SOLUTION FOR SEPARATE BLACK-AND-WHITE DEVELOPMENT OF DIRECT POSITIVE PHOTOGRAPHIC PHONOGRAMS Russian patent published in 1994 - IPC

FIELD: cinematography. SUBSTANCE: separate development of black-and-white photographic phonograms is carried out in solution containing 5-10 g/l of SnCl₂·2H₂O, 15-22 g/l of NaOH, 20-25 g/l of KCNS, 30-35 g/l of sodium acetate, 25-30 g/l of carboxymethyl cellulose (to viscosity of 120-125 cSt) and water (to 1 l) to enhance density of direct positive photographic phonogram. EFFECT: enhanced density of direct positive photographic phonogram. 1 tbl