US2387754A

US2387754A - Material for the production of partial color selection pictures from subtractive multicolor images

Info

Publication number: US2387754A
Application number: US333429A
Authority: US
Inventors: Gaspar Bela
Original assignee: Chromogen Inc
Current assignee: Chromogen Inc
Priority date: 1936-03-24
Filing date: 1940-05-04
Publication date: 1945-10-30
Anticipated expiration: 1962-10-30
Also published as: CH207532A; FR822419A; GB494341A

Description

B. GASPAR Oct. 3G, i945.

MATERIAL FOR THE PRODUCTION OF PARTIAL COLOR SELECTION PICTURES FROM SUBTRACTIVE MULTIGOLOR IMAGES Original Filed March 23, 1957 2 sheets-Sheet 1v fig. 1.

GREEN Bl-Uf Snventor EaP/ lafsdoar' Gttorneg Oct. 30, 1945. B

GASPAR MATERIAL FOR THE PRODUCTION 0F PARTIAL COLOR SELECTION PICTURES FROM SUBTRACTIVE MULTICOLOR IMAGES Original Filed March 23, 1937 2 Sheets-Sheet 2 @Auf gwdmvs' EMaLJ/o/v 76105 fffyffnrfz-Mazs/av SUP/ORT l//r/f attorney y Patented Oct. 30, 1945 OFFICE MATERIAL FOR THE PRODUCTION OF PARTIAL COLOR SELECTION PIC- TURESv FROM SUBTRACTIVE MULTI- COLOR IMAGES Bela Gaspar, Brussels-Forest, Belgium, assignor to Chromogen, Incorporated, a corporation of Nevada Original application March 23, 1937, Serial No.

9 Claims.

- tures out of subtractive multicolor images, more Divided and this application May 4, 1940, Serial No. 333,429.

In Germany March particularly multicolor transparencies or translucent master images. Such a multicolor image contains colored monochromatic partial. images covering and completing each other subtractively to a colored image. 'I'he necessity of producing the individual partial selections of such multicolored images arises in various circumstances. For instance, the multicolor image may have been obtained directly in the cameraand the individual partial selections may berequired in order to serve as intermediary elements for the printingprocess. In other cases, it might be necessary to reobtain from a multicolor print, such as a transparent multicolor cinema. print, the Various` individual color selection images out of which the multicolor print has been produced. 'I'his may not only be the case if these single master images themselves are no longer available, but also if in the course of time they have changed to such an extent by unequal shrinking that they can no longer be brought into exact register. A multicolor picture, however, is modiied uniformly by such shrinking and the single partial color selections produced from it are in exact register, thereby permitting the production of a print of the multicolor image even if the original photograph or the partial color selection images are no longer utilizable.

It is understood that the following-examples involve the use of some of my earlier processes and materials such as those described and claimed in my Patents 1,956,122 and 1,956,017 of April 24, 1934; Patent 1,985,344 of Dec. 25, 1934; Patent 2,183,393 of Dec. 12. 1939; Patent 2,020,775 of Nov. 12, 1935; Patent 2,071,688 of Feb. 23, 1937, and Patent 2,183,394 of Dec. 12, 1939 and Patent 2,137,336 of Nov. 22, 1938.

It is known that the individual partial color selections of a multicolor image may be obtained by printing with a printing light which is absorbed by the color of the desired partial selection picture and by using as printing material a layer which is sensitive to this particular light. In the case of a three-color image, the three partial selections are thus produced by way of three printing steps.

It has, however, been found that, even if the work is performed in a, most exact manner, it is not possible to print partial selections of such a multicolor image in the'above mentioned way which are asatisfactory reproduction of thosev color-selection-pictures by means of which the multicolor image was originally produced. It is therefore not possible to reobtainthe single color selection images used for the production of this complete image, Without introducingfthe didiculty of departing from the complete multicolor print and therefore the prints produced later on do not suciently resemble the multicolor image, the duplication of which is intended.

Exact photographic printing cannot be performed unless the printing light acts on the master image to be printed with uniform intensity throughout the whole area. In 'passing through the master image, the intensity of this light is diminished in proportion to the graduation of opacity of the master image and thereafter acts on the printing layer with the graduation of intensity produced by the master image.

In the same manner,`since it is not possible to obtain a correct print if the intensity of the light acting on the individual spots of the material to be printed is not uniform, the print is bound to be incorrect if the printing light, even though originally of uniform intensity, is subarises if an image of diiferent color must be traversed by the printing light as most colQrS4 have the quality of absorbing to a certain extent even the light-which they ought to transmit. For instance, a purple-red dyestuif diminishes the intensity of blue printing light although it theoretically ought to transmit this light without diminution. A blue-green dyestui which ought to be transmittant for blue and green is in reality attitude towards red light, which is almost completely transmitted by them. As a result of the above described phenomena, the blue light, for example, which is to be used for the printing of a yellow master-image does not penetrate to the printing layer with uniform intensity if it pre-v viously is led through a layer lying in front and containing a blue-green or a purple-red dyestuii in an image-like distribution. A colored image lying behind the colored master-image has the same eiect, as in this case a certain portion of the light` which is Ato fall on the printing layer image on the printing material is made im- V possible.

