Verfahren zur Herstellung von Silberhalogenidemulsionen mit Silberhalogenidkristallen kubisch-regulaerer Form

Photographic emulsions comprising cubic-regular grains free of reduction sensitization are prepared by running an aqueous solution of silver nitrate and an aqueous solution of a silver halide simultaneously into an agitated aqueous solution of a peptizer in a double-run precipitation procedure while maintaining the pH at no more than 4.0 and the pAg at a value within the range of 8.6 to 9.1. In one aspect of this invention, emulsions prepared by the above procedure are chemically sensitized with a compound containing a labile atom selected from the group consisting of sulfur, selenium and tellurium and spectrally sensitized with a cyanine dye having an anodic half-wave potential less than 1.0 volt and a cathodic half-wave potential less than -0.8 volt.