1999 Volume 62 Issue 3 Pages 216-227
The progress of development may be classified into two extreme types, that is, parallel development (P type) and granular development (G type), but the reason for the difference between them have not been clearly elucidated. The morphology of silver particles in a mono-grain layer of an AgBr emulsion developed with typical developers was examined by a transmission electron microscope (TEM) as such, and the characteristics of anodic oxidation of these developers were evaluated by stationary electrode polarography. It was found from these results that the oxidation potentials of developers belonging to G type were more negative than those to P type. The developed silver-time curves which were simulated on the basis of an electrochemical model of development, supported the conclusion that a dominant factor affecting the development types was the redox potential of developers rather than the rate of development.
