US2016666A - Colored photograph and method of making same - Google Patents

Description

Oct. 8, 1935. w. T, cREsPlNEl. 2,016,666

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WML/nro 7. CessP/Nsp HTrce/vsy relatively small number of Patented Oct. 8, 1935 PATENT GFFICE COLORED PHOTOGRAPH ANO METHOD or' MAKING sAME William T. Crespinel, Los Angeles, Calif., assignor to Cinecolor Inc., a corporation of California Application December 2, 1932, Serial No. 645,439

13 claims. (c1. sns-2) My invention relatesY to the art of color-pho tography and comprehends the production of a photograph, which will faithfully reproduce substantially all of the colors inthe object photographed. -My new and improved method may be used both in the production of still photographs and in the production of motion pictures in color, although its greatest applicability will be found to be in the latter art for the reason that less progress has been made in this eld of endeavor than in the former. That being the case I will confine the description-of my process, and the illm produced thereby, to its application to the production of motion pictures in color, and it will therefore bev understood that wherever I use the term film I wish to include plates and other photographic media suitable for the reproduction of images.

It is an object of my invention to provide a method of making photographs in color which is comparatively simple in operation and which by reason of its `flexibility may be used under various adverse conditions-without in any way'impairing the 'quality of the product obtained thereby.

It is also an object of my invention to provide a method of making photographs in color which is positive and sure in its operation and which does not require constant attention and manipulation ofV the solutions and equipment, thus making it possible to operate on a large scale with a highly skilled technicians.

A further Object of my invention is to produce a coloredv photograph by the use of only two cumbersome and wasteful. It is therefore an- 'other object of my invention to produce a satisfactory colored film at a cost that compares favorably with the present cost of producing black and white lm.' f y Y Other objects andadvantages ofmy invention will become apparent from the following detailed description of a preferred form cf my invention.

In the drawing, Fig. 1 is a representation of a positive made according to the invention; Fig. 2 is a modification of the positive of Fig. l; and Fig. 3 is a ow sheet of the process of treating `sich positives, the process being set forth below in detail. s

In the practice of my invention, two colorvalue negatives are produced by any of the well known methods, one of the negatives recording the blue-to-green color-values and the other negative recording the orange-to-red color- 5' values of the objects photographed. These negatives may be produced by what is known as a light-splitting camera which divides the light v com ingfthrough the lens, and passes part of it through a blue-to-green lter onto a sensitive 10 lm, while passing the balance 0f the light through an orange-to-red lter onto a second sensitive fllm. While the production of the colorvalue negatives forms no part of my invention I will also describe briefly what is known as the 15 Bi-Pack system .of producing such negatives, which system I nd works admirably in conjunction with my method of producing a colored posi` tive.

The Bi-Pack system-as generally known to the 20 art consists in running two negative lms, in face to face contact through a standard camera which`has the aperture plate slightly modified to accommodate the increased thickness of the two illms and which has a special magazine with 25 extra spools therein for the second iilm. The front nlm may be what is termed an orthochromatic nlm, being sensitive to the blue-to-green end of the spectrum only, and is usually provided with a red surface dye on its face. The rear film 3 may be the usual type of panchromatic iilxn common to the art whichrecords substantially all colors but is predominantly sensitive to the orange-to-red end of the spectrum. When these two films are exposed in the camera the blue- 3.5

to-green objects are recorded on the front or orthochromatic film and the red objects are recorded on the rear or panchromatic fllm, the red surface dye on the face of the front film acting as av lter toprevent the passage of4 any but 0.-

Orange-to-red rays of light to the rear lm.

The color-value negatives after exposure,

whether obtained by the Bi-Pack, light-splitting or other suitable means are developed, fixed and dried in the usual manner well known in the art 45 and are then ready for use in my invention.

For thev positive print I prefer to use a lm havi an emulsion on each side of the base. this type of nlm being commercially available by the name of double-coated, or duplitized stock. 50

although by a slight m liication of the process as hereinafter explained I can use afilm having" either an extra thick emulsinvor two standard emulsions on one side of the base. In the practice 'of the preferred form of my invention f print A55 the negative which has 'recorded the blue-togreen color values to one side of the positive stock and on the other side of the positive stock I print from the negative which has recorded the orangeto-red color values. This printing may be done in any .convenient manner so long as accurate registry is had between the respective images of the two negatives. The positive emulsions have incorporated in them a removable light-restraining dye which prevents the printing light used in exposing one emulsion from penetrating through the emulsion and base to expose the other emulsion. The two negatives may be printed siriultaneously or successively depending on the equipment available,l and' by contact printing or by projection printing, the particular method used forming no part of my invention.

