I’m imaging at quite high resolution (0.55 arcsec/pix), guiding using OAG, and finding a problem getting both correct focus and good centering.
The thing is:
- if I leave the autoguider running while focusing, either (a) the focus is ruined (if autoguider is not waited to settle) or (b) takes forever (if autoguider settles)
- if the autoguider is off while focusing, depending on the last centering slew, the guide star may go out of the autoguider field (drift due to backlash).
As with SGP full frame focusing being centered beforehand is not really needed, I think first focusing, next centering, is better. At least it is for me