A metering system that uses several sensors to take readings from various sections around the image and calculates an exposure based on these values. This type of metering, also known as matrix or segment, is better for difficult lighting situations, such as backlit subjects, as it can determine when several sections are brighter than the area that you have focused on and adjust to compensate. Some of the more sophisticated versions couple up to the focusing system to offer even more precise exposure. Basic systems have as few as two metering zones where advanced ones can have eight or more segments.ephotozine
Exposure is determined by reading many different zones in the frame. This gives a more optimum exposure than those cameras using just a central zone metering system.