The Direction Of Light
The direction that light is coming from relative to your camera's position is important because it affects the shadows that will be visible in your picture. Four main types of lighting are illustrated here: side-lighting, front-lighting, backlighting, and top-lighting. Notice the position of the shadows in these photographs and how they affect the subjects.
Side-lighting increases the sense of texture and volume because such cross-lighting casts shadows visible from the camera's position that emphasize surface details. Landscape photographers often prefer to work early in the morning or late in the day because the sun low in the sky will sidelight scenes and add interesting surface textures.
Front-lighting decreases visible shadows and so minimizes surface details such as skin texture. Front-lighting also tends to minimize the apparent roundness
or volume of the subject.
Backlighting puts the side of the subject that is facing the camera in shade. Automatic exposure tends to make backlit scenes too dark. You can add exposure to lighten the picture, especially those parts that are in shade.
Top-lighting can occur outdoors at noon or indoors in public buildings or other places where ceiling lights predominate. If you are photographing a person, you will notice that top-lighting tends to cast shadows in eyesockets and illuminate the top of the nose brightly. To avoid this effect, you might try moving the person into the shade.
Top-lighting, such as that found at midday, can selectively
illuminate things, such as this flag in the man's back pocket, that would be in shadow with light
coming from a lower angle.