In accordance with this invention, the described image-like diminution in intensity of the printing f light is supplemented by an equal diminution of intensity graduated in the opposite sense. That is to say, if blue printing light, used in printing for example the desired-yeliow part image, as mentioned above, is to a certain extent undesirably diminished in intensity by a disturbing bluegreen image, the printing light is in addition intentionallyfiltered by a compensation-mask. 'Ihis mask is absorbent in those regions in winch the disturbing blue-green image is more or less transparent and therefore has not weakened the printing light, whereas it is transparent at those places at which the disturbingblue-green image exerts the most intense absorption. The compensation mask has therefore the character-of a negative as compared with the blue-green image, if this image is assumed to be positive, and vice versa. In the simplest case, the compensation mask is of the same color as the image by which the intensityof the printing light is undesirably weakened, and in this case the distribution of color in the mask completes the image causing the undesirable e'ect to a homogeneously colored area, when both are superimposed. ,The compensation mask may also be represented by a black and white image or an image in any lother color which to a certain extent absorbs the print- In case three-color images in blue-green, magenta and yellow are printed, a blue-green as well as a purple-red mask are used, first. the bluegreen mask is employed alone, and thereafter both masks are employed together when printing the yellow image as described above. This procedure is to be recommended for the printing of multi-color images by successive use of dinerent printing lights on multi-layer material possessing several layers of diilerent sensitivity.

In the following, the invention is described by means of illustrations based vou Fig. 2. For the sake of simpliilcation it is assumed that the multi-color image Il! from which the single Ipart images are to be reobtained, consists of a blank lm I i on which three colored letters A+, B+ and C+ appear as positives, B+ in purple-red, C+ in yellow, and A+ in blue-green.

In the following example the application of this invention to the production of negative master images from a multicolor image is deing light. By-means of the compensation mask.

the local diminution of the intensity of the printing light is completed to a uniform diminution of this light, whereby the correct printing of the partial images is made possible. Another way of carrying out the idea of theY invention in practice is to make up for the undesirable deficit in the printing light by means of an additional illuminating of the print behind a compensation mask which represents a coloredl or black and white negative of the disturbing part image. In this case the intensity of the additional printing light at all points of the image must be equal to the diminution of intensity caused by the disturbing part images. In each case, the compensation applied is adjusted in such a manner as to equalize, either by addition or subtraction, the disturbing absorption of light by the other partial images.

The application of the general principle may be illustrated by the following example. A multicolor image i shown in Fig. 1, .consisting of a purple-red colored Vpositive part image and a blue-green colored positive part image is used. From this a. negative 2 of the blue-green colored part image is produced by use of red printing light. This negative is dyed blue-green at the exposed points and is then imposed on the twocolor film which is to be printed. Thereafter, the purple-red partial image is printed by green light coming from light' source 3 through filter 6. The

Therefore the presence of the blue-green partial image no longer has a detrimental eiect on the printing process, except that the printing must be slightly intensified. As shown at A5, a print is obtained of the purple-red partial image,

scribed.

A. Reobtaining of a master-image of the bluegreen colored part image contained in the multtimage-The multicolor image Ih is printed in,

the usual manner by use of green light or a green filter on a green-.sensitive or panchromatic layer I4. Before developing and xing this image, the negative A which has been produced previously is printed on it in faint contrast by use of the same green printing light with which the multicolor image has been printed. Or, alternatively the negative may be colored blue-green at the exposed points and may be printed in superposition with the multicolor image. The print is then developed and fixed, thereby becoming a negative B- as shown at I5 of the purple-red colored partial image B+ contained in the original multicolor image.

C. Producing a master-image of the yellow colored part image contained in the multicolor images-The multicolor image l0 is printed on an ordinary photographic layer I8' in the ordinary manner. However, the layer is not developed, but first the negative A- and thereafter the negative B- are additionally printed on this layer. In doing so, the .intensity of the printing light is regulated in such a manner as to print the negative B- witha lower light intensity than the negative A, the latter, on the other hand, being printed with' a lower intensity than the original multicolor image. Thereafter, the print is developed and fixed, whereby a negative C- as shown at il of the yellow colored partial image C+ Vcontained in the Voriginal multicolor image is obtained.

