Hi Leonardo, All,
I’m a few clear nights into Voyager now, having made the jump from SGP; the LocalField focus method is working really well on my Edge14 setup - I’ve not seen the system focus as quickly as this before. There’s one issue I’m battling, and that’s an occasional shift in target position between focus runs.
The attached subs show an example of the problem - in this case, NGC891, which is nicely centred in the field in the first image, but off-centre in the other (the exposure is otherwise fine - guiding via PHD2 was good in both cases). This happens quite often, though the direction and amount of offset varies.
I’m certain that the root cause is mirror shift in the Edge design while focusing - PhD 2 is then picking up a nearby but different guide star after the focus run. I’ve dialled in some focus backlash compensation which helps, but isn’t perfect.
I was watching the system as this happened earlier in the week, and noticed that there wasn’t a precise pointing cycle after the focus run. Now, from an earlier post (Forcing plate solve after autofocus?) I think it’s the case that the RoboStar method automatically includes a precise pointing after the focus run, so I might have to switch to this method. But is there any way of getting LocalField to do the same? I’ve had success with LocalField that I’d like to continue using this method if possible.