I triple-checked the FITS headers, and everything matches between the lights and darks—exposure time, gain, offset, temperature, binning, all aligned.
The patch is near the edge of the frame, so I initially thought it wouldn’t be a big deal. But it’s actually throwing off background extraction a bit, and I’d really like to get it sorted before going any further with this project. In the image I posted below, it doesn’t look too bad at first glance, but the artifact gets worse the more I stretch the data.
I’m using the default calibration settings in WBPP and don’t recall this happening before. Any thoughts?
Also this problem seems to happen with my Ha only. I captured Luminance with same 300s Darks and it turned out fine. WBPP version 2.8.4.
I have another setup at home with same camera (I have two 294mm Pro's) and it is also showing a similar behavior in Ha. The elephant's trunk nebula and the M82 is from my setup at home and the Markarian's chain is from remote observatory.
Adam Block suggested to use a pedestal value which I did and I am still getting the same result on both my setups. There are no light leaks in the master darks from both cameras.
Any help will be greatly appreciated. Posting 3 different targets from 2 different cameras (both 294mm's) at 2 different locations. This issue is recent. Never had it before.
. The fact it doesn't show in the L case is because the background is so bright relative to the Ha case but that tiny difference quickly builds up when you stack. The way to manage this is ditch WBPP and check what happens when you calibrate the frames. If you can share the raw frames and the darks I can check them for you (I also have the same camera so this will be making things easier).
