US1808584A - Color photography - Google Patents

Description

Jne 2, 19.31. 1..'1'. TRoLANb 1,808,584

coLoR PHOTQGR'APHX Filed Sept. 9, 1921 .mantenne z, 1931 uNf'rlezD STATES PATENTOFFICE l N LEONAEDT. TBOEAND, or MALDEN, MASSACHUSETTS, ASSIGNOE To OOMSTOOK a WES- COTT, TNO., OE BOSTON, MASSACHUSETTS, a CORPORATION or MASSACHUSETTS COLOR THOTOGRAPHY applicati@ ineav september 9, 111m. serial No. 499,425.HE|

This invention relates to photographic films vand the production and reproduction of same, particularly in color photography, whether for still or motionl pictures, this application being in part a continuation of my prior application Serial No. 377 ,7 55, filed April 3o, 1920.

A principal, object of the invention is simultaneously to produce at a Single ex- ?.0 posure, a plurality of separate superposed complement-al images on a single film adapted to beused in an ordinary still picture or cinematographic camera without substantial modification ofthe latter. f Other objects of the invention are to simplify the art of producing color pictures, to reduce the time and cost required to produce such pictures, to afford al simple automatic way ofobtaining accurate ratios of exposure between complemental images, to obtaincomplemental images whichare in accurate registry throughout `their entire area and Vwhich may be reproduced .with automatic registry, to secure good definition, to minimize halation and generally to improve the ,art of lcolor photography.

In order to clarify the subsequent description of the invention the following 'definitions are here inserted.v Unless otherwise specifically limited the term photographic film is herein employed generically to in-y clude all photographic records or recording articles or devices, whether the emulsion is supported upon celluloid `or other support or is self-supporting, and Whether the film is adapted for either still'or motion pictures.

. The term emulsion is used generlcally to'v connote either a true emulsion or other composition' which is sensitive to light. The 4 entrant side of the emulsion is -the .side

emulsion, whether or not 1t be next .t0 the celluloid or other support, and the emergent l dominates. The warmercolors are t Osev nearer thered end ofthe spectrum and the colder colors. vare' those nearer the violet through which the exposing light 'enters' the.

.end of the Spectrum. The term complemental images is used to designate images representative of different color aspects of an object field, which when combined by printing, projection or otherwise, will yield a more or lessaccurate color reproduction of the object field, the images themselves not necessarily being colored, and the colors which the images represent not necessarily being exactly complementary. The term developed images connotes images which have been developed whether .or not they have been subsequently bleached. The term transparent image means an image which is substantially transparent to light of one or more colors 'though not necessarily to all colors.

The invention involves a photographic film having an emulsion which 1s more sensi-l tive to -light of a predetermined color throughout a part of its depth than throughout another part of its depth, or which is predominantly sensitive to one color only throughout a part of its depth, or whose sensitiveness to light is adjusted differently 715l for diierent colors-throughout atleast a part of its depth, or preferably which possesses lall of these characteristics. The variation of the color sensitiveness of the emulsion ma be gradual or by steps or Stages. Av gray ual variation may be obtained by bathing the film in a suitable dye and ermitting the dye to penetrate to successive 'epths in gradually decreasing measureor by thus sensitizing one side of the emulsion with one dye and similarly sensitizing the'other side with.

another dye. A step by Step variation may be obtained by building up the emulsion as a succession of layers predominantly sensitive to dierent colors. However, there are many advantages in forming the emulsionin a single layerand I therefore deem it highlfy desirable nottoform the emulsion in the orm of separate superposed coatings. By exposing the film to light from. a` multi-l colored object field an image corresponding to one color aspectfof the field is formed throughoutv the lwholel or a part of the depth of the emulsion which vis -predominantly sensitive ton that color and an image correspo'11d4-- 100 sol . ing to another color aspect of the field is formed throughout the whole or a part of the depth of the emulsion which is sensitive to `the other color and so on depending upon the number of complemental images comprised 1n each set of lmages. In two-color work a Ablue-green record may beformedi'n one de th and a red record in another depth. A ter the'images are thus formed they may be treated and reproduced in various wa s, examples of which will hereinafter be scribed. f y

In order to restrict the light reaching the emergent side of the emulsion to the color to which the emergent sidejis specially sensitized, the whole emulsion, or at least a portion -toward the entrant side, is preferably dyed or otherwise colored so as to obstruct light of other colors and to transmit light ofy the color to which the emergent side is sensitized.` This serves to restrict the image or images of the other color or colors to the en- `trantside of the emulsion. y In -two-color work, e. g., the emergent side may be sensitized to the warmer colors and the emulsion may be dyed with a dye which will transmit the warmer colors and obstruct the colder colors. When the film is exposed an'- image of the warmer colors will beformed on the emergent side andan image of the colder colors will be formed on the entrant side. While the light of warmer color passing through. the entrant side may expose the entrant side to some extent, and while some of the colder light may penetrate to the emerent side, these ee'cts can be rendered neggible as will hereinafter appear.

For-certain uses of the film it is desirable that one of the images b e more intense than the other or others. Forexample, according to one method of using the film hereinafter described one image should be so much more intense than the other or others that in reproducing the images b passing flight through all of the imagesyofea'ch compDlemental set in series the vimage or images other than the intense image will be negligible for practical purposesv compared with the intense image. This may be accomplished in various Ways as for example by treating or preparing t h e emulsion, or at least that part of the emulslon intended to bear the less intense image, so as to render theless intense image relatively flat (i. e. having a relatively low gamma). The dye hereinbefore referred to which obstruct's the light of the color represented by the -entrant image also performs this'function, although in order to obtain a pronounced flattening effect the dye should ordinarily be more intensely absorptive vthan is necessary to prevent the passing of the light of the particular color to the` I emergent s ide of the film.

When employing certainof the methods to which my improvedfilm is adapted itis de- 'sirable (although not always necessary) that the portlons of the light-sensitive strata bearing the .respective superposed complemental images be separated by 'a free gelatine layer.

For example, if it is desired to separate the images produced in the portions which vare predominantly sensitive to different colors or if it isdesired to impregnate or otherwise treat the portion bearing one image wlt'hout affecting the other image or images, as Aherevindescribed, it is advantageous to havev the portions somewhat separated.

For good results in two-color work the negative filmshould have the following characteristics. The entrant stratum of the "emulsion should be insensitive or relatively insensitive to orange, red and possibly yellow l light, thatv is, light having wave lengths greater than approximately 590 ma. This stratum should be sensitive to blue, bluegreen, and preferably green and yellowgreen light. The same stratum should be of such color as strongly to absorb substantially all of the spectrum to which it is sensitive. The exact degree of this absorption is determined by the method of subsequent treatment and by the effects to be produced in the finished pictures, but inA general it should be many times (e. g. of the order of one hundred times) greater than that which results from ordinary impregnation with dyes for the purpose of 'green sensitizing or orthochromatizing the emulsion. The emergent .'stratum'of the emulsion should be sensitive to orange, red, and possibly yellow light. In general it is immaterial whether this stratum is also sensitive to other rays of the spectrum lsince the other rays are absorbed before reaching this stratum.

One method of producing a the-above characteristics involves the use of a recoated film. The first coating of emulsion may have ordinary silver bromide sensitivity, being responsive to ultra-violet, violet, blue and blue-green rays only. The film n may then be recoated (on the same side) vwith an ordinary panchromatic emulsion which is responsive to practically all the rays of the spectrum if previously 4sensitized to green, yellow and red with isfocyanine'd es as orthochrome T (color index 807) an pinacyanol (color index 808) as is customary in making panchromatic emulsion. This recoated film is then bathed in a dye adapted to impregnate the emulsion strongly and to make it strongly absorptive of blue, blue-green, green and yellow-green rays, and preferably at the same time to sensitive the emulsion throu vhout. gto' green, yellow-green and possi ly yellow rays. Instead of incorporating the dye by bathing it may be mixed intothe emulsion of the first coating. before the coating is applied to 4the Celluloid. This permits a more reliable determination of the concentration of the dye the-emulsiombut film having sion.

in vgeneral does notaford such a fast emul- Another method of producing a lm hav.-y

ingA the above characteristics 1nvolves the The dye for Vstaining the negative stock as aforesaid should have the following characteristics. It should be capable of impregnating gelatinev strongly. It should absorb blue, blue-green, green and yellow-green rays. It should sensitize silver bromide to vgreen and yellow-green rays. It should not interfere with or destroy the action of the isocyanine or red-sensitizing dye, and it should Wash out of the gelatine after development and fixation with fair facility.

