US923019A - Color photography. - Google Patents

Description

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EDGAR CLIFTON, OF ENFIELD, ENGLAND.

COLOR PHOTOGRAPHY.

To all whom it may concern:

Be it known that I, EDGAR CLIFTON, a subjcct of His Majesty the King of the United Kingdom of Great Britain and Ireland, residing at 3 BeaufortVillas, London Road, Enfield, in the county of Middlesex, England, have invented certain new and useful Improvements in Color Photography, of which the following is a specification.

This invention relates to improvements in the methods of color photography known as the two color process; the three color process; and the four plate process whether this latter is carried out with four colors in the ordinary sense, or with three colors in the ordinary sense and a monochrome or key All these methods consist in superimposing transparent photographs or photographic elements so that the assemblage gives more or less natural color effects, the superimposed photographs or photographic elements being mounted together so as to form a transparency, or being mounted on white paper, or other suitable basis, for viewing by reflected light.

The invention is directed to obtaining in a completed heliochrome a truer color effect than is (in most cases) practicable by merely superimposing the usual developed reliefs or so called colored carbon transparencies or elements as obtained by the ordinary and well known methods.

WVith this end in view the principal improvements according to the invention consist, firstly; of a system of temporary reconstitution of the color efiect with after staining if required so as to produce a heliochrome while each element is on a temporary support, and secondly; of viewing such a temporarily constituted heliochrome under conditions which eliminate the disturbing influence of the thickness of the supports and their separation, separation being necessary if the color elements are wet.

The following description applies to a three color photograph, but it will be understood that the invention is equally applicable in the other cases above referred to.

In carrying out the invention I make individual components of the composite heliochrome, z. e., the various photographic elements or the various individual photographs as reliefs in colored gelatin by what is commonly known as the carbon process. In order, however, to obtain a truer efiect than would be obtained by merely superimposing Specification of Letters Patent.

Application filed January 15, 1909.

Patented May 25, 1909.

Serial No. 472,445.

the three usual developed reliefs or so called colored carbon transparencies or elements as obtained by the ordinary and well known method (such color transparencies being ordinarily on glass, or the like, as for example, celluloid, talc, hardened gelatin or a similar transparent material) I adjust or regulate the tints of these in the following manner :To increase the intensity of any one transparency formed by the so called carbon process on glass, whether plain or collodionized, I soak it in a solution of a dye of similar color or tint and rinse away the excess of soluble dye. To locally increase the intensity of any one transparency or element, I apply locally a solution of a dye having a similar color or tint, either by means of a brush or mop on the one hand or by means of a spray apparatus, air brush apparatus, aerograph, or the like, on the other hand, and after such local treatment the excess of soluble dye must be rinsed away. In other cases I alter or modify the tints of the carbon reliefs by treatment with dyes of a different color. Thus the yellow relief may be tinged with a red or orange or blue dye, the blue relief or element may be treated with a solution of yellow dye to render it greener and again the red relief or element may be rendered more purple by treatment with a blue or violet dye. It will be understood that there are many soluble color dyes which would be suitable for such general, or local, intensification, or alteration, or modification, of the tints of the carbon reliefs, and also that the strength of the color dye solutions is widely variable under diflerent conditions, but the following, which any one skilled in the art can readily vary to suit any particular case, may be taken as typical examples. As the blue dye: indulin blue, Lyons blue, or I-Ioft'manns violet (blue shade). As the yellow dye: naphthol yellow, or berberin. As the orange dye: chrysoidin, or aurin. As the red dye: alizarin (with alumed reliefs), cochineal red (or carmin with am monia), or magdala red.

Approximately the strength of the dye solutions would be 25 parts of the dye per 1000 parts by weight. Ordinarily the solvent would be water but a variable amount of alcohol may be added which need however seldom if ever, exceed one half.

