The sun, source of natural light and of life itself, is a potent photographic image, stirring feelings and memories that lie below the level of consciousness. Although its sheer energy and intensity make it difficult to handle, its presence never fails to give vitality to landscapes or seascapes, and its hues varying from white to blood red may decide the whole balance and mood of a color photograph.
Taken directly, in the middle of the day, the sun will burn out a picture, and causing flare or halation. But there are many ways of avoiding this, some of them illustrated here. By photographing the sun when it is rising or setting, obscured by cloud or haze, shining through translucent materials or half-hidden by foreground objects, accurate exposures can be calculated, especially if half-filters, polarizing or neutral-density filters are used. A reading from a weak sun should be taken about 25º off-center. Remember, however, that the light intensity changes rapidly at dawn or sunset. So recheck constantly and vary exposures by one stop either side. Use of a long lens and the inclusion of a distant object, particularly one with a sympathetic shape, will help to show the sun at a suitable size. Unless you are prepared to leave the body of the picture to reproduce as a complete silhouette, it is usually necessary to allow the sun to burn out a little.
Although the sun is the ultimate source of natural illumination, the sky, in its infinite variety of atmospheric moods, is the great mediating influence in all outdoor photographs. Purely as a background, its colors, varying from blood red to the palest shades of blue, can determine whether the atmosphere of a picture is calm or turbulent nous or happy. Depending on whether it is clear or overcast, the sky constantly alters the hues of the world below. And as a subject in its own right, it offers a marvelous range of material as cumulus clouds form and re-form in sculptural shapes, or as cirrus clouds create delicate patterns of light and shade, tone and hue.
The best cloud effects are found at times of change and transition – autumn and spring, at dawn or at dusk, before or after storms – often when most people are still in bed or huddled around fires. In mountainous country, thermals give added interest as wind currents push clouds up and over the peaks. When traveling you should look out for landscape features or buildings that will record well against the sky which can bring alive even the least interesting countryside or dullest stretch of water.
In photographing the sky, either as a substantial part of the background or as the main subject, exposure is often a problem, especially if foreground detail is to be included. A bright sky may need up to four stops less exposure than the land it illuminates. If exposure is calculated for the sky alone the foreground will block up into dense shadow with silhouetted features. Exposure for the foreground, on the other hand, will show the sky as a flat, featureless area of white. Averaging the two-meter readings does not always solve the problem, although an adjustment of the angle of view will help. A better solution is to watch out for reflective surfaces a road, wall, or stretch of water-that will act as a link between sky and ground, reducing the contrast. Partial filters can be used to filter the light from only half the scene and a polarizing filter will darken the sky and increase cloud contrast without creating a color cast.