Help with Stacking master darks/flats

[lnlarxg]

Hi wondering if anyone can help.  
 

Can light frames in .fits format be stacked with master dark/flat/bias frames in .tiff?

when stacking light frames in .fits format, with each of master calibration frames in .tiff, really bad final picture comes out 

but if I chose all the .fits darks/flats/bias (the individual frames that make up the master), for stacking with the .fits light frames, the stacking Result is fine

Do master Calibration frames need to be in same format as the light frames?

you can see the picture on the right is the bad one.  Both had a simple stretch in PIxinsight

 

Edited October 7, 2020 by lnlarxg

[Tommohawk]

Not sure I know the answer to this, and it must depend on the stacking software. I'm guessing you're using DSS?

In DSS you can definitely use different formats for lights and calibration - I routinely used CR2 files for lights and tiff for master calibration. DSS stores the master calibration files as TIFFs. 

Having said that, your example suggests otherwise. I seem to recall DSS uses 16bit masters which isn't ideal... although I dont think that would cause your issue.

TBH although I used DSS happily for some years, I found it a bit unpredictable and in the end paid for Astropixel processor.