From BlenderWiki

Spot Raytraced Shadows

Spotlights can use either raytraced shadows or buffered shadows. Either of the two can provide various extra options. Raytraced shadows are generally more accurate, with extra capabilities such as transparent shadows, although they are quite slower to render. Buffered shadows are more complex to set up and involve more faking, but the speed of rendering is a definite advantage. Anyway, it shares with other lamp types common shadows options described here.

The raytraced shadows settings of this lamp are shared with other ones, and are described here.

See Also

• Shadows
• Common lamp shadows options
• Common lamp ray shadows options
• Spot light source
• Spot buffered shadows
• Spot halos