Abstract: Color photographic images are produced by decomposing hydrogen peroxide on nuclei present in imagewise distribution and bleaching out a dye by the hydrogen peroxide on those parts of the image where no such nuclei are present.

Abstract: New silver halide emulsions are prepared at least partly by converting a silver phosphate with a water soluble halide.

Abstract: Silver halide emulsion with an average grain size of at most 0.6 .mu.m containing Co-, Ce- or Cu-salts are suitable for the production of vesicular images.

Abstract: Silver halide emulsions, which have been precipitated in the presence of polymers having recurring units with a 8-hydroxy quinoline structure are suitable for the preparation of vesicular images.

Abstract: New triazoles of the formula ##STR1## are suitable stabilizing agents in photographic materials.

Abstract: New thioethers of the formula ##STR1## in which Ac represents an acyl radical have been found. They are useful for producing silver halide emulsions for photographic materials.

Abstract: A polymer of at least one compound A with at least one compound B, in which A and B correspond to the following formulae ##STR1##B: H--S.sub.n --Q.sup.1 --W).sub.m Q.sup.2 --S--H is useful in light sensitive photographic materials comprising at least one silver halide emulsion layer.

Abstract: Polymers, containing polymerized units of at least one compound of the formula ##STR1## and at least one compound of the formula ##STR2## are useful for the preparation of silver halide emulsions.

Abstract: A homo- or copolymer containing copolymerized monomeric units of the formula ##STR1## is a valuable peptizing agent for the precipitation of silver halide. Sensitivity, onset of development and silver covering power are advantageously influenced.

Abstract: Silver halide is precipitated in a large excess of a soluble chloride that forms together with silver ions a silver salt more readily soluble than the silver salt of the final emulsion. By precipitation of silver halide in the presence of the soluble chloride used in excess part of the silver chloride is carried along with the less soluble silver halide and may subsequently be converted into the less soluble silver halide.

Abstract: Fine-grain silver halide emulsions of the Lippmann-type are described which comprise derivatives of heterocyclic mercaptans corresponding to the formulae: ##STR1## wherein: each of Z.sub.1 and Z.sub.2 represents the atoms necessary to complete a 5- or 6-membered heterocyclic ring system,n is 0 or 1,X is --CO-- or --CS--,R is an alkyl group or an aryl group, andY is --CO--, --COO--, --CS--, --SO.sub.2 --, --CON(R.sub.1)-- or --CSN(R.sub.1)--, R.sub.1 being hydrogen, alkyl or aryl.Both in reversal and negative processing sharpness of fine detail is improved and the distortion of image-details is reduced. Upon reversal processing yellow staining is also reduced.

Abstract: A copolymer containing 0.1 to 20 mol-% of recurring structural units of the formula ##STR1## is a valuable peptising agent for the precipitation of silver halide. Sensitivity, onset of development and silver coating power are advantageously influenced.

Abstract: A silver halide emulsion is made by continuous conversion of a more soluble silver halide into a less soluble silver halide. From a first part of up to 50% of the total amount of silver nitrate by reaction with a first water soluble halide a silver halide is precipitated consisting at least partly of a more readily soluble silver halide, e.g. silver chloride. In the presence of this more readily soluble silver halide the remaining silver nitrate is reacted with a second water soluble halide composition to form the residual silver halide (main precipitation). The amount of total halide in the precipitation is slightly more than equivalent to the amount of silver ions. However the amount of halide that forms the less readily soluble silver halide is less by at least 5 mol% than equivalent to the amount of silver ions in the precipitation medium.

Abstract: The sensitivity of silver halide emulsions is increased if the silver halide is precipitated in the presence of a peptization agent which consists partially or wholly of a copolymer comprising 0.1 to 20 mol% of recurring structural units of the formula ##STR1## in which X is hydrogen or alkyl having 1 to 4 carbon atoms and Y is a 8-hydroxyquinoline group attached through its 5- or 7-position.

Abstract: The mechanical properties of gelatin layers for photographic materials are improved by the addition of water-insoluble, elastic copolymers which consist of acrylic acid or methacrylic acid esters (I) which may be mixed with other vinyl and divinyl monomers (II) and which contain comonomers (III) which contain disulfone imidoester or sulfonimidophosphoric acid ester or amide groups.