GB295643A - Improvements relating to kinematography - Google Patents

Abstract

295,643. Bernardi, A., Burger, P. L., and Auto Natural Color Films, Ltd. April 14, 1927. Colour kinematography.-A kinematograph projection system using films of the kind in which each normal picture space is occupied by triple pictures arranged two side by side of half the usual depth and the third midway above or below the other two, utilizes a group of three rhomboidal prisms, or optically equivalent elements, by which the beams are spaced apart to enable projection lenses of normal size to be used. The photographs may be taken with an ordinary kinematograph camera having lenses triangularly placed and a gate divided into three spaces by webs forming a T-piece, but such small lenses are insufficient for projection purposes. The rays of light from the source a pass through a condenser c to the film gate, before which small angled prisms d are placed to compensate for the uneven distribution of the light. Beyond the gate and before the projection lenses g<2>, b<2> are placed prisms g<1>, r<1>, b<1>, with their entrance faces coplanar and arranged as shown in Fig. 4. To enable the exit faces of the prisms to be increased in size so as to cover the projection lenses and at the same time to ensure that the pictures are centrally arranged with reference to the prisms, the arrangement shown in Figs. 9 and 10 is provided in which the prism B is fitted into sloping recesses cut in the prisms R, G, the pictures ra, ga, ba being on the centre lines of the prisms. In a modification of this construction the inserted prism has its upper angular edge removed slightly to avoid crowding the exit beams into the adjacent corners of the prisms. The colour filters are mounted in the gate as described in Specification 295,662.