The earliest calibration standards were developed for use with wide-angle averaging reflected-light meters (Jones and Condit 1941). Although wide-angle average metering has largely given way to other metering sensitivity patterns (e.g., spot, center-weighted, and multi-segment), the values for determined for wide-angle averaging meters have remained.
The earliest calibration standards were developed for use with wide-angle averaging reflected-light meters (Jones and Condit 1941) Although wide-angle average metering has largely given way to other metering sensitivity patterns (eg spot center-weighted and multi-segment) the values for determined for wide-angle averaging meters have remained