METHOD OF PREPARING SILVER BROMIDE-IODIDE AMMONIA PHOTOGRAPHIC EMULSION Russian patent published in 1997 - IPC

FIELD: photographic materials and processes. SUBSTANCE: method consists in introducing, in dispersing stage, 0.0125-0.0187 mol (always per 1 mol silver halide) of sodium benzenesulfinate; before beginning of chemical sensitizing, (0.23-0.625)•10^-4 mol of sodium thiosulfate, (4.6-12.5)•10^-2 mol of sodium benzenesulfinate, (0.93-2.5)•10^-3 mol of potassium thiocyanate, and (0.056-0.15)•10^-5 mol of gold thiocyanate (on conversion to gold chloride); and, 20-40 min later, the same reagents in the same quantities and, additionally, (2.5-5.0)•10^-4 mol of sodium benzenethiosulfonate. EFFECT: increased resolution and decreased optical fog density. 2 tbl