The E (Exposure Compensation) Button
In modes other than b, exposure compensation can be used to alter exposure from the value suggested by the camera, making pictures brighter or darker. Choose from values between –5 EV (underexposure) and +5 EV (overexposure) in increments of 1/3 EV (photographs only; the range for movies is –3 to + 3 EV). In general, positive values make the subject brighter while negative values make it darker.
To choose a value for exposure compensation, press the E button and rotate the main command dial until the desired value is displayed.
At values other than ±0.0, the camera displays a E icon (movie mode) or a E icon and the exposure indicator (photo mode) after you release the E button. The current value for exposure compensation can be confirmed by pressing the E button.
Normal exposure can be restored by setting exposure compensation to ±0. Exposure compensation is not reset when the camera is turned off.
In mode M, exposure compensation affects only the exposure indicator; shutter speed and aperture do not change (ISO sensitivity will, however, automatically be adjusted according to the exposure compensation value selected when auto ISO sensitivity control is enabled; 0 Auto ISO Sensitivity Control). The exposure indicator and the current value for exposure compensation can be displayed by pressing the E button.
When an optional flash unit is used, exposure compensation affects both flash level and exposure, altering the brightness of both the main subject and the background. Custom Setting e3 (Exposure comp. for flash) can be used to restrict the effects of exposure compensation to the background only.