
7. Enable Shadows
-
Spotlight Selected
-
Properties menu >> Object Data button
-
Shadow tab >> Shadow checkbox

8. Only Shadow checkbox
-
Spotlight Selected
-
Properties menu >> Object Data button
-
Shadow tab >> Only Shadow checkbox
Note:
-
Only Shadow checkbox disabled: Shadow and light from spotlight
-
Only Shadow checkbox enabled: Shadow only. No light from spotlight.

9. Buffer Shadow Size
-
Spotlight Selected
-
Properties menu >> Object Data button
-
Shadow tab >> Quality: Size
-
Range: 128 to 10240 kilobytes
Note:
- A large shadow buffer size can overload a video card's frame buffer.
- If this happens, you won't see any real time shadows. If you are really unlucky, it will crash Blender 3D.