Diagnose 26 of 29 Processing

Plastic background

The background is smooth and blotchy, like wax, with no grain.

At 100 %: Empty sky after noise reduction. No fine grain at all, only soft blotches.
Causes, most likely first: Too much noise reduction
Noise reduction pushed past what the data supports smooths the grain into soft blotches.
FixUse less noise reduction, and leave some grain.
Looks like, but isn't: Too little integration, smoothed over
Look at the stack before noise reduction. If it is very noisy, more hours will help more than a lighter touch.
One frame can't tell you: The finished image shows the texture. Whether the data needed that much smoothing shows only in the stack before noise reduction.
How to confirm the fix: A background with fine, even grain and no blotches at full size.
Sources: No outside source is cited here. The signature, the causes and their order are the atlas’s own, from imaging experience. The order is a judgment of likelihood; no measured frequency is behind it.

In the symptom picker

The background is smooth and blotchy, like wax, with no grainweight 3
It appeared after sharpening, deconvolution, noise reduction or star removalweight 2