Abstract: A method of producing direct-positive images is provided which comprises developing an exposed direct-positive silver halide emulsion comprising electron-traps and fogged silver halide grains in the absence of halide ions so as to obtain higher maximum density. It is possible to decrease the degree of fogging so as to obtain direct-positive emulsions of high-sensitivity which, when developed in the absence of halide ions, still provide favorable maximum density values.

Abstract: In the preparation of silver halide emulsions silver halide grain-growth is accelerated by the addition to the precipitation medium during or before silver halide precipitation of a compound of the formula ##STR1## wherein: N IS AN INTEGER FROM 1 TO 5R.sup.1 is C.sub.1 -C.sub.5 alkyl or substituted alkylR.sup.2 is hydrogen or C.sub.1 -C.sub.5 alkyl or substituted alkyl, or a carboxylic acyl groupR.sup.3 is hydrogen or C.sub.1 -C.sub.5 alkyl or substituted alkyl, andR.sup.4 is hydrogen or C.sub.1 -C.sub.5 alkyl or substituted alkyl group, aryl or substituted aryl or a salt-forming cation.

Abstract: Direct-print images of improved stability against prolonged light-exposure are obtained in a photodevelopable element by spectrally sensitizing the photodevelopable emulsion, providing in the emulsion layer or a superposed layer a compound absorbing radiation in the inherent sensitivity range of the silver halide, and effecting image-wise exposure with radiation comprising light of the spectral range for which the silver halide has been spectrally sensitized.

Abstract: Direct-positive silver halide emulsions are described which have been fogged so that a test portion thereof when coated at a coverage of 0.50 to 5.50 g of silver per sq.m. gives a density below 0.50 upon processing without exposure for 6 min. at 20.degree.C in a developer I and an identical coated test portion gives a density that is at least twice that of the first test portion with a minimum of 0.50 upon processing without exposure for 3 min. at 20.degree.C in a developer II.The emulsions have high photographic speed and though fogged to a very low degree can yield direct-positive images of satisfactory density.