'Ihe negatives A+, B- and C- obtained in this manner constitute a. series of master images,

which may either be used as such, if in the furand 20 in the usual manner if required. 'Ihe I three master images A, B-.and C- or'the podhave been additionally printed on same rua-` tives A+, B+ andC1L produced from them may be converted into dyestun images. The dyestufl to be used depends on the manner in which the printing layers are sensitized'on to which the master-images are subsequently printed. In any case, a dyestui is used which absorbs light rays to which the respective printing layer is sensitive.

As a modiiication of the foregoing process the negative A, corresponding to the blue-green partial image of the multicolor image, is mordanted and dyed red at the silver places, for instance by staining by means of a. basic red dyestui. This negative is printed on to the printing layers used to produce negatives B- and C- with green or blue light insteadl of using the black and white negative A as heretofore described. On the other hand, this red image may also be employed l, later for other purposes, for example, to print the partial image A- on a layer sensitive to green or blue.

'I'he same holds good for the negative B-, which may for instance be of a yellow, green or red color and may serve the same purposes as the black and white negative.

In the following example the application of this invention to the production of positive master images is described.

A. Reobtaining the master image of thebluegreen colored partial image contained in the multicolor image.-The multicolor image is rst printed on a red-senstive or panchromatic layer by red light or by use of a red lter. The print obtained in this manner is developed and ilxed, thereby resulting in a negative A- of the bluegreen colored partial image contained in the original. By way of printing on an ordinary photographic layer, a positive A+ is produced. This positive A+ is used in further printing processes which require positive master images of the color selection pictures, for instance for processes in which a dyestui is produced at the non-exposed places of the print or in which a dyestui which was originally present is destroyed at the exposed places.

B. Reobtaimng the master image of the purplered colored partial image from the multicolor imager-Tha multicolor image is printed on a green-sensitive or panclnomatic-layer by means of green light. The print is then developed and xed. In this manner a negative image B- of the purple-red colored partial image contained in the original is obtained, which negative is how; ever not quite correct due to the fact that the printing light does not fall onthe colored image B with uniform intensity as it is subjected to certain influences, originating for instance from the blue colored part image. 'I'his negative B- is printed on an ordinary iilm. Before developing the print the positive A+ is additionally printed on it in low intensity. After developing it isxed and serves as the second positive master image B+ for above described processes.

C. Reobtaining the master image of the yellow colored partial image from the multicolor im- I tioned in connection with image B, is not a correct reproduction. 'I'his negative isprinted on an ordinary nlm. VHowever this film is not developed until the positive A+ and the positive B+ mann Enzyklopdie der Technischen Chemie, 2nd v The three positive master images A+, 'B+ and C+ may for instance be printed on a multilayer material (not shown) consisting of three layers superimposed on each other, one sensitive to blue and dyed purple-red by diamine fast Pink G (Ulledition, volume 3, page 6 47) the second sensitive to red anddyed yellow by chrysophenine (color index number 365) and thethird sensitive to infra-red and dyed blue-green by diamine pure blue FF (color index number 518). The master image A+ is printed on to the blue-green dyed layer by infra-red light, the master image B+ on ,the purple-red layer by -blue light, and the master image C+'on the yellow dyed layer by red light. The lm is then developed.' iixe`d and treated by a 5% thiocarbamide solution containing also 21/r% citric acid. Thereafter it is bleached by a solution. The image obtained after this treatment is a color-true reproduction' oftheoriginal multicolor image.

supposing that the original multicolor image does not correspond in its colors to the natural -object, but that for instance the blue-green colred light, and the positive C+ on the blue-green layer with infra-red light. In this manner a color-true print of the natural object is obtained although a multicolor image has been taken as basis which does not represent the original colors.

In the following example three single master images are tov be produced of a multicolor image. containing three partial images in superimposed layers in the three colors purple-red, blue-green and yellow, and these are to be printed on a sirvilar material. Referring againto Fig. 2 and the multicolor image l0 which is to be reproduced: the positive lm 2l which is to be used for printing consists of three layers, i. e. a blue-green colored and blue-sensitive emulsion on one side of the support and a yellow-colored red-sensitive emulsion on the other side of the support. the latter layer being covered byl a purple-red colored and blue-sensitive emulsion. The images I8. I 9. and 20 are printed on this material from both sides by use of blue light for the outside lavers andthe middle layer is simultaneously printed on by way of red light traversing the purple-red layer. After the silver-image has been produced. the dyestuil is destroyed at the silver places.

2| must be positive images of the three partial selections and may be three mas/ter images in col-o ors complementary to the sensitivity of the layers in which they are to be printed. In such case the two images which are to be printed on the two exterior blue-sensitive layers, (one of which is colored purple-red and the other blue-green) are .colored yellow, whereas the image which is to be printed on the middle layer is of a blue-green color. l For producing these three-colored master images, three individual layers are employed, i. e. a yellow-dyed red-sensitive one I2,v a yellow-dyed The master images used for printing on the material green-sensitive one Il and a blue-green dyed layer It sensitive to green andblue. The two yellow layers may be sensitized for both green and red, in which case it is possible to carry out the following process by use of only two diierent printing materials.

