Racira Calculator

Exposure Value Calculator

Exposure Value Calculator

Exposure Value
EV 12.97
f/8 · 1/125 s · ISO 100 (EV 13.0 adjusted)
EV @ ISO 100
12.97
Estimated Lux
20,000
Scenario
Daylight
QuantityValue
Aperture (f-number)f/8
Shutter Speed1/125 s
ISO100
EV at ISO 10012.97
EV at Selected ISO12.97
Estimated Illuminance20,000 lux
Lighting ScenarioBright daylight

EV at ISO 100 vs Selected ISO

Summary Statistics
EV (ISO 100)12.97
EV (ISO 100)12.97
Lux20,000
Aperturef/8
Shutter1/125 s
ISO100

About the Exposure Value Calculator

Exposure value condenses aperture and shutter speed into one number: EV = log₂(N² ÷ t). At f/8 and 1/125 s, EV = log₂(64 ÷ 0.008) = log₂(8,000) ≈ 13. Every stop of aperture or shutter changes EV by exactly 1 — the basis of the exposure triangle.

ISO as an EV Offset

ISO doesn't change the light arriving at the sensor, but it changes the exposure index. Doubling ISO is equivalent to a +1 EV shift, which is why low-light photography trades image noise for exposure headroom: EV₁₀₀ + log₂(ISO/100) gives the effective value.

Frequently Asked Questions

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