Heya guys!
Can anyone help identify the issues in this stacked image please 🙂
Shot during a full Moon – which I believe caused the large halo and streak?
I'm really struggling to identify the smaller "coffee stain" artifacts.
Calibrated with flats, biases, and darks. I've checked all 3 masters and can't see the artifacts, which makes me think its isolated to the light frames.
Processed in Siril – OSC_Preprocessing + manually discarded poor frames.
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Shot 02.01.26
Bortle – 6/7
Target: Horse head
240x30sec
Askar 80ED + 0.85x
SV605CC – cooled -10c
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ps- Are there any websites/tools which catalogue common visual artifacts in astrophotography?
Cheers!
by Cracksi
7 Comments
Try posting in r/AskAstrophotography . you will get more answers there.
As for the blemishes, it looks like your flats dont align with your lights
Do you have a dew heater strip for the front of your lens? If not try that and work from there. If you still have trouble upload your individual dark/flat/bias frames and a subset of like 20 light frames and ping me to check on it
This is definitely an issue with flats. Looks almost like you took flats with dew on the lens
Yeah there’s something wrong with the way flats are being used here and also yes this is the result of a full moon
How old are your flats? Were they done after that session?
I think there is an issue with the stacking program as well. Probably because its having a hard time aligning the images or the rejection algorithm has gone haywire. Have you tried stacking in another program?
The black spots are from dust, dirt, or debris on the camera and not the telescope is what I would bet. The darker and more defined the spot it, the closer to the camera it is.
The distortion around Alnitak is very concerning because that looks like an optical issue. But I dont really see the same distortion on other bright stars.
The halo is definitely from the moon. Not much you can do about that.
try stacking without flats, if you have bad flat data your stack will show mumbo jumbo like this
I would definitely reshoot your darks and flats and retry calibration, I had this issue in the past with bad calibration frames