An increase in gamma of fourteen can be obtained with a loss of one-third stop in speed by treating a silver halide film in a ten to thirty percent solution of hydrogen peroxide for five to fifteen seconds and heating it in sixty to ninty degree centigrade steam. Light refracting oxygen bubbles are formed in the emulsion proportional to the amount of silver metal present. Increasing the concentration of hydrogen peroxide was found to decrease speed while increasing gamma. Temperature of the steam was not a significant factor for speed or gamma. Increasing hardness of the gelatin, increasing peroxide immersion time, and increasing pH decrease the gain in gamma. Film samples fixed by non-hardening fixers yeilded the most uniform vesicular images.

Library of Congress Subject Headings

Images, Photographic; Photography--Films; Photographic emulsions

Publication Date


Document Type


Department, Program, or Center

School of Photographic Arts and Sciences (CIAS)


Francis, Ronald


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.S87


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