In a dry physical development photothermographic element for a dry thermal silver-dye bleach process wherein the element comprises a silver halide complexing concentration of a silver halide complexing agent improvements are provided when the complexing agent is an organic ammonium chloride, bromide or iodide. After imagewise exposure of the element, a dye image can be produced by uniformly heating the element. Improvements are also produced by providing a dry activator element for producing a dye image in a separate photographic element by means of a dry physical development thermal dye-bleach process, wherein the activator element comprises a support having thereon a layer comprising a synthetic hydrophobic polymeric binder, a silver halide complexing concentration of a silver halide complexing agent, as described, a bleachable dye and a thermal solvent.