Silver halide photographic elements with increased contrast

摘要

A silver halide photographic element comprising a silver halide emulsion in reactive association with a compound of the formula <IMAGE> wherein R1, R2 and R3 are each independently an aryl, alkyl or arylalkyl group; and wherein Z represents the atoms necessary to form a 5 or 6 membered heterocyclic ring and contains at least one atom selected from N, O, S, and Se; and methods of making same.