Star defects

[StefanT]

Ivo,

I'm not sure, whether this is a ST-bug or not. Quite often stars in my images have coloured "edges" and/or "holes" as you can see in the following cropped image:

Image after initial auto-dev

StarDefect-ST.jpg (281.6 KiB) Viewed 5087 times

If I take a look at the original FTS, the holes and edges are not there:

[StefanT]

FITS-Image as seen in FITS-Work

NoStarDefect-FitsWork.jpg (156.63 KiB) Viewed 5086 times

This is how it looks in FITSWork. I don't have the slightest idea what goes wrong - any idea?

The original file is available here
https://www.dropbox.com/s/9y5369fjirv5v ... ctTest.fit

Please excuse the bad image quality an the heavy CAs - I'm using old M42 lenses at the moment....
Thanks in advance - let me know if I can be of any help

Stefan

[admin]

While I'm not sure how to replicate this, looking at the data, it seems that what appears to be saturated in the source image is not, in fact, completely saturated. There is color information there that can be recovered (and StarTools does so, while other software will happily destroy/desaturate it). The color information that is there seems to be anomalous though, possibly caused by misalignment, the chromatic abrration or somethingthat went wrong during stacking.

StarDefectTest.jpg (9.46 KiB) Viewed 5077 times

If you want to though, you can white out or overexpose the star cores by various means.

[StefanT]

Thanks, Ivo! I'll keep on investigating...