1. First the multicolor image is printed on the yellow-colored red-sensitive printing layer I2 by red light, whereupon the print is developed and fixed in the usual manner. 'I'his lm'then shows a black silver image on the yellow colored material and is transparent (i. e. yellow) at those places4 corresponding to the blue-green partial selection image of the multicolor image as shown at I3.

2. Thereupon the multicolor image is printed on the yellow colored green-sensitive iilm Il by green light, and in addition, the black silver image I3 previously produced, is also printed on the same material Il by the same light. 'I'his print is then developed and fixed and thereupon shows a black silver image on a yellow background as shown at i5, on which those places which correspond to the purple-red partial selection of the multicolor image I are transparent (i. e. yellow).

3. The multicolor image is then printed by blue light on the blue-green dyed layer I6 which is sensitive to blue and green. In addition to that,

the negative silver images I3 and I5 previously obtained, are printed on the same blue-green dyed layer I6 by use of green light. 'I'his illm is then developed and iixed. A black silver image is obtained as shown at I1, which is transparent (bluegreen) at those places corresponding to the yellow partial selection o! the multicolor image.

4. The three silver images I3; I5 and I1 produced in this manner on the two yellqw illms and the blue-green nlm are thereupon treated withr a dyestuH-destroying solution, e. g. with a thiocarbamide solution containing in addition 21/2% citric acid, and converted in the usual man ner into dyestufi images. In this manner, the positive intermediary master images 4shown at I8, I9 and 20 are obtained from which the yellow images are then printed on the multilayer material Ii by blue light and the blue-green with red v light in the manner described above. 'I'he dyestuff is simultaneously destroyed in all three layers of the multilayer material by bathing in a thiocarbamide solution of above mentioned composition and the further treainxent resultsv in a print 22 which is identical to the multicolor image Ill.

In some cases the multicolor image of which individual partial selections .are to be produced contains positive partial images in blue-green and yellow colors, of which the yellow image represents the red selection of the photographic object and the blue-green image the green selection of this object. Such multicolor images may be obtained by photographing with a bipack, the front film of which is not colored and is sensitive to blue, whereas the back iilm bears two superimposed layers, one dyed yellow and sensitive to red and the other dyed blue-green and sensitive to green, and thereafter locally destroying the dyestuff at the exposed places after exposure'and development. After separation of the bipack, the front nlm is developed separately to a negative or to a positive. By use of red printing light the blue-green parts of the rear nlm of 'the bipack appear yellow.

By use of blue light the back illm is printed on a purple-red dyed layer sensitive to blue and red and removal oi the remaining silver, a. yellowprint of the blue-green partial image contained in the rear lm of the bi-pack nlm, that is to say of the green selection, is obtained. On the purple-red printing material, a purple-red image oi' the yellow colored partial image registered on the rear film of the bi-pack. that is to say oi the red selection, is obtained. These master images may be printed on the two exterior layers oi the three-layer material 2l in the same manner as explained in the previous example, the yellow colored image (green selection) being printed on the purple-red layer, the purple-red colored image (red selection) on the blue-green layer of the multilayer material, the latter layer in this case having rto be sensitive not only to blue but also to green. The blue selection produced on the colorless front lm is printed from a positive master image on to the middle layer of the positive three-layer lm by means oi red light.

In case, in the described example, the bluegreen layer of the positive nlm is not to be made sensitive to green, and if it is desired to use a completely identical positive material, as shown at 2l, a colorless panchromatic orred and blue sensitive lm is used for the master image of the yellow colored partial image, instead of a purplered colored layer.- The two-color image produced on the back lm oi the bi-pack is printed on this material by use of blue printing light, whereupon the black and white image oi the blue-green partial image,` produced on the yellow master image is additionally printed on the same material by red light. This negative master image 'must then be transformed into a positive and is printed by blue light on the blue-green layer of the three-layer material. The negative may also be dyed by a yellow dyestui after producing the silver images in the layer and converted directly into a yellow positive by treatment with above-mentioned thiocarbamidesolution,

V'I'his yellow positive is then printed on the blueireen layer of the three-layer material by blue Sht.

In the preceding example the silver image originally produced by printing into the colored layer served as a compensation mask and thereafter was used for the destruction of the dyestui! at the points where silver is present thereby lproducing from the mask a reversed dyestui! image constituting the required master image. A silver 4image originally produced by printing into ordinary colorless layers, may also serve as a compensation mask and thereafter be transformed into a. reversed image, constituting the requiredV -master image.' In this case the unexposed silver halide is allowed to remain in the image during its use as a' compensation mask and the reversed image is produced afterwards by dissolving the silver image and developing the silver halide to form the master image. The general theory of silver image in which the parts corresponding to '(5 the above examples may be explained as follows:

' even in all of them.

