US1222925A

US1222925A - Film for color cinematography.

Info

Publication number: US1222925A
Application number: US84696614A
Authority: US
Inventors: Percy D Brewster
Original assignee: Individual
Current assignee: Individual
Priority date: 1914-06-24
Filing date: 1914-06-24
Publication date: 1917-04-17
Anticipated expiration: 1934-04-17

Description

P. D. BREWSTER.

FILM Foa COLOR clNEMAToGRAPHY.

APPLICATION FILED IUNE24, 1914. 1,222,925, Patented Apr. 17, 1917.

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FERCY D. BREWSTER, OF EAST ORANGE, -NEW JERSEY.

FILM FOR COLOR CINEMATOGRAPHY.

Specification of Letters Patent.

Patented Apr. 1*?, 1917.

Application filed J' une 24, 1914. Serial No. 846,966.

filed May 29, 1914, for the production of two negative films, each having a separate color record, from which a positive film sensitized on both sides can be printed to record one color or group of colors on one side and another color or group of colors on the other side, thereby producing a final result like that described in my co-pending applications Serial No. 747 ,712, filed February 11, 1913, and Serial No. 843,351, filed June 6, 1914; that is, a two-color film with a different color on each side.

Several convenient and effective forms of the invention are illustrated in the accompanying drawings, in which- Figures 1, 2 and 3 show three embodiments in cross section. Fig. ,4 is a. detail plan view of a spacer used to separate the two strips of film. Figs. 5 and 6 are plan views of the film shown in Figs. 1 and 2, respectively. Fig. 7 is a plan view of a separator that may be used in Fig. 3. Fig. 8 is a sectional plan view of a camera suitable for utilizing film of the types contemplated by the present invention. Fig. 9 is a plan View of the refiecting and transmitting surface of one of the prisms used in the camera.

My improved film comprises two transparent supports or

films

4, 6, superposed one on the'other and having color-

sensitive emulsions

5, 7, with a spacer 8 and a separator 9 between the two films. The two emulsions may both be panchromatic; but I refer to have one sensitized chiefly for light of one or more colors above, say, yellowgreen of the spectrum, and the other for colors below yellow-green. Of course the dividing line in color-sensitiveness can be at any other desired point 'in the spectrum. The emulsions may be color sensitive when coated or they may be treated with dye baths of well known compositions after coating,hsuch as eosine or erythrosine for the green sensitiveness, and a derivative of cyanine for the red. It is usually necessary t0 filter out the ultra-violet, violet and part of the blue from the light before it reaches the red-sensitized film, as even specially dyetreated emulsions are more or" less sensitive to these colors. The same system of color sensitiveness may be applied to any of the film described herein. I

The emulsions may be on the outside, as in Fig. 1, or on the inside facing each other, as in iFig. 2. The two films and the spacer are attached to each other in any preferred .manner; for example, they may be laced together through the holes 19, 19, by the lacing 19, Figs. 1 and 5. The separator 9 may be integral with the space-r, as in Fig. 7, or it may be separate, as in Figs. 1 and 2, but it should be made of a material sufficiently opaque or colored to prevent the passage of material amount of light.

The function of the spacer between the two films is to maintain a separation between the films equal to the thickness of the positive film upon which the pictures are made from the negative; and the function, of the separator is to prevent the passage of any light through one film against the other and -to maintain the films, during eXposure,fiat

and in the same relative positions that they will occupy when the positiveY is being print-' ed, so that proper registration of the image will be secured.

In cinematographic work, for which the film is primarily intended, great accuracy must be attained, as the small picture (an inch by three-fourths of an inch in size) is enlarged ahundred and twenty to a hundred and fifty diameters, or fourteen thousand to twenty-two thousand times. Hence an error of a thousandth of an inch on the film amounts to from an eighth to a `sixth of an inch on the screen, which causes lack of sharpness and banding of colors. It is therefore important to makethe spacer of a thickness as nearly as possible equal to arator simply acts 'as a dummy for the posi-v tive nlm while the exposure of the two nega- ,tive films is being edected.

After exposure, the two iilms are separated, as by removing the lacing 19a, and are developed and fined, and (if desired) stained. The films are then reassembled with the spacer between as before, but without the separator. (1f the separator and spacer were originally in one piece kthey must be cut apart.) The positive film, coated on both sides with light-sensitive emulsions, is now placed between the negative lms in place of the separatory and is printed on l both sides through the negative films.

The two lms and the spacer can be inseparably fastened together along one edge (as by gluing or cementing, or by pinning as at 19h, Figs. 2 and 6) in which case the two films can be held open along the opposite edge during development and such other treatment (fixing and staining) as may be desired; the separator being first removed, especially if the emulsions are on the inner surfaces of the lms. 1n printing, the two lms, fastened together along one edge,.are opened or spread apart along the other to receive 'the positive lm.

A plan view of a combined spacer and separator is shown in Fig. 7. Like the separators in Figs. 1, 2, 5 and 6, it is perforated with standard sprocket holes (10, 10) used in cinematographic film, and, also provided with a series of

holes

11, 11, along which the separator may be torn from the spacer.

rlfhe standardholes

10, 10 are preferably punched in the lms and separator simultaneously, so as to insure an even feed of film through the film gate, as will be readily understood.

