I’m beginning to have trouble with dithering. Last night, I set up with my mount and camera using a 200mm lens. My guiding was rock solid and I had it set to “Very High” dithering settings.
I began noticing odd behaviour in PHD2. Every time SGP finished a frame, it would state that it was sending a dithering command. This caused my PHD graph to jump off the charts, usually in both RA and Dec. Most of the time, it would recover after 30-45 seconds, but sometimes it would fail and go into recovery mode. Furthermore, it appears that no dithering is actually happening, as I checked five images and found the stars in exactly the same spot as before. It appears that PHD recovered, but put the star back in its exact location, not the dithered location.