§ 11 — Tools / 01Light & exposure● Runs in your browser
Equivalent exposure calculator
Change aperture, shutter speed or ISO and keep the same exposure. Every matching combination, in full or third stops.
All tools- Solved shutter
- 1/500 s
- New exposure
- f/4 · 1/500 sISO 100
- EV100
- 13Metered f/8, 1/125 s, ISO 100. New settings: EV100 13.
| Aperture | Shutter at ISO 100 |
|---|---|
| f/1 | 1/8,000 s |
| f/1.4 | 1/4,000 s |
| f/2 | 1/2,000 s |
| f/2.8 | 1/1,000 s |
| f/4 | 1/500 s |
| f/5.6 | 1/250 s |
| f/8 | 1/125 s |
| f/11 | 1/60 s |
| f/16 | 1/30 s |
| f/22 | 1/15 s |
| f/32 | 1/8 s |
How it works
The method behind the numbers.
Exposure value ties aperture and shutter speed into one number: the amount of light a scene needs. Any aperture, shutter and ISO with the same value expose the picture the same way, only the look changes. A wider aperture lets in more light and thins the depth of field, a slower shutter blurs motion, a higher ISO adds noise.
EV = log2(N² ÷ t)
EV100 = log2(N² ÷ t) − log2(ISO ÷ 100)
N² ÷ (t × ISO) stays constant between equivalentsN is the f-number, t the shutter time in seconds. EV100 is the value normalised to ISO 100, so it is the same for every ISO you shoot at.
- Enter what your meter reads, pick the value to solve for, then change the other two. The unchosen settings start equal to the metered ones, so a lone change is one clean trade.
- Results snap to the nearest mark on a third-stop scale. Marked values are rounded (1/125 s is really 1/128 s), so a result can sit a few hundredths of a stop off.
- A value is flagged when it lies beyond the ends of the scale: 1/8000 s to 30 s, f/1 to f/32, ISO 50 to 102400. Your camera may stop sooner.