Exposure Calculator
Find the exposure value (EV) from aperture, shutter and ISO.
Exposure value combines aperture, shutter speed and ISO into a single number.
The math behind it
EV = log2(aperture^2 / shutter) adjusted for ISO. Each whole EV step doubles or halves the light.
Worked example
f/8, 1/125 s, ISO 100 gives about EV 13.
FAQ
What is the exposure triangle?
Aperture, shutter speed and ISO trade off to set the total exposure.