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What gain/exposure time to use with a CMOS camera
I'm using an ASI071MC-cooled. I realise CMOS cameras are a completely different kettle of fish to CCDs. Read noise, variable gain etc.
I know not many have the ASI071 which I'm using, so if there are ASI1600 or like users who could tell me what gain/exposure times they use and why. What issues should I consider? Or am I trying to make things to complicated for myself (I am a complete noob at this).
The standard ascom interface for the asi071 has:
- zero gain (2.6e-/ADU). Gives full well capacity of 46k e- and read noise ~ 3.3e-.
- unity gain. Gives well capacity ~18k e-. Read noise ~ 2.7e-.
- or higher gain. Say 0.5e-/ADU. So get well capacity of ~ 8ke- and read noise ~ 2.5e-.
My mount will track for up to 10min (that's the most I've tried). So far I have been using unity gain with 5-6min subs or higher gain with 3min subs. I've used these sub lengths because it gives a histogram that peaks at ~ 10-20% though the range.
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