Exposure value (EV)
Belichtingswaarde (EV) · Exposure
A number that expresses the total amount of light in a photo.
EV 0 is the reference point. EV 1 is half the light, EV -1 is twice the light. The exposure triangle (aperture, shutter, ISO) together determines EV. The same EV can be achieved in multiple ways: f/2.8 at 1/500 sec gives the same exposure as f/8 at 1/60 sec.
Tools that help with this: