Abstract: A photographic silver halide material comprising a compound which is capable of being reduced by a silver halide developing agent at a rate slower than that of image-wise developable silver halide and in reduced state is capable of releasing a photographically useful group, characterized in that said compound corresponds to the following formula: ##STR1## wherein: R.sup.10 and R.sup.20 (same or different)(1) represent an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group or an aralkyl group including said groups in substituted form,(2) represent an aryl group including a substituted aryl group, or(3) represent a heterocyclic ring residue including such residue in substituted form, orR.sup.10 and R.sup.20 are ringclosed, either R.sup.10 or R.sup.20 containing a ballasting group conferring diffusion resistance to the compound in hydrophilic colloid media when penetrated by an aqueous alkaline liquid;L.sup.1 and L.sup.2 (same or different) represent a ##STR2## --SO.sub.