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WBPP Calibration Problem with Multiple Flats and Multiple Flat Darks

John Williams
in PixInsight
Flats and Flat Darks are not loading into WBPP so they can be properly calibrated for each filter automatically in the same instance at the same time. Even by loading in my Flat Darks separately via the Add Custom or by auto header detection. WBPP puts all the Flat Darks together instead of by each filter, even though each one has different exposure times.

Example: I have 20 Flats for Ha, Oiii and Sii for a particular target. I run NINA for sequence and automated capture control.  NINA has an automated wizard to take Flat frames and they call Flat Darks by the name of DarkFlats.  It automatically adjusts the exposure times for each filter to optimize the Flat and then creates the DarkFlat with the same exposure times. When I load into WBPP each set of Flats they are correctly separated by filter and exposure.  Each set of Flat Darks (Darkflat) however do load into the Darks tab, but all three are bunched together and it shows the three exposure times represented in the group in parentheses in the group title.  But you run Diagnostics and it says that only Bias frames will be used to calibrate two of the Flats.  As if to say that one of the Flats will be calibrated from the entire set of Flat Darks, but it's not seeing that there are three separate sets of Flat Darks. 

I suggest that they need to update WBPP to deal with Flat Darks specifically. That would mean adding one more Tab to isolate the Dark Flats from the Darks and properly align them to the Flats, or to place the Flat Darks specifically within the same tab as the Flats so as to put that calibration procedure together properly. It's almost done right now like an afterthought and not implemented correctly at least as much as I understand it now. The way it currently works I guess means I'll have to do each Flat with Flat Dark calibration separately. Please let me know if I'm missing something.

Comments

  • BlockHeadBlockHead
    I do think you are indeed missing something. 
    There is a tolerance parameter for the darks. If you lower the tolerance setting by a value smaller than the difference of your darks- they will all be separate. However, this implies that the darks need to match in time the flats or lights in order to calibrate properly. 

    On another note, if you have matching Flat Darks... there is no need for a bias frame (unless there is something special going on I am not aware of). 


    A couple of other things.. you wrote:"WBPP puts all the Flat Darks together instead of by each filter" ... of course darks are only matched by time. 

    You also mention NINA and its adjustment for exposure times. This is also an option in WBPP when using optimize. I strongly advise do not do this initially... match everything and have optimize unchecked.

    Have you had a chance to review my WBPP series? 

    -the Blockhead

  • John Williams
    Thanks Adam, I did go through the WBPP series but I don't remember that you had the same kind of situation. Now I'll have to go back to them to check.  Maybe that tolerance setting could help because there is not a lot of exposure time differences between the Flat Darks, but each set does exactly align with the Flats when captured in my data frames.  But WBPP loaded all the flat darks into one section as if they were all the same exposure time, but yet showed the three different exposure times in parenthesis at the title area of the section. Maybe that time tolerance will auto segregate them, I'll give it a try.
  • BlockHeadBlockHead
    Yes... It is "grouping" the exposure times based on the tolerance. So if you decrease the tolerance... viola... separated darks.
    -the Blockhead
  • John Williams
    I did verify and you did address this in your tutorial  videos, I'm sorry to have been a little too quick to draw conclusions.
  • BlockHeadBlockHead
    Happy Thanksgiving!!
    -the Blockhead
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