What is Exposure Value (EV)?

EV is a single number that represents the combination of aperture and shutter speed. EV 0 equals f/1 at 1 second. Each step up doubles the amount of light required.

EV100 is EV adjusted for ISO 100. It lets you compare exposures taken at different ISO settings on a common scale. Higher ISO lowers the EV100 needed.

How do I use EV in practice?

A bright sunny scene is around EV 15. An overcast day is around EV 12. Indoor lighting is EV 5-7. Match your camera settings to the scene EV and your exposure will be correct.

Does changing ISO affect EV?

Changing ISO adjusts sensitivity, not light. The base EV formula uses only f-stop and shutter speed. ISO shifts the effective EV: doubling ISO reduces the required EV by 1 stop.

One stop is a doubling or halving of light. Moving from EV 10 to EV 11 means the scene is twice as bright (or your settings need twice as much light).

Exposure Value Calculator

Calculate photographic Exposure Value (EV) from aperture, shutter speed, and ISO to dial in correct exposure settings.

Camera Settings

Aperture (f-stop)

Shutter Speed

ISO

Exposure Value Result

Base EV

f-stop & shutter only

EV₁₀₀

ISO-adjusted to 100

EV by ISO

Same aperture and shutter speed at different ISO values.

ISO	EV	Difference
Press Calculate to see results

EV Reference Chart

Typical EV values at ISO 100 for common lighting conditions.

EV	Scene / Lighting Condition

Summary

Calculate photographic Exposure Value (EV) from aperture, shutter speed, and ISO to dial in correct exposure settings.

How it works

Select your aperture (f-stop) from the dropdown.
Choose your shutter speed in seconds.
Pick your ISO setting.
The tool applies EV = log2(N² / t), where N is the f-stop and t is the shutter speed, then shifts by log2(ISO / 100) to show the ISO-adjusted EV100.

Use cases

Match your camera settings to a measured scene brightness.
Cross-check manual exposure settings before shooting.
Learn how aperture, shutter speed, and ISO interact.
Compare exposures across different lighting conditions.
Match calculated EV against real-world lighting condition references.

Frequently Asked Questions

Last updated: 2026-09-22 · Reviewed by Nham Vu