Problems with flats in WBPP

D

dpdallolmo@aol.com

Well-known member
Hello,
I am having trouble with WBPP. I am obtaining images with a ZWO ASI 2600 CMOS camera. My lights are 600 sec in duration at -10C. I have a library of darks and typically use a matching master dark (600 sec, same temp etc). I typically will use a master bias to calibrate my flats. I typically take flats (#25) after every session.
So I add my light frames and my flat frames to WBPP. I then add my master dark and master bias. I check "use master bias" and "use master dark" in the global options section. Use master flat remains unchecked.
On the flats page, I have checked "Calibrate with flat darks". Everything else on that page is defaults.
On the lights page, I use Cos Correction, Debayer, subframe weights and apply image registration. I typically do image integration after WBPP has completed.
Under Global options all are checked EXCEPT "optimize dark frames and "Use master flat".

Now is where I have a problem.
When I check the Diagnostics, I get a 2 warnings
#1) "only master bias will be used to calibrate flat frames".....This I expect as I am asking WBPP to do that

#2) "No matching master flat frame have been found to calibrate light frames"
This is my problem....I don't have a master flat frame yet it says one can't be found. What's worse is, if I run the program, flats never get "subtracted" so I see my dust motes. If I first create a master flat, then add that in place of the 25 individual flats and check "use master flat", I get the same warning...No master flat found to calibrate the light frames.
Again, if I run WBPP, my images still show the dust motes as if no flats were factored into the WBPP process.
Any Idea why WBPP does not seem to recognize either my individual flats or a master flat?
Thanks,
Dan
 
well I tried something something that worked. I retook my flats with my camera cooled to the same temp as the lights. The warning in WBPP no longer appears. I also retook flats for this object with the camera NOT cooled. The warning re-appeared. I suspect my flats need to be of the same temp as my subs although for the life of me, I don't understand that. This is a new camera for me and I'm still learning the ins and outs of it. I use SGP for my session management software. I don't know if flats need to be taken in the "sequence" or if they can be taken in their own sequence. I'll figure it out. Anyway....Cancel the crisis :)
 
the temp shouldnt matter... i don't think any part of PI considers the temperature at all. when you run the diagnostics, what does the error say? could it be that for whatever reason there is a mismatch between the filter name for the lights and for the flats?

rob
 
pfile said:
the temp shouldnt matter... i don't think any part of PI considers the temperature at all. when you run the diagnostics, what does the error say? could it be that for whatever reason there is a mismatch between the filter name for the lights and for the flats?

rob
Click to expand...
"No matching master flat frame have been found to calibrate light frames" This is the warning message I get when trying to use non cooled flats for calibration. I just checked the nomenclature of images to make sure they are identical except for "frame type" (i.e. lights of flats). Don't know if the nomenclature has anything to do with it being recognized as a flat for calibration. Can't I just call the image "flats" and not put in any other details such as "target name", "Exposure time", "frame #" etc??
 
Is it possible that your capture software is including the temperature in the image filename in a way that is being interpreted as a filter id? To check, look in your output folder, "master" subfolder. Is there a file there called something like "masterFlat-BINNING_x-FILTER_y.xisf"? If so, what are x and y?
 
Oooh.. Interesting. I would think you would need to put a time in for a raw Flat. Otherwise there might be logic that it is a master flat since these files do not contain exposure time information. It would be hard for me to recreate this on my end...but would you mind loading your flats using Custom..but be certain to input an exposure time?

It just seems like something a computer programmer would do. If I have a flat..and no other information (including exposure time)...I am going to assume it is a master flat.

Just a weird guess.
-adam
 
I have stopped using darks with my ASI2600. I found that a 180s dark is indistinguishable from a 0.032ms bias frame - they both show a bias level of 500ADU +/- one or two ADU. The slight (noise, I assume) variation in bias level results in slight clipping of the flat / light frames when bias corrected, so I add a small pedestal (10 ADU) to flats and lights before processing. So far this has worked well.
 
dpdallolmo@aol.com said:
Hello,
I am having trouble with WBPP. I am obtaining images with a ZWO ASI 2600 CMOS camera. My lights are 600 sec in duration at -10C. I have a library of darks and typically use a matching master dark (600 sec, same temp etc). I typically will use a master bias to calibrate my flats. I typically take flats (#25) after every session.
So I add my light frames and my flat frames to WBPP. I then add my master dark and master bias. I check "use master bias" and "use master dark" in the global options section. Use master flat remains unchecked.
On the flats page, I have checked "Calibrate with flat darks". Everything else on that page is defaults.
On the lights page, I use Cos Correction, Debayer, subframe weights and apply image registration. I typically do image integration after WBPP has completed.
Under Global options all are checked EXCEPT "optimize dark frames and "Use master flat".

