Abstract: A photographic element comprising at least one silver halide emulsion layer in which the silver halide is sensitized with a compound of the formula: wherein A is a silver halide adsorptive group that contains at least one atom of N, S, Se, or Te that promotes adsorption to silver halide, and Z is a light absorbing group including for example cyanine dyes, complex cyanine dyes, merocyanine dyes, complex merocyanine dyes, homopolar cyanine dyes, styryl dyes, oxonol dyes, hemioxonol dyes, and hemicyanine dyes, and XY is an fragmentable electron donor moiety in which X is an electron donor group and Y is a leaving group other than hydrogen, and wherein: 1) XY has an oxidation potential between 0 and about 1.4 V; and 2) the oxidized form of XY undergoes a bond cleavage reaction to give the radical X• and the leaving fragment Y. In a preferred embodiment of the invention, the radical X• has an oxidation potential ≦−0.7 V.

Abstract: A photographic element comprising at least one silver halide emulsion layer in which the silver halide is sensitized with a compound of the formula: ##STR1## wherein A is a silver halide adsorptive group that contains at least one atom of N, S, Se, or Te that promotes adsorption to silver halide, and Z is a light absorbing group including for example cyanine dyes, complex cyanine dyes, merocyanine dyes, complex merocyanine dyes, homopolar cyanine dyes, styryl dyes, oxonol dyes, hemioxonol dyes, and hemicyanine dyes, and XY is an fragmentable electron donor moiety in which X is an electron donor group and Y is a leaving group other than hydrogen, and wherein:1) XY has an oxidation potential between 0 and about 1.4 V; and2) the oxidized form of XY undergoes a bond cleavage reaction to give the radical X.sup..cndot. and the leaving fragment Y.In a preferred embodiment of the invention, the radical X.sup..cndot. has an oxidation potential .ltoreq.-0.7 V.

Abstract: A radiographic element is disclosed containing in a high bromide tabular grain emulsion layer a 5-mercaptotetrazole to increase covering power. The 5-mercaptotetrazole is additionally capable of increasing imaging speed and producing colder image tones when provided with a phenyl substituent in the 1 ring position, which phenyl substituent is in turn substituted in its para position with a substituent satisfying the formula R(OCH.sub.2 CH.sub.2).sub.n O-- wherein n is an integer of from zero to 5; when n is 1 to 5, R is hydrogen, methyl or ethyl; and, when n is zero, R is methyl.

Abstract: The invention provides a black and white photographic element comprising a support having situated thereon at least one silver halide emulsion, the element containing a release compound that provides a non-imagewise distribution of a photographically active moiety, wherein the release compound has the structure ##STR1## wherein R.sup.1 is an electron withdrawing moiety;m is 0, 1, 2 or 3;R.sup.2 is a group containing an aqueous solubilizing group;q is 1 or 2;TIME is a timing group;n is 0, 1, 2 or 3; andPAM is a photographically active moiety.Also provided is a method of preparing a photographic emulsion comprising precipitating silver halide grains in a colloidal medium, washing the grains, sensitizing the grains by adding dyes, chemical sensitizers and heating, and adding to the emulsion a methanolic solution comprising a release compound as described above.

Abstract: Photographic elements and emulsions are described which are capable of providing high contrast images. The elements and emulsions comprise negative working silver halide and contrast enhancing arylhydrazide nucleating agents. A process for utilization of the elements and emulsions is also described.

Abstract: Silver halide photographic elements which are capable of high contrast development having incorporated therein, as a nucleating agent, an aryl sulfonamidophenyl hydrazide of the formula: ##STR1## where each R is an alkyl group, n is 1 to 3, X is an anion, m is 1 to 6, Y is a divalent aromatic radical, and R.sup.1 is hydrogen or a blocking group.