Jacqui Greenland replied to the topic 'Ioptron ipolar' in the forum. 2 years ago

The frames I was solving definitely had a 0.25s exposure dark frame but thinking about it there may not have been a 0.5s dark frame in the library for the refresh/alignment portion. It definitely looked like the dark frame wasn't being subtracted but I thought I had tried it with a 0.25 refresh as well and got the same result - this may not be the case and I'll try again next window I get (might get lucky tonight looking at weather).

In terms of the noise it doesn't show up much at all in the live view which is why it surprised me to see it at that point and so I'm not sure the V4L settings beyond gain and image size had much impact on it. That said I will do furthur experimentation with them to see what I get. Even when using the iOptron provided software on windows we typically had to crank the gain up to 2-4x to get solving to happen (it goes up in half step increments on their software so that's functionally equivalent to 192-288 ish on the V4L driver which is why I first played with that parameter).

That said, looking at the dark frames I do have it seems to be a pretty noisy device - the ioptron software dark frame seems to be a custom format so I've not been able to open that on my desktop to look.