exposure meters Reference library
Roger W. Hicks
The Oxford Companion to the Photograph
...The earliest commercially successful spot meter, the SEI Photometer ( 1947 ), had no ‘mid point’ index, just shadow and highlight indices. Spot meters can also be used to measure overall brightness ranges, in order to determine the need for modified development (for monochrome) or additional lighting or contrast‐reducing screens (for colour). Most spot meters read a 1‐degree circle and are photoelectronic, though the SEI read 0.5 degrees and was a sophisticated visual comparison photometer. Flash meters are variants on the three modern meter types. Many...