The image formed by dyestuil' A in the multicolor image to be printed will yield at those places where neither the dyestuf! A nor the dyestuff B are present a maximal blackening Sw of the printing material. Sm is determined by the intensity of the printing light and the a two-color image consisting of a yellow colored partial image and a blue-green colored partial image, the two-color image is first printed with red light on a lm sensitized to red or panchro- En B A21, 1l/, in which expression A /:r, y/ represents the absorption produced by dyestuil' A at the point at, y: B /a:, y/ represents the absorption at the same point of the image by dyestui B-of the printing light used for printing partial image B. The term BB represents the ratio between the absorption of dyestu B in the printing light used for printing the partial image dyed by dyestui A and the greater absorption of this dyestui B in the printing light used for printing the partial image dyed by. dyestufl B. correspondingly, the intensity ofthe print of the partial image dyedby dyestui B produced by the printing light which is intensively absorbed by B is represented by the symbol B /a:, y/-lTEAA /a:,

ll/. It results `from these formulae that the compensation required for the one image is En B/z, v/, whereas the compensationrrequired for the other image is expressed by the'term EA A/z. W.' In accordance herewith,- the latter is super-printed on the former in the ratio En and the former is super-printed 'on the latter in the ratio Es. In this manner the images are corrected, however, they are to a slight extent weakened in intensity. This decrease in intensity may be compensated by acorresponding increase in the total intensity of iight employeddor printing. Frequently it 'is not necessary to super-print the partial selections printed by light of a short wave-length on the other partial selections printed by light of a long wave-length.

I now will describe a further possibility of executing the invention. In this modus operandi, for the intermediate print oi' at least one of the color selection pictures, multi-layer material is used as printing material. One of the layers is used for registering the desired color selection image printed from the multicolor original,

whereas the other serves as receptor of the compensation image which is to supplement the print of the desired selection in such a manner, as to compensate the errors produced in thecourse of the printing process. The latter layer, that is to` say, the layer used for printing'the coni-4 pensative image, diners from the layern on which the selection'itself is printed in'color sensitivity', in contents of silver, in gradation, 'or vin .coloring or in more than one of these properties-or This manner of executing the invention is iirst to be described by way of an example, and thereafter the possibilities of vagrying the procedure are to be described, by which the principles in accordance with which the invention' may be applied in other cases will easilybe'recognized.

In order to produce on separate supports the l ers, one of which is of a diierent composition matically sensitized, whereby a print of the bluegreen colored part image of the multicolor image is obtained. It thelatter was a positive, the intermediate print obtained will be a negative.

Thereafter the multicolor image is printed with blue light ona two-layer intermediate printing A material. This two-layer printing material may be composed in various ways, several o! the possibilities of composition being illustrated in the attached drawings. For instance, the intermediate printing material may be made up as illustrated in Fig. 3,' of two blue-sensitive layers, one

on each side of the support, the latter being as thin as technically possible. This support is dyed intensely yellow, so that it is non-transmittant for blue rays striking the material from either of the two sides. Another possibility is to separate the two blue-sensitive emulsions, as is illustrated in Fig. 4 by coating the support lwith a gelatine layer dyed yellow by admixture of 2 gr. of' tartrazine per sq. metre ofthe surface. This coat-4 ing must be decolorizable by washing.

Ot the two blue-sensitive emulsions, one is dyed sumciently intensely by a yellow dyestu, for instance by 0.5 gr. of Chrysophenine G to produce prints by blue light which are of a very much slighter contrast than the images produced by blue light of approximately the Vsame time-intensity value, in the colorlessdayer on the other side of the material.- The same effect may be obtained by employing colorless silver halide laythan the other. For instance, as is shown in Fig. 5, an' ordinary silver halide emulsion layer containing e. g. 8 grs. of silver bromide per mn may 40 be combined with a silver halide emulsionl layer with reduced silver content e. g. 2 grs. of silver bromide per m2. The latter layer produces va print very much softer in contrast than the former. The two-color image, fromwhich the blue-green partial image has been printed before- .hand is printed by `blue printing light layer against layer, on the colorless side of' the intermediate printing film. that is to say, onthe side ot the illm bearing the emulsion producing the greater contrast when printed upon. 'I'he latent image oi an incorrect print of the yellow part image of the two-color image is thus obtained. It the latter was a positive, the latent image will be a'negativ'e. n

The previously produced negative selection of the blue-green partial image of the multicolor image is laid layer against layeron the yellow which can be done separately on each side of the intermediate printing illm a correct negative re,-` production of the yellow partial image contained' dyed emulsion. that is to say'on the emulsion producin'g the prints of softer contrast. It is then printed with blue light., In this way a latent positive image oflow contrast of the blue-green VPartial image of the two color image is obtained.

