PixInsight Forum (historical)

PixInsight => General => Topic started by: RadOD on 2018 July 19 17:51:41

Title: What kind of image artifacts are these?
Post by: RadOD on 2018 July 19 17:51:41

Any advice on what is causing these?  In particular I see a thick diagonal hazy band bottom right.  I similar thin horizontal band at the level of the core. And color splotchiness I've exaggerated in the second image.

(https://s15.postimg.cc/l48qi7e2z/Capture.png)

(https://s15.postimg.cc/txzmz0qob/Capture.png)

To the integrated image I have
1. Auto background extracted
2. Background neutralized
3. Photometric color calibrated.

Images were acquired DSLR RAW and integrated with dark, bias and flats using the method described here: http://lightvortexastronomy.com/tutorial-pre-processing-calibrating-and-stacking-images-in-pixinsight.html

Any advice on whether this is from acquisition or processing or both?

Title: Re: What kind of image artifacts are these?
Post by: pfile on 2018 July 19 19:01:25

could be the ABE step, or could just be LP gradients... what does the raw stack look like without any processing?

rob

Title: Re: What kind of image artifacts are these?
Post by: RadOD on 2018 July 19 19:58:20

I think you must be correct about the first two.  Here is the integrated image with only an increase in contrast:

(https://s15.postimg.cc/s1c3ltc63/Capture.png)


Splotchiness looks like chrominance noise described here? https://pixinsight.com/forum/index.php?topic=5498.msg37760#msg37760

Title: Re: What kind of image artifacts are these?
Post by: pfile on 2018 July 19 21:11:44

yes that kind of color noise is pretty common with a DSLR... also was the image dithered? i feel like is see some 'walking' or 'rain' noise (diagonal streaks) in there as well

rob