After the negatives have been printed to opposite sides of the positive, it is developed, fixed and Washed in the usual manner and is then ready for coloring. It will be understood that my process belongs to that general class of the color art known as Subtractive Processes wherein a` colored image is obtained on the screen by means of ltering out or subtracting certain wave lengths or colors from white light before it reaches the screen. In the practice oi' my invention the positive image secured by printing from the orange-to-red 'color value negative is colored blue-to-green and the positive image printed from the blue-to-green color value negative is colored orange-to-red all in the manner hereinafter specifically disclosed.

' After printing, developing, and iixing, the positive has two sets of silver images thereon, -one corresponding to the orange-to-red colors photographed and one corresponding to the blue-togreen colors photographed. 'Ihese images may be termed black and white in that the free silver is black, shading down to grays with clear or 4white spaces where no light was received by the respective emulsion. The nlm is now immersed in a solution which we may for descriptive pur* poses call a priming solution or primer. A suitable formula for such a solution being:

Potassium iodide 60 grams Potassium iodate l 2 grams Pepsin 2 grams Water 1000 c. c.

The iilm is allowed to remain in this solution for approximately two minutes or for'such additional time as may be necessary to insure all traces of the nxing solution of Hypo being removed. Any hypo left in the nlm when immersed in this priming solution is oxidized to a substance which is easily soluble in water and not detrimental to the subsequent coloring. It is very necessary that the hypo be entirely removed before the subsequent steps for any traces of it remaining will produce irregular and faulty color. The pepsin in this solution in conjunction with the bleach used in the next step insures a.

fine-grained transparent and well dened image,v

due to the fact that as` pepsin is a protective colloid, it has a tendency to bring the silver iodide formed into a colloidal state insteadvof a granular one Iwith a consequently finer grained image than could otherwise be obtained. Furthermoretleppepsn assists the mordanting in that the the grain of the image, the more complete can-.Ebel the mordanting action.

After removal from the priming solution the surface moisture is removed from the nlm by any convenient means as by air blast or wipers,

yellow color.

Thereupon that side only of the Apositive which was printed from the blue-to-green color value negative and which is to be colored orange-tored is treated by any convenient means with a bleaching solution, which is also a mordant for 5 basic dyes and which may be made up substantially as follows:

The silver image on the bleached side of the film is converted by the bleach into a silver iodide l5 image which is capable of mordanting basic dyes. The film is then given a brief 'water wash to remove any excess bleach adhering to the emulsion and is immersed in a clearing solution of potassium metabisulphite and water which can be 20 made up in the proportion of 5 grams of potassium metabisulphite to i000 c. c. of water. The action of the clearing solution is to convert any free iodine remaining in the emulsion after bleaching, to potassium iodide which is soluble 25 in water and which is then removed by means of another water wash.

At this stage of the process 'we have a bleached image on one side of the `iilm which is to be colored orange-to-red, and on the other side of 30 the lm a free silver image which has remained substantially unchanged and which is tobe subsequently colored blue-to-green.

The film is now immersed in a solution of basic dye which will give the desired orange-to- 35 red color to the bleached images. Two suitable dye solutions for this step are as follows:

Each of the component solutions mentioned 45 above is made up by dissolving 1 gram of solid dye in c. c. of distilledwater.

Whenever it becomes necessary to mix dyes to get a resultant color partaking of the individual colors of the respective dyes the inherent problem 50 of constant controlof proportions arises. Consequently I have found it advisablein some instances to produce the orange-to-red images by a combination of a single dye and a colored metallic tone. In this variation oi.' my process 55 I prefer to use a dye such as Safranine Y (Shultz 679) which is of a magenta color, and then lmmerse the lm in a weak solution of mercurio nitrate which replaces the colorless silver iodide image with a mercuric iodide image which has a 60 The combination of this yellow iodide image with the magenta dyed image gives the desired orange-to-red colors with substantially a yellow in the,\very thin portions 0I the image. 65

Following this step the film is immersed in a blue toning solution a suitable formula for which is as follows:

vWater A'1000 c. c.

The free silver images in the unbleacned emui- 75 4sion are converted by this solution to ferrieferrocyanide images which have a blue-to-green color. Some opaque silver ferrocyanide' is also formed in this reaction which is removed by subsequent treatment as hereinafter described.

eration by merely adding a small amount, say 1 A gram, of mercurio nitrate to the blue toning'solution made up as before mentioned. When the film is immersed in this combined solution the blue toning constituents do not interfere with the action of the. mercurio nitrate on the silver iodide images and the nitrate in no way hinders complete toning of the silver images by the other constituents of the solution.

When the film vhas remained in the toning solution approximately 2 minutes it is given another water wash and the surface moisture'removed in any convenient manner. The iron-toned images are then subjected to a weak fixing solution containing for example 4 oz. of sodium thiosulphate to 1000 c. c. of water which removes the white silver ferrocyanide from the toned images, leaving a transparent film with a series of blue-togreen images on one side and a series of orangeto-red images on the other side thereof in regis'try with the respective blue-to-green images.

