sunbeams

Sunbeams are shafts of sunlight that become visible when light from the sun is scattered by particles in the atmosphere or when it passes through gaps in clouds. The phenomenon occurs because atmospheric molecules, dust, and water droplets scatter some of the light toward the observer, making narrow, bright columns that stand out against the darker surroundings. The beams themselves travel in straight lines, but only portions are visible; the space between them may appear darker because less light is scattered toward the eye.

Visibility is enhanced when the sun is low on the horizon, and when the atmosphere contains enough aerosols or mist. Sunbeams are commonly observed in forests, canyons, or over open water where sunlight streams through openings in cloud cover or through gaps in the foliage.

When sunbeams pass through clouds, the bright columns are often called crepuscular rays, especially during sunrise or sunset. If seen on the opposite side of the sky, they are termed anticrepuscular rays. The term "god rays" is a lay term used in photography and popular culture.

In photography and visual observation, exposure and contrast can influence the apparent intensity of sunbeams; long-distance perspective makes parallel rays appear to diverge toward the horizon.