DE335088C - Process for the production of three-color over-the-counter photographic images by copying the three monochrome negatives obtained by color filter recording - Google Patents

Description

Process for the preparation of three-color reflective photographic images by copying the three 1monochrome negatives obtained by color filter recording on top of one another. In certain color photographic processes, the image of an object is thereby created makes it photograph sequentially on three panchromatic plates which colored behind orange-red, green and bluish-violet in the apparatus Color filters are arranged, and then three by means of the negatives produced in this way positive blue, red and yellow colored images layered on top of one another on an image carrier will. The means of layering and coloring these images are different; as is well known, they present numerous difficulties, particularly with respect to the close and accurate layering of the monochromes.

The procedure described below is also based on the three negatives produced behind color filters (orange-red, green and bluish-violet) off, but it uses the special one to generate the three positive monochromes Property of the gelatin-bromide silver emulsions that their two components, namely. on the one hand the silver salts and on the other hand the gelatin in different ways can be used to generate the colored 'individual images.

The image carrier can be made of opaque paper or the like or of transparent Glass, celluloid or the like. Consist. When using paper for the image support, the same is made waterproof beforehand in a known manner. * One such carrier is coated with a slow working I den bromide silver gelatin emulsion. i I. Generation of the blue positive image. The one obtained behind the orange-red color filter As usual, negative is copied onto this bromide silver gelatine emulsion. After this the generated image is developed and washed but not fixed, it will be in the dark chamber treated with three percent potassium ferricyanide solution, washed thoroughly and immersed in an iron salt solution with a certain amount of chlorvanadine added is.

Solutions of the following composition are expediently used A. Iron sulfate .....: ...... 5 g, Tartaric acid ............. xg, distilled water ....: roo cc. B. Ferric chloride ........... 5 g, distilled water ..... zoo cc. C. Vanadium chloride. . . . . . . . . q. G, distilled water ..... xoo cc. A mixture is produced from these which contains from A. 60 percent, from B. ao percent and from C. 20 percent.

The solution is composed in such a way that the resulting blue image one for the tone of the yellow and red color of the other pictures more correct Reproduction of the colors receives appropriate tone. The addition of vanadium chloride makes it easier the further treatment to produce the yellow image. II. Generation of the yellow Positive image. After the picture carrier with the blue picture in the darkroom washed and dried, what is produced behind the bluish-violet color filter is produced Negatively copied exactly onto the blue image. The exposure time is longer here, it is determined by experience. In general, this exposure time is six or ten times the exposure time for the blue image for an equivalent Negative.

The image is then developed in a developing bath, which cannot destroy the previously generated blue image. Alkaline developing baths accordingly should not be used. It is in this way on the image carrier in the bromine over gelatin emulsion, a black image overlying the blue image generated, which corresponds to the yellow image. To translate this into a yellow picture, The image carrier is washed without damaging the underlying blue image and fix the picture with hyposulfurous soda, as usual, whereupon the picture it is washed thoroughly to remove any trace of hyposulphurous soda. These and the following treatments can be done in daylight.

Then the picture is immersed in an iodine bath, which z. B. from g cc iodine tincture, x g iodine potassium and ioo cc water and for use with 2 volumes of water is diluted. In this bathroom, the black yellow image becomes white while the blue image remains unchanged.

After washing out, the image becomes a five percent aqueous solution immersed in tartaric antimonyl potassium (tartar emetic), which gives the yellow color a gets more or less yellow color, while the blue image remains unchanged. In addition, when paper is used as an image support, the parts of the same which came into contact with the iodine solution and thereby colored bluish-black were white again.

After washing out, the sample is finally placed in a third bath brought, which consists of an aqueous mercury chloride solution. These are weak (i or i '/. "percent) solutions are most suitable; this is where the picture washed again. `` In the picture there are now blue, yellow and green shades, as they appear on the photographed object itself. To the second exposure of the bromosilver gaiatine emulsion to produce the yellow image to make the yellow areas particularly prominent, the blue image can be broken down into lines or points by a grid when copied as is already known for multicolor photography. The through the Lines of the grid covered areas of the emulsion are then during the first Exposure not struck by light, so that the emulsion remains unchanged in these places remains and is then used with better effect in the second exposure. III. Generation of the red positive image. After the yellow-blue picture has dried, it is dipped in a chromate solution and then dried in the dark. Appropriate double chromic acid ammonia is used in aqueous solution, the percentage of which known to change according to the temperature conditions.

Then the picture is under a mirror-inverted slide, which was produced using the negative generated behind the green color filter, exposed to a red imbibition image by immersion in an aqueous red color solution over the yellow-blue image. The image remains in the dye solution as long as until the red image has the desired intensity. As a red color solution is used preferably a 10% solution of Pinatypie Red F from the inking units vorm. Master, Lucius & Brüning in Höchst a. M. used with the addition of a few drops of ammonia. The solution is diluted with water as necessary before use.

Claims (1)

PATENT CLAIMS Process for the production of photographic three-color overhead images by copying the three monochrome negatives obtained by color filter recordings, characterized in that a bromide-silver gelatin emulsion layer is used as the only light-sensitive and re-light-sensitive layer in the following manner a) First, the blue image is used by copying the bromine-silver gelatin negative layer under the blue-silver gelatin layer , Developing (without fixing) and converting it into an iron blue image. b) After drying, the yellow negative is copied onto the bromosilver gelatin layer containing the blue image after prolonged exposure, the latent image is created with a non-alkaline developer and converted into a yellow image overlying the blue image with iodine mercury. c) After the yellow-blue picture has dried, the gelatin of the picture is made light-sensitive by means of a bichromate solution and a slide of the red negative is copied on in register. The copy is developed into the red image over the yellow-blue image by imbibing with red dye solution.