EXPOSURE COMPENSATION
When you’re shooting in one of the camera’s semi-automatic exposure modes, such as Aperture Priority, Shutter Priority or Program, you can fix metering problems using exposure compensation. This allows you to increase or decrease the exposure value of subsequent pictures you take; use plus exposure compensation to make them brighter and minus exposure compensation to make them darker. Remember to cancel this once you’ve finished taking pictures: exposure compensation doesn’t reset itself, even when you turn the camera off.