Gain for ZWO 294C

[GrampyG]

What 'gain' value would be suitable for a ZWO 294C on an f7.5 refractor? I'm using 120 at the moment.

Thank you

[The Lazy Astronomer]

120 is probably your best bet as it's where the high conversion gain kicks in (read noise drops significantly, and dynamic range increases back to the same level as gain 0). 120 also happens to be unity gain on this camera (where 1 electron = 1adu).

I have seen some people using high gain values with narrowband filters (e.g. 200 - 250) with pleasing results, but I've not seen any direct comparisons of high gain vs 120, so it may not make any appreciable difference. I have the mono version, and personally, I stick to 120 for now.

Edit: I've just checked the specs, and unity gain is actually 117, so at 120 it's about 0.9ish electrons per adu, but, close enough! 😉

Edited October 12, 2021 by The Lazy Astronomer
Correction on unity gain

[GrampyG]

Great! Thank you. I'll leave it as it is

Thanks once again