Light-sensitive photographic material with increased sensitivity to light

Abstract

Abstract 1. A LIGHT SENSITIVE PHOTOGRAPHIC MATERIAL OF IMPROVED SPEED AND GRANURALITY ESSENTIALLY CONSISTING OF A SUPPORT AND IN SUPERPOSED RELATIONSHIP A FIRST SILVER HALIDE EMULSION OF SILVER BROMIDE OR SILVER BROMO-IODIDE CLOSER TO THE SUPPORT AND A SECOND SILVER HALIDE EMULSION OF SILVER BROMIDE OR SILVER BROMO-IODIDE SUPERPOSED OVER THE FIRST EMULSION WHEREIN THE IMPROVEMENT COMPRISES THE SECOND EMULSION IS IN A LAYER HAVING A THICKNESS OF AT LAST 2$ AND THE FIRST EMULSION IS IN A LAYER HAVING A THICKNESS OF BETWEEN 5 AND 15U AND IS GREATER IN THICKNESS, THE FIRST EMULSION HAS A SENSITIVITY ABOUT 0.1 TO 0.4 LOG 1.T UNITS LESS THAN THE SENSITIVITY OF THE SECOND EMULSION AS MEASURED BY THE POINTS ON THE CHARACTERISTIC CURVES WHICH ARE ABOVE THE EXPOSURE REQUIRED TO PRODUCE VISIBLE DENSITY, AND WHICH IMPROVEMENT RESULTS IN THE FIRST EMULSION GIVING A DENSITY OF AT LEAST 1.5, THE SECOND EMULSION GIVIMG A DENSITY OF NOT OVER 0.9 AND THE SLOWER EMULSION HAVING THE THRESHOLD OF ITS CHARACTERISTIC CURVE COINCIDING IN LOG 1.T UNITS WITH THE SHOULDER OF THE CHARACTERISTIC CURVE OF THE FASTER EMULSION AND WHEREBY OVERALL SENSITIVITY IN LOG 1.T UNITS OF SAID LIGHT SENSITIVE MATERIAL IS GREATER THEN THE SENSITIVITY OF THE MORE SENSITIVE SECOND EMULSION MEASURED BY THE POINTS ON THE CHARATERISTIC CURVE ABOVE THE EXPOSURE REQUIRED TO PRODUCE VISHIBLE DENSITY.

Inventors

• 👤 E Hellmig
• 👤 W Saleck
• 👤 F Moll
• 👤 A Randolph

Bibliographic Details