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Strange vertical lines

Pleiades Astrophoto PixInsight OIII Artifacts
9 replies•1.1k views
AstroRBA avatar
AstroRBA avatar
Hi All,

Probably an easy answer to this> ( I hope?)

This is a short O3 stack using WBPP  (about 18x600seconds, gain 100) with some bizzare vertical lines (image cropped and stars removed to show better)  - I got the same on a luminace stack as well but not on RGB or HA? (please ignore the dust motes - I need some new flats but this isnt flat related I'm sure)




Thanks!

Pete
Die Launische Diva avatar
Die Launische Diva avatar
Hello Pete,

you have probably forgot to disable Linear Defects Correction in WBPP. The aforementioned setting is irrelevant/unnecessary for CMOS sensors and tends to create such artifacts when the frames contain bright objects.
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Nathan Barnard avatar
Nathan Barnard avatar
It might not be much help but I experienced the same problem about 6 months ago. There was no reason for those lines to be in the data but for some reason they just were. They looked almost identical to yours and they were only visible for one filter on one night. I took my camera off of the scope and did a visual inspection, blew out the ports with canned air, and set everything back up. It went away as quickly as it came and I’ve not seen it since. For my situation I believe it must’ve been a weird software glitch, or a bad physical connection. Best of luck!
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Rob Calfee avatar
Rob Calfee avatar
Die Launische Diva:
Hello Pete,

you have probably forgot to disable Linear Defects Correction in WBPP. The aforementioned setting is irrelevant/unnecessary for CMOS sensors and tends to create such artifacts when the frames contain bright objects.

This was my problem at one time, too. Once I turned it off, it went away.
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Oleg Stas avatar
Oleg Stas avatar
Seems like reflection in the scope.
Alain L'ECOLIER avatar
Alain L'ECOLIER avatar
Hello Die Launische Diva
I had exactly the same problem with vertical lines
with WBPP in HA image integration
Your proposed solution of unchecking LDC in the Pipeline works perfectly. 
Thank you very much
Alain (France)
Scott Stirling avatar
Scott Stirling avatar
Same issue was recently reported here and in a PI Facebook group:

http://astroquest1.blogspot.com/2023/08/interesting-stacking-issue-with-sulfer.html

Vincent Peris Baixauli responded with the tip to disable linear column pattern correction on WBPP unless needed.

I don’t use WBPP but this issue has recently affected multiple users who have CMOS sensors and do not need the feature enabled.
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Quinn Groessl avatar
Quinn Groessl avatar
Thanks to the replies in this thread. I believe I've had the same issue months ago and never figured it out. I'm glad I keep all my subs and am going to reprocess some data today and see if it fixes it.

Edit: Thanks again to everybody here. I'll link the image I had trouble with. You can see pretty easily in the old revisions the lines that I was dealing with around the tip of the trunk, compared to the one I uploaded today. https://www.astrobin.com/dwecya/D/
Die Launische Diva avatar
Die Launische Diva avatar
Alain L'ECOLIER:
Hello Die Launische Diva
I had exactly the same problem with vertical lines
with WBPP in HA image integration
Your proposed solution of unchecking LDC in the Pipeline works perfectly. 
Thank you very much
Alain (France)

Hello Alain, I'm happy to hear that! Clear Skies!
AstroRBA avatar
AstroRBA avatar
Many thanks to everyone!

I disabled this (and removed two frames that were a bit out of whack with star size no lines apparent) and the issue vanished (I know, I did the "two things at once thing" but it worked in any case!)

Pete