After leaving the fixing solution the iilm is washed and thoroughly dried and is then ready for use. If it is desired to increase the life of the lm it may be treated with av transparent varnish to give it a protective coating which will reduce the wear and tear/attendant on its being run through projection machines. y

In many cases for sound motion picture work it is desirable to have a sound track on the positive print. In this case the sound track negative is printed to the lside of the picture positive that sible in its practice without in any waygoing out-4 side of its proper scope. As previously mentioned my invention may employ a film having two images on the same side of the base, obtained in different levels of an extra thick'emulsion or in two superposed-emulsions. The only modication of my process necessary to utilize a film of this structure is to regulate the time of immersion for `those steps requiring treatment of one image only. In brief the operations involved in treating such a iilm would be as follows:

'I'he image to be colored blue-to-green is printed through the base of the positive stock on to the bottom or inner emulsion and the image Ato be colored orange-to-red is printed to the face of the nlm on the outer emulsion. The lm is then developed xed and washed as before, and immersed in the priming solution. From the primer it goes to the bieach'end is left in this solution' Just longy solution containing mercurio nitrate for a length of time suiiicient to allow the iron tone to fully convert the inner silver image while the outer dyetoned image is being converted to mercurio iodide to give the resultant orange-to-red color 5 as hereinbefore explained. In the nal fixing bath it will be found-desirable to add a small quantity of potassium iodide so that there will be no danger of the hypo breaking down the iodide` image which has the red dye mordanted thereon. l0 It will be understood that the formulas given` are illustra-tive only, and while I have found the proportions set out to be very successful 'in my work so far, I recognize that the quantities of the various ingredients may be varied between ratherwide limits while still obtaining good color. Likewise -there are othergchemicals which may be substituted for some of the ingredients of thevarious solutions used in my preferred form which secure equivalent results.

These and other variations, modiiications and equivalents will be evident to those skilled in the art, all of which may be practiced without in any A manner falling outside the scope of my invention.

I claim as my invention: f 1. In a colored photograph the vcombination of a transparent base; an iron-toned blue image carried by said transparent base; and amercurytoned yellow image carried by said transparent base and in registry with said first image, said mercury toned yellow image having a magenta basic dye mordanted thereon.

2. In a colored photograph the combination of a transparent base; an iron toned image carried by said transparent base; a mercury toned image carried by said transparent base and in registry with said iron toned image; and a basic dye mordanted in situ on said mercury toned image.

l3. The method of making photographs in color 0 which includes: producingcomplementary colorvalue images on a lm; treatingsaid images with a priming solution; bleaching one of said images with a solution which is also a mordant for basic dyes; treating said film with a solution of basic dye; treating said film with an iron toning solution containing a mercurio salt; and fixing said images to make them transparent.

4. 'Ihe method of making a colored photograph 5o which includes: producing complementary colorvalue images on opposite sides of a film; treating said images with a priming solution; treating the image on one side only of said nlm with a solution which will mordant a dye in situ;,subjectlng' said 55 mordanted image to a dye; toning the other of said images while converting said mordanted image to a color complementary to the color of said toned image; xing said images; and drying said images.

5. The method of making a photograph in color which includes: producing complementary color-value images on a nlm; converting one of said images to silver iodide; dying said image with a basic dye; toning said second image blueto-green while converting said silver iodide image to mercurio iodide; and xing said images.

6. The method of making a photograph in color which includes: producing a'plurality of images in registry on a illm said images being of A said images; and giving to the second of said images a color substantially complementary to the y color of said dyed image.

8. The method of making photographs in color which includes: producing an image on one side of a lm; producing an image on the opposite side of said lm and in registry with said first image, said second image being of a color value substantially complementary to that of said rst image; treating said rst image only with an iodide mordant; immersing said lm in a solution of magenta basic dye; immersing said film in an iron toning solution to give said second image a blue-to-green color; converting said first image to a mercurio iodide without removing said basic dye; and fixing said images to make them more transparent.

9. Inv a colored photograph the combination of a base; a toned image 'carried by said base; and a mercury toned image carried by said base in registry with said rst named image, said mercury toned image having a basic dye mordanted thereon.

10. The method of making a photograph in color which includes: producing complementary color-value images on a film in register with each 5 other; converting one oi said images to silver iodide; dyeing said image; toning said second image blue to green;. and converting said silver iodide image to mercurio iodide. y

11. The method of making a photograph in 10 color which includes: producing complementary color-value images on a film; dyetoning one of said images orange to red; mercury toning said vimage; and toning the other of said images blue 1 to green. l5

12. The step in dye-toning a developed photographic image which consists in treating said developed image with pepsin prior to said dyetoning operation. L

13. The method of dye-toning a photographic 20 image which includes: treating said image with a solution containing pepsin; bleaching said image; and submitting said bleached image to the action of a basic dye.

WILLIAM T. CRESPINEL. 25

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