Difficult background extraction/Improper flats calibration

m_abukhalid

Well-known member
Seems like each image presents its own challenge. This one was taken on a night with a full moon, but despite all precautions, it looks like I have strong reflections in the image/flats and the resulting stacked image after ABE looks like this:
veil_noOpt.png


Images were taken with a DSLR on a 6 inch newtonian through an LPro filter and a coma corrector. During imaging I had the camera and focuser covered as such so Im not sure where these rings are coming from. In any case, I was hoping someone could see if its possible to properly flatten this image using DBE. I spent a lot of time and they seemed quite persistent. They remain as a brownish ring. Theres good data and Id like to salvage this if possible.

The best way to resolve this is proper calibration... I have flats, darks, flat darks, and a superbias based on data less than 3 weeks old. I am not using the biases anymore and simply calibrating flats with flat darks (as a bias), and lights with the flat and dark masters with optimization and calibration disabled. I tried this with optimization enabled and used my superbias but the result was slightly worse. I also noticed that pixinsight was applying k0 factors >1 to several of the images which was odd to me. I have some sample files available at the following link if someone can help me figure out the calibration issue or perhaps how to process the problem out of the stacked image:
https://drive.google.com/drive/folders/1oMtTOAjfxHvPjLR-Wo9v5SUA1l6NQ8dD?usp=sharing

Thanks in advance for your help!
 

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if the gradient is difficult, do not use AEB, it does more harm than good. try DBE with carefully placed sample points and the smoothing factor turned to 0 and see if it helps.
 
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