Most methods used for determining the modulation transfer function of a photographic film require that a sinusoidal intensity distribution object be imaged on the film and the resultant effective exposure modulation compared to the object modulation. This paper describes the investigation of the feasibility of generating a sinusoidal intensity distribution from a crenelate pattern by incoherent spatial filtering using non-monochromatic radiation. Using a Kodak Ektar Enlarging Lens (focal length of 100 mm.) at f/8 it has been found that images may be spatially filtered up to 30 cycles/mm while maintaining a modulation of 62# in white light (tungsten illumination). At this frequency the third harmonic is about 10# of the D.C. level in white light and approaching 13# in blue (Wratten Filter #47) radiation. The magnitude of the third harmonic appears to limit the range of this system from 5 "to 30 cycles/mm if the user can tolerate a 10# third harmonic. At frequencies lower than 30 cycles/mm the third harmonic was considerably less. The average energy required in the object plane for this particular type of system is 70 lumens/cm2- steradian. All work on this project was carried out using a General Electric DVY, 120 volt Quartzline lamp as a source and Kodak Panatomic X film (ASA 40).
Library of Congress Subject Headings
Photographic optics; Optical transfer function
Department, Program, or Center
School of Photographic Arts and Sciences (CIAS)
Gray, Joel, "Generation of sinusoidal test images by incoherent spatial filtering" (1970). Thesis. Rochester Institute of Technology. Accessed from
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