Guiding should be paused during AF, not stopped

[Cedric Raguenaud]

Currently, when autofocus is started in a sequence, autoguiding (with Phd) is stopped, then started again when autofocus is done. Instead of stopping it, NINA should pause is so that Phd picks up the guiding star again, and if needed searches it within the search square. By stopping, a situation is created where the guiding could drift (sometimes AF is slow) and a new guide star is selected, changing the original framing.

[Linwood Ferguson]

Actually pausing (if there is that ability) will cause a different problem - if the guide star moves during the focus, and guiding is simply resumed in place, then guiding will need to recenter the guide star. If upon resume the next exposure begins, this re-center will occur while guiding while refocusing. It would need to treat the resume kind of like a dither, where it waited for things to settle, and you are back to about the same amount of time as a start-guiding. The only real advantage I see is that you might end up in the same exact position once it did re-center the guide star. but you could also, depending on displacement during AF, end up with a star lost, and then a need to somehow recover with a stop/start guiding anyway (but extra handling to get to that point).

I am sensitive to this as the recent change to AF without stopping guiding caused a similar issue, where it had to recenter the guide start due to AF focuser displacement, and it occurring during exposure.

[Stefan B]

Not planned to change. If drift is of concern the Recenter after Drift trigger will ensure being on target.

[Stefan B]

Removing version: 2.0 Beta (automated comment)