I have been using a camera lens system and a well aligned Paramount with a large model and Pro Track. It is able to track well enough so that at 200 mm I can get nice round stars even on 20 minute exposures so do not need to guide that system and therefore use SGP’s “dither by mount” which works very well and is very fast. No PhD there at all.
I also have, on the same mount, a 1000 mm refractor with a guided camera (STT 8300 self-guide). With that well aligned mount and Pro Track, even at 1000 mm, moderate length unguided images are possible (although only limited testing done so far as to possible maximum times - but probably less than 5 minutes).
So that begs the question:
Is it possible, instead of having PhD dither by guider, to have SGP randomly bump the mount as in “dither by mount” and just order PhD to reacquire the guide star instead of a conventional dither? Conventional dither often fails with extremely long guide times (30 seconds and up) or at the very least takes a very long time.
Andy at PhD where I first posted the suggestion, thinks it more easily done in SGP than PhD and said:
“SGP could command PHD2 to stop guiding (send the “loop” or “stop” server command), do the “dither by mount”, then tell PHD2 to start guiding without any settling delay.”
The reason for all of this is that I would like to go for guide times as long a 2 minutes - this would allow excellent averaging of seeing and fewer corrections - It is very clear from watching PhD guiding at such long guide times with the well aligned and Pro-Tracked mount that this works great. The problem now is that the conventional dither works poorly and/or takes too long in terms of settling to work with the guiding as presently done.