A system for generating custom variable neutral density filters has been built, characterized, and demonstrated. The desired densities for a neutral density filter are entered into the controlling computer as a function of distance. The program which generates the filter density profile is designed to vary the exposure time by controlling the velocity of the film as it moves under a slit aperture. A custom illumination system was designed and built to provide constant lamp output. The technique can provide the film with the exposure necessary to produce a given density profile.
Library of Congress Subject Headings
Photography--Light filters--Design and construction--Computer programs; Photographic optics--Computer programs
Department, Program, or Center
School of Photographic Arts and Sciences (CIAS)
Gary A. Dir
Hermanson, Gregory A., "The production of custom variable neutral density filters using film and a computer controlled imaging device" (1985). Thesis. Rochester Institute of Technology. Accessed from
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