Abstract

The procedure outlined by Matejec, Photograpische Korrespondenz, 104, 153 (1968), fixation in a thiosulfate-sulfite solution to which AgBr has been added, followed by washing in 1% sulfite solution, and development in a metol-sulfite-AgNO3 developer, was tested on seven silver iodobromide emulsions, each of a different average grain size. Samples were exposed, and processed by chemical and physical development. Matejec’s results, equality of threshold speed with post-fixation physical and chemical development, could only be realized with a very fine grain emulsion and high intensity exposure. It was found that the efficiency of physical development, relative to chemical development, is inversely related to grain size. The intensity of the exposing light was found to be an important factor which had large effects on the efficiency of physical development for the three emulsions tested. Samples of Kodak Spectroscopic Film, Types 103-0 and 103-F, were exposed by white light and developed in a time-temperature series, chemically and physically. The dye in the type F emulsion retarded post-fixation physical development and greatly increased fog, while decreasing gamma. A positive-type silver iodobromide emulsion dyed with 3,3',9-triethyl-5,5'~dichlorothiacarbocyanine bromide was exposed by white and by blue light and processed chemically and physically. Development retardation was identified with chemical and post-fixation physical development. Contrast decreased and fog increased as the dye concentration approached 85% of monolayer coverage, for both chemical and physical development. However, fog was much more severe on the physically developed films. Matejec’s reported developer pH values were found to be in error. For better results, the solutions should be used as mixed, and not modified to pH 6, the value reported in the article. Sensitivity and fog suffer when the developer solutions are modified to pH 6. The color of the safelight used during the development step in physical development can have a significant effect on the fog density obtained when Matejec’s developer is used.

Library of Congress Subject Headings

Photography--Developing and developers

Publication Date

1973

Document Type

Thesis

Department, Program, or Center

School of Photographic Arts and Sciences (CIAS)

Advisor

James, T.

Comments

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: TR295 J47

Campus

RIT – Main Campus

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