I have found that alkaline fluoresceinates and their halogen derivatives, such as uranine `(color index 7 66),-eosine (color index 768),

' sodium di-bromo-fluorescein, erythrosin (colorindex 772-773), etc., are completely with- :out desensitizing action and otherwise fullll the aforesaid requirements. Other suitfabe dyes are filter yellow Kand kodachrome re v A highly satisfactory dye for average conditions is a mixture in aqueous or aqueousalcoholic solution of uranine (sodium llue- 'oresceinate) and ordinary eosine (sodium tetrabromofluoresceinate),` although this mixture permits a certain amount of yellow, in addition toorange and red, to. penetrate to the second stratum.` `There it is desired to eliminate the yellow rays from the second stratum and to render the first layer more sensitive to these rays, as'in taking outdoor scenes where the green of vegetation is involved, better results may be obtained by adding to the above mixture xylene red B (Schultz No. 579). The absorption band of xylene red B ends labruptly at about 600 ma andthe sensitizing action extends approximately to 610 mn. This dye has all .the other desired properties; s

In bathing a recoate'd film such, as above decribed the dye may comprise 90 parts water, 10 partsalcohol, 1 part of said uranine, and 0.2 part of said cosine; or, when employing said xvlene-red, 90 parts water, 10

parts alcohol, 0.8 part of said uranine, 0.08.

part of said eosine, and 0.05 part of said xylene red. To insure adequate and uniform penetration of the dye to the first coatingl the film is preferably bathed aplroxirlaelydone an rie at hour at approximately 65 approximately F.

In the accompanying figures, i Figure 1 is a' diagrammatic view form of my improved film;

Figure 2 is a diagrammatic view of one way i of roducing the images thereon;

`igure 3 1s a diagrammatic view of one wayl of reproducing same; and i Flgure 4 is a dlagrannnatic view of the application of theinventionto the production of threel color pictures.

In Figure l I have illustrated ferred embodiment of the invention wherein F represents' a support of celluloid or other suitable material and E represents the emul-y sion which may be of the kind predominantly sensitive to the colder colors.

out the cross-hatched portion W. This may be accomplished bv bathing thev film' in a sensitizer (e. g., said pinacyanol dissolved in alcohol and water) the sensitizer being per-V mitted to penetrate, at least in substantial measure, only throughout a .portion of the depth of the emulsion. The portion W of the emulsion is thus renderedsensitiv'e to the.

The emulsion is sensitized to the Warmer colors through-V one preposed through the back (i. e., through the celluloidhas is essential for some purposes,

theemulsion maybe -dyed orange as, e. g., byV

use of dyes previously specified, including one such as said filter yellowv K which absorbs violet and vultra, violet, thus rendering the emulsion predominantly transmissive to the warmer colors. Upon exposing the film to -a camera, proiection printer or the like, and

F represents the Celluloid, thusv illustrating my preferred method .of exposing through After the y the celluloid or yother support, film hasbeen exposed it is developdfor the time required to give the proper gradations of the variousl areas of the. images or each set relative to each other and ofthe respec` tive sets relative-to each other.

Instead of using the entire spectrum of col- Zors and dividingthe entire i ght from the 11e a colored obiect or' image field through the i portions as described, the light may be passed .ponent to pass to the emergent side.

through a color filter adapted to absorb a part of the spectrum before the light reaches the film, in which case a different dye is used in the emulsion to divide the used portion of the spectrum in the desired proportions.

For example, the exposing light may be passed through a yellow filter X (Fig.l 2) which absorbs the blue end of the spectrum (e. g. violet and ultra violet) and an acid scarlet dye (e. g. said eosin in combination with said uranine in the proportions already stated) may be used in the emulsion to rcstrict thegreen component of light to the entrantside and permit the red or orange com- Inasf much as the filter has substantially no absorbing action on the rays to which the emergent side is sensitive, exposure balance between the complemental images may be regulated by l changing the filter. v

Instead of using a color filter the 'Celluloid film may be impregnated with a yellow dye having the desired absorption, for example phosphene; or the dye maybe applied, as a `constituent of gelatine ,or other transparent coating on the back of the Celluloid after the manner of the well-known non-curlingcoating. Another method is to employ an ex'" tremely heavy staining of the emulsion itself with a vdye very strongly absorbing ultra violet and violet, as for example said filter yellow K or Eastmanyellow (color index 640) as already indicated.

Development of the exposed film should kbe bythe time-temperature method, since the ratio between the red and green records' in the two strataof the film depends not only upon exposurevbut toa considerable degree upon development, both as regards the apparent inertia of the records and their apparent contrast. It isdesirable to soak the film in cold water for a few minutes before placing it in the developer; this causes a preliminary swelling of the gelatine and enables development to begin throughout the film more near- 1y simultaneously than would otherwise be the case.' Y

The green record canA often be improved inspeed and in the form of its characteristic Curve by slightly fogging it previous to development by exposure of the film through' the back to rays which'are strongly absorbed Owing to the fact that the developer-acting upon the green record image in the first stratum'must firstpenetrate the second stratum there is a strong: tendency for itto become'lol cally exhausted by its reaction with the red record image. This has the effect of producingva local reduction ofdevelopment of the green record image Aunderneath relatively high densities of the red record image, Awith a correspondingly bad effect upon the final color rendering. In order to reduce this socalled exhaustion 'effect to a minimum it is desirable to use a developer possessing'a high diHusion tendenc and a relatively low reduction potential.v uch a developer is hydroquinone combined with an alkaline carbonate (e. g. in the ratio of one part hydroquinone to ten parts of carbonate in one hundred parts of water). A small amount of metol (color index 875) may also b e added to render the development more rapid.

After development the negative is `fixed in a plain hypo fixing bath, is then washed until the dye has substantially disappeared, and is then dried in any suitable manner.

The following are examples of the Vuses tol which my new film is applicable after it is developed and otherwise suitably treated, two-color films being referred to for the purpose of illustration.

The images on the opposite sides of the emulsion may be separately printed by reflecl 'opague white material may be provided in the emulsion as for example in the form ofv silver bromide not lfixed out.

If one of the complemental images (the image representative of the warmer color in the foregoingl example) is made much more intense than the other, e. g. ten times as intense, this image m'ay be reproduced by projecting light through both images of a coml plemental set, the intense image predominating to such extent that the combined effect of v all the images is virtually that of the intense image. n After the intense image has been reproduced, or in thecase of a motion picture film after the series of intense images have been reproduced, the intense image or'images may be rendered ineffective, as e. g; by bodilyv removal after which the less intense im'age may be reproduced either in superposition with the intense-image or otherwise. When the intense image is on the outside of the film as illustrated, it may bel removed by bleaching the film in a solution which produces both images in hardened gelatine and thenetching the film in hot water about l120" F.) which dissolves the soft gelatine betweenfthe images and allows the intense image tofloat ofil but leaves the other image adhering to the celluloid or other support.

, The bleaching solution may comprise approximately 100 parts water, 2 parts chromic acid, 5 parts sodium chloride, and 0.1 part sodium sulphite.. Before placing the film in the solutionit is preferably soaked in cold 'water until the gelatine has swelled to a proximately an equilibrium' condition'. T e solution converts the silver and at the same time hardens the gelatine in the :form of the iso ' 1,sos,ss4

to break up in the etching process. These` two tendencies can be remedied by a slight chemical reduction of the bleach, which is accomplished by the additionof sodium sulphite or other reducer. The reduced bleach yields a more pronounced and more coherent relief.

However, an excessive bleach reduction must be avoided, since a greatly reducedl bleach, especially if diluted or slow acting, has the peculiar .effect of-impressing upon the green record relief an image component which is proportional tothe superposed red recort In other words a ositive o f-the red recor is added to or combined with the green record, for which reason I have called -this phenomenon the bleach-.positive effect.` This effect can be substantially avoided by` employing a rapidly acting bleach, such as above specified, inasmuch as the effect depends upon the diffusion of gelatine-hardening substances from the red record into the stratum occupied by the green record.v y

The bleach-positive effect is in general the reverse of the exhaustion effect; consequently b regulating the bleach-positive effect as a ove outlined it lmay be utilized approximately to neutralize the'exhaustion effect'.

After the image remaining on the .film is thoroughly etche with the hot water to clear up the relief,'the silver salts arefixed out in plain hypo, the hypo being subsequentlyremoved by washing, andthe film is then preferably dried before further treatment.

