Exposure Triangle Equivalence Solver

Solve for the setting that keeps the same exposure when you change one.

About this tool

An exposure-triangle equivalence solver for photographers learning manual mode. Enter a base exposure (ISO, aperture, shutter) and change one setting; it computes the scene's exposure value and solves for the remaining setting that keeps the exposure identical. It also lists several equivalent ISO/aperture/shutter combinations at the same EV.

Frequently asked questions

How do I keep the same exposure when I change aperture?

Enter your base ISO, aperture and shutter, then add new_aperture=. The solver returns the shutter speed that holds the exposure value constant, plus the scene EV.

What is exposure value (EV)?

EV is a single number for a brightness/exposure combination: EV = log2(aperture² / shutter) referenced to ISO 100. Equal EV means equal exposure regardless of which settings you use.

Can I solve for ISO or shutter instead?

Yes. Provide exactly one of new_aperture, new_shutter or new_iso and the tool solves for the matching remaining setting.

Does changing ISO change the scene EV?

ISO doesn't change scene brightness, but raising ISO lets you use a faster shutter or smaller aperture for the same image lightness. The tool accounts for ISO when solving.

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