Photo Tip #6-The Sunny F/16 Rule
Learn what the “Sunny F/16” rule is and how to use it (From the wikipedia: “On a sunny day set aperture to f/16 and shutter speed to the reciprocal of the ISO/ASA or file speed.”) For example, on a sunny, cloudless day, if you’re shooting at ISO 100, set your camera to F/16 and your shutter speed to 1/100th of a second for proper exposure. Try using the F/16 rule without checking the meter in either your camera or a hand-held light meter. After you have set it manually, then allow your camera (or light meter) to meter the subject and see how close you can come by “guessing” at proper exposure.
Training yourself to shoot in manual mode, without the help of a meter (or your camera’s built-in meter) will teach you a lot about lighting and help train your eye to see various lighting conditions.