This positive of low contrast .represents a correction of the errors which have arisen in printing the 'yellow partial image. After developing,

employed. A machine equipped in this manner should likewise -be employed in producing intermediate prints on the one-layer printing material. In this manner, the individual part-images may be printed into each other in exact register and also exact register of the image which is to 1 .blue-green color. In this case colorless s upports which is to be corrected with the corrective image on one and the same printing lm is the simplification of the further procedure, as in this manner both images may be developed at the same time, so that the desired differences in contrast are produced automatically, provided that the layers of the intermediate printing material ,are balanced against each other accordingly,

` The color selection images printed on the intermediate printing material may be employed in any way whatsoever, either directly or indirectly, for producing multicolor prints. However, attention must be paid to the fact that the presence of the yellow color in the .two-layer intermediate printing material in accordance with Figs. 3 and 4 excludes .the employment of blue light in the further treatment of the material. In, other the other side of the material.

words, the yellow color must either ilrst be' rel moved or the illm must be printed by use of green or red printing light.

VThe described example, in which the incorrect print of the partial image in question, as well as the image serving as corrective image, are printed on the multilayer intermediate printing material as black and white images represents the simplest form of application ofthe use of multilayer material for producing corrected selection pictures. It is for instance possible according to the invention to produce either the print of the image which is to be corrected or the partial image serving as corrective image or both of these prints as colored prints. For instance, the silver image produced in the yellow`dyed layer of the two layer intermediate printing material may be converted into a yellow dyestuif image by destruction of the dyestu present; If the dyestufl destroying agent, for instance an acid solution of thiocarbamide in accordance with U. S. Patent 2,020,775 issued October 30, 1931, acts at those places of A.the image where silver is present and therefore produces a reversed image of the partial color selection printed as a. corrective image, then instead cf using a negative of the blue-green partial image contained in the original to print on the yellow side of the two-layer intermediatey printing material (i. e. the side producing prints of soft contrast), as described above, one must use a positive of this blue-green partial image whereupon one will obtain a. colored positive on this side. The compensated intermediate print produced in this manner shows, after destruction of the dyestu and removal of any silver, which might still be present in the layer containing the dyestuff image, the desired negative partial selection in the form of a silver image on one side and a positive dyestui image serving as a. cor-f rection of this print on the other.4 An intermediate print of this kind corrected by a dyestu compensation picture is printed by use of light is absorbed by the dyestuiI to a printing light of for which the respective dyestutt is more or less non-transmittant,. for instance blue light is used in the case of a yellow dyestui! image, and green light in the case of a red dyestui! image.

An intermediate print corrected by a yellow dyestufl compensation image and representing the red selection of the original object may be printed directly onto a blue-sensitive layer of are used, or if yellow iilter-layers are employed, these must be decolorized before the printing is performed.

If the final print is desired inthe form of a positive master, image, positive intermediate prints are produced from the negative intermediate prints obtained. For producing such iurther intermediate prints as may be required, an intermediate print consisting of blackv and white images or preferably intermediate images produced on the multilayer material described above in -which the corrective imageis represented by a dyestuil picture may be used. In this case it i possible to regulate the contrast or the correct coyerage of the corrective image with the image to be corrected once more by choosing a printing light which is absorbed by the color of the corretive dYeStuf-f image to the extent desired. A second regulation of the contrast may be obtained by printing the silver image contained in the two-layer intermediate printing .material for a longer time than the dyestuii' image present on For example by switching over from a printing light color which a color which isA transmitted lby the dyestui in question, the printing effect of the dyestuif image is stopped after a predetermined time. This method is applied in case the corrective image is too intensely colored and the basic negative is to be accentuated in comparison to the latter.

In case the primarily produced intermediate print, negative or positive, is not directly printed on the final Iprinting material, but is employed for producing a further intermediate print, the twolayer intermediate printing material described may be used for the further intermediate prints and all of the individual partial selections may iirst be printed on ordinary printing material without employment of the correcting images, these images being employed when the iinal intermediate prints are produced on the multi-layer material described.

