For most photographers, luminance photometers aren't practical. When the moon's luminance can't be measured, it can often be estimated, and exposure determined accordingly. Table 1 gives the approximate luminance of the full moon at various altitudes above the horizon. The best exposure usually is based on the landscape, but may require some adjustment from the meter indication. As the sky grows darker and the moon moves higher, the contrast between the moon and the foreground can pose an additional challenge.
Exposure meters render whatever they measure as a middle tone.
This works well for daytime landscapes, but is usually less effective for evening scenes. Often, the most effective way to convey the feeling of twilight in a scene facing opposite the setting sun is to control the rendering of the sky. Doing so usually also results in a satisfactory rendering of the foreground. During the first few minutes after sunset, basing exposure on the meter reading usually is a good choice. When the pink in the sky has given way to the blue of the earth's shadow, the rendering can be slightly darker, perhaps one step less than the meter indication.