WBPP Flats not correcting

Dan Kohn:
I have been having a problem with WBPP correctly identifying the dark and flat masters, I've needed to manually assign them in the calibration tab (and also requires restarts of WBPP as dark and flat masters are generated, the next step is not finding the newly created master).  Sounds like you are having a similar issue if the linking icon is going away.

Sam Badcock:
Hi all,

Recently I’ve noticed a problem with my flats not correcting properly and leaving the remnants of the large dust mote on my lights!! It’s only a single dust mote along the top edge but that’s besides the point!!

Now in WBPP I load all the frames required, add relevant keywords (generally *NIGHT* and filter names) then manually link each filter and corresponding flat frame

Execute WBPP everything runs smoothly

Once WBPP has finished and you end back up in the original window, I notice on my light frames in the calibration tab some of the chain links have disappeared in the flats column 

Anyone know what’s going on here or is this a potential bug??

When I get to the computer and it happens again I’ll attach screenshots

Christoph Nieswand:
Since 1.9.3 they did some changes in the keyword handling and automatic linking of master flats and darks. Especially when you define your proper keyword FILTER. It seems to be used internally by some specific logic and seems to collide with a custom keyword FILTER. Give it a different name or rely completely on the internal mechanism on determining the filter from FITS header keywords in the file.

Rick Schneider:
Since my last PI upgrade, I'm having the same issue as Dan: WBPP not finding the path to the newly created masters, so requiring restarts with the new masters loaded directly. But this doesn't sound like Sam's problem, as WBPP is running to completion without failure, just not calibrating properly.

Rick Schneider:

Sam Badcock:

Rick Schneider:
Since my last PI upgrade, I'm having the same issue as Dan: WBPP not finding the path to the newly created masters, so requiring restarts with the new masters loaded directly. But this doesn't sound like Sam's problem, as WBPP is running to completion without failure, just not calibrating properly.

What if …. Hear me out ….. it’s the same problem or atleast similar BUT WBPP doesn’t always throw and error??

Could be - easy to check - just load WBPP with your already created calibration masters and run again, and see if it fixes your problem

Terry Doran:
Have you tried different exposure levels for your flats?  I find I need lower exposures for flats when using a tri-band filter for instance.  I also find auto exposures for flats with ASIAIRs are far too bright.

Jeff Bennett:
From GROK:  
Summary

• New Flats Per Session?: Not required if your ASI2600MM Pro setup is stable (no optical changes, clean filters/sensor). Reuse master flats for weeks or months, but capture new flats if you adjust the rig, notice dust, or change filters.
• Verification: Test reused flats by checking calibrated lights for artifacts. If issues arise, take new flats (20–50 per filter, ~25,000 ADU).
• WBPP: Load master flats or new flats in WBPP, match with bias or flat darks, and verify calibration links.

If you have specific setup details (e.g., filter changes, dust issues, or flat exposure times), or encounter WBPP errors, provide them, and I’ll refine the guidance. For further help, consult the PixInsight Forum or ZWO’s ASI2600MM Pro documentation.


Version 1.9 Lockhart Notes

• Stability: Update to 1.9.3 for WBPP bug fixes (e.g., alignment, calibration issues). Check via Resources > Updates.
• Metadata: Ensure flats and lights have consistent FITS headers (FILTER, EXPTIME, GAIN, OFFSET) to avoid grouping errors in WBPP’s XISF-based metadata handling.
• Performance: 1.9.3’s thread optimization speeds up flat calibration but doesn’t affect flat frequency requirements.

Vandewattyne:
Do it the old way, I calibrate my files manually and use WBPP oly for normalisation and stacking. You have more control what you do and you see if something is wrong after a few calibration. Putting your flatdarks in your bias can help with issues whet not correcting flats on your frames.