Abstract: A process for the treatment of a photographic material particularly a high speed photographic material, comprising an emulsion containing silver halide grains the treatment being to reduce the sensitivity of the material to ionizing radiation comprises prior to exposure, subjecting the material to a treatment that reduces the surface image dispersity so that fewer centers develop on each grain. The process may involve subjecting the photographic emulsion to physical pressure to deform the grains to introduce internal trapping centers for latent image formation so that a proportion of the latent image can be formed within the grains rather than on the grain surface.