Exclusively Internal Latent Image

Abstract

The presence of emulsion grains bearing only internal latent image (“exclusively” internal image) can be fairly definitely established by firstly developing fully, in a surface developer, and then either bleaching and developing internally, or observing if there is a further density increase on transferring the surface-developed samples to an internal developer, both methods gave similar results, which indicated that digested emulsions at normal exposure levels form internal image only in grains also bearing a surface image. An undigested emulsion formed much exclusively internal image. Solarization has often been thought to proceed by the destruction of surface image on grains in which build-up of internal silver is continuing. In agreement with this concept, good equivalence was found between solarization density losses as shown by surface development, and density gains shown by development for the exclusively internal image.