To illustratethis procedure we may consider that a three-color film bearing blue-green partial vimages on one side of the support and purple and yellow images on the other side is to be printed on a multi-layer material, as shown at 2l and 22 in Fig. 2, the outside layers of which are magenta and blue-green and are sensitive to blue, Whereas` the middle layer is yellow and sensitive to red. The image is to be produced by destruction of the dyestuff by the aid of thiocarbamide at the places at which silver is present. First the printing is performed successively with red, green and blue light onto three layers, each of which'is sensitive respectively to red, green or blue light and is coated on a separate support. In printing, the lm on which a .print is to be produced with red light is arranged layer against layer on the blue-green side of the multicolor image, and the films' on which printing is to be performed with green and blue light are laid layer against layer on the purple-red side of the master image. 'I'he negative intermediate print produced mediate prints of the two negative intermediate prints produced with green and blu/e light, a twolayer lm as shown in Fig. 6 is used as a printing material The support is coated with a silver.

which a second coating is added consisting of a plain silver halide emulsion containing a normal silver content and sensitive to blue. The negative produced by green light' is printed on the material shown in Fig. 6 by blue light, the two lms being arranged layer against layer whereby a latent image is obtained in the upper layer which is however not correct. Thereupon a previously produced negative corresponding to the bluegreen partial image of the original is laid upon the two-layer intermediate printing material, the support of the negative being placed directly on the upper layer of the two-layer material, and is printed into the lower layer by use of green light. Thereby a latent positive image is obtained in the green layer. Thereafter, the nlm is developed and xed in the usual manner and is then bathed in a solution of thiocarbamide. By this bath, the dyestuif in the lower layer is destroyed and the silver is dissolved. In the upper layer, however, which contains more silver, the silver image is only slightly affected. In the upper layer therefore a positive black silver image remains,-

whereas'in the lower layer a negative green colored dyestui image is obtained. This intermediate positive is printed on.the blue-sensitive purple colored layer of the nal three-layer material by use of Iblue light, for which purpose it is laid directly with its layer against the purple layer of the printing material.

The intermediate print for the third partial image is produced in exactly the same manner as has been described above. This intermediate print is laid layer against layer on to the purple side of ythe iinal three-layer printing material and is printed with red light, the final print being produced in the yellow layer 0f the material. As concerns the further treatment of the multilayer material, it is now only necessary to destroy the dyestuii in the silver regions in the usual manner by use of,'for instance, thiocarbamide, whereby the nal multi-color image is obtained.

In the example described above only one single on the iinal printing material, but instead is used to produce a further two laye? intermediate print,

Athe corrective image may be produced asa silverimage of low contrast instead of as a dyestuif image, if, instead of the negative image corresponding to the blue-green partial color selection of the original, the positive produced from this negative is printed into the material, in which case, however, the printing is performed by laying the positive layer against layer on to the intermediate printing material. 'I'he contrast of colorl intensity on the image may be regulated by ad- J'usting the printing light used accordingly. If a corrective image showing a hard. contrast is desired, more green light is used; on the other hand, if an image of softer contrast is desired, more red light is used.- In this case the treatment by thiocarbarnide is replaced by a treatment with a 2% solution of sodium hydrosulphitethis treatment being continued long enough to completely bleach out all the dyestuff present in the lower layer of the two-layer material.

In case a master image on an opaque support is to be printed, the manner of procedure described in the immediately foregoing example, using secondary intermediate prints may be followed.

Other examples of the two-layer intermediate corrective image was printed -into each of the.' 60

two multi-layer intermediate printing 4lms for' compensation purposes. However, a previously produced and corrected intermediate print as described above may in addition be pn'nted into the multi-layer lintermediate print before printing the latter in to the red sensitive yellow layer of the lfinal three-layer material.

In producing the two images as described labove in the two-layer intermediate printing material, the' method employed may deviate in various ways from the manner of procedure laid down in above examples. For instance, in the immediately preceding example where the intermef diate print, rst produced, is not directly printed are indicated in Figs. 'l and 8. The material represented by Fig. 8 comprises two supplementary layers, both lof which contain only small pro-A portions of silver, these proportions diering from each other. This material is to be recommended if it is necessary to produce more than one corrective image and if the corrective images produced are to show diierent degrees of contrast. By using this material in addition to the print of normal contrast, two further corrective prints of weak contrast are obtained in the two supplementary layers. In general, that is to say in the present example as well as in the examples described in the foregoing, the corrective layers are produced or developed in such a manner that the gamma infinite of the layer intended for the corrective image is at the most half the value of the gamma infinite of the other layer.

'Ihe words positive and negative are dened as meaning the mutual relationship of the images thus designated, i. e. that the points of maximum density oi' the respective images are inverse with respect to each other.

Instead of employing separate layers coated on each other, emulsion particles of diii'erent sensitivity, coloring or contrast may be mixed with each other and coated on the support 'as a singleA layer.

In addition to that, in accordance with the invention, the intermediate printing material may be composed by combining an ordinary emulsion optical printing method may be employed in all Y of the processes.

