Diagnose 24 of 29 Processing
Star bloat from stretching
Stars grow large and pale as the nebula is stretched.
A labeled frame from our own archive, with its acquisition data, is coming to this page.
- At 100 %
The stretched image beside the linear stack. Stars that were small in the stack are now wide and washed out.
- Causes, most likely first
Stretching the stars along with the nebula
A stretch strong enough for faint nebulosity also lifts the faint outer parts of every star, so the stars swell.
FixSeparate the stars from the nebula before stretching, stretch them less, and recombine.
No star separation
Without star removal there is no way to stretch the stars less than the nebula.
FixRemove the stars with StarNet2, which is free, stretch the starless image, then add the stars back.
- Looks like, but isn't
If the stars are fat in the linear stack too, it is a focus problem. Check the stack first.
- One frame can't tell you
The finished image cannot separate this from soft focus. The linear stack can.
- How to confirm the fix
Stars in the final image no larger than in a screen stretch of the linear stack.
- 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
- Stars grew large and pale as the nebula was stretchedweight 3
- The linear stack looks fine; the problem appears when you stretchweight 3
- Stars are round but fat, everywhere in the frameweight 1
Tools for this
- Processing Pathnot built yet
Last updated All 29 failure modes, and the symptom picker