noun
Usage: usually capitalized H&D
Etymology: after Ferdinand H urter and Charles D riffield fl 1890
: a system for determining the speed of photographic materials that is based on the characteristic curve and related to the inertia of the material
noun
Usage: usually capitalized H&D
Etymology: after Ferdinand H urter and Charles D riffield fl 1890
: a system for determining the speed of photographic materials that is based on the characteristic curve and related to the inertia of the material
Webster's New International English Dictionary. Новый международный словарь английского языка Webster. 2012