Stops and EVS explained
The term ‘exposure value’ (EV for short, also known as ‘stops’) recognizes the fact that many different combinations of shutter speed and aperture can produce the same overall exposure: 1/125 sec at f/8 or 1/250 sec at f/5.6, for example. In practice, we mostly encounter EV when setting exposure compensation or exposure bracketing, where it serves as a measure of the difference between two or more exposures. A difference of 1EV (or one stop) doubles or halves the amount of light admitted. This usually makes a noticeable difference in the final image. The smallest increment, or difference between two exposures, that can be set on our Nikon cameras is 1/3 EV.