By the present invention correct partial selection pictures vwill be obtained in each case in which the latitude of the correcting print combined with the print to becorrected, is the same as the latitude of exposure of the latter, i. e., when thegradation of densities of the correcting print is of opposite sign ,to the gradation oi' densities in the part image to be corrected. Of the combined images the correcting. image has a maximal density' which is as many times lower than the maximal density of the image to be corrected as the absorption of the disturbing dyestui in the printing light used for printing the desired image is lower than the absorption of the dyestuff forming the desired image. 'I'his means also that the gamma ofthe correcting image and the gamma of the image to be corrected are in the same proportion to each other as the maximum absorptions ofthe disturbing dyestufl! in the image and the dyestuil' of the part image of the multicolor image to be printed.

What I claim is: Y i 1. A multi-layer photographic material comprising two light sensitive silver halide emulsion layers coated on a support, one of. said layers being sensitive to green and dyed by a dyestui! which transmits green light yand absorbs red and blue light, said dyestuif` being i'ast to ordinary photoi 4 3. A photographic film for making color sepao ration negatives comprising two colorless layers one of which is a negative photographic emulsion sensitive to light in one spectral region, andthe other of which is a direct positive photographic emulsion sensitive to light in another spectral region.

4. A multilayer' photographic material comprising a plurality of superposed light sensitive layers on a single support, said layers being. formed by silver halide emulsions sensitized for light of different spectral regions and differing in contrast, one of said two layers being adapted to record a desired color selection picture having un' desired absorption at various points thereof and 55 the'other being adapted to record a compensationl -solutions but capable of being locally destroyed with the aid of a metallic silver image, said two emulsion layers having substantially different ccntrasts, the relationship between said contrasts beins a function of the ratio between said undesired absorption the balancing absorption necessary in said compensation image, and one of said v layers being an ordinary photographic emulsion Land the other being an emulsion directly producing positives by simple development. r

6. A'master image for color photographic printing purposes comprising a' transparent support carrying a colloid layer containing a silver image and a colloid layer containing a dyestui! image,

the silver image constituting a color selection picture record falsined by a record of a different color selection and the dyestui! image constituting a reversed record of said different color in registry therewith.

'1. A photographic material comprising a plurality of light sensitive emulsions on a single support, at least two of said emulsions being silver halide emulsions sensitized for lightof diiierent spectral regions, one oi' said two emulsions being adapted to record a desired color selection picture having 'undesired absorption at various points thereof and the other being' adapted to record a compensation image in register with said desired color selection picture for balancing said undesired absorption, and oneoi' said two emulsions being dyed with adyewhich is fast to ordinary photographic treating solutions but capable of being locally destroyed with the aid of a metallic silver image, said two emulsions having substantially dierent contrasts and the relatiombetween said contrasts being a function of the ratio between said undesired absorption and the balancing absorption necessary in said compensation image.

8. A photographic material comprising aplurality of light sensitive' layers on a single support, at least two of said layers being silver halide emulsion layers sensitized for light of dierent spectral image in register with said desired color selection` picture for balancing said undesired absorption, one of said layers being a silver halide emulsion oi' normal silver content and another of said layers being a silver halide emulsion layer of reduced silver content, at leastl one of said last mentioned emulsion layers being dyed with a dye which is fast to ordinary photographic treating solutions 00 with the aid of a metallic silver image, said two layers having substantially different contrasts and but capable of being locally destroyed with the aid of a metallic silver image the relation of the silver content in said layers being a function of the ratio between saidundesired absorption and the balancing absorption ,necessary in said compensation image.

V5. A multilayer photographic material comprising .is-plurality of superposed light sensitive layers on`= a single support, at least two of said layers beim vformed by silver halide emulsions regions, one of said two layers 4being adapted to record a desired color selection picture having undesired absorption at various points thereof and the other being adapted to record a compensation image in register with said desired color selection picture for balancing said undesired absorption. and one of said two layers being dyed with a dye which is fast to ordinary photographic treating solutions but capable of being locally destroyed the relation between said contrasts being a function of the ratio between fsaid undesired absorption and the balancing 'absorption necessary said compensation image.

9. A multilayer photographic material comprising a plurality of superpcsed light sensitive layers on a single support, at least two of said layers being silver halide emulsion layers sensitized for 70, light of diner-ent spectral regions, one of said two layers being adapted to record a desired color selection picture having undesired absorption at various points thereof and the other being adapted sensitized for light ot different spectrarregions, 7o to record a compensation image in register with ass'mss f l 9 said desired color selection picture tor balancing said undesired absorption, and one ot said two layers being dyed with a dye which transmits 'green iight but absorbs blue light. said dye heinz fast to ordinary photographic treating solutions but capable of being locally destroyed with tbe aid of ametaliic silver image. and aseeond one 'of said two layers being positioned in front oi said green sensitive layer and beingoolorless and sensitive to blue, said two layers having substantially diierent contrasts and the relation between said contrasts being a function of the ratio between said undesired absorption and thev balancing absorption necessary in said compensating im- BELA GASPAR.