Diagnose 29 of 29 Processing

Edge artifacts

Odd frames, streaks or stacking seams run along the borders of the stacked image.

At 100 %: Each edge of the stack, zoomed out. A band along the border looks different from the rest of the image.
Causes, most likely first: Not cropped after registration
Registration shifts each sub to line up the stars, so near the edges not every sub covers every pixel.
FixCrop the stack to the area every sub covers.
Dithering moved the stack around
Dithering shifts each frame on purpose, which widens the ragged border.
FixCrop the stack to the area every sub covers, and keep dithering.
Looks like, but isn't: The atlas lists no look-alike for this one.
One frame can't tell you: A single sub does not have this. It appears in the stack.
How to confirm the fix: A cropped stack with no seams or bands at any edge.
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.

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