Photostory #198: Space Clock for Space Age
National Film Board of Canada
February 24, 1959
Canadian Museum of Contemporary Photography fonds, National Gallery of Canada Library and Archives
The moon camera is designed to hold the moon fixed against a background of stars for a 10- to 20-second exposure. A circular filter intercepts the image of the moon reducing its brightness one thousand times. At the same time the filter tilts at a uniform speed causing the image of the moon to be displaced backwards the exact amount of its forward motion through the stars. In the photograph above each star is identified with its special catalogue number. The stars have been accentuated for the purpose of reproduction.