated.

i While we have described our preferred form of positive film as being provided with three rows of perforations, it will be understood of course that only two rows are necessary for properly registering the films. We have. found that by providing the perforations'on opposite edges of the film, we are enabled to obtain accurate registry during the printing operation, and that it is usually not necessary to use the perforations 24, it being understood that if it is desired to use the perforations 24 as additional means for registering they films, similar perforations would be provided in the strip I4 0f the printing negative 9. in Fig. 6 is preferably employedwhich has a spool portion 35 provided with raised shoulders 36 and 31 on its opposite ends, each of said shoulders being provided with sprocket teeth. A substantially centrally disposed shoulder 33 is also provided on the spool portion 35 and has suitable teeth corresponding to the teeth on shoulders 36 and 31, the position of shoulder 38 being such as to mesh with the perforations 24 and I4 of the films. As mentioned, we find that usually it is not necessary to provide this additional precautionary means. However, it is sometimes highly desirable to employ rollers of this type in the developing and processing machines, particularly if long lengths of film are to be pulled therethrough, it having been our eX- perience that the three-point pull on the film during processing reduces the strain on the individual perforations considerably.

As will be readily understood, so far as the In this case, a sprocket such as illustrated printing operation goes any two of the three sets or rows of perforations will suffice, although we prefer to employ the outside rows as illustrated, However, if for any reason, it is not desired to perforate the strip 26, the printing negatives may be provided with perforations I4, corresponding to perforations 24 in the positive stock and the printing operation can be carried on by registering the perforations II` and I4 with perforations 2| and 24. Likewise, it is possible but not particularly advantageous to provide the series of perforations 24, and not supply the perforations 2| until after the films have been processed.

By using 35 mm. stock for producing the 16 mm. films, we overcome several disadvantages which are encountered in processing 16 mm. film strips. In the first place, 16 mm. lm because of .its narrow width has more of a tendency to stretch and become distorted which makes regmentioned, it is impossible to accurately register color negatives with only the one set of perforations present on 16 mm. sound films. Thirdly, all 16 mm. stock is made with an acetate base instead of the nitrate base usually used'for 35 mm. stock, which is much'more difficult to handle in the laboratory because of its tendency to curl and stretch. Even 35 mm. safety (acetate) stock is diiiicult to process, and when the width of the film is reduced to 16 mm., it becomes virtually impossible to float it across a solution as is necessary in many color processes.

Also by leaving the 3 mm. strip along one edge of the film, we obtain a number of distinct advantages. In the first place, an area is provided for an auxiliary set of perforations, which as mentioned is our preferred means of registering the films during printing. Secondly, without the 3 mm. strip,'the sound track image comes out to the very edge of the film, and during the printing and processing thereof, the edge of the film is bound to rub against the iianges 33a and 34a of the rollers of the machine and 36al and 31a of the sprockets. This rubbing will very often result in chipping small portions of the emulsion away from the base which of course produces defects inthe sound track. Furthermore, if double-coated stock is used, i. e., film having a light sensitive emulsion` on each side of the base, it is obviously impossible to run the film through a developing or coloring machine without ruining the sound track, since when the emulsion is dampened, it has a tendency to stick to the rollers and without the protective strip 26, the sound track 21 would be riding over one of the shoulders 33 or 34 of the rollers or 36 or 31 of the sprocket, and would also rub against any surfaces such as tracks or guides provided in the printer. However, by providing the 3 mm. protective strip on the outside edge of the film, this condition is entirely obviated and the entire picture and sound track area of the film is thoroughly protected.

A modified system for producing two 16 mm. prints at on time from a single strip of positive stock is illustrated in Figs. 8 and 9. In this form of our invention, we likewise prefer to first produce a set of 35 mm. color-separation negatives in any suitable manner, but instead of using them to product a. set of 35 mm. printing negatives such as shown in Fig. 2, we produce a set of 32 mm. printing negatives such as shown in Fig. 8. By inverting one series of 16 mm. images in the printing operation, we are enabled to place the two sound tracks together on the inside of the stock and to eliminate the necessity of the 3 mm. strip 26 along one edge o1' the positive. However, as will be seen in Figs. 8 and 9, we nevertheless have a. row of `perforations along each edge of the film, so that accurate registry can be had as previously explained.

In Fig, 9, we have illustrated the final step of our system which is the same as illustrated in Fig. 4, except that but one slitting operation is necessary. In this figure, we have shown the films asA having a variable area sound track whereas in Fig. 4, a variable density track is illustrated. The same numerals have been used in these figures as in the figures which illustrate the first form of our invention, it being noted that the two series of 16 mm, pictures and tracks are reversed with respect to each other. By thus placing the perforations of each of the 16 mm. films on the outside edge of the positive step, we again provide protection for the emulsions when the flxns are being processed. It will also be understood that this modified form of our invention can be used to produce 8 mm. sound prints in color from 16 mm. stock, so long as sufficient precautions are taken to prevent curling and breaking of the film. However, in making 8 mm. sound prints in color, we prefer to produce four of them at once on 35 or 32 mm. stock, as previously described.

It will `be understood of course that if it is desired to produce the printing negativesv direct-r ly by exposure in a suitable camera, that this procedure may of course be followed, such being easily accomplished by providing a pairof lenses, or a beam-splitting apparatus in the camera of reduced size picture images in color and sound which are duplicates of each other.

2. The method of producing a plurality of re-k duced size motion picture prints in color and sound which includes: producing a set of 35 mm. negatives having a series of color-value images thereon; producing from said set of negatives a plurality of 4series of reduced size positive images' in color on a single 35 mm. film strip having two sets of perforations therein, at least one set thereof being of reduced size to correspond with the reduced size of said images; producing a plurality of reduced size sound tracks on said film strip, said picture and sound images all together occupying but 32 mm. of said lm; removing said unused 3 mm. strip; `and slitting said film longitudinally to produce a plurality of film strips.

` each having a series of reduced size picture imadapted to expose they two portions of the iilm q simultaneously to produce duplicate or substantially duplicate 16 mm. images direct. However,

our experience has shown that much better photography can be accomplished if the pictures are originally photographed in the mm. size, and subsequently reduced to the 16 mmrsize.

Thus it will be seen that we have provided a system of producing 16 mm. colored motion 'pictures with sound tracks thereon by utilizing double width stock throughout, which makes it possible t0 secure accurate registry of the images during printing, and to protect the emulsions during printing and processing, thus insuring pictures of high quality in every regard.

It is to be understood that when in the claims,

we speak of ,double width films, the term is meant to include both 32 mm. and 35 mm. films.

We claim as our invention:

1. The method of producing a plurality of reduced size motion picture prints in color and sound which includes: producing aset of 35 mm,

ages in color and aV sound track thereon.

3. The method of producing a plurality of reduced size motion picture prints in color and sound which includes: producing a set of 35 mm. negatives having a series of color-value images thereon; producing from said set of negatives a plurality Aof series of reduced size positive images in color on a single 35 mm. film strip having two sets of perforations therein, at least one set there-v of being of reduced size to correspond with the reduced size of said images, and located along one edge of said film; producing a plurality of reduced size sound tracks on said lm strip, said picture and sound images ture strip; and slitting said film to produce a plurality of film strips each tions, a series ofreduced size picture images in color, and a sound track thereon.

4. A 35 mm. motion picture film strip which alternating across said f film, there being an area for perforations between each composite reduced sound `and pichaving a set of perfora- Y

Images