#shotonlightmeter
Pocket film camera
sunny 16 calculator
The oldest light meter there is: in bright sun, a film is correctly exposed at f/16 with the shutter set to about one over its speed. ISO 400 film, bright sun, f/16 — shoot it at 1/400. Everything else follows from there, a stop at a time.
aperturef/16
shutter1/500
ISO 400 · bright sun · hard shadows with sharp edges
| Aperture | Shutter |
|---|---|
| f/1.4 | needs an ND filter |
| f/2 | needs an ND filter |
| f/2.8 | needs an ND filter |
| f/4 | needs an ND filter |
| f/5.6 | 1/4000 sec |
| f/8 | 1/2000 sec |
| f/11 | 1/1000 sec |
| f/16 | 1/500 sec |
| f/22 | 1/250 sec |
why the pairs all work
Closing the aperture one stop halves the light, so the shutter has to stay open twice as long to match. Every row in that table is the same exposure, reached a different way — pick the one that suits what you are shooting. A fast shutter to freeze a moving subject, a wide aperture to throw the background out of focus.
where the rule runs out
It assumes front-lit, average subjects in open air. Backlight, snow, a dark interior or a subject much lighter or darker than its surroundings will all pull it off. That is the point at which you want a reading of the actual scene rather than a rule of thumb — which is what Lightmeter does, off the phone in your pocket.
Private by design
Launching soon