Reciprocity-Failure Characteristics of the Internal Latent Image

Abstract

It is shown that the internal-image reciprocity-failure curves of members of a grain-size series of unsensitized emulsions are all of the same basic shape. With increasing grain size the optimum of the reciprocity-failure curve shifts to shorter exposure times so as to maintain the optimal intensity roughly constant. As a result the optimum tends to be associated with a fixed rate of absorption of quanta per unit volume of silver halide. This suggests that through a grain-size series the number of internal sensitivity centres per unit volume and their overage trap-depth tend to remain invariant with grain size.