The adheringimage is then intensified optically after which it may be readily printed. The intensification may be effected by stainving the gelatine relief with a dye which strongly absorbs the actinic rays of the spectrum. The dye should have greatafiinity for gelatine in orderl to produce a heavy staining of thel relatively .thin`relief; and itshould wash out slowly so that the superficial dye adhering to the surface of the film may be rinsed off without unduly bleeding the film.-

A satisfactory dye for the purpose is croceine scarlet in'a 3 per cent. solution with 5 per cent. acetic acid, thisdye affording an enormousintensiflcation of the original'image.' The time of immersion of the film in this solution determines the degree of printing contrast which it attains, the contrast continuing to increase slowly over a period -as 'long as twelve hours. Ordinarily. an immersion of about 20'minutes suilices when employing a dye of the above composition. When properl contrast is attained the film is removed from the dye, rinsed and dried rapidly, after which itis ready for printing.

Instead of forming one of the complemental images with negligible contrast and then intensifying it after the more intense -image has been reproduced, I have discovered various subtraction methods of reproduction 4 which do not depend upon this difference in contrast. When the contrast of the entrant image need not be kept down to a negligible amount, the quantity of dye with which the emulsion is vdyed may be greatly reduced, thereby increasing the speed of exposure.

The followingis one substraction method of reproduction'such as referred to above. A positive is made byprint'ing through both negative records. The exposure and characteristiccurve (depending upon the exposure and the emulsion employed) of the positive should be such as tov render it substantially an exact black-and-white complement o-f the original negative, so that when the two are supe posed in registry no picture, either positive or negative, is visible.

The original negative may then be treated .to remove the red record by the same or equivalent method as described above for this pury pose. It is desirable, however, to retain the silver of the green-record image in its original form and densities. This can be accomplished if the development of the film is initially by means of a pyro formula, which will give hardening of the gelatine in the formy of the image simultaneously with development thereof. Any pyro developer containing little or no sulphite preservative may be employed for this purpose. The green-rec-` ord image thus separated is now superposed in register upon the complement of the total record which was previously obtained. This produces a positive which is substantially thatv of ,the red record alone. From this positive is printed a negative which corresponds to the original red-record negative.

ftradistinction to -a subtraction of the exposures which would result in using interpenetrating images formed by exposing the same emulsion stratum to the respective color components of light. By subtracting densities instead of exposures .the component image A resulting from the subtraction process has far more accurate density gradations than when subtracting exposures.

Among the other possible methods of separatly'reproducing the superposed complemental negatives there are various rede yelopment methods which do not necessitate 'making one of the-negatives extremely ii'at. One such method involves converting both negatives into unexposed light-sensitive silver salt, exposing onenegative without substantially exposing the other negative, de `veloping the exposed negative, fixing out the v silver salt of theunexposed and undeveloped Aeo negative with hypo to render the gelatine transparent, printing the redeveloped image,l then etching. olf the printed image leaving the transparent image adhering to the Celluloid in the form of a relief, and then staining and printing the relief. The conversion of both'images into light-sensitive silver salt may be eifected by bleaching in the' dark with a solution of copper bromide. One negative may be exposed withoutbsubstantially exposing the Iother by heavily dyeing the emulsion, thereby absorbing the light before it reaches the secondy negative, the dye originally incorporated in the emulsion before the original exposure ordinarily being suiicient for this purpose. In redeveloping the reexposed negative a low potential developer` such as hydroquinone is recommended. The negative which is notreexposed and rcdeveloped may be converted into a transparent relief in either yof the 36 aforesaid ways, viz., by using a pyro development.- The transparent relief preferably represents the green aspect of the object field. This mode of reproduction I call the invisible image method.

vAn alternative method of separating the component negative images in preparing the positive is to transform each of these images into an image in pure -dye or other coloring 4matter, each'image absorbing exclusively cervtain spectral rays or colors. F or' example, in the case of a two-color record the cold color image might be converted into an image -in yellow or minus-blue dye and the warm color image into Aan image in magenta or minusgreen dye or other coloring matter. There are various ways in which this could be acf complished. For example, both images may be converted into a dye suchas Metanil yellow; (color index 138,) which when acted upon by an acid becomes magenta in color. A small amount of acid may then be diffused into the 'film so that the image next to the su'i'-, face .isl converted into magenta while the other4 image is not sensibly "adected Another method 4is to convert the image next to the surface directly into a magenta dye image.

p image. p ,Y

-One'such method consists 1n, converting tives. may be made much shorter.

both negatives into unexposed light-sensitive i silver salt, exposing one negative without sub'- stantially exposing'the other negative, andployed as a mordanting base for a dye of the appropriatecolor which is not absorbed by the metallic silver image. The latter may be colored the desired color by any well-known toning process which does not act upon the' silver salt or dye of the other negative. By4

employing. a bleachv which will convert the silver into silver iodide in -the aforesaid bleaching loperation a considerable variety of dyes are available in the mordanting process. For example safranine' may be employed to reduce a magenta color. In the toning process a yellow image may be produced by em ploying a titanium salt. The negatives thus diHerently colored may be separately printed by using lights of different colors, the -light used in printing each negative being absorbed strongly by.tliatnegative and weakly, at all, by the other im ge.

It is clear that when this conversion of the images into respectively different colors, as

above specified, has been accomplished, if bluel light is employed to print through the combined lilm, only thev yellow or minus-blue colored image will be printed, since the blue light will not be absorbed'by1 the' magenta image. Qn the other hand, if green light is employed, only .the magenta lor minus-green image will be printed, since the green light will not be absorbed by the yellow image. In this way it will be possible to effect an optical separation of the two images without removing either of them from the iilm and also without involving any appreciable adulteration of one image by traces of the other.

"In the last aforesaid method the original exposure need not be made through the celluloid or other support inasmuch as it is not necessary physically to separate the nega- Consequently the original exposure It is evident that a negativel film of the character above described maybe used to print both negative records simultaneously if a positive film having the general struc ture of the ne ative film which is described in these speci cations is employed. In this case the two strata ofthe positive film may be rendered sensitive to blue 'and green rays respectively, the entrant side of the positive emulsion being sensitive only to the blue whilethe emergent side-is sensitive also to the green. The entire emulsion is stained with a dye which. absorbs blue, so that only los the green rays reach the emergent side, while only the blue rayscan act on the entrant side. If the multiple colored negative is used to print on such a positive with combined blue` and green light, 1. e. yellow or possibly white,

the cold record image of the ne ative will be printed on the entrant side o the positive emulsion andthe warm record image on the emergent side of the` latter. This method of printing is illustrated in Fig. 3 wherein Fn represents the celluloid baseof the negative film, Cn' and Wn the strata of the negative emulsion bearing the cold and warm images respectively, Pp'the Celluloid support of the positive film, and Cp and Wp the strata of the positive emulsion intended to receive the positive images respectively. The strata Cn and Wn may, e. g. be dyed with a blue-absorbing (yellow) dye and with a green-absorbing (magenta) dye respectively, in which case the strata Cp and Wp maybe receptive to blue and green colors respectively. The arrowat the top of the figure indicates the direction of the printing light, which in this example is preferablyv formed of blue and green components.

Selective stainingof the two separated positive images thus obtained may then be carried out so that the positive from the cold color record is converted into a color complementary to that' which originally produced the record in the negative, with a corresponding conversion of the print from thewarm color record.

From the foregoing it will be evident that inthe more limited aspect of the invention a cardinal feature consists in formi-ngl the film so that the face of the emulsion next to the celluloidor'other-support is the entrant face, instead of the emergent face'as is usual, and so that the more intense image is formed on the emergent side of the emulsion.

' While the invention has been described with particular reference to two-color work it is also applicable to the production of pictures with a greater number of color compo-- nents, one application-to three-color work being illustrated in Fig. 4,' where two films, each with its own celluloid base, are employed with their emulsion surfaces -in contact.

One of these films may be similar in struc:

ture 'to the one shown in'Fig. l, (differing ordinary panchromatic film. Thus in Fi 4 F represents the Celluloid of the first lm carrying an emulsion .E theinner stratumA C of which is sensitive to cold color or colors e. g. violet, blue, and blue-green, and the outer stratum of which is sensitive to warmer Acolor or colors, e. g. green and yellow-green.

The outer stratum may or may notbe sensitive to the colder colors.

The Celluloid of the secondfilm is designated F and carries an emulsion H which is sensitive to still warmer color or colors, e. g. yellow, orange and red. Eithei` the inner stratum C or both strata C and W are impregnated with a dye which rapidly absorbs the colors to whlch the inner stratum is sensitive but which does not absorb the colors to which the outer stratum is sensitive. If the stratum H. is also sensitiveto green and yellow-green a filterabsorptive of these colors may be provided between the two films, which filter ma be in the form of entire emulsion E may be dyed With tartrazine and the outer surface of this emulsion may be further dyed with Congo .red (colorv index 370) or rose bengale (color index 77 7- 779). The emulsion H may be sensitized throughout with pinacyanoL By using a direct cotton dye, such as Congo red for example, the dye is confined to a very thinl stratum at the surfaceA of the emulsion.

