Photographic silver-halide materials for producing negative images with ultrahard-gradation contrast, which contain a hydrazine compound and a contrast-boosting amino compound and/or phosphonium compound, demonstrate a marked tendency to form "black fog" which results in inadequate acutance. By adding 200 to 2500 mg per mol of silver of a polyvinyl lactam to the emulsion, the fog is inhibited and acutance is improved without reducing sensitivity. The invention can be used to produce images during reproduction in the pre-printing stage.