A Polygonal Floodlighting Mirror

The reasons that make it desirable for the motion picture studio to employ large floodlighting units are the high levels of illumination required for high speed photography and the peculiar sensitivity characteristic of the photographic film. These two factors indicate the use of a high intensity arc, and there is a national tendency to take the high intensity searchlight just ae it has been developed for military service and by refocusing got a beam of wide spread. The defects of this method are illustrated and it is shown that a more suitable optical arrangement is to use apolygonal mirror rather than aparaboloid. The method ofcomputing the dimensions of the polygons is given along with data on a photometric comparison of the two types of reflectors.

Print ISSN

0096-6460

Published

1927-07

Content type

Original Research

DOI

10.5594/J06617