With these films in contact (instead ofv slightly separatedas shown in Fig. 4 they are, exposed from the side indicated y the arrow. The violet, blue and blue-green rays n expose stratum C and are absorbed thereby so that none of them reach the other strata. The green .and yellow-green rays expose stratum W. And the yellow, orange and red i rays expose emulsion H. The latent images in strata C and W are treated and reproduced asdescribed above in connection with" the'two strata inthe two-color processes and the image in emulsionl H may be developed and printed in the ordinary way, it being understood that the three positives are'suit:

ably colored to give the desired color effect y when combined.

The vpresent invention aords many advantages over prior methods of making color photographs, viz:

The methods herein `described have vthe obvious advantage over the taking of separation negatives by successive exposures in that both of the negative records must necessarily record the same time phase of the object so that color fringes are impossible. Thesingle exposure also naturally involves fewer operations than the taking of two successive exposures, besides consuming less'time.

The requirement of simultaneous exposure on'the two-color ele-ments could of course be met byy meansof a specialcamera, butthe sity of this very expensive method since it is ap licable to'any'ordinary camera.

he present invention is readily applicable to roll-film cartridge o r film-pack cameras, and does not involve any different manipulation than black-and-white film, exceptas to length of exposure and. possibly the use of a color filter although the filter is not essen- ,present invention dispenses with` the necesv The A'development of the negatives is similar to the development of bl'ack-and-white negative for each finished positive instead of two or more detached component negatives as in other `prior processes.

y When reproducing one of the complemental negatives by transforming it into a gelatine relief and lthen dyeing the relief the contrast of the posit-ive printed .therefroml can be Well controlled by regulating the amount of dye incorporated in the relief,

thereby accurately balancing thecontrasts of the two positives against eachother.

One of the greatest difficulties in securing satisfactory color separation records lies in balancing the exposures. According to this invention exposure balance 'is practically built into Athe Vnegative film which has been properly manufactured, so that errors on this point cannot be IIliade by the operator.

The single iilm feature of the presentmethod permits automatic attainment of register between the two color components of v the positive, provided proper devices are employed. For example, the original negative and the positive blanks to be printed -upon may be similarly punched and, in printing, these punchings may be held in regis'er by fitting both lillms over pins so placed in the printing frame as to fit the original perforations. Since the negative is geometrically identical inthe printing of both color component positives, the application of the above method insures that both positive lilms may then be registered with respect to each other (or in the case of imbibition technique with' respect to a third element or transfer blank) by use of the same perforations. If the mechanical lfeatures of this method are accurately adjusted this insures register vof the final color images without placing any re-l liance on the eyes o'r mechanical skill of the operator.

Another important advantage of the presv ent invention lconsists in that the emulsions for the respective complemental images are integrally joined together so that there-are no surfaces ,of separation to scatter the exposing light and produce halation.

For the purpose of simplifying and clarifying the description I have in many` instances rferredto the images being reproduced as negatives and the imagesl being printed as positives but it is to be understood that the invention is likewise applicable to the production of negatives from positives if such reverse procedure is desired for any purpose.

I claim:

1. '-A -sensitized element foruse in color 'I photography comprising an emulsion which is sensitive to complemental colors at difl'erent depths respectively.

2. A sensitlzedelement for luse in color photography comprising an emulsion whichv is sensitive to complemental colors at different depths, the first sensitive depth being coats-4 substantially insensitive to.l the complemental color to which a succeeding depth is sensitive.

3. A sensitized element for-use in color photography comprising a transparent support carrying an emulsion which is sensitive to com lemental colors in different -strata respectively, the sensitivity to warmer colors progressively increasing from the support outwardly.

4. A sensitized element for use in color photography comprising an emulsion which is sensitive to complemental colors at different depthsthe irst sensitive depth being substantially ab-sorptive of the complemental color to which it is sensitive.

5. A sensitized element for use in color photography comprising an emulsion which 1s sensltive to complemental colors at diferent depths, the first sensitive depth being substantially absorptive of the vcomplemental color to which it is sensitive, and being sub- Ito complemental. colors in different strata respectively, the sensitivity Ito warmer colors progressively increasing from 'the support t outwardly, and the inner stratum being substantially insensitive to the complemental color to which a succeedingstratum is sensitive.

8. Al sensitized element for use in color photography, comprising a transparent supp'ort carrying an emulsion which is sensitive to complemental colors in different strata respectively, the sensitivity to warmer colors progressively increasing from the support outwardly,.the inner stratum being substany tially absorptive of the color to which it is sensitive and being substantially'k insensitive to the complemental color to which a succeeding stratum is sensitive.

9. A sensitized element foruse 'in color photography comprising an emulsion having a pluralityof different strata'fast together in superposition, theJ differentstrata being sensitive to complemental colors' respectively.- photography comprising an emulsion having I 10. A sensitized element for use in color a plurality of different strata "fast together. in superposition, the 'different strata being sensitive to complemental colors respectively, and at least one stratum being substantially 'insensitive to the complemental color which a succeeding stratum is sensitive.

11. A sensitized element for use in color photography comprising an emulsion having a plurality of different strata fast together in superposition, the different strata being sensitive to complemental colors respectively, and the lirst stratum being substantially absorptive of the color to which it is sensitive.

12. A sensitive element for use in color photography comprisingan emulsion which is sensitive to different colors at different depths, the first sensitive depth being sub-I stantially absorptive of the color to which it is sensitive. l

13. A sensitive element for use in color vphotography comprising an emulsion which is sensitive to one color on its emergent side and on its entrant side is both sensitive and relatively opaque to another color.

14. A sensitized element for usein color photography comprising a transparent support carrying an emulsion which is sensitive to different colors in different strata respectively, the sensitivity to warmer colors progressively increasing from the support outwardly, and the inner stratum being substantially absorptive of the color to which it is sensitive.

15. A sensitized element for use in color photography comprising a transparent supp-ort carrying an emulsion which is sensitive to .different `colors in diii'erent strata respectively, the sensitivity to warmer colors progressively increasing from the support outwardly, and the inner stratum being substantially.` insensitive to a color to which a succeeding stratum is sensitive. y

16. A sensitized element for use in color photography comprising a transparent support ycarrying an emulsion which is sensitive to di'er'ent colors in different strata respectively, the sensitivity to warmer colors progressively increasingv from the support outwardly, the inner stratum being substantial- '.ly absorptive of the color to which it is sensitive and being substantially insensitive to a color to which a succeeding stratum is sensitive.

17. A sensitized element for use in color photographyA comprising an emulsion hav-wv ing a plurality of diierent strata fast together in superposition, the diiere'nt strata Ibeing sensitive to different colors'and vone stratum being substantially absorptive of the color'to which it is sensitive, the vlatter stratum being nearer the entrant side of the emulsion than another stratum.

1 8. A sensitized element for use in color photography comprising an emulsion hav ing a plurality of- `diierent strata 'fast totive to the color to which a succeeding v depths, one depth being sensitive to' reddish color and a depthl in advance thereof being both sensitive and substantially opaque to a colder color. y

. 20. A sensitive element for use incolor photography comprising an emulsion which is sensitive to different colors in diierent strata,van outerstratum being sensitive tp a reddish colorv and an inner stratum belng both sensitive and substantially opaque toa colder color.

21. Asensitive element for usein color hotography com rising an emulsion whic is sensitive to di erent colors in diierent strata, an outer stratum beingsensitiveto a reddish color and an inner stratum being both sensitive and substantially opaque to a colder color, and the latter stratum being substantially insensitive to the reddish color.

22. A- vsensitive element for use in color photography comprising an emulsion which is sensitive to a reddish color on itsA emergent side and which is both sensitive and substantially o aque to a greenish color on its entrant si e.

23. A sensitive element for use in color photography comprising an emulsion which is sensitive to di erent colors in different strata, an outer stratum being sensitive to a reddish'oolor and an inner stratum being both sensitive and substantially opaqueto a greenish color.

V24. A sensitized element for use in color photography com rising an emulsionhaving a plurality o diiferent strata fast together in superposition, one stratum being sensitive to a reddish lcolor and another stratum in advance thereof being both sensi'-l color.

25. A sensitized element for use in color photographytcomprising 'an emulsion 'have lng aplura y of rdifferent strata p fast together in superposition, one stratum being sensitive to a reddish color and another stratum in advance' thereof being both sensitive and substantiallyopaque to a greenish color. f

26. A sensitive element for use in color photography comprising an emulsion having a layer sensitive to red and a layer both sensitive and substantially 'opaque to green.

