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I'm enjoying APP but one thing that irks me which should be quite simple to integrate into the program is that there is no option to calibrate with flat darks. A lot of us use CMOS cameras which have amp glow where the best method for calibration is taking darks to match the flats and only calibrating the flats with those, and not using bias. If nothing else, I would like to at least have the option to choose to only subtract bias from flats and omit bias subtraction from darks. This would solve the problem as well though it would probably be cleaner to have an option of flat darks ala DSS. Thanks for consideration of this.
Hi jtrezzo,
Thank you for your question and welcome to the APP forum.
Flat darks are perfectly possible in APP. Basically, flat darks are just darks only to calibrate flats instead if light frames. So in APP I simply call them darks. I use flat darks all the time with my asi1600mm-c and don't use any bias frames because of several reasons having to do with the cmos sensor characteristics, like you indicate 😉
The current calibration rules can be found here and you will see that flat darks are thus supported.
FLAT FRAMES
Flat frame calibration has several options, you need to choose 1 option from 1-3:
- can and should be calibrated by a master bias of the same ISO or gain + offset as the flat frames
- can and should be calibrated by a master dark of the same ISO or gain + offset and the same exposure length and temperature as the flat frames
- can and should be calibrated by a master dark of the same ISO or gain + offset and the same exposure length and temperature as the flat frames, made of darks which were calibrated by a masterbias of of the same ISO or gain + offset as the dark frames + the master bias of the same ISO or gain + offset as the dark frames. So in this case, you use 2 master calibration frames to perform flat frame calibration.
So flat calibration rule 2 is what you refer to.
And information on using Bad Pixel Maps can be found here, which I recommend to use:
https://www.astropixelprocessor.com/community/tutorials-workflows/creating-a-bad-pixel-map/
Let me know if this is clear and if you have any other question 😉
Kind regards,
Mabula
Great thanks, I think I was thrown by not seeing the term then. I'll have time to look at those later, but quick question - so I will be adding the "flat darks" as a second set of "darks" when calibrating and they will be recognized?
Great thanks, I think I was thrown by not seeing the term then. I'll have time to look at those later, but quick question - so I will be adding the "flat darks" as a second set of "darks" when calibrating and they will be recognized?
You're welcome jtrezzo,
Yes indeed, add the "flat darks" as a second dark set, APP will match the "flat darks" with the flats if they have the same exposure and iso/gain as the flats 😉
Let me know if this works for you.
Mabula
Thank you, Mabula, this worked perfectly!
Thank you, Mabula, this worked perfectly!
Excellent 😉 !
