Matrix metering, a system of automated exposure determination that divides the viewed field into six or more segments, several of which may overlap. The weighted responses from the various segments are fed to a central processor, which analyses the separate luminance differences and the average luminance value, and matches the result to one of a large number of stored data for different types of subject. Matrix metering is a highly sophisticated system that became possible only with the advent of cameras incorporating onboard microprocessors.
— Graham Saxby
