Optimizing the Compound-Reflector Framing Spotlight

For many years, framing spotlights have been designed following a tradition of using elliptical-reflector systems. The deficiencies of such light-collecting systems have been analyzed, as have those of the lens systems used, the framing shutters, and the useful life span of color media exposed to the high radiant-energy concentrations in those spotlights. A compound reflector is described which far surpasses the light collecting efficiency of the earlier designs. Also, a vari-focal lens system has been incorporated, permitting variable field coverage with a single lighting unit. An improved framing shutter and its design, construction materials and location are described. To protect the color media used with this spotlight, the distribution of the radiant energy has been evened out over the area of the color gel. The harmful infrared radiation is kept away from the fragile filter material and it is directed toward a heat sink through the use of a hot mirror. Methods for measuring the deterioration speed of a color gel exposed to a high-intensity source have been developed and are described. In the new design, the useful life span of the color media employed is greatly increased. A complete description of the design of the new framing spotlight and of the action of its compound reflector is given.

Print ISSN

0036-1682

Published

1978-10

Content type

Original Research

DOI

10.5594/J16662