Damage of Silver Halide Photographic Materials by Natural Background Radiation

Abstract

High speed color negative films are inclined to suffer from increase in fog, decrease in speed and deterioration in graininess during their preservation. This damage was mostly caused by natural background radiation. We classified the natural background radiation into three groups: cosmic rays, radiation from radioactive substances around film and radiation from radioactive substances in film. We made clear the degree of influence of each group on high speed color negative film properties. The sensitivity of silver halide photographic emulsion to gamma ray is in proportion to the absorption of gamma ray by the emulsion and the intrinsic sensitivity of the emulsion.