27; A -sensitive element for use in color photography comprising an emulsion having a layer sensitive to red anda layer both sensitive and substantially opaque to green, and also substantially insensitive to red.

28. .A sensitive element for use in color pho.. tpgraphy comprising a transparent support carrylng lan emulsion which is sensitive'I to different colors in different strata, lan outer stratum being sensitive to red and an inner stratumv being both sensitive and substantially opaque to green.

29. A sensitive element for use in color photography comprising a transparent support carrying an emulsion which is sensitlve to dlfferent colors 1n different strata, an

outer` 'stratum being sensitive to red and an inner stratum being both sensitive and substantlally opaque to green, and also substantially insensitive to red.

` stratum being sensitive to red and orange and an inner stratum being both sensitive and substantially opaque to green and blue-green.

32. A- sensitive element for use in color photography comprising a layer of emulsion sensitized to reddish light and a layer of emulsion dyed Withxylene red.

33. A sensitive element for use in color photography comprising a layer of emulsion sensitized to reddish-light and a layer ofemulsion dyed with uranine and eosine.

34. A sensitive yelement for use in color photography comprising a layer of emulsion sensitized to reddish light and a layer of emulsion dyed with uranine, eosine and xylene red.

` 35. A sensitive element for use in color photography comprising` a layer ofl emulsion :sensitized to reddish light and a superposed ylayer of emulsion dyed with a solution con- -taining approximately one-tenth to twotenths per cent. eosine and at least approximately .five times as much uranine. v

36. A sensitive element for use in color photography comprising a layer of emulsion sensitized to reddish light and a superposed layer' of emulsion dyed with a solution containing approximately one-'half per cent. uranine'-, one-tenth percent. eosine and fivehundredths per cent. xylene red.

37. An emulsion sensitive'to reddish light l and dyed with a dye which further sensitizes to a colder color withoutsubstantially desensitizing to reddish light.

38. An emulsion sensltive to reddish light a-nd dyed with a dye'which further sensitizes to a greenishy color without substantially desensitizing to reddish light. A' v 39. A photographic film for making color pictures which comprises an emulsion hav- `mg one stratum which is sensitive to a color to which another stratum on the entrant sideof said first .stratum is substantially insensitive and the latter stratum being suiciently 40. A photographic film for making super-v posed complemental images which comprises an' emulsion having different strata sensitive -to complemental colors, one stratum being suiiiciently absorptive of colors other than the color to which a succeeding stratum is sensitive effectively7 to restrict the exposure is sensitive.

5 of the latter stratum to the color to which it V7 41. A photographic film for making color pictures which comprises an emulsion having sensitive and the latter stratum being 'sufiiciently absorptive of colder colors to cause said irst stratum to record an image of the reddish color aspect of an object field to which the emulsion is exposed from said entrant side.

' 42. A photographic film for making vsuperposed complemental images Whichcomprises an emulsion whosestrata are sensitive to complemental colors, one stratum'being substantially insensitive to the complemental color to which a succeeding stratum is sensitive and being sufficiently absorptive ofA the complemental color to which it is sensitive simultaneously to cause said strata res `ectively to record complemental images 'o said color aspects of'an object field to which the emulsion is exposed-from the sideof the latter stratum.

43. A photographic film for making' superposed complemental images which comprises an emulsion having one stratum which is sensitive to a reddish color and another stratum which is sensitive to a complement'al color but relatively insensitive to the reddish color, the

latter stratum being suiciently absorptive of' said complement-al color simultaneouslyy to cause lsaid strata respectively to record complemental images of said color aspects of an object eld to which the emulsion is exposed Efrom the side of the latter stratum.

v 44. A photographic film for making superposed complemental images which comprises n emulsion having different strata Adierently sensitized to complemental colors respectively. l

45. A photographic film for making superposed complemental images comprising an emulsion having different strata differently sensitized, one stratum. beingl sensitive to a greddish color and another stratum being sensitive to a complemental color.

46. A-photographic film for making vsuperi posed complemental images compusing an 4 emulsion havingdierenhstrata differently sensitized, an outer stratum being sensitiveto areddish color rand an inner stratum Vbeing sensitive to a colder color.-

147.A photographic lm for making supergle emulsion coating substantially/sensitizedv to one colorv only throughout a portion of its depth.

50. A photographic film'comprising a single emulsion coating substantially sensitized to one color only throughout its outer stratum.

51. A photographic film comprising a 'single emulsion coatin substantially sensitized to reddish color 011 y throughout a'. portion of its depth.

52. A photographic film comprising asingle emulsion coating substantially sensitized to reddish color only throughout its outer stratum. A

53. A photographic film for making color pictures which comprises a single emulsion coating having one stratum which is sensitive to a color to which another stratum on the entrant side of said first stratum is substantially insensitive and the latter stratum being sufficiently absorptive of other colors substantially to restrict the exposure of the said first stratum to light of said first color.

54. A photographic film for making superposed complemental images which comprises a single emulsion coating having different strata sensitive to complemental colors, one stratum being sufficiently absorptive-of colors other-than the color` to which a. succeeding stratum is sensitive effectively to restrict the exposure of the latterstratum tothe color to which it is sensitive.

55. A photographic'film for making color pictures which comprises a single, emulsion coating having one 'stratum which is sensitive to a reddish color to which another stratum on the entrant side of said first stratum is substantially insensitive and the latter stratum being sufi'iciently absorptive of colder colors to 'cause said first stratum to record an image-of the reddish color aspect of an Object field to which the emulsion is exposed fromk 'said entrant side. e i

56. A photographic film for making superposed complemental imagesl which comprises va single emulsion coating whose strata are GQ sensitive to complemental colors, one stratum being substantially insensitive to the complemental color to which a succeedin stratum is sensitive and being sufliciently a sorptive of the complemental color to which itis sensitive simultaneously to .cause said strata. re-

spectively to record complemental images of said color aspects of an object field to Which` the emulsion is exposed from the side of the latter stratum.

= 57. A photographic film for making superposed complementalimages which comprises l a single" emulsion coating having one stratum .Which 1s sensitlve to a reddish color and another stratum Which 1s sensitlve to a comple- 4mental color but relatively insensitive .to thev reddish color, the latter stratum being sufficiently absorptive of said complemental color simultaneously to cause said strata respectively to record complemental images of said color aspects of an object field to which the emulsion .is exposed from the side of the lat- Iter stratum.

58. A photographic film for making superposed complemental images which com rises a single emulsion coating having di erent strata differently sensitized to complemental colors respectively.

59. A photographic film for making superposed complemental images comprising a single emulsion coating having different strata differently sensitized, one stratum being sensitive to a reddish color and another` strat-um being sensitive to a complemental color.

60. A photographic Film for making superposed complemental images comprising a singlel emulsion coating having different strata differently sensitized, an outer stratum being sensitive to a reddish color and an inner stratum being sensitive to a colder color.

61.4 A photographic film for making superposed complemental images comprising' a single emulsion having different strata differently sensitized,- an outer stratum being' sens1t1ve to a reddish color and an inner stratum being sensitive to a complemental color.

posed complemental images comprising a f single emulsion coating having different strata differently sensitized, one stratum being sensitive to a reddish color and another stratum being sensitive to a greenish color.

63. A color photographic-film or -plate bearing an emulsion sensitized torecord the color values of one portlon of the spectrum, sa1d emulsion being transparent to certaln of 4said color values and being treated to restrict the remainder of said color. values substantially to the surface of the emulsion.

v 64. A color photographic film or plate comprising an emulsion sensitized to the orange red of the spectrum, a second emulsion sen'- sitized to the blue-green of the spectrum and colored yellow to thereby diminish the effect lof the blue-violet values upon the body of the second emulsion. i

65: Atcolor photographic film or plate coinprising an4 emulsion'sensitized to the orange red ofthe spectrum, a second .emulsion 4sensitized to the blue-green of the spectrum and having incorporated thereinayellow dye for -the purpose of restricting the blue-violet record to the surface of the second emulsion, but permitting a green record throughout the body of the said second emulsion.

. 66. A photographic film comprising a support carrying on one side thereof strata of emulsions having different sensitivity for recording different color aspects of a scene in these strata respectively and an intermediate stratum having different characteristics. 67. A photographic film comprising a support carrying on. one side thereof strata of emulsions having different sensitivity for recording different color aspects of a scene in these strata respectively and an intermediate stratum which is relatively insensitive.

68. A photographic film comprising'a support carrying on one side thereof three separatelyapplied layers, the first and last of said layers having different sensitivity for ref cording dierent color aspects of a scene.

