Silver halide photographic emulsions

摘要

A silver halide photographic emulsion chemically sensitized by a sulfur compound of the formula: <IMAGE> wherein R1 represents a 5-membered or 6-membered heterocyclic ring containing a nitrogen atom; R2 represents a hydrogen atom, a lower alkyl group, an allyl group, an aryl group, or an aralkyl group; and R3 has the same definition as R1 or R2; or R2 and R3 may join to form a heterocyclic ring; is disclosed.