Apologies if this question has been asked (and answered) before, but I haven't found it mentioned elsewhere.I recently purchased a RisingCam (rebranded ToupCam) camera: Sony IMX571 26MP APS-C sensor, TE, OSC. I ired it up for the first time last night. It was immediately recognised by NINA and cooled down quickly to a set point of -20C. So far so good!The trouble started when I tried to collect dark frames. About 70% of the dark frames look absolutely fine, with a mean pixel value just above the programmed offset level and a small standard deviation. However, about 30% of the frames show a gross 'glow' - it doesn't really look like amp-glow, but it shows large scale structure. The appearance, structure and intensity of the glow is consistent between bad frames. However, bad frames seem to appear at random eg good, good, bad, bad, good, bad, good, good, good etc. The settings I used where minimum gain value (100), offset 250, sensor temp -20C, high gain off, ultra-low noise on, 60 s integration. I tried changing the high/low gain, sensor temperature setting and ultra-low noise settings but it made no difference. I then tried collecting some light frames and observed the same effect: good and bad frames are randomly intermixed, with the bad frames showing the same sort of superposed 'glow' as the bad dark frames. Again, about 25-30% of frame were bad with the remainder fine. The attached image illustrates the problem, showing typical 'good' and 'bad' dark frames (top) stretched to cover the ADC range 0-1000, and 'good' and 'bad' light frames (bottom) stretched to cover the ADC range 0-3000.I would appreciate if anyone has any insights or suggestions for further tests!
