Abstract: Room light handleable direct reversal silver bromide emulsions, with up to 70 mole percent chloride, have a broad Dmin window when from 1.times.10.sup.-6 to 1.times.10.sup.-4 mole per silver mole of a polybromo coordination complex of iridium is incorporated in the silver halide grains. The emulsions are stabilized against deterioration on keeping with mercapto compounds.

Abstract: A high-contrast room-light-handleable black-and-white silver halide photographic film especially adapted for use as a dry-dot-etchable contact film in the graphic arts is comprised of a support having in order on one side thereof (1) a radiation-sensitive layer comprising silver halide grains, a hydrophilic colloid and a polymer latex, (2) an interlayer comprising a hydrophilic colloid and a polymer latex, and (3) an overcoat layer comprising a hydrophilic colloid, a matting agent and a light-scattering agent, wherein the interlayer has a refractive index in the range of from about 1.4 to about 1.7 and a thickness which is in the range of from about 0.5 to about 5 microns and is at least twice that of the overcoat layer, and wherein the film contains in the radiation-sensitive layer, or a layer contiguous thereto, a hydrazine compound which functions as a nucleating agent.

Abstract: A high-contrast room-light-handleable black-and-white silver halide photographic film especially adapted for use as a dry-dot-etchable contact film in the graphic arts is comprised of a support having in order on one side thereof (1) a radiation-sensitive layer comprising silver halide grains, a hydrophilic colloid and a polymer latex, (2) an interlayer comprising a hydrophilic colloid and a polymer latex, and (3) an overcoat layer comprising a hydrophilic colloid, a matting agent and a light-scattering agent, wherein the interlayer has a refracive index in the range of from about 1.4 to about 1.7 and a thickness which is in the range of from about 0.5 to about 5 microns and is at least twice that of the overcoat layer. The combination of the light-scattering agent in the overcoat layer and the thick interlayer facilitates optical spreading of the image during contact exposure, and thereby enhances the performance of the contact film in use with multi-layer originals and in processes of dry dot etching.

Abstract: A method of making a thin lens having a desired high order curvature includes the steps of providing a layer of transparent photoresist; generating a continuous tone exposure pattern for exposing the photoresist such that when exposed and developed the layer of photoresist will possess the desired high order curvature; exposing the layer of photoresist; and developing the layer to produce the thin lens.