When should I use different metering modes?
Almost all digital cameras offer the ability to change the type of metering used to choose exposure settings. Three settings are usually on offer: spot, centreweighted and evaluative/matrix/multi-pattern. This last setting is called different things on different cameras and is always the default setting, being the most versatile option. So why choose anything else?
Well, multi-pattern-type metering looks at the whole scene, which means it can get confused when the main subject differs in brightness from the background. Spot metering, on the other hand, looks at just a very small area of the scene, typically 1-5 per cent of the frame. This lets you base your exposure on only the subject, ignoring everything else. Centreweighted metering is a kind of halfway house between this and multi-pattern.
There are many uses for your camera’s spot-metering setting. When shooting portraiture, try picking exposure from just your subject’s face, or when you are shooting architecture use it to measure light reflected off the pavement. The golden rule is to make sure you point at something that is a midtone or something that you would like to be a midtone in the final shot. Spot metering from the sky immediately next to the sun is a sure-fire way of getting the right exposure when shooting sunsets.