In spite of the current excitement and novely of magnetic, i.e., diskette, tape and 'solid-state' imaging techniques, photographic film still provides the highest resolution and most beautiful images of any imaging medium. This book systematically describes the theory and mechanisms of photographic sensitivity, with topics stressing the understanding the characteristics of silver halide photography. The topics include the structure and preparation of silver halide grains, physical properties of silver halides, mechanisms of latent image formation, spectral sensitization, chemical sensitization and stabilization, photograhic development, and the future prospect. This book is based on the author's knowledge, gained by 30 years' experience in the field. The audience ranges from chemists and physicists who work with silver halide imaging techniques, to those working in solid-state imaging, who need to compare their work with that of silver halide experts.