How Is My Guiding

[gnomus]

I recently started using an ST-80 for guiding.  The mount is a CGEM, and the guiding camera is a ZWO ASI120.  Tonight I tried 16 x 7.5 minute exposures.  Four of them had obvious trailing.  (I've had better results than this.)  I've attached a screenshot from my PHD2 guiding session.  There seem to be a couple of "very off" patches (that I have circled in yellow).

It would be helpful to know what I can expect from my CGEM, whether my results are typical, and if there is anything I can do to improve the guiding.

Thanks in anticipation.

[kalasinman]

I'm learning currently as well. I hope you don't mind a couple thoughts. The areas you've circled are large guiding corrections, rather than guiding errors, although the left part of the second circle has a problem.

Your correction commands seem to come in a little late. I'd try reducing min move and increasing aggression while reducing Hyst.

Aggression-95  min mov .05 hyst 3 . As is, your RA is sagging below the center line.