Dear fellow happy users of ZWO products,
I belong to you. I am a happy user of many ZWO products. However, I had recently to sets of light frames that I could not use at all. Those two sets of frames where produced in the same evening, with an ASI294MC pro, a l-ultimate filter, and the rest of my gears (200/800, EQ6r pro, ASI120MM for guiding). They where produced using APT as imaging software and the ZWO drivers, just as during all other session since mid 2022. Gain is at 121 and offset at 30 in all files.
1) whereas my lights frames have usually the following type of values :
10:52:37: Canal B&W : Moyenne : 2193.3, Médiane : 2188.0, Sigma : 110.3, Min : 1884.0, Max : 65532.0, bgnoise : 122.2
2) my lights frames of those two defective sets had the following typcal values :
22:10:02: Canal B&W : Moyenne : 424.0, Médiane : 424.0, Sigma : 248.3, Min : 68.0, Max : 65532.0, bgnoise : 138.4
3) my masterdark has the following values :
22:02:52: Canal B&W : Moyenne : 1923.6, Médiane : 1920.8, Sigma : 50.0, Min : 1871.7, Max : 65532.0, bgnoise : 3.7
This makes calibration impossible : you cannot substract 1920 from 424 without clipping a significant portion of the frame.
This master dark was successfully used for many images where the light frames have the typical values represented by (1) above. See for yourselves : https://www.astrobin.com/users/patrice_so/
So my question at this point is : does anyone have an idea why the values of my lights frames may have dropped for one session ? That is completely unaccounted for at this point. Note that since then, I had further sessions where everything was back to normal.
Any hint would be appreciated.
Thanks for these amazing products. Best,