Non-point Source
For a non-point source of light, the shadow is divided into the umbra and penumbra. The wider the light source, the more blurred the shadow. If two penumbras overlap, the shadows appear to attract and merge. This is known as the Shadow Blister Effect.
If there are multiple light sources there are multiple shadows, with overlapping parts darker, or a combination of colors. For a person or object touching the surface, like a person standing on the ground, or a pole in the ground, these converge at the point of touch.
Read more about this topic: Shadow
Famous quotes containing the word source:
“As soon as man began considering himself the source of the highest meaning in the world and the measure of everything, the world began to lose its human dimension, and man began to lose control of it.”
—Václav Havel (b. 1936)