[DavidTrap (David)]

Ok, subjective report on my experience last night.

OAG at 1875mm focal length on a Paramount GT-1100S, lodestar Autoguider, 1 sec exposures with 1second delay after corrections.

With single star guiding, there was much more jumping around on the guiding graph above and below the line, but still within +/- 1-2 arcsec. With multi star guiding enabled, the graph was smoother, and the excursions were within the +/- 1-1.5arcsec range, and usually contained to one side of the graph, not oscillating above and below the line.

In CCD inspector, the aspect reading (roundness measure) on the images taken were 1 or 2 better with multistar guiding, eg. 9 vs 10 or 11 (so pretty good regardless).

The seeing last night was atrocious. The out of focus stars that appeared during a FocusMax run were distorted and varying wildly.

My hunch is that multistar guiding is worthwhile to mitigate the effects of scintillation - not in the same league as AO, but it doesn't cost anything to activate it in software.

DT