To become familiar with the nature of outdoor lighting, you should have a clear impression of the basic daylight lighting conditions and the exposures they require. Even though most 35 mm cameras have built-in exposure meters, you can use the exposure guidelines to verify that you're using your exposure meter correctly or to determine the correct exposure to use if your meter is not working properly. The sun is shining with a blue sky or the sun is covered with a thin haze. The sun is unobstructed and clearly defined, though scattered clouds may be present.
Shadows are sharp and distinct.
You can use this formula to find the exposure if you don't have an exposure meter or if your meter is in need of repair. We will refer to this basic exposure in our discussion of other lighting conditions. The sun and sky condition is the same as for the first lighting condition given above, but the subjects are on very light sand or snow. Since these bright surfaces reflect a lot of light, the recommended exposure is 1 stop less than the basic exposure for average subjects. Note that the exposure corrections given in this section are for use with the basic daylight exposure defined on above, not with exposure meter readings.