15th Feb 2024: Astro Pixel Processor 2.0.0-beta29 released - macOS native File Chooser, macOS CMD-Q fixed, read-only Fits on network fixed and other bug fixes
7th December 2023: added payment option Alipay to purchase Astro Pixel Processor from China, Hong Kong, Macau, Taiwan, Korea, Japan and other countries where Alipay is used.
Sometimes when I include my bias I get a completely black or completely white frame upon integration. Removing the bias and reintegrating renders and nice image. I think it happens mostly with hydrogen Alpha but RGB also but only sometimes. Have you any idea why this might happen?
@gregwrca, yes I do. It has to do with how data calibration works at the moment in APP. In APP 1.060 this shouldn't happen anymore 😉
Let me explain: in APP (versions lower than 1.060) if you load bias and dark frames of the same ISO/gain, then the darks will be subtracted by a masterbias created form the bias frames. If you calibrate lights then, you need to load both masterdark and masterbias for correct calibration.
But if you only create a masterdark by loading only darks (no bias/masterbias) then the bias signal and pedestal is not subtracted from the darks in creation of the masterdark.
In that case, if you later add a masterbias to the masterdark and try to calibrate your lights, you will be subtracting the bias signal and pedestal twice from your light frames. And that will explain the problem that you describe.
I understand this is a bit complicated and not very user friendly. So in APP 1.060 the new calibration engine should prevent problems like this 😉
Cheers,
Mabula
So skip bias for now? Will that work? Or should I load the master bias when I create my darks and flats Masters and leave it there for every step of the way
