US1376940A - Color photograph or film and method of producing same - Google Patents

Description

, ,produced and suitably blended for exhibit-- ing or projecting. The two-image plan has been heretofore tried, but the results have."

UNITED STATES PATENTfOFFICE.

rnnnnnio EUGENE IVES, or PHILADELPHIA, i nimsrnvimm.

oonon rrro'roomrii ORFILM AND METHOD OF PRODUCING sum.

No Drawing.

To all whom it may concern.

Be it known that I, FREDERIO Ivns, acitizen of the United States residing at Philadelghia, in the county of lhiladelphia and tale of Pennsylvania, have invented certain new and useful Improve- EUGENE ments in Color Photographs or Films and";

larly to a system of color photo aphy or color motion pictures in which on y two, in-

steadof the theoretically necessary three,

color selection negatives are produced, from which two color positives are subsequently been too inaccurate to be wholly satisfactory. The attempt to obtain the more perfect effects of a three-image system by means of two images is at best a compromise, but the systems heretofore tried 'have been quite defective in color rendering, and it is the main object of the present invention to afford in a two-image system a, better compromise, that is, a better representation of the colors of nature which the three-image system would afford. Further objects and advantages of the present invention will be pointed out in the hereinafter following description of one embodiment hereof, or will be apparent to those skilled in the art.

Before describing the present invention, it will be advantageous to refer in outline to prior known systems. In the three-image system three negatives are made, namely,

by selective exposure to red light, to greenlight, and to blue-violet, which will be termed blue light. These are the primaries, From such negatives secondaries of-the respective complementary colors, namely,

' blue-green, magenta-pink and yellow are produced and blended. With thetWo-iinage system heretofore tried'the R negativei rep 4 the green rays, but the resenting the red rays, has been pro uced as before, and the G negative, representing negative has been s mplyomitted, followed by the omission of the y llow fie ondary or positive element in Specification of Letters Patent.

Patented May 3, 1921.

Application flledseptember 26, 1919. Serial No. 826,536.

the final picture. positive of blue-green or preferably green has been produced from the R negative, and a positive of some selected red from the G negative, and these blended to secure an approximation of the original. With such system no yellows are reproduced- ;-these appearing white, a dis- If a greenpositive from the s been produced, no blues or greet-f are possible. If blue-green or peacock blue 18- the selected positive color, no true 'i'greens are producible. Orange colors appear as dilute red,'and various other important hues are objectionably falsified.

The general plan of the present improvement is, instead of employing the usual R vgositive of a green or blue, and the usual herein describe how to produce such a dichroi'c image, giving yellow in the palest portions, orange in the intermediate and red in the deepest portions of the image. I will first describe the result of such com-- motion picture film.

In the first place, in carrying out the present novel system I prefer from the It negative to produce an R positive of a blueposite or two-image color photograph or a 'd1- chroic yellow-to-red image; and I will green color, although, as is well known, the

shade may be, varied to any point between blue and green. In exposing for the otheror G negative I prefer to admit to the sensitive film a slight amount of blue light,

enough to give a pale or feeble eflect. Fromthisa positive dichroic yellow-to-red image is produced, as already stated. The result will be that, when this image is blended with the blue-green image, desirable colors and shades are ossible in the final'picture which render it ar more practical and pleasing, as compared with prior stems. I w ll now describe the result of t 'swith regard to certain spec' 0 colors.'

resent system Taking yellow 'light inthe subject be portraiture fle photographed, this will simply develo white or clear in the first or R positive; ye low light passes freely through to the R sensitive plate. In the second or G" image,

5 owing tothe admission of a trace ofiblue ,inaddition to green rays, yellow (minusblue) will be represented and will reproduce palely, with the result that yellow in the subject is represented by the lightest or thinnest shades or parts of the dichroic or positive image. Thus, yellow is afforded in the final or blended picture. The fact of having yellow so represented enable the first positive image to be of a true peacock blue, so that peacock blue'hues are reproduced with out degradation.

A true green, fully differentiated from the peacock shade, is producible as follows.

Light of this color in the subject is shut out in exposing for "the R negative, with the result of yieldingadark ordeep blue-green jposit-ive. In the other positive this color would under the prior system appear. as white, but owing-to the admission of a slight amount of blue light with the green, the

' in the dichroic positive. That is, it reproduces as a yellow. This yellow, blended with the blue-green of the first positive image, reduces thelatter to a true green color. I

4 Red light, of course, gives clear or white in the first positive image, but full and deep shades in the second. I This being a dichroic image which is'red in the deeper shades, we have satisfactory reproduction of the reds. The oranges'similarly affect the images, ex-

, cept that the de vth is medium instead of 'full', andthe dic roic image is orange-col- 40 I .ored in its medium portions.

Pure white l'ght gives an ab.-olutely clear or -white. positive image from both nega-j tives, and therefore white is reproduced.

- Thus, all the main colors are desirablyrepresented in the final blended image. This is not claimed to be as perfect as a three-image picture,-but, on the; other hand,

" the-limitations aremore obvious from a scientific than from a practical or pictorial aspect. Cobaltblue will ap ear almost black, and inks andpirrples-wi lappear dull and reddlsh, but, as stated, the main primary and'secondary colors which are of the greatest importance are reproduced su-fliciently accurately for ictorial purposes. Thus, for

s li color reproduces well, and also blue, y and brown for the eye, and yellow, au urn and brown for the hair. With landscapes the green foliage and blue ski'es.are properly differentiated, and fruits and flowers will reproduce in yellows, or-.

anges and reds.

