Exposure
The third method of controlling the tonal range of a shot is
adjusting the lens or camera. This type of control is less
selective than reflective or incident. As the camera’s
shutter or the lens’ f-stop is adjusted, the entire picture
will get brighter or darker. Exposure control can’t
selectively make a shirt lighter or a wall darker without
affecting everything else in the shot. The tonal range of
the normal exposure is given an overall shift by changing
the f-stop.