Lighting Tips
From Hash, Inc. WIKI
Size of a light/Definite shadows
The size of the light matters. The way to get definite shadows is to use raytraced shadows with two ray casts. Though this can shoot the rendertimes up a bit. (MB)
Raytraced shadow falloff
If you don't want automatic raytraced shadow fall-off, set the light's "width" to "0". (MH)
See also: