So I’ve had an interesting experience with the native ZWO Camera driver and my ASI 1600 Pro. When I first connected it to SGP, I used the ZWO Camera native driver and started to take some dark frames. The gain was set in the “Gain” section of the camera settings (in the “1x1” box), however offset seemed to stay at 10 no matter how high I made the gain (offset was retrieved from the FITS headers).
Now, I hooked it up to the ASI Camera ASCOM driver, opened the camera settings, and set it to 139 gain and took some dark frames. The gain in the FITS headers was 139 as expected and offset was not reported in the headers because they’re not available over the API I guess.
I disconnected from ASCOM and connected to the camera through the ZWO Camera native driver and took another dark. Now the FITS header shows gain of 139 and an offset of 50! This is very weird. I know the ASI Pro automagically sets the offset for you, but I thought an offset of 21 was used for gain 139, not offset 50. Without disconnecting the ASI from SGP’s native ZWO Camera driver, I set the Gain to 200 in the camera settings “1x1” box.
And just now I did some more disconnecting/reconnecting and offset was sometimes 10 and sometimes 50. The mean readout when at 139 gain and 200 gain is virtually the same when using the ASI Camera driver (both right around 780 mean). Is that the ASI adjusting offset so that the mean readout is always the same?
It’s all very strange and confusing to me. If someone could tell me the best way to control gain with the ASI Pro and SGP3 I’d be very grateful. I don’t think I’m doing it right at the moment. What driver should I use?
Thanks