US1391310A - Color photography - Google Patents

Description

W. FRIESE-GREENE.

COLOR PHOTOGRAPHY.

APPLICATION FILED IAII.`3I,'I92I.

Pandsept. 20,1921.

)VM im,

UNITED STATES PATENT OFFICE.

WILLIAM IRIESE-GBEENE, 0F LNDDN, ENGLAND, ASSIGNOR T0 COLOUR PHOTOG- MPHY LIMITED, 0F LONDON, ENGLAND.

COLOR PHOTOGRAPHY.

Specication ot-Letters Patent. Patented Sept, 20, 1921,

Original application illed July 8, 1919, Serial No.` 309,455. Divided and this application led January 31, 1921. Serial No. 441,495.

To all /wwm it may concern.'

Be it known that I, WILLIAM FRmsE- GREENE, a subject of the King of England, residing in London, England, have invented certain new and useful Improvements in Color Photography, of which the following is a specification.

This invention is for improvements in or relating to color photography, and has for one of its ob'ects to improve the production of colored p otographs whether for use as transparencies or for mounting on opaque mounts The invention is applicable both to the photography in colors of still life and animate or inanimate objects and to'cinematography, and renders such color photography morefsimple in operat1on.

Another part of the invention relates to an improvedI process of color photography in which two sensitized surfaces are simultaneously or substantially simultaneously exposed the one through a color filter and the other without such filter.

A specific object of the invention is to improve color photography processes based upon the employment of two colors whereby an approximation to natural color effects 1s obtained. In particular the invention alms at improvin two-color cinematography.

These an other objects and features of the invention will now be described in detail, with the aid of the accompanying drawin in whichsiguresl and 2 diagrammatically illustrate two arrangements of the sensitized surfaces upon which the original exposures are made; and

Fig. 3 illustrates diagrammatically two superimposed surfaces bearing the resultant photographic images.

The color sensitizer according to the present invention comprises pinacyanol, pinaverdol, pinachrome, lavazine sometimes avazin or lavasine) and ammoniamixed with Water, and preferably the proportions employed are as follows Pinacyanol 2grains Pinaverdol Ggrains Pinachrome .12 grains Flavazine 4grains Ammonia (.880) 4ozs.

Distilled water 65 pints In making up the sensitizer therst four ingredients in the quantities stated are preferably placed in 10 ozs. of boiling alcohol and stirred for say 10 minutes until thoroughly dissolved, after which 65 pints of distilled water ma be added at a temperature of about 70 ahr. and then the v4: ozs. of ammonia added.' The film or plate to be color-sensitized is immersed in th1s mixture for about 5 minutes and kept constantly in movement. The drying should be effected quickly at a temperatureof about 75 Fahr.

The light-sensitive surface of a photographic .plate or iilm color-sensitized by this formula is panchromatic, and such plaines or films may be used for any urpose .for which panchromatic plates or lms are suitable, givlng very eilicient results and satisfactory color effects. According to the present invention, however, panchromatic plates or films color-sensitized by the above formula, are used in improving color-photographyon the two-color rinciple.

The ingredients detai ed above are referred to by the -names commonly given to them in the chemical and color photographicindustry. It will be understood, however, that pinacyanol (sometimes known as sensitol red) isobtained by treating quinaldinium salts with formaldehyde followed by alkali.

Pinaverdol is p-toluquinaldinquinoliniummethylc aninbromid.

Pinac rome is p-thoXyquinaldin-p-methox quinoline-ethylcyaninebromid.

lavazine is one of the few important dyes belonging to the small class of pyrazolone dye-stuffs and is a dye similar to tartrazin. f

In the photographic process according to the present invention, the two superimposed light-senstitive surfaces 1 and 2, Fig. 1, are supported by separate backngs of glass or transparent films 3 and 4, respectively, as commonly employed in photographic proc- 'esses or, as shown in Fig. 2, they are both erably on separate backings placed face-toface, as shown in Fig. 1, and are simultaneously ex osed in the camera, the front surface 1, t at is to lsay the one which is first acted u on by the incident light being prepared rom the ordinary non-color-senslsitized or not, is acted upon by the incident light without the interposition of any colorscreen or filter and, in the case of a nonspeciall -sensitized surface, will be particularly a ected by light from the blue end of the spectrum and only slightly or comparatively slightly by light from the red end of the spectrum. The red rays, however, together with some green and blue, will pass through the front surface and will operate upon the rear surface which is specially sensitized as above described.

