Stan,
Thank you for all the suggestions. I think my guiding is fine. I've been watching the actual graph many times to figure ?out what's going on. Aberration is always on a part of the frame, which makes a guiding problem unlikely anyway. Vibration resonance sounds more plausible. I now have three fans - two to cool down the mirror and one on the camera. Will try to see if some of those are to blame. I actually never imaged without the reducer. Meant to try though... Perhaps it's time to do so!
Clear Skies!
Ian
