When shooting on auto, your camera takes an overall metering of the scene. When you have a particularly bright background, this can result in a poorly exposed subject. The good news is that you can over-ride this.
The purpose of the different metering modes is to tell your camera how to expose.
There are four different metering modes:
This is the default mode for your camera. The metering is linked to, and concentrated on the active Autofocus point. Light values measured at the active AF point are compared with light values measured from the metering segments surrounding the active point, and the camera’s metering system attempts to provide an accurate exposure based on that comparison.
This metering pattern is often effective when photographing people, but may not be quite as effective when photographing brightly lit, or backlit scenes.
Use this mode for general subjects without larger shadowed or extreme bright areas.
Spot [( )]
This metering mode gets exposure information only from the single exposure zone in the center of the frame (approximately 3% of the total picture area). This mode meters a small area in the center of the scene.
Use this mode when there are big differences in brightness
(e.g. between foreground and background) or for subjects that require precise measurement, such as close-up photography.
Partial [ o ]
Partial metering is similar to Spot Metering, but covers a slightly larger area, reading only the cross-shaped central five metering zones (approximately 10% of the total picture area). This mode meters a small area in the center of the scene.
Use this mode when you have a very specific area of the photograph that you wish the exposure to be based upon. Great for Natural light Portraits!
Centre-weighted [ ]
This metering mode averages the exposure for the entire picture area, but with greater emphasis on the center metering zones.
Use this mode when you main subject covers a large portion of your image (e.g. with peripheral shadows)
Once you have mastered the skill of using your metering modes, you will be able to get beautiful photos, even during bright midday sun, hooray!