US1676580A - Photograph and method of making the same - Google Patents

Description

July 10,1928. 1,676,580

5. E. SHEPPARD PHOTOGRAPH AND METHO.) OF MAKING THE SAME Filed Aug. 27, 1925 Emulsion ZqgerZ 5 jaaque whitish image.

ZDazJE blue Zrammifiiqg .szgvporl".

Emu/Lswzv layer 2 V ,w. mm

v INVENTOR,

SamueLESJzep am) Patented July 10, 1928.

UNITED STATESQPATENT [oncm sAmuEL E. snErrAnn, E nocH sTEn, NEw onx, A ssIGNon '10 EASTMAN xonAz COMPANY,"OF noonEs'rEn,

NEW YORK. A CORPORATION 01 NEW YORK:

rno'roonArn AND METHOD oE MAKING THE sAM Application filed August 27, 1925. Serial No. 52,776.

This invention relates to photography and more particularly to the formation in a single process of a photograph that can be used both asa negative and as a. positive.

To obtain this result, I use as the support for the photograph a material which visually is very dark and indeed may approach opacity while it is capable of transmitting considerable light of wave lengths to which ordinary photographic emulslons are sensitive. In an emulsion on such a support is formed a photographic image which is preferabl whitish by reflected light. While it is ofconsiderable density so that the image is negative by transmitted light, it is positive when viewed by reflected light.

Reference will now be made to the accompanying drawing in which Fig. 1 isa section on an enlarged scale of one embodiment of my invention and Fig. 2'is a section of a second embodiment.

In the example shown in Figure 1, the base or support 1 is made of a light transmitting material such as glass or celluloid, in which there is incorporated dye or light absorbent material preferably of very dark blue color. When viewed by ordinary light, it appears to be so dark as to be almost or quite opaque. It is, however, capable of transmitting light in the blue and violet region of the spectrum. Upon this support is an emulsion layer 2 which ispreferably of the ordinary gelatine bromide type. In the second embodiment of my invention, the base 4 is transparent but has upon one surface a layer 5 which may be of gelatine or other colloid in which is incorporated a dyehaving the properties mentioned, and upon the support which consists of these two layers there is placed an emulsion layer 2.

This photographic element is exposed .in a camera or other photographic apparatus to a light image and is treated in photographic baths so as. to transformtheafi'ected particles into a permanent image 3, which is preferably of a whitish color and of.sufl'icient opacity to be used as a printing image for the making of photographic cop1es, 'and where I use the term opaque I mean an opacity of this extent:

This image may be formed in one of several ways. One method is by development in a bath of the type well known in the literature for the making of images by the Ferrotype process. A- typical method of procedure is as follows.-

The following baths are prepared:-

- Bath A,

. Parts. Sodium thiosulfate 4 Water 20 Bath B. 6

Sodium carbonate 200 Sodium sulphite 100 Hydroquinone v 12.5 Potassium bromide 29 Bath. (A) 25 Vlarmwater to 1000 In the above formulae the parts are by welght. Bath B is allowed to stand for two days and the clear solution is ured off for use. The exposed sensitive p ate is developd in bath B until the high lights and halftones are well out, and the plate is, then rinsed in water and fixed in Bath A. Both the development and fixing take place in a very short time at normal temperatures. The resulting image is whitish in appearance and appears as a positive with a dark ground.

when viewed as any ordinary photograph.

Many modifications of this bath have been described in the literature and may be used in carrying out the process.

A second method is by development in any well known developer such as those of the Pyro or M. Q. type, no one formulabeing preferred, followed by the ordinary fixing bath of sodium thiosulfate and by a bleach bath such as the following:

Potassium bromide 23 Mercury bichloride- 23 Water to 1000 Part3.

as for military purposes." .The image obtained can be viewed atonce-without the appears as a positive upon: adarkground,

rapid in action and can be carried on in the air and the completed photograph, if on'film,

can be dropped to the earth and viewed within a few minutes after exposure.

Letters Patent is:

1. A; photograph comprising a support that is absorptive of a high percentage of visible light rays but is capable of vtransmitting photographically-actinic light rays, and a layer thereon containing an image that is substantially opaque but is of a light appearance by reflected light, whereby the p otograph is capable of use as a photographic printing negative by transmitted light, but the image appears as a positive upon. a dark ground when viewed by reflected light.

2. A photograph comprising a support that transmits only photographicallyactinic light in a limited portion of the spectrum and that appears very dark and a layerupon one surface of the support containing a photographically formed image that is substantially opaque but is of a lightappearance by reflected light.

3. The method of forminga direct positive capable of use as a photographic printing negative that comprises the exposure to a light image of a sensitive layer carried on a support that transmits principally photographically actinic light and the transformation of the sensitive portions thus exposed into an image that is substantially opaque'to transmitted light but is of a light I a light image of a layer "containing sensitive silver salts carried on a support that transmits only photographically actinic light and the transformation of the exposed silver salts. into an image that is of a light appearance by reflected light but substantially opaque to transmitted light.

Signed at Rochester, New York, this 19thday of Aug, 1925.

SAMUEL E. SHEPPARD

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