Metering for Part of Any Scene
Partial Metering (Pink Area Below) – This setting is useful when your subject is strongly or overly backlit. The metering is weighted towards the centre of the viewfinder covering approximately 13.5% of the area. This will inevitably lead to your subject being correctly exposed, with a blown out background.
This effect can be quite nice and concentrates the eye on your well exposed subject, but if you wanted a more evenly spread image it is worth having an image that is “slightly” overexposed behind the subject with the actual subject being “slightly”underexposed. You can then darken the background and lighten the subject later on for a more evenly spread exposure.