Artifacts after stacking

AndreyGapulenko

AndreyGapulenko

Member
Good day to you!

After stacking, I get these artifacts in my photo.

Flats made and applied. All settings are stock.

On Fltas, too, there are such artifacts and i think after stacking they must leave, but do not leave.

Can you please tell me what the problem is?

Screenshot_8.jpg
 
Hello @AndreyGapulenko
This is a flat correction issue: either your flats don't match your lights exactly, or it's a pure calibration issue.

Have you used WBPP?
How did you calibrate your flats?
Can you share a light frame and your masterflat?
 
AndreyGapulenko said:
nico1038 said:
How did you calibrate your flats?
Click to expand...
In WBPP
Click to expand...
Ok but did you input bias (or darks) in WBPP to calibrate your flats?

I can't see any movement in the dust spots between the lights and the masterflat so I believe it is a calibration issue.
If you did use bias, can you verify that their gain and offset match your flats?
Have you used yourAsiair to acquire all your calibration frames?
 
Found information on the forum that reflections or optical problems, such as reflection from a reducer, can create artifacts that cannot be fixed with FLAT frames. It looks like it’s going to be a cloudless night - I’ll try to photo without reducer|flattener.
 
AndreyGapulenko said:
Found information on the forum that reflections or optical problems, such as reflection from a reducer, can create artifacts that cannot be fixed with FLAT frames
Click to expand...
I don't think that is your problem. The artifacts in you image in post #1 look to me like slight calibration scaling errors, which can occur as the result of small offsets between dark-corrected lights and flats. To check this it would be useful to upload the masterDark used for calibration. I am interpreting your posts above as saying your flats were calibrated with a masterBias (rather than matching darks). If so, could you also upload the masterBias and a single representative (uncalibrated) flat.
AndreyGapulenko said:
Do I understand correctly that BIAS is done at the least possible camera exposure?
Click to expand...
Yes (and with the aperture covered, just like darks).
 
fredvanner said:
I am interpreting your posts above as saying your flats were calibrated with a masterBias (rather than matching darks). If so, could you also upload the masterBias and a single representative (uncalibrated) flat.
Click to expand...
I'm new to this and I do everything standardly. I made all the calibration files: BIAS, DARK, FLAT. I calibrated everything as standard in WBP without changing anything. I see all these artifacts on the FLAT, but I can't understand why they are not subtracted.

Here is the link for the final stacking files - https://drive.google.com/drive/folders/1axTemOWrFICvPOCoqYvaipq24Zyb1Qht?usp=drive_link

And in the Uncalibrated folder there are one uncalibrated files each. I would be very grateful for a hint on what to do and what the problem is(

P.S. maybe the problem is that I use two types of LIGHT files (before and after meridian flip)?
 
Hello @AndreyGapulenko

I can't see anything really obvious but your bias files are quite old, taken with a previous version of the Asiair software and the gain is not strictly the same as your other files (101 vs 100).
I would try to take bias again and reprocess your files with these new bias to see if the result is better.

The meridian flip shouldn't make any differences in the preprocessing of your files
 
AndreyGapulenko said:
I'm new to this and I do everything standardly. I made all the calibration files: BIAS, DARK, FLAT. I calibrated everything as standard in WBP without changing anything. I see all these artifacts on the FLAT, but I can't understand why they are not subtracted.

Here is the link for the final stacking files - https://drive.google.com/drive/folders/1axTemOWrFICvPOCoqYvaipq24Zyb1Qht?usp=drive_link

And in the Uncalibrated folder there are one uncalibrated files each. I would be very grateful for a hint on what to do and what the problem is(

P.S. maybe the problem is that I use two types of LIGHT files (before and after meridian flip)?
Click to expand...
Why are your source darks and biases debayered, and your flats not? (This propagates through to the masters, as well.)
 
nico1038 said:
Hello @AndreyGapulenko

I can't see anything really obvious but your bias files are quite old, taken with a previous version of the Asiair software and the gain is not strictly the same as your other files (101 vs 100).
I would try to take bias again and reprocess your files with these new bias to see if the result is better.

The meridian flip shouldn't make any differences in the preprocessing of your files
Click to expand...
I don't deal much with CFA images, but to my eyes the histogram of the flat looks odd. The low red signal might be an issue, but I don't understand why the green and blue channels look virtually identical.

Screenshot 2024-03-17 121025.png
 
I did a quick WBPP test run with your raw lights and I get what seems to be a very good flat correction. I can't see any dust spots
Can you post your WBPP log?
 
nico1038 said:
I did a quick WBPP test run with your raw lights and I get what seems to be a very good flat correction. I can't see any dust spots
Can you post your WBPP log?
Click to expand...
I deleted all the logs. Now I will do the same as before and with the new BIAS. And I'll post everything after
 
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