Recent Advances in the Theory of the Photographic Process

A photographic film consists of a layer of gelatin coated on cellulose base in which are dispersed a great number of very small silver bromide crystals. When exposed to light, electrons are liberated in the crystals and these collect at certain points, where they are neutralized by silver ions which deposit atoms of metallic silver. This metallic silver deposited in definite specks forms what is known as the latent image, which makes possible the development of the crystal. The surface of each silver bromide crystal in the gelatin layer of an emulsion immersed in the developer is protected by charged layers of bromide and potassium ions. The development of the grain is initiated by the break in this charged layer caused by the presence of the silver latent image. When the developer acts on the silver bromide crystal, metallic silver is produced in a ribbon-like form, a tangled mass of which forms the developed silver grain.

Print ISSN

0097-5834

Published

1941-07

Content type

Original Research

DOI

10.5594/J16545