Zone system

The Zone System is a photographic technique for determining optimal film exposure and development, formulated by Ansel Adams and Fred Archer in 1941. The Zone System provides photographers with a systematic method of precisely defining the relationship between the way they visualize the photographic subject and the final results. Although it originated with black and white sheet film, the Zone System is also applicable to roll film, both black and white and color, negative and reversal, and to digital photography.