" absorptive of light of the color correspond-g 69. A'photographic film comprising a support carrying on one side thereof three separately applied layers, the first and last of said layers having different sensitivity for recording different color aspects of a scene and the intermediate layer comprising gelatine substantially free from sensitivity.

70. A photographic film comprising asupport carrying on one side thereof three strata for recording different color aspects in the first and last strata respectively, and at least' one strat-um in advance of the last stratum being largely absorptive of light of the color corresponding to the. record of the first stratum. ,v

71. A photographic film comprising a support carrying on one' side thereof three sepa-- rately applied layers for` recording different color aspects in the first and last layers respectively, and at least one layer in 'advance vof the last layer being largely absorptive of lightof the color corresponding to the record of the first layer.

72. A photographic film comprising three.

strata of gelatine integrally throughout their transverse and longitudinal coextents, the first and last strata being sensitized to record different color aspects and one of the strata in advance of the last stratum being largely inv to the recor o f the first stratum.

3. A photographic film comprising three separatelyapplied layers of gelatine integrally united throughout their transverse .and longitudinal coextents, the first and last layers being sensitized to record different color aspects,- and one of the layers in advance of the last lay?? being largely .absorpti've'of light of the color corresponding to the record of the first layer.

74. A photographic film comprising three strata of gela-tine integrally united throughout their transverse and longitudinal coexjof light tents, the first andlast strata being sensitized to record different color aspects, and one of the strata in advance of the last stratum.

being largelyabsorptive of light of the color corresponding to the record of the first stratum andthe absorptive stratum being relatively insensitive.

,. 75. A photographic film comprising three .separatelyapplied layers of-gelatine inteings 0f gelatine directly connected to each s' other, the first and last coatingsbeing sen- Sitized and one coating being largely ab` tized coatings are sensitive.

77. A photographic film comprising a support carrying on one side thereof three strata integrally united throughout their transverse and longitudinal extents, thelirst and last strat-a being sensitized and one stratum being largely absorptive o f light.

78. A transparent support having a photographic emulsion, the outer surface of said -sorptive of light to which both of the sensiemulsion being superficially dyed with a dil rect cotton dye.

tographic emulsion, the outer surfaceof said emulsion being dyed with Congo red.

80. 'A transparent support having1 tographic emulsion impregnated wit a light absorbing dye, and being superficially coated emulsion is sensitive.

'79. A transparent support having a phoa pho- 4with a dye absorbent of lightto which said 181. A support having a photographic emulsion sensitive to a portion of the spectral range, a second support having a pho-` tographic emulsion sensitive to another portion of the spectrum, said emulsions being placed in close contact between the twosupports, and the outer surface of one of said emulsions beingdyed with a dye absorbent to which the preceding emulsion is sensitive.

82. A support having a photographic emulsion sensitive to a portion -of the spectral range, a second support having a photographic emulsion sensitive to another portion of the spectrum, the outer surface of one of sai-d emulsions being. dyed with Congo red,

said emulsions being placed in close between the two supports.

83. The method of making a s'ensltized elecomprises `forming a film and sensitizing different strata thereof to complementa] colors. 84. The method of making a sensitized elecontact ment for use in color photography which i ment for use in color photography which comprises forming a ilm sensitlzing dierent Y strata thereof to complemental colors, and

rendering the entrant stratum substantially absorptive of the color to which it is seny sitive.

85. The methodof making a sensitized elevment for use in color photography `Which comprises forming a film, sensitizing different strata thereof to complemental colors, and rendering the entrant stratum substantially absorptive of the color to which it is'sensil tized, one stratum being sensitizedby ybathcomprises forming a film and'sensitizing difg" ferent strata thereof to complemental colors, .one stratum being sensitized before it is joined to another stratum and the other stratum being sensitized by bathing after the two strata have been joined.

88. The method of making a sensitized element for use in color photography which 'com rises coating a trans arentv su ort with a layer of emulsion,recoatingthesupport With another layer of emulsion presensitized to reddish color, and then sensitizing the first emulsion to a greenish color. 89. The method of making a sensitized element for use in vcolor photography which comprises coating a transparent support with a. layer of emulsion, recoating the support with another layer of emulsion presensitlzed to reddish color, and then bathing the element in a dye, adaptedy to sensitize the first layer to a greenish color Without'desensitizing the second layer to the reddish color.

90.y The method of making a sensitized element for use in color photography which comprises coating a support with supe'rposed l strata of emulsion, sensitizing one'stratum .to one color, sensitizing'another stratum to another color, and staining the latter stratum to render it substantially opaque lto the color to which itI issensitized.

91. The method of making a sensitized element for use in color photography which' comprises coating a support with an emulsion substantially insensitive to light of certain color. recoating the support with an emulsion,

sensitizing the latter coating to' said color,

an-d dyeing the first'coating to render it sensitive and substantially opaque to another color.

92.` The method of making a sensitized ele- .ment for. use in color photography which.

comprises coating a support with an emulsion substantially insensitive to light of certain color, recoating 'the ,support with an emulsion, sensitizing the latter coating to said 93. The method of making a sensitized element comprising forming an' emulsionv Awhich is sensitive to reddish light and imz -pregnating the emulsion with a dye which further sensitizes toa colder color without substantially desensitizing to reddish light.

y 94. The method of maklng a sensitized element comprising forming an emulsion which is sensitive toreddish light Aand impregnating the emulsion with a dye which further sensitizes to a greenish color lWithout substantially desensitizing to reddish light.

95. The'method of making a photographic film comprising forming a layer of emulslony which is predominantly transmissive to light 'of a predetermined color, and sensitizing the emulsion throughout a portion of its depth to approximately the same color. l

96. A photographic I4element lcomprising 4an image-bearing strip having latent complemental images at different ldeptlis therein. 97. A photographic element comprising an image-bearing strip having latent complemental images at different depths therein, 'one of the images being relatively lat compared .to another. l

98. A photographic element comprising an image-bearing strip having il'atent complemental images at different ldepths therein, one ofthe images having negligible contrast compared to another.

99.-A A photographic element comprising an.

imagebearing strip having latent complemental images at different depths therein,

the colder-color image being relatively flat compared to the warmer-colei` image.

' 100. A hotographic element comprising an `imageearingstrip having latent substantially non-interpenetrati'ng images at different depths therein.

101. A photographic element comprising an image-bearing strip' having latent substantially non-interpenetrating images at dii'erent depths therein, oneof the images being relatively fiat compared to another.

- 10 2.A photographic element comprising an image-bearing strip having latent substantially Anon-interpenetrating images at different depths therein, one of the images halying negligible'contrast compared to anot er.

v103. A photographic elementcomprising i an image-bearing strip having latent substanc tially non-interpenetrating complemental images at different depths therein.

104. A photographic element comprising I an image-bearing strip having latent substantially non-interpenetrating complementalimages at different depths therein, one of the images being relatively fiat compared to another. 105. Aphotographic element comprising an image-bearing strip having latent substantially non-interpenetrating complemental images at different depths therein, one of the imy ages having negligible contrast compared to another.

106. Aphotographic element comprising .an

'image-bearing -strip having latent substantially non-interpenetrating'complemental images at different depths therein, the coldercolor image being relatively flat compared to the warmer-color image.

- 107.l A photographic element comprising a support .and a coating on the support, the coating having at different depths therein latent images corresponding to complemental color aspects.

108. A photographic element comprising a support and a coating on the support, the coating having at different depths therein latent images corresponding to complemental color aspects, one ofthe images being relatively flat compared to another.

109. A photographic element comprising a support and a coating on the support, th'e p coating having at different depths therein latent images corresponding to complemental color aspects, 'one of the images having negligible contrast compared to another.

110. A photographic element comprising a support and a coating on'the support, the

coating having at differentdepths therein latent images corresponding to com lement-al color aspects, the colder-color image eing relatively flat Acompared to the Warmer-color image.

111. A photographic element comprising a support and a coating on the support, the coating having at different depths therein substantially non-interpenetrating latent images corresponding to complemental color aspects.l

112. A photographic element comprising a support and a coating on the support, the coating having atl dierent depths therein substantially non-interpenetrating latent images corresponding to complemental color aspects, one of the images being relatively fiat compared to another.

113. A photographic element comprising a support and a coating on the support, the coating having at different depths therein substantially non-interpenetrating latent images corresponding to complemental color aspects, one of the images having negligible contrast compared to another.

' 114.V A photographic element comprising a support and a coating on the support, the coating having at different depths therein substantially non-interpenetrating latent images corresponding to complemental color aspects'. ,I

115. A photographic element comprising a f one of the images having gelatine layer having superposed complementhe colder-color image'being relatively fiatcompared to the Warmer-color image.

