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I am preparing to render an animation, and I am experiencing banding colors on a background generated in Blender Internal using a world texture created with a color ramp:

enter image description here

The render generates banding as shown here, highlighted by brown dashed lines:

enter image description here

Earlier versions of the scene used a purer color selection... more in the deep-sea cobalt ranges, and I either did not see banding or there was none...?

Other settings that may be of interest:

enter image description here

Gaussian anti-aliasing on with 16 samples... and I have tried 11 and 8. It is present when no antialiasing is used, as well.

All input welcome!

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  • $\begingroup$ And, for what it is worth, turning mist off decreases the problem, but does not eliminate it... $\endgroup$
    – rcgauer
    Oct 15, 2016 at 23:13

1 Answer 1

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I am very appreciative of information found on blendhelp.com... (Has the site died?) https://www.youtube.com/watch?v=YwrTaXXSZsY

In any case, the solution to my banding involved:

** Select PNG output and 16-bit color depth

** In post-processing, select an appropriate dither amount. I worked between 1 and 2 and seem to get a nice smooth transition.

This explains why I did not see it earlier, as the original color range was probably narrow enough not to generate this banding.

Hope this helps someone in the future!

Please note all input from troy_s below, as these are really helping me dial this in. PNGs did not work as well as Targas, which do not seem to work as well as EXRs.

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    $\begingroup$ Better would have been a Half EXR container. PNG is a worthless format that both destroys your scene's data (useful if you are going to grade) and also uses an absolutely junk alpha format. Also, bear in mind that posterization is a byproduct of what is known as perceptual quantization. Changing your transfer curve can reduce or eliminate posterization. The sRGB EOTF is quite awful at quantizing data from scene referred data. $\endgroup$
    – troy_s
    Oct 16, 2016 at 19:56
  • $\begingroup$ troy_s I ended up using TGA... I also tried exr, but I am getting good results with targa with a little less file size... and I am going to mess with curves as soon as I get some frames rendered as a starting point... Thanks or the helpful information. $\endgroup$
    – rcgauer
    Oct 16, 2016 at 21:53
  • $\begingroup$ The problem is that TGA is also display referred, and I suspect that Blender will mangle up the alpha. I'd strongly encourage you to go with Half EXR at the very least. It's quite easy to demonstrate the reasons why if you are at all interested. You can also try the compressed EXRs if disk size is an issue. $\endgroup$
    – troy_s
    Oct 16, 2016 at 22:13
  • $\begingroup$ will do so! Anxious to see... $\endgroup$
    – rcgauer
    Oct 16, 2016 at 23:19
  • $\begingroup$ To start, you might want to learn about scene referred versus display referred models. Try this post to start blender.stackexchange.com/questions/46825/… $\endgroup$
    – troy_s
    Oct 17, 2016 at 3:17

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