GB222173A - Improvements in and relating to stereoscopic cinematography - Google Patents

Abstract

222,173. Daponte, D. L. March 29, 1923. Printing - apparatus.- Stereoscopic effects in kinematograph projection are produced by alternately diminishing and increasing gradually the intensity of illumination or sharpness of definition of the image of one member of a plurality of i-tereoscopieally related views. In one example when taking the negative from which the positives used in projection are subsequently printed, a series of views are taken in succession in which the views presented to one eye are of gradually diminishing exposure while those presented to the other eye are of gradually increasing exposure, the variation being effected by a graduated screen or by stopping down one lens and increasing the aperture of the other. The speed of the emulsion of the film may also be varied for the same purpose. When printing positives from a uniform negative film, similar means for varying the illumination of the positive may be used. A single film having the right- and left-hand views superimposed is made in a printing device fitted with two lenses 29, 29<a>, reflecting prisms 30, 30<a>, and a lens 31 to produce an image on the film 32, before which rotates a shutter 33 having graduated sections arranged alternately in addition to a shutter for presenting the right- and left-hand views alternately.