Agfa Gevaert Nv

Richard A Ooms

Piet Kok

Jean-Marie O Dewanckele

Robert J Pollet

Marc B Graindourze

A method for the production of a silver image with improved contrast by the development of an image-wise exposed photographic silver halide emulsion layer material with a developer liquid containing a hydroquinone in the presence of an auxiliary developing agent, wherein said developer liquid is applied to said photographic material containing silver halide grains that have been chemically sensitized with organic thiosulphonic acid anions in combination with a gold sensitizer in the absence of thiosulphate ions.

Method for increasing the contrast of photographic silver images

A new class of photographic masked stabilizers is disclosed showing following general chemical formula (Ia) or (Ib): ##STR1## wherein X and Y each independently represent N or CR, R being hydrogen or lower alkyl,

Class of masked stabilizers in photographic materials or developing

A method for high contrast development of an image-wise exposed photographic element comprising a support and at least one silver halide emulsion layer, which method comprises contacting said exposed element in the presence of a hydrazine compound with an aqueous alkaline developing solution which has a pH between 10 and 13 and contains a dihydroxybenzene developing agent a 3-pyrazolidinone or an aminophenol developing agent sulphite ions and a contrast promoting amount of an amino compound characterized in that said developing solution further contains an aprotic solvent corresponding to general formula (I) or (II) : ##STR1## wherein R.sub.1 represents alkyl, substituted alkyl, alkylamino or substituted alkylamino, and

High contrast developer containing an aprotic solvent

A developer liquid suited for use in development of photographic silver halide emulsion layer materials which liquid contains:

Developer liquid for high contrast development

A method of effecting high contrast development of an image-wise exposed photographic silver halide emulsion layer material wherein the developing proceeds in an aqueous medium having a pH of 10 to 12 and containing:

Method of effecting high contrast development of an image-wise exposed

A high contrast silver metal image can be formed in an exposed photographic silver halide emulsion layer material, the silver halide of which is at least 90 mole percent silver bromide, with the balance being silver chloride and/or silver iodide by developing the same in a developing medium in the presence of hydroquinone as sole developing agent, a large amount of sulphite derived from an inorganic sulphite compound, a nitro-indazole anti-fogging agent, and a polyoxyethylene polymer, and an inorganic alkaline compound to impart to the medium a pH of at least 10.5 provided the amounts of these ingredients meets certain requirements.

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Hofstade, Belgium

Richard A Ooms