The Reflecting and the Absorbing Power of a Photographic Emulsion

Measurements have been made upon the reflecting and the absorbing power of silver bromide emulsion with wave-lengths between 2100A and 5782A. The reflecting power of silver bromide emulsion averages about 7 per cent for the region 2100A to 5200A. A thickness of emulsion (0.021 mm) as found in a commercial photographic film absorbs about 96 per cent of incident radiation between 5218A and 5782A, and more than 99.99 per cent of radiation whose wave-length is less than 3247 A. From 5782A to at least 2294A the gelatine in a photographic emulsion has a negligible absorption as compared with the absorption of the silver bromide of the emulsion