GB409287A - Improvements relating to the production of colour-photographic copies on sensitized material comprising a plurality of layers - Google Patents

Abstract

409,287. Colour photography. GASPAR, B., 38, Innsbruckerstrasse, Sch÷neberg, Berlin. July 21, 1932, No. 20639. Convention date, July 29, 1931. [Class 98 (ii).] In copying multicolour master images on to sensitized material comprising superposed layers, the copying material is exposed to different coloured lights and the relative intensity or period of action of the different lights is varied to compensate for variations in the sensitivity of the layers. Exposure may be made by contact or optically and behind a coloured negative or diapositive or a multi-colour screen master image. In one form, the material is exposed to light from a lamp fitted with a slide or disc carrying different filters and the time of exposure to each coloured light is adjusted to give correct exposure for each layer. The appropriate exposure times are determined by exposing a test strip of the multi-layer material below a scale of graduated opacities and through filters similar to the copying filters. The copying filters may also be combined with a grey screen. In a modification, the layers are exposed simultaneously to differently coloured lights, the intensity of which is adjusted, e.g. by shutters, or by grey dry or liquid filters or by altering the spacial adjustment of the different light sources. A source of white light may be split into different coloured lights by optical elements such as prisms, reflectors, filters and the different colours reunited. An electric globe may be covered with two or more filter sectors and the relative intensities adjusted by partially covering or shading the different filter sectors. Adjustment is made in accordance with a test strip exposure and may be modified to give any desired predominance of colour. Specification 408,991 is referred to.