Photographic silver halide development in the presence of thioether development activators

Photographic elements containing image-wise developable silver halide are developed in the presence of an oxathioether development activator according to the formula: R1-A-(OCH2CH2)n-S-A'-(X-A'')m-Y-R2 wherein: R1 is H, alkyl, hydroxyalkyl, or R2-Y-(A''-X)m-A'-S-, A, A', and A'' is alkylene, with the proviso that A is a monovalent bond when R1 is hydrogen or alkyl or hydroxyalkyl, X is -OCO-, -SO2-, -CONH-, or Y, Y is ligand or complexing function of the type of -S- and -N(Q)- (Q=H or alkyl), R2 is alkyl, which may be substituted by OH, or when Y is -N(Q)-, R2 together with Q may represent the atoms needed to complete a nitrogen-containing saturated ring, n is at least 2, and m is 0 or 1. The development activators can be used in black-and-white development or in color development. They can be incorporated in the photographic material or in the developing solution. In reversal processing they can also accomplish the task of the second exposure or of the fogging agent to render the silver halide remaining after the first development developable.