I will now explain the dichroic or yellow- "to-red' image above referred to. Dichroism is the property. of a substance of appearing -in different colors under different conditions. For example, the organic substance chlorophyl, if examined in solutions of considerable thickness, appears red, but in thin layers appears green; it is dichroic. There are certain dyes or dye combinations that exhibit the same properties. For example,-

an almost saturated solution of auramm, a yellow dye, to which has been added a small quantity of saffranin, a red dye, appears yellow in thin la ers, orange in medium layers and red in t e thickest layers. This is not the equivalent, but is the contrary, of the employment of an ordinary red dye which has been heretofore proposed, the latter not being dichroic, and in its thinner layers appearing as pale red, and in its thicker layers as deep red.

From the above it is thought it will be understood by those sln'lled in the art how to produce the dichroic image and to blend it with the other selectively produced image.

I will, however, refer to certain available methods. Thus, the imbibition method referred to in my prior Patents Nos. 1,121, 187, of December 15, 1914:, and 1,186,000, of June 6, 1916, is available. From the second or G negative exposed by green light with a slight amount of blue is produced a gelatin relief positive in accordance with the prior patents.- This may first be thoroughly dyed m a solution of red or magenta dye stuff,

A and then transferred to a yellow dye bath for a moderate length of time, when it will be found that the yellow has substantially displaced the red in the thinnest layers of the image. The result is the desired dichroic yellow-to-red positive image. Suitable formulae may be as follows.

For the red dye:

Fast red D (sodium salt of p-sulfonaphthalene a'z'zo B naphthol-di-sulfonic acid) Acetic acid Water 1 For the yellow dye: I Brilliant yellow (sodium salt of dis11lfo-stilbene-disa'zo-biphenol) 1; gram Acetic acid 5 c. c. -Water; 1000 c. c.

Simultaneous rather than such successive dyeing may be employed. For example, a mixture of a very soluble acid red or magenta dye having but slight affinity for elatin, with a so-called direct, yellow dyafiia'ving great aflinity for gelatin will give the desired result. The relief print immersed in such .solution will be found to first dye red, which 1% grams -5 c. c. c. e.

is later partly replaced by yellow, this action taking place earlier and more completely in the thinnest layers, giving again .the

yellow-to-red dichroic mage. The dyesset ed with the blue-green image already or later formed. This method is good for afi'ording final color prints on paper. Another is to bodily superpose the relief print with a separately formed bluereen print, as described inmy Patent 0. 1,122,935, of

' December 29, 1914.

For motion ictures'I prefer the mordant dye method of Suitable dyes may be mordanted by proper metallic mordants. or example, a silver gositive image may be produced from the negative. This, when dry, may be immersed in a solution made up of water, 1000 a transparent image, composed of silver 0. c., potassium ferricyanid, 5 grams, chromic acid, 5 grams. ThlS converts the silver into ferricyanid. After thorough washing this image willtake up basic dyes. For-example,

red may be first applied, and later yellow to replace the red in t e paler shades. Safiranin red and auramin yellow dyes are suitable. The resulting dichroic image may be blended with a peacock blue imagefrom the l I R negative by resensitizing the colloid layer with ferric ammonium citrate and printing a cyanotype image in the samelayer similarly to my prior Patent No. 1,278,668, of Sep:

tember 10, 1918. If desired the peacock.

blue image may be produced as a separate print and superposed upon the dichroic yellow-to-red print.,

Equivalent results are obtainable by producing three positive images from the two negatives. Fromthe first negative I may make the usual positive. From the second negative I may make a first positive, underexposed and contrasty, and produce this in a magenta or red-color, and from the same neigtativea second positive fully ex osed and to be colored yellow. Suita le blending of these with each other and'with the first positive will give approximately the results sought.

It will thus be seen that I have described a color photograph or film and method of producing the same, embodying the principles and attaining the advantages of the present invention. Since many matters of relative detail, such as the particular ste s or order of steps em loyed, and the mgre 1- ents or formulae use mag be variousl modified without departing om the un erlying principles, it is not-mtended to limit the creating the dichroic image. 1

invention to such features exceptgin so far as specified in the appended claims. What is claimed is:

1. The method of producing a color photograph or motion picture film by two blended or blendable images consisting in producing a dichroic image showing two secimage showing. the third secondary.

2. The method of producing a color photograph or motion picture film from two color selection negatives consisting in producing positive images from one negative showing in two secondary colors and from the other negative showing in the third secondary.

3. The method of producing a color photograph or motion picture film from two color selection negatives consisting in producing a dichroic positive image from one negative showing yellow in the thin places and another secondary color in the deep places and blending the same with a positive from the other negative showing the third secondary co or.

4. The method of claim 3, and wherein the first negative is exposed mainly to green and slightly to blue light and from which is produced a yellow-to-red dichroic positive,

'ondaries and blending it with 'a second blended with a blue-to-green positive from the other negative. 5. The method of claim 1, and wherein the dichroic image is produced by selective dyein of colloid material by two dyes acting differently upon the colloid.

6. The method of claim 1, and wherein the dichroic image in colloid is produced by successive dyeing in dyestuffs of different. colors and actions.

7. Method of producing a yellow-to-red dichroic image in a selectively absorbent. gelatin layer consisting in dyeing in a red film having two blended photographic images, one of which is a yellow to-red dichroic image, the other a blue-green image. 10. A support or base carrying a dichroic image for color photography wherein the thin parts show distinct colors from th deeply colored parts. A

11. A support or base carrying a dichroic image showing yellow in the. thin places, orange in the deeper and red in the deepest. In testimony whereof, I have 'aflixed my signature hereto.

FREDERiC inner-un- IVES.