Occasionally you will produce better photographs if you override the exposure settings suggested by the camera. You can use exposure compensation, which allows you to increase or decrease the exposure set by the camera. Two, three or five stops compensation can be applied, depending on the camera.
Exposure compensation works by altering the shutter speed or the aperture (sometimes both), depending on the shooting mode set on the camera.
The amount of compensation needed is something you will have to learn by experience. Until you are confident, you can make use of another feature of EOS cameras – Auto Exposure Bracketing (AEB). This allows you to take three pictures in rapid succession using three different exposures. You can then select the image that gives the result you want.
Auto Exposure Lock (AEL)
Your camera normally meters the exposure for each shot. Sometimes, though, you want to lock the exposure, so that it does not change as you move the camera around. You can do this by pressing the shutter button halfway and pushing the star (*) button). A * will appear in the viewfinder or on the info screen.
When shooting a portrait, for example, move in close to get a meter reading from just the face. Lock the exposure. Now move back to include the background, perhaps composing with the face off-centre. As long at the * remains visible, the original meter reading will be used, exposing just for the face.