Sunny 16 Rule

The essential part of the Sunny-16 rule is that you set the shutter speed nearest to the film speed. All the following items are based on that assumption. You can change the EV any way you want, of course. The lighting conditions are for frontlit subjects. The rule is supposed to be good from 2 hours after sunrise to 2 hours before sunet.

1. In bright or hazy sun on light sand or snow, use f/22.
2. In bright or hazy sunshine with disctint shadows, set the aperture to f/16.
3. If the sun is dimmer, weak and or hazy with soft shadows, open up one stop to f/11. Use f/5.6 for closeups of backlit subjects
4. If it is cloudy and bright, such as a light overcast, and there are no shadows, open up to f/8.
5. If under heavy overcast or in open shade, open up to f/5.6

I have seen a variation of this model which closes down everything by 1 stop. Bright light with light background is f/16, bright sun is f/11, etc. Most of my experience tends to agree with the bright sun is f/16 variant, but I wanted to mention the other.

Possible generalizations and deltas to the above ruleset might be:

• If close to a back-lit subject, open up two stops (f/16 to f/8, f/11 to f/5.6).
• If close to a side-lit subject, open up one stop (f/16 to f/11, etc).
• A more general version of the first rule might be to close down a stop if the background reflects a lot of light.