A Higher-Efficiency Condensing System for Picture Projectors

F. E. Carlson

In motion picture projection optical systems for tungsten-filament sources, the condenser design is such that the source is imaged well ahead of the picture aperture. This position is dictated by considerations of uniformity of screen brightness. It is not the optimal position from the standpoint of utilization of light, for it entails losses at the aperture. At the best position for efficiency, the degree of brightness uniformity is inacceptable because of the non-uniform brightness of the source. The paper describes a method for reducing such losses without sacrificing picture quality.

Print ISSN
Published
1938-08
Content type
Original Research
DOI
10.5594/J12947