GB656908A - Optical arrangement for colour photography and cinematography - Google Patents

Abstract

656,908. Optical systems for colour photography. CRISTIANI, L., BORELLA, L., GAMBAROVA, E., and MASCARINI, V. M. Aug. 6, 1948, No. 20875. Convention date, April 30, 1941. [Class 97 (i)] A system for colour photography and cinematography and for the projection of the photographic images obtained thereby comprising a multiple prism which, in taking, decomposes the rays from a forward optical system into a plurality of variously deflected beams and directs them through colour filters to a rear objective forming a plurality of adjacent images is characterized in that the multiple prism is located in the exit pupil of a telescopic or substantially telescopic system comprising a field lens and forming the said forward optical system. As shown, an objective 1 forms an image in the plane of a diaphragm 2, light from which is rendered parallel by lenses 3 and 4 before falling on a prism system 5 which divides the incident light into four beams which intersect at an objective 7 focusing four identical images in the plane 8 of a photographic film. Each of the divided beams passes a colour filter 61 and a diaphragm 611, the four diaphragms being each independently adjustable to vary the intensity of each beam. Plano convex lenses 6 may be inserted in the beams to maintain the achromatism of the system. The prism system 5 may comprise two prisms enclosing a liquid of high dispersive index but of substantially the same refractive index as the prisms. The system may be used in reverse for.projecting four colour images in superposition on a screen. Specification 528,588 is referred to.