Recent Developments in Background Projection

The complexity of background projection is generally known. It has been widely applied in cinematography with great success. A new field offers tremendous opportunity, namely, still photography. Two types of background projector are described, one to cover screens up to 10 × 12 feet, the other up to 13 × 18 feet. The following elements of the problem are discussed: — (1) The spot condition: what causes it and how to reduce it, even to eliminating it entirely. (2) Screen texture: nitrate or acetate base sprayed with polarising material for diffusion (flatlight type); the new Trans-Lux screen of the high-transmission type. (3) Theory of light refraction through screen. (4) Light brightness vs. diffusion of screen. (5) Optical conditions, condensers, objective lenses, etc. (6) Light-source: brightness vs. current, behavior of different types of carbons; spectral consideration in color projection. (7) Cooling the slides with refrigerated air. (8) Electrical and optical characteristics, remote control of arc, douser, air-cooling system.

Print ISSN

0097-5834

Published

1938-05

Content type

Original Research

DOI

10.5594/J16577