Volumetric Halo Spotlight Banding


I have made at least two dozen attempts to get rid of the banding shown in the attached image.

Here are some relevant settings.

  • Lamp. Dist: 15, Energy: 1.25, Red: 0.637
  • Shadow and Spot. Buf.Shadow. SpotSi: 75.00, SpotBl: 0.250, HaloInt: 1.000, ShadowBufferSize: 10240, Samples: 16, Halo step: 1, Bias: 1.000, Soft: 100.00
  • Clippings. ClipSta: 0.5, ClipEnd: 11.25
  • OSA. 16I have changed the Dither settings from 0 to 1 to 2 with no difference in banding (with either the volumetric haze, or the shadow of the spheres).

I have even tried rendering with only 1 Xparts and 1 Yparts.

I’ve toyed around with the amount of energy in the spotlight. I’ve moved about the Halo step from 1 to 12 (uses more CPU time, but the banding remains).

Alas, the banding stays edgy and undithered. At this point, I figure I should just run a blur in The GIMP to try and convince the banding that it really is a smooth gradient.

Turning up the energy level of the spotlight seems to help … but then that changes the feeling of the scene.

Any ideas? (Blender version 2.45, 32-bit on Linux, fwiw.)


Hmmm. It seems that part of the problem was in the render window. When I loaded the second image into The GIMP, the banding was no longer visible.

Still, any tips to eliminate banding that I may have missed are most welcome!

It seems that your video card is set to display colors with 16 bit accuracy. Set it to 24 of 32 bits.