An altered Bausch and Lomb metallograph, in conjunction with a 150 watt high-pressure Xenon-arc lamp, was used to image 50µm uniformly illuminated round spots on several vesicular emulsions and a silver emulsion to determine image spread characteristics with increasing exposure times. Vesicular films tested include Kalvar Types 16, 143, 163, and 164, a sample of Xidex Blue and a high resolution aerial film. It was found in all cases that image spread was more profound in vesicular films than in the silver film tested. It was also found that ten minute and twenty minute periods of time between exposure and development had varying effects on the final image size usually causing the image to shrink with increasing time interim. Many observations were made including an adjacency effect, "latent images" under the microscope, and what might be described as a three-dimensional view of the vesicle distribution in the image.

Library of Congress Subject Headings

Images, Photographic; Photographic emulsions; Photography--Films--Testing

Publication Date


Document Type


Department, Program, or Center

School of Photographic Arts and Sciences (CIAS)


Todd, Hollis


Note: imported from RIT’s Digital Media Library running on DSpace to RIT Scholar Works. Physical copy available through RIT's The Wallace Library at: TR283.L66


RIT – Main Campus