119. A photographic element comprising a' gelatine layer having superposed substantially non-interpenetratinglatent images in different strata thereof. f

120. A photographic element comprising a gelatine layer having superposed substantially non-interpenetrating latent images in dierent 'strata thereof, one of the images being relatively flat compared to another 121. A photographic element comprising a gelatine layer having superposed substantially 'non-interpenetrating latent images in.

differentv strata thereof, one of the images having negligible contrast compared to another.v

122. A photographic element comprising agelatine layer having superposed substantially non-interpenetrating latent images iny different strata thereof, the images corresponding to complemental color aspects.

123. A photographic element comprising a gelatine layer having superposed substantially non-interpenetrating latent images in dierent strata thereof, the images corre sponding to complemental color aspects, one

to another.

124. A photo raphic element comprising a gelatine layer l(having superposed substantially non-interpenetrating latent images in of the images being relatively fiat compared different strata thereof, thev images corresponding to complemental color aspects, and negligible contrast compared to another.

125. A photographic element comprising a gelatine layer havingl superposed substantially non-interpenetrating latent images in different -strata`thereof, the images corresponding to complemental color aspects. .i

126. photographiefilm comprising a single emulsion containing in successive strata superposed -complemental `images based in the same direction. Y l 127. A photographic'I film comprising a support and a single emulsion coating onv one side of the support contalning 1n successive strata a plurality of complemental images based toward the support.

the images being based in the 128. A photographic film comprising asin- 4gle emulsion containing distinct images in successive strata respectively, a'plurality of i p same direction. 129. A photographic film comprising a single emulsion containing distinct images in successive strata respectively,

the images being based toward the support.4

a plurality of I passing through the first image.

133. A emulsion containing complemental images in successive layers, oneimage being fiat relatively to the other image.

134. A photographic element comprising a lsupport and a plurality of coatings on the same side of the. support, two of said coatings having therein, respectively, non-interpenetrating latent images corresponding to complemental color aspects.

135. A photographic element comprising a support, and aplurality of coatings on the same side of the support, two of said coatings having therein, respectively, non-interpenetrating latent images corresponding to complemental color aspects and being separated by a third coating.

136. A photographic negative, comprising an imageearing strip having complemental images therein at different depths.

137. A hotographic negative, comprising' an image-bearing strip having substantially non-interpenetr'ating images therein at different depths.

` 138.V A photographic negative comprisingl an image-bearing strip having substantially l a transparent support non-interpenetrating complemental images therein at different depths.

139. A photographic negative comprising and-a coating on the a transparent support having at different support, the coating depths therein substantially non-interpenetrating images representing complemental color aspects.

140. A photographic negative comprising and a coating on the having complemental support. the coating images therein at different depths, the image nearest the support bein'g relatively flat compared to another image.

141. A photographic negative comprising a transparent support and a coating on the support, the coating having substantially" noninterpenetrating images therein at di photographic film comprising an ferent depths, the image nearest the support'4 being relatively fiat compared to lanother image. 4

142. A photographic negative comprising a transparent support and a coating `on the support, the coating having substantially-noninterpenetrating complemental images there` in at different depths, the image nearest the support being relatively flat compared to an.

other image.

143. Aphotographic negative havingapluy of superposed developed images, one

rality of the images being substantially transparent. 144. A photographic negative having a vplurality of superposed developed comple-` mental images, one of the images-being sub-V stantially transparent.

a transparent support, a coating on'the support having a plurality of superposed vdeveloped images, the image next to the support being substantially transparent.

149. A photographic negative comprising a transparent support, a coating on the support having a plurality veloped images, the image next tothe support representing the colder color and being substantially transparent.

150. A photographicA negative having a plurality of superposed developed images on the same side o the support, one of the images being constituted by transparent silver salt.

151. A vphotographic negative having a plurality of mental images onthe same side of the support,

superposed developed compleof superposed deone of the images being constituted by trans. i

parent silver salt 152. VA photographic negative .having` a *..j-i.

plurality of superposed substantially non-1nterpenetrating developed images on the same side of the support, one ofthe images being constituted by-transparent silver salt.

153. A photographic negative having a plurality of superposed developed images on the same side of the support, the' image representing'th'e colder color being constltutedl by transparent silver salt.

154. A photographicnegative comprlsing a transparent support, a coating on the support having a plurality of superposed 'developed images, the image next to the support being constituted by transparent silver salt.

155. yA photographic negative comprising images of a colored scene in respective strata- `the component with which the veloped images,the image next to the support representing the colder color being constitutedby transparent silver salt.

156.'.The method of producingmultiplex images which comprises simultaneously Vforming different color-value images in successive strata' of an emulsion by selective exposure to different color components of a polychromatic beam and obstructing the passage of any component to a stratum nantly'exposed thereby.

157. The method of producing multiplex images which comprises simultaneously forming two different color-valueimages in two successive strata of anemulsion by selective exposure to two different color components of a polychromatic beam and with the first stratum substantially preventing the passage of first stratum is predominantly exposed.

158. taneously forming, with a single polychromatic beam of light, different color-value images in successive strata of an emulsion sensitized to different color components of lightby selectively absorbing, with certain of the strata, the color component to which each'such stratum is sensitive.

' 159. The method which comprises simul- `vtaneously formingI different color-value of an emulsion with a single polychromatic 'beamv of light by selectively absorbing and transmitting the color components of the light in accor ance with the color sensitivity of the successive strata.

160. The method which ,comprises concomitantly formlng complemental images respectively in successive strata of an emulsion by selective exposure to different color components of a polychromatic beam and absorbl I yimg Certa'n of the components by the stratum selectively exposed thereby.

ll-. The method which comprises c on- ;comitantly forming two complemental images respectively in two successive strata of an emulsion by selective exposure to two different color components of a polychromatic beam and with the first stratum substantially preventing the passage of the component with which the first stratum is predominantly exposed.

. 162. The method of making superposed complemental images in a single emulsion -which comprises forming the images in latent form in different depths of the emulsion recomitantly.

spectively, and developing the images con- 163. The method of making superposed complemental images in a single emulsion which com vrises simultaneously forming the` images atent form in different depths of beyond that predomi- The method whichV comprises simulvages recording the emulsion respectively, and developing the images concomitantly. -l 164. The method. of making superposed' being restricted to a partial depth of the emulsionby the light-retarding dye, and developing the images concomitantly.` i

165. A method of producing a color photograph comprising forming in layers of emulsion sensitized respectively to record different color values, a plurality of superimposed latent images of different color sensations, developing said latent images and coloring the images thus developed respectively in colors other'than those'whose ,values are re-` corded in the said respective images. y 166. A method of producing a color hotographcomprising forming in layers o emulsion sensitized respectively to record dift'era plurality of superimposed ent color values, latent images of different color sensations, develo ing said latent images and coloring .each oi) the respective images thus developed with a color whose values are recorded by another of' said images. v

167. The method of producing a color photograph in two colors comprismgforming in layers of emulsion sensitized respectively to values and combined to record different color constitute a substantially unitary body, two

- superimposed latent images of different colon an'd a 4 then fixing said two images and then co oring` sensations, simultaneously developin each of said: images 4with that color whose .values are recorded by the other ima e.

of producing a co or pho- 168. The method tograph` which comprises concomitantly forming, in united layers of emulsion respectively sensitized to record different color val-" ues, a plurality of superposed latent images recording different color values.y 169. The methodof producing color photograph which "comprises concomitantly forming, in superposed strata of emulsion mounted on'the same side of a support and sensitized to different color values-'respectively, a plurality of superposed latent images recording different color` values.

170. The method of producing a color l photograph which forming, in,.unite'd layers of emulsion respectively sensitized to record different color values, a pluralittiy of superposed latent imifi'erent color values, and concomitantly develo ing said images.

171. The method o producing a color photograph with 'a suitable support having on one side layers of .emulsion sensitized respectively to record different colorvalues,` which comprises forming simultaneously in sald layers of emulsion two ,latent images 13ecomprises concomitantlyv Cil images in an emulsion sensitized to complementalcolors at diti'erent depths, which comprises exposing the emulsion with light of the complemental colors, restricting to the first depth substantially all light of the color to which it is sensitized, and transmitting to a succeeding depthl light of the color to which it is sensitized,'vvhereby complemental im-` ages are formed in the respective depths.

173. The method of making a photographic element having images :1t-different depths which includes the step of treating the images with a developer having a high diffusion tendency and a low reduction po-l tential.

174. The method of making. a photo-Y graphic element having images at different.

depths which includes the step of reducing the exhaustive ei'fect of thel outer image on the inner image by the use of hydroquinone and bromide.