Now is where I have a problem.
When I check the Diagnostics, I get a 2 warnings
#1) "only master bias will be used to calibrate flat frames".....This I expect as I am asking WBPP to do that

#2) "No matching master flat frame have been found to calibrate light frames"
This is my problem....I don't have a master flat frame yet it says one can't be found. What's worse is, if I run the program, flats never get "subtracted" so I see my dust motes. If I first create a master flat, then add that in place of the 25 individual flats and check "use master flat", I get the same warning...No master flat found to calibrate the light frames.
Again, if I run WBPP, my images still show the dust motes as if no flats were factored into the WBPP process.
Any Idea why WBPP does not seem to recognize either my individual flats or a master flat?
Thanks,
Dan
Click to expand...

Hello, I have the same issue. Any clue?
Same camera. ASI 2600 MC
Here is a screen shot showing the Flats files selected and the diagnostic messages...
 

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PH1L1PP3 said:
Hello, I have the same issue. Any clue?
Same camera. ASI 2600 MC
Here is a screen shot showing the Flats files selected and the diagnostic messages...
Click to expand...

Look at the names of your Filters. They do not match. You have "No Filter" and "1" ... these need to be the same names to match.
In addition, you are trying to use a master flat- but you have loaded raw flats.
Finally, you are trying to calibrate a flat with a 300 second dark frame (which may cause problems).
Do you have a dark of the same time as the Flat?
-adam
 
I'm fairly sure now that your problem is with your file name structure; WBPP is misinterpreting the components of your filename (probably reading the exposure as a filter name). If you run WBPP using only "add custom" to add your files in groups with explicit type / filter / binning / exposure, then it is my guess that it will work fine.
 
ngc1535 said:
Look at the names of your Filters. They do not match. You have "No Filter" and "1" ... these need to be the same names to match.
In addition, you are trying to use a master flat- but you have loaded raw flats.
Finally, you are trying to calibrate a flat with a 300 second dark frame (which may cause problems).
Do you have a dark of the same time as the Flat?
-adam
Click to expand...

Thank you for your answer Adam.

1/ OK about the files name. I was wrong.
2/ I am not trying to use master flat. [Use master flat] is not ticked
3/ I am trying to treat the lights... So I use Dark with same duration than the lights.
4/ I do understand that I should, First calibrate the flats with a flats darks, to get a master flat. Then process for the Lights treatment with the master flat.

Sorry I am noob. But this never happens to me before I shot 1sec flat... So I understand that below 1sec flat darks are not necessaries, but from 1sec. Right?

Again Adam, thank you for your support ;)
 
Have you tried just adding all your frames using the appropriate "add custom" and running WBPP with the default settings?
 
I still think there is some miscommunication going on here.
Could you do me a favor and review my WBPP series? I think it could help?
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PixInsight: New WBPP Script Series

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fredvanner said:
Have you tried just adding all your frames using the appropriate "add custom" and running WBPP with the default settings?
Click to expand...
Fred: If you are interested, your feedback to my efforts in the video would be welcomed.
PH1L1PP3 said:
Thank you for your answer Adam.

1/ OK about the files name. I was wrong.
2/ I am not trying to use master flat. [Use master flat] is not ticked
3/ I am trying to treat the lights... So I use Dark with same duration than the lights.
4/ I do understand that I should, First calibrate the flats with a flats darks, to get a master flat. Then process for the Lights treatment with the master flat.

Sorry I am noob. But this never happens to me before I shot 1sec flat... So I understand that below 1sec flat darks are not necessaries, but from 1sec. Right?

Again Adam, thank you for your support ;)
Click to expand...

1. OK..good.
2. You are correct... good!
3. Either a bias or a Flat Dark is very likely necessary to calibrate your data. I would reccommend acquiring the 1 second dark frame and check "Calibrate with Flat Darks." In this way you will have exactly matching calibration files. The first warning will go away.
4. To be clear, you will want to load your Raw flats (as you did) into WBPP and it will create a master for you in the right way subtracting the Flat Dark you load in the Darks tab. This should clear the two warnings you are seeing and give you the right results.

So now your Light Frames and your Flat Frames both say "No Filter" correct?

-adam
 
ngc1535 said:
Fred: If you are interested, your feedback to my efforts in the video would be welcomed.


1. OK..good.
2. You are correct... good!
3. Either a bias or a Flat Dark is very likely necessary to calibrate your data. I would reccommend acquiring the 1 second dark frame and check "Calibrate with Flat Darks." In this way you will have exactly matching calibration files. The first warning will go away.
4. To be clear, you will want to load your Raw flats (as you did) into WBPP and it will create a master for you in the right way subtracting the Flat Dark you load in the Darks tab. This should clear the two warnings you are seeing and give you the right results.

So now your Light Frames and your Flat Frames both say "No Filter" correct?

-adam
Click to expand...

Of course, I was almost 99,9999% sure that the issue was me...
And after your explanation I can correct the % to 100! ?

So now everything is right.
Thank you Adam, particularly for your patience. ??
 
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