Silver halide emulsion sensitized with a heavy metal compound and a thiourea compound

摘要

The invention is generally accomplished when a heavy metal compound and a substituted thiourea sensitizer are used together as chemical sensitizers. There is a surprising increase in photographic efficiency and, therefore, in photographic sensitivity. This effect does not depend on the presence of a dye. The preferred heavy metal compound is potassium hexachloroiridate (IV), and the preferred thiourea is 3-acetamidophenyl thiourea.