GB246154A - Process for obtaining kinematographic multi-colour photography - Google Patents

Abstract

246,154. Heide, E. Wolff-. Jan. 14, 1925, [Convention date]. Void [Published under Sect. 91 of the Act]. Colour kinematography.-In the production of kinematob aph multicolour pictures by the additive process, each of the separate partial pictures is coloured with more than one colour by special treatment of the transparent parts and the silvercontaining parts of the positive film. A negative film is first produced, divided into two series of partial images recording respectively (a) red, yellow, and blue-violet and (b) orange, yellowgreen, and blue, and a positive is printed therefrom. In the positive partial pictures, the blue and violet colours are represented by half-tones, and the remaining colours by transparent areas in their respective pictures. The colours may be applied to the positive in various ways. For example, the positive may be treated with a dilute iron blue bath, which imparts a blue colouration to the silver portions, and also differentially hardens the gelatin layer in these portion in proportion to its silver content. A colouring-bath such as pinatype yellow is then applied, which dyes the transparent parts yellow, and the silver-containing parts blue-green. The partial pictures on the film are additively superimposed by projection through a rotating colour disc, which alternately imparts violet and greenish-blue colours respectively to the red and to the green partial picture. The film may be differentially hardened by baths, other than iron blue, which do not colour the film blue; but in this case the blue colour must be contained in the rotating colour disc. This disc may be dispensed with if the pictures on the films are themselves coloured in the primary colours. For example, the positive may be treated as described above in an iron blue bath, and the red partial pictures be then treated in a bath which yields a red colour in the transparent portions and a redviolet colour in the silver-containing portions. The green-blue partial pictures may be similarly coloured. A modification is described in which the positive is resensitized with bichromate and differentially hardened by exposure to light before colouring; and a further modification is described in which the positive is first dyed with the primary colours, which are then mordanted, thereby producing differential hardening of the gelatin, whereafter the film is treated with a dye such as pinatype yellow.