Hi,

I have an FCUSB module but have never used it and I'd like to. Actually, I need to, if it does what I'm hoping. Basically, over time during an imaging session, my scope (SCT) loses focus like it did last night when I left it imaging M97 and then M51 during the night. I got very little useful data as focus shifted.

I watched this video but it isn't entirely clear. The capture module has a setting to "Autofocus if HFR> (some value)" - I presume I need to use the focus module to get the initial HFR value (as shown in the video), and Ekos or whatever adds some to that value (as per the video) - does it evaluate every frame? What if you switch targets? I presume one would check "Autoselect star"?

Thanks.

If you have never used FCUSB, you need an analog motor connected to your focuser first. After that, you have to find the optimal step size for the focus module to drive your motor. Finally, I would just tell the capture module to refocus every 60 min, that should do it.

I have the motor, and I have "tested" to make sure it functions, but that's about it.

Refocus every 60 mins - LOL I am blind. I didn't even see that setting.

Thanks very much!

Just an update.

While autofocus tried to work, it never got to within its limits even though the star was about as focused as it was ever going to be. I thought it was perhaps because the chosen star was nearer the edge than center. Choosing a different, smaller star near center started with a number of 20 (I presume for the entire shot) before dropping to -1 once the subframe kicked in. But once autofocus started, the value never got below 2.8. The autofocus then failed. Unfortunately, this also causes the imaging session to abort. I get why, though I would prefer to be given a warning and choice on the matter.