GB262876A - Improvements in stereoscopic kinematography - Google Patents

Abstract

262,876. Cairns, A. Sept. 22, 1925. Stereoscopic kinematography; periscopes.-Projection screens are arranged in a hall so that spectators can see directly only one screen at a time, and the right and left members of stereoscopic pairs of kinematograph images are projected respectively on to the two screens; the spectators are provided with viewing means enabling them to view one or both sets of images indirectly and to bring the two sets of images into register. The screens may be at opposite ends of the hall, the floor of the hall being sloped downwards from the middle to each end. Half of the seats ma.v be arranged to face each screen and the operators' box may be suspended over the middle of the hall. The viewing means may consist of a plane mirror, of apparatus of the type described in Specification 2119/95, or of a periscopic apparatus. The Figure shows a periscope comprising a plane mirror m and convex lens c in a sliding tube t, and a concave lens c<2> and an adjustable mirror m<2> in a tube t<2> held friction tight by a clamp p secured by an extension p<2> to a handle or bracket. The adjustments enable the images viewed indirectly to be registered with those viewed directly, and the images viewed indirectly are projected so as to appear inverted and laterally reversed when viewed directly. The images view indirectly may, when the viewing apparatus produces inversion or lateral reversion, be corrected by prisms &c., or may be projected so as to appear to direct vision inverted or laterally reversed. Titles &c. may be correctly projected where the images are laterally reversed. Specification 117,030 also is referred to.