As an analogue photographer, you have probably already heard someone speak about the "sunny 16" rule when it comes to determining the correct shutter speed and aperture combination. But what's this about? Read on and I will tell you.
Well, where did you have your head again? Now you’re standing there, wanting to take beautiful photos with your awesome analogue camera, but you left the light meter on the table at home. Something like that certainly happened to many of us, but this is not a reason to abandon shooting. To the rescue in this time of need is the “sunny 16” rule.
This rule says that when shooting under direct sunlight, the correct exposure time corresponds to the inverse of the film speed, with the aperture set to f/16. In other words, in the blazing sun, a 100 ISO film is exposed best at 1/100, and a 400 ISO film at 1/400, and so on.
But when the sun doesn’t shine so wonderfully during the rest of the year, you can to determine the correct exposure with the “sunny 16” rule. Just double the time if there are some clouds in the sky, or halve the aperture; with completely gray skies, just work with a factor of 4.
With this knowledge in mind, you can avoid the first mistake that could otherwise lead to overexposure. But the “sunny 16” rule is only a rough guide. Other things must also be considered, e.g. changing the aperture if you go under the shade. But surely, the “sunny 16” is better than a light meter left at home.