My treatment with dyes is not an operation of the nature of ordinary retouching,

but part of the system of temporary reconstitution of the color effect so as to produce a heliochrome while each element is on its said temporary support, and of viewing the temporarily constituted heliochrome under conditions which eliminate the disturbing influence of the thickness of the supports and their separation; separation being necessary if the color elements are wet. In order to attain this end in viewing the temporarily constituted heliochrome I proceed as follows. The constituent elements or reliefs prepared by the so called color carbon process having been developed, in a usual manner in warm water and each being on a plate of glass previously waxed (or French chalked) and, if considered desirable, also collodionized, the reliefs are arranged one over the other, 2'. 6., are superimposed, in a composite frame consisting of a sutlicient number of carriers (for a three color photograph, three carriers would be provided) arranged over each other and provided with adjustments controlled by convenient handles for bringing the several photographic elements exactly over each other or in register, but as the adjustment has ordinarily to be made while the reliefs are damp or wet'the plates in that case must not be in absolute contact.

In the above mentioned assembling of the photographic elements, glass is mentioned as the support, as under ordinary conditions it is convenient, but celluloid or the like whether as a thick plate or as a thin film may be used, or indeed talc. Obviously if a thin flexible film is used it must be strained in its frame. In case celluloid is used the collodion coating must be omitted. The said separation, when the reliefs are damp or wet, the fact that the substance of the glass intervenes, and the distance between the eyes of an observer, all tend to render the assembled images confused or out of register. In order to obviate this inconvenience and to enable the effect of the color combination to be properly judged, I prefer to view the temporary combination by a telescope adjusted at a convenient distance.

Inspection having taken place any required adjustment of the colors is made as specified above, and further inspection followed by color adjustment may be repeated as often as may be considered necessary.

In the telescopic axis I may interpose such reflectors as are desirable for shortening or folding the range and in practice I prefer to bring the eyepiece (which is preferably of the type known as a diagonal eyepiece) of the telescope near to the registering frame, so that the observer shall have the adjusting handles of the frame immediately before him. The color elements when finally adj usted for tint and color depth may then be successively transferred to a prepared paper by any proceeding well known to color printers by the carbon process, but I prefer to use a thin translucent paper or a film of celluloid or the like, prepared or surfaced with gelatin after the manner of double transfer paper as the permanent support of the assembled carbon color elements, as by this course the obtaining of register is facilitated. The thin translucent paper or celluloid or the like bearing all the carbon color elements may be stripped from the final glass plate or other temporary support when all is dry, so as to yield a transparent heliochrome. Or while the assemblage is on the glass or other support it may be backed up with one thickness of paper or more to form a thin or thick support in the manner well known to carbon printers.

To facilitate the exact joining together or registering of the constituent parts of the composite heliochrome I adjust two objective crosses or more or an equivalent such as black crossing lines on a white disk in the scene so that the images of the cross lines come conveniently to the margins or corners of the negative plates. If while viewing the temporarily constituted heliochrome any of the reliefs appear to require reducing, this may be done by scraping or rubbing down in manner well known.

In the above description when I refer to carbon prints or color elements, I also include prints in colored Q'elatin produced by the W'oodbury type or stannotype methods or the like, such prints being in their nature mechanically reproduced replicas molded from an original gelatin relief or print.

Having thus described my invention, what I claim and desire to secure by Letters Patent is 1. T ie method of producing a heliochrome with true color effect, which consists in preparing a plurality of colored carbon transparencies, super-imposing the same to temporarily constitute the heliochrome, and adjusting the combined effect by modifying any of the tints or color depths of any or all of said transparencies.

2. The method of producing a heliochrome with true color effect, which consists in preparing a plurality of color carbon transparencies, and treating one or more thereof with a dye of a corresponding color to intensify its or their color effect.

In testimony whereof I atlix my signature in presence of two witnesses.

EDGAR CLIFTON.

W'itnesses HENRY CONRAD Huron, LEONARD CoULsoN.