An investigation has been made on the interaction effect of the hydrogen ion (pH level) and the bromide* ion on the development response variables. A pH range of 8.8 to 11.2 and bromide ion concentration levels of 0.125 to 8.0 grams per liter were used. The hydrogen ion-bromide ion interaction as tested on Kodak film type Fine Grain Release Positive 5302 had a significant effect on the rate of development, gamma, and photographic film speed in buffered metol-hvdroquinone, phenidone-hydroquinone, and hydroquinone sulfite developers. The trend for all developers was a decrease in the effect caused by the bromide ion with increasing pH level. The variation in the bromide effect with pH level was the greatest for the hydroquinone-sulfite developer. A rate equation of the form: RATE=k(Br-)^b(H+)^a, where rate is 1/t for 0.2 density, was found to approximate the data for all developers tested. This rate equation failed noticeably at the low bromide ion concentrations for the high, exposure level, where in all developers a greater pH was needed to keep the rate of development constant. A satisfactory explanation for this effect cannot be determined from the data here.

Library of Congress Subject Headings

Photographic chemistry; Photography--Developing and developers

Publication Date


Document Type

Senior Project

Student Type


Department, Program, or Center

School of Photographic Arts and Sciences (CIAS)


Carroll, Burt


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