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
Department, Program, or Center
School of Photographic Arts and Sciences (CIAS)
Long, Ira and Turner, Alan, "Image Spread Characteristics of Vesicular Films" (1972). Thesis. Rochester Institute of Technology. Accessed from
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