Over the years, some general rules of thumb have been applied to photography. We’ve talked about the Rule of Thirds in the past. The Sunny 16 Rule gives you the best results when used on a bright sunny day. I know that’s silly of me to state it but I wanted to be absolutely clear on the sunny part. Luckily for us, Orlando averages 233 sunny days per year (SOURCE).
Here is the rule: Set aperture to f/16 and shutter speed (in reciprocal seconds) to the ISO setting.
You will need to switch to manual mode to use this rule correctly. Something this rule fails to mention is the sun position. The sun should be behind you and frontlight your subject. The photograph I took below of the Haunted Mansion in the Magic Kingdom on a bright, sunny day uses the Sunny 16 Rule. I put my Nikon D70 in manual mode, checked the ISO setting which was at 200 and set my aperture to f/16 and shutter speed to 1/200th of a second (1/ISO).
The Haunted Mansion in bright sun.
Nikon D70/80-200D, 1/200s, f/16, 200 ISO, 155mm Focal length
Sometimes, the 1/ISO comes out with a funny shutter speed. In that case, use the closest one to it. Digital SLRs and advanced Point and Shoot cameras have more shutter speeds than the old film cameras the Sunny 16 Rule was first used with. Making it much easier to match up the 1/ISO with a shutter speed.