Exposure Calculator

Find the exposure value (EV) from aperture, shutter and ISO.

Exposure value (EV) 12.966

Formula: EV = log2(N^2 / t) - log2(ISO / 100)

Step-by-step with your numbers:
1. Values used:
2. Aperture (f-number) = 8
3. Shutter speed = 0.008
4. ISO = 100
5.
6. Exposure value (EV) = 12.966
Did we solve your problem today?

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.