Exposure Value Calculator
Exposure value from aperture, shutter and ISO, with the EV at ISO 100 and the light level it corresponds to.
Results
Exposure value
12.96578
Exposure value
12.96578
Seconds
0.008000
s
Scene luminance
100,000.000
cd/m²
Shutter speed (1/x s)
0.03
1/s
What this tool does
Every whole EV is one stop: half the light or twice it. That is why f/8 at 1/125 and f/11 at 1/60 give the same picture brightness — trading one stop of aperture for one stop of time. Bright sun sits around EV 15, an overcast day around 12, a well-lit room around 7, and a candle-lit one near 3.
Formula
EV = log₂(N² ÷ t) − log₂(ISO ÷ 100)
Variables
| Symbol | Meaning | Unit |
|---|---|---|
ap | Aperture | f/ |
sh | Shutter speed (1/x s) | 1/s |
is | ISO sensitivity | — |
EV | Exposure value | — |
E1 | Exposure value | — |
TT | Seconds | s |
LV | Scene luminance | cd/m² |
SH | Shutter speed (1/x s) | 1/s |
Worked example
- Aperture8 f/
- Shutter speed (1/x s)125 1/s
- ISO sensitivity100
- Exposure value12.96578
- Exposure value12.96578
- Seconds0.008000 s
- Scene luminance100,000.000 cd/m²
- Shutter speed (1/x s)0.03 1/s
Limitations
- The default values are typical reference figures, not measurements of your situation. Replace them with your own data whenever you have it.
- The result is an estimate based only on the values you type. Real situations often include factors this calculator does not know about.
- The calculation runs at full precision and only the display is rounded. If you copy an intermediate value and retype it, small differences can appear.