Wikipedia
Contre-jour
Contre-jour ( French for "against daylight") is a photographic technique in which the camera is pointing directly toward a source of light.
Contre-jour produces backlighting of the subject. This effect usually hides details, causes a stronger contrast between light and dark, creates silhouettes and emphasizes lines and shapes. The sun, or other light source, is often seen as either a bright spot or as a strong glare behind the subject. Fill light may be used to illuminate the side of the subject facing toward the camera. Silhouetting occurs when there is a lighting ratio of 16:1 or more; at lower ratios such as 8:1 the result is instead called low-key lighting.