17 6. The method .of making a photographic element having images at diierent depths which includes the step of reducing the exhaustive effect of the outer image on the inner image by the use of hydroquinone and an alkaline carbonate and bromide.

177. The method of making a photo.- -graphic element having images at diierent depths which includes swelling Vthe gelatine by introducing al liquid thereinto, and subsequently developing the images.

178. The 'method of making al photographic element having images at different depths which includes swelling'the gelatine by introducing a liquid thereinto, and subsequently treating the images with a devel'- oper having a high diusiontendency' and a low reduction potential.

179. The' method. of making .a photographic element having images at'diiferent depths therein which' includes the step of ,fogging a stratum of the emulsion before developingthe images.

.180. The method of making a photographic element having ima es at diliaent depths therein which inclu es the step of fogging an inner stratum of the emulsion before developing the images.

181. The method of making a photographic element having images at di'erent depths therein which includes the stepy of fogging and swelling the gelatine before developin the images.

182. 'he method graphic element having images at dierent depths therein which includes the step of fog-ging and swelling the gelatine and subof making a photosequently treating it with a developer vhaving a. high diiusion tendency and a low reduction potential. l.

183. The method of producing la color photograph which comprises concomitantly forming, in united layers of emulsion respectively sensitized to record dierent color values, a plurality of superposed latent images recording different color values, and reproducing said images in united layers of emulsion respectively sensitized to record different color values. c

184. The method of producing a color photograph which comprises concomtantly forming, in united layers of 4emulsion respectively sensitized to record .diii'erent color values, a plurality of superposed latent images recording different color values, and reproducing said images Without separating saldlayers.

185. A method of producing a color photograph with a suitable support having on one side layers of emulsion sensitized respectively to record diferent color values! which 4comprises forming simultaneously In said tive from the negative thus formed.

186. The methodof producing a color photograph `With a suitable support having on one side layers of emulsion sensitized respectively to record dierent color values, which comprises forming in said layers of emulsion a lurality of superimposed imagesof` the ject photographed, each of said images recording a diierent color sensation,

individually coloring said images to' form a negative in diiierent colors without 'disturbing the relative positions of said images in said enulsion to thereby produce two superimposed images in different colors in an emulsion on one side of saidsupport, printing from this negative in a. single operation a positive to form on said positive a `pl'urality of superimposed latent images of different color sensations, and subsequently developing and. coloring said positive.

187. The method of producing a color photograph with a suitable support having on one side layers of emulsion sensitized respectively to record different color values, which comprises forming simultaneously said layers of emulsion a plurality of latent l images of different'color sensations, developsubjected to a similar treatment to produce the lfinished picture.

188. -The method of producing a color` photograph with a suitable support having on one side layers of/emulsions sensitized respectively to record different color values, which comprises forming simultaneously in said layers of emulsion a plurality of latent images-of different color sensations, subsequently developing and coloring the respective images to form a negative, forming a` positive comprising a plurality of coatings sensitized respectively for colors complementary to the colors employed in the negative, printing the'positive in a single operation, and subsequently developing and toning the images formed on said positive.

189. The method of reproducing ilnages superposed on the sameside of a support which comprises rendering one image relatively ineffective on printing light and passing light through both images to print the other image.

190. The method of making color pictures which comprises separately printing superposed complemental pictures, one image being printed by light passing through the other image, and the latter image being rendered relatively ineffective during the printing of the first image.

191. The method of separating superposed components of a representation of two color aspects ofv an object field on the same side of a support which comprises printing one component by light passing through the representation of both fcolor aspects, the other component being rendered substantially ineffective during the printing of the first component.

192. The method of separating superposed components of a representation oftwo color aspects of an object field which comprises printing one component by light passing through the representation of both color aspects of 'an' object field which comprises printing one component by light passing through the representation of both color aspects, the other component being rendered substantially` ineffective during the printing of the. first component, removing the first component, and then rendering the second component effective and printing the same.

194. The method of making color pictures from superposed complemental images which comprises printing one image without separating the images, and then removing the printed image and printing the other image.

195. The method of making color pictures from superposed complemental images which comprises printing one image without separating the images, and then etching off the printed image and printing the other image. 196. The method of making color pictures from superposed complemental silver images which includes treating the images with a bleach containing a. reducer. y

197. The method of making color pictures from superposed complemental silver images which includes treating the images with a A bleach containing an alkali sulphite.

198. The method of makingcolor pictures from superposed complemental silver images which includes treatin the images with a,

'bleach acting with su cient rapidity substantially to prevent the images from affecting each other.

199. The method of making color pictures from superposed complementalv silver images which includes treatin .the lmages wlth a bleach to harden the ge atine throughout the which comprises printing oneimage, bleaching the images, etching off. the printed image, and printing the other image.

202. The method of making color pictures from superposed complemental silver images which comprises printing one image, bleaching the images, etching off the printed image, and then intensifying and printing the other image. f

203. The method of making color pictures from superposed complemental silver images which comprises printing one image, bleaching the images, etching ofi' the printed image,

and then staining and print-ing thev other image.

204. The method of making color pictures from superposed complemental silver images which comprises bleaclnng and separating the images, and dyeing one image with a dye having a heavy staining power.

205. The method of making color pictures from superposed complemental silver images which comprises bleaching and separating the images, and dyeing one image with a dye having a heavy staining power and having a slow washing out rate.

206. The method of making color pictures from superposed complemental silver images .which comprises printing one image, bleach'- ing andseparating the images, and dyeing one image with a dye having a heavy7 staining power.

207. The method'of making color pictures comprising simultaneously forming, by composite light, complemental images at different' depths in an emulsion ada ted to respond predominantly to different light components at different depths, and separately reproducin the complemental images Ain ldiie-rent coors. v

208. The method of making color ictures comprisin simultaneously. forming, y composite lig t, complemental images at different depths in an emulsion adapted to respond predominantly tov different light components at dili'erent depths, and separately `sus through the other layer, the image of' the other layer being. rendered substantially in-` effective during the printing of the first image.

210. The .methodof making color pictures l comprising exposing an emulsion having superposed strata sensitive to light components of different colors, simultaneously to form complemental ima es in the respective strata, andprinting the images to form complemental pictures, at least one image being printed without separating the layers.

211. The method of separating superposed components of a representation of two color aspects of an object field which comprises printing one component by light passing through the 'representation' of both color aspects, the other component being rendered substantially ineffective during the printing of the .first component.

212. The method of making color pictures which comprisesforming a latent image in one stratum of a sensitized emulsion, simultaneously forming a relatively thin complemental latent image in another stratum of theirst image-by passing light through both images, lremoving the first image,'and printing the second image.

213. The method of making color pictures' lwhich comprises simultaneously forming complemental latent images in different strata of an emulsion by .exposing the emulsion through its transparent support, making `the first image nextv to the supportsubstantially negligible 'compared to the. second f image, printing the second image by light passing through both images, removing the second image, and printing the lirst. image.

214. The methodof making color pictures Vwhich comprises forming superposed complemental silver images on the same side of a support, dyeing the images different colors. and then printing the images respectivelyv with light of different colors.

215.. The method'of making color pictures comprising simultaneously forming, by composite light, complemental images at dierent depths in an emulsion adapted to respond vpredominantly to dierent light'components at different depths, and subsequently converting the respective images into a composite color picture.

216. The method of vmaking 4color pictures comprising simultaneously forming complemental negatives at different depths lin an emulsion, and subsequently producingi p ositives from the negatives, the production of the positives including passing a ,beam of light through 'the negatives in series. 217. The method. of makingcolor pictures which comprises producing at different depths in an emulsion superposed components of a color representative of an object field,

and" subsequently reproducing the components by printing operations which include simultaneously passing a b'gam of light through all the components.

218. The method of making color pictures Y which. comprises simultaneously producing components of a color representation in superposed layers of emulsion on the same side of a support. and subsequently reproducing the components by printing operations which include simultaneously passing a beam of light through all the components,

219. The method of producing a` color photograph, comprising forming in layers of emulsion on the same side of their support and sensitized respectively to record different color values a plurality -of superimposed images of the 'subjectfpliotographem each of said images recording aditferent color sensa-- tion, individually coloring said images. to-

form a negative in proper colors, printingfrom this negative in a single operation a positive to formen said positive 'a plurality of superimposedflatent images of dili'erent color sensations, and subsequently developing and coloring said positive. the emulsion, developing the images, printing As ideof their support and sensitized respectlvely to record different color values a-plurality 'of latent images of different color sensations, developing .all of said latent images,

supcessively coloring the respective images,

Images