[Flash Compensation] + [Exposure Compensation]
This function allows you to combine exposure compensation and flash compensation, and you can control both at the same time with the Front Dial.
Normally, with this function set to Off, when you want to do exposure compensation for your image you simply turn the Front Dial (in P, A, and S modes) and dial in exposure compensation from –5.0 EV to +5.0 EV.
However, when you have a flash unit mounted on your camera, its output is not increased or decreased based on the exposure compensation. Instead, the camera simply opens or closes the aperture, or raises or lowers the shutter speed, to provide more or less exposure. The flash provides a constant output.
Sometimes increasing or decreasing the entire ...