Color-images can then be produced from the two negatives thus-obtained whether on separate backings or on a single backing, either by toning or staining the negative images themselves or positive images obtained therefrom, or in any other suitable way. The colors preferably used are, say, orange-pink or some other color toward the red end of the spectrum and blue-green or some other color toward the blue end of the spectrum. Whether the negatives themselves are being colored or whether an opaque positive Yis in question, the negative image nearer the lens or the positive image produced from it, will be colored orangepink and the other negative image or the corresponding positive image will be colored blue-green.

Where two transparentpositives are to be used to ether, for example for cinematograph lms as pictures or transparencies viewed by transmitted light or as lantern slides the positive image produced from the negative that was nearer the lens will be colored orange-pink and the other bluegreen.

In either case the coloring may be effected in a toning bath or by staining applied to the negative or positive as the case may be. After coloring, the negatives, such as 6 and 7 Fig. 3, or positives are mounted in register on a single backing 8 or, in the case of cinematograph films, they are suitable for simultaneous individual exposure to be superimposed in register on the screen onto which they are projected.

Any suitable means may be employed for toning or staining the two negatives or positives, the colors being adjusted t0 the coloreffects desired in accordance with the subject under treatment.

The marked difference of color values ohtained by the use of the special sensitizer aforesaid, leaves room for considerable manipulation of the colors in the toningor staining-bath, so that the depth of color of either plate may be modified as requiredto obtain a proper balance according to the color effects desired and according to the subject under treatment. This balance can only be judged by the operator for each Subject, and will depend largely upon individual taste, but the fact that 'a large difference of color value is obtained by means of this invention leaves scope for the desired I manipulation.

For quick work, the employment of two panchromatic plates or films prepared with the special sensitizer aforesaid is preferred.

If one print is on paper and the other on a transparent material, the transparent print will be superimposed upon the opaque print in register therewith in the relatlve positions indicated in Fig. 3, and the two may then be mounted in any desired manner. With practice a colored photographic print having considerable resemblance to nature can thus be obtained.

Although plates, such as 3, 4 and 5, have been referred to, obviously films may be employed in their. place, and also the nished product may be made as a transparency suitable say for cinematograph projection, b utilizing transparent material for both prints.

In applying the invention to cinematography,l the celluloid portion of the films may be of ordinary manufacture but the sensitizing material for one or both of the films should preferably be made as aforesaid. The two films can be run simultaneously through the camera for exposure, as, for example, with the sensitized surfaces in contact as shown in Fig. 1, and the subsequent treatment will be the same as has already been described with reference to plates. The final product, however, will be a transparency, with the parts in the relative positions of Fig. 3. Instead of toning the final product to different colors, the film may be stained the desired colors on opposite sides though, for the production of ordinary colored photographs the process as first described may be used. For cinematograph work the staining is possible because of the persistency of vision and the strong light behind the film.

The present application is a division of my application Serial No. 309,455, led July invention and desire atent 1s:-

What I claim as m to secure by Letters 1. A color-'photography process, compris,

ing simultaneously exposlng two superimposed sensitized surfaces whereof at least one is color-sensitized with pinacyanol, pinaverdol, pinachrome, flavazine and ammonia mixed with water.

2. A color-photography process comprising making a simultaneous exposure of two superimposed sensitized surfacesl of which the one remote from the object is colorsensitized withpinacyanol, pinaverdol, pinachrome, iiavazine and ammonia mixed with l Water. 3. A color-photography process compriscolor-sensitized with pinac anol,pinaverdo1 pinachrome, avazine an ammonia. mixe with water.

4. A color-photography process' .comprising simultaneously exposmg without a light lter or other color-screen two superimposed sensitized surfaces placed face-to-fac'e of which the one nearer the incident light is an ordinary-non-color sensitized surface and he other 1s a panchromatic sensitized surace.

In testimon whereof I aiix m si nature.

WI IAM FRIESE-G E NE.

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