Metering System - This is how long the camera measures the amount of light being reflected by whatever you are trying to photograph, to determine the correct exposure for that particular scene. Different types of metering used by digital cameras include spot metering, multi-pattern metering and centre-weighted metering.
Spot Metering - Found on the more expensive cameras, this metering mode enables the photographer to take a particular light reading from a small area on the middle of the frame, usually marked in the viewfinder. This is the best way with dealing with difficult lighting conditions such as backlighting, and is normally used in conjunction with auto-exposure lock.
Selective multizone metering
Digital ESP. (Exposure metering, spot metering, reflected-light metering, exposure metering, light metering)
Selective zone metering
As with spot metering, selective zone metering just takes the readings for a specific section in the frame – usually in the centre. However, unlike spot metering, the measurement area covers a larger portion (up to 20% whereas the spot metering just concentrates on an area below 5%.)
Multi-spot exposure metering
With this system, the user can take readings from a number of freely-definable points. The camera recalculates the average exposure after each reading.
