3D color matrix meter
From The Glossary of Digital Photography
A metering system, developed by Nikon to evaluate brightness, contrast, selected focus, distance information, and the color characteristics in a scene, that is fed to a camera-based microprocessor to provide very precise exposure control. It uses a CCD that has more than 1,000 pixels with RGB information from each and a microprocessor with more than 300,000 exposure possibilities stored in its database.