Fig. 3 illustrates in cross section a single film of about double the 'standard width, bent to form a double lm with a separator Y9 between. A spacer 8 may be also incorporated between the lms and held in place by any convenient means.' 1f Celluloid be used for the film support, it can readily be 'bent by the local application of heat along the line on which thebend is to be made. 1f the lm be placed in contact with a tube containing'steam or hot water the celluloid may f be readily bent and if this heat be applied v f' where the pictures are to be talren will not be carefully, the emulsions on the portions aected as there will ordinarily be a margin of about an inch between the two .series of pictures. This form of double Elm is denaaaeaa veloped, etc., and is used in printing, in the same manner as the double film shown in Fig. 2.

A type of camera that may be used for exposing the negative film is shown in Fig. 8, and comprises a casing 12, provided with lens 13 and diaphragm 14. rFhe light from the lens passes into the prism 15, and part of `it is reflected from the surface 23 through filter 16 (adapted to permit the passage of light of the red group of colors) in prism 17 and is reflected by surface 28 of prism 1'? against the red sensitized emulsion 2 6 on film 29m the film gate 18; while the other portion of the light passes through prism 2O and filter 21 (adapted to permit the passage of light of the green group of colors),

` into prism 22 and is reflected from surface will be reflected while the portions cementedl together with the balsam will transmit the light. Any desired proportion of reflected and transmitted light may be secured in-this way.

As methods of intermittently feeding the lilm through the iilm gate are well known in the art, it is not necessary to illustrate or describe the same herein. 1 do not claim the apparatus described, such as the camera, prism and redecting systems.

lf vpanchromatic film be used, suitable light filters, as 16, 21, should be interposed in the paths of the rays', so as to permit light of only the desired colors from reaching the respective emulsions.

The line of perforations 11, 11 (Fig. 7) in the spacer or separator may be omitted and the spacer otherwise weakened along that line in any manner, so ythat the spacer may be readily torn along the line of weakness.

Inasmuch 'as any detachment of the two lms from each other for the purpose of dedescribed as permanently fastened together,

to distinguish from prior schemes in which two films are attached to an intermediate yfugitive element. Insuch schemes (as for example in Ives lPatent No. 927,244, dated July 6, 1909), the negatives are not reassembled after development and fixing, as they were before, but are used separately for printing separate positives which are then combined.

It is to be understood that the invention is not limited to the procedure and apparatus herein specifically described but may be practised in other Ways without departure from its spirit.

I claim:

l. As a new article 4of manufacture in the art of color photography, photographic film for the purpose described, comprising two color-sensitive films superposed one on the other and provided with means for holding the two in the same relative positions during exposure in a camera and during subsequent printing operations, and capable of opening along one edge for the insertion of another film between the two for printing purposes.

2. As a new article of manufacture in the art of color photography, `photographic film for the purpose described, comprising t-wo films, one sensitized for one or more colors and the second for one or more colors different from the first, the two films being superposed on each other and provided with means to hold the two in the same relative positions during exposure in a camera and during subsequent printing operations, and capable of opening along one edge to permit the insertion of another film between the two for printing purposes.

3. As a new article of manufacture in the art of color photography, photographie film for the purpose described, comprising two color-sensitive films superposed one on the other and spaced apart, and provided with means for holding the films in the same relative positions during exposure in a camera l and during subsequent printing operations,

but permitting the two films to open along one edge for the insertion of another film between the two for printing purposes.

4. As a new article of manufacture in the art of color photography, photographic film comprising two superposed color-sensitive films, a spacer between the two films, and means fastening the spacer and the two films together alongl one edge of the latter and permitting the films to open along the other' edge for the insertion of a third film between the other two.

5. As a new art of color photography, photographic lm comprising two superposed color-sensitive films, a permanent spacer between the two films along one edge thereof, the films and article of manufacture in the the spacer being fastened together, and a removable separator arranged between the twoV films and extending over the areas thereof that are to be exposed to light.

6. As a new article of manufacture in the art of color photography, photographic film comprising two superposed color-sensitive films, a spacer arranged between the two films along one edge and permanently se cured thereto, and a separator detachably connected to the spacer and extending therefrom toward the opposite edge of the film.

7. As a new article of manufacture in the art of color-cinematography, cinematogra-phic film comprising two long and relative narrow color-sensitive films superposed on each other, and a spacer between the two films along one edge thereof, the films and the spacer being permanently fastened together but permitting the films to open along the opposite edge to receive a third film for printing purposes.

8. As a new article of manufacture in the art of color -cinematography, cinematographic lm comprising two long and relatively narrow color-sensitive films superposed on each other, a spacer between the films along one edge thereof, the two films and the spacer being permanently fastened together, and a removable separator between the two films and extending over the areas thereof that are to be exposed to light.

9. As a new article of manufacture in the art of color cinematography, cinematographic film comprising two color-sensitive films su erposed on each other, a permanent spacer etween the films along one edge thereof, and a removable separator arranged between the two films and extending over the areas thereof that are to be exposed to light.

10. As a new article of manufacture in the art of colorcinematography, cinematographie film comprising two color-sensitive films superposed on each other, a spacer arranged between the films along one edge thereof and permanently fastened thereto, and a separator between the films, detachably connected to the spacer and extending toward the opposite edge.

In testimony whereof, I have signed my name to this specification in the presence of two subscribing witnesses, this 23rd day of June, 1914.

PERCY D. BREVSTER.

Witnesses:

A. S. Bimws'rnn, C. ODoNoGHUn.