There really isn't enough detail in the little Rosette .jpg to show much in the way of flaws, so it must be good! :-)
[Really nice work on your Flickr/Instagram pages, BTW]
I did have a look at your PHD2 log, and I do see a couple of things there.
PHD2 is not happy with your Polar Alignment (check the Drift tab in the log viewer), and that's borne out by the DEC corrections that always seem to be South and frequent, with North corrections only seeming to appear during a Dither, and not vey often at that. So calming down the DEC corrections by improving your PA would probably help you. [Note: Seems like PHD2 *always* complains about the PA, so single digits and a bit more is pretty normal. Yours is much larger, and the DEC corrections are pretty one-sided]
I checked the PHD2 doc and apparently yes, even when guiding, depending on where you point, how bad the PA is, and how big your sensor is, you can still have field rotation that PHD2 can't correct for. So *maybe* that's a factor in your star problem.
Your RA is pretty active, too, but unlike the DEC, it's back-and-forth.
If I look at the scatter diagram in the log viewer, it appears that seeing conditions weren't the best, so that won't have helped you.
No real opinion on whether differential flexure is an issue for you, but my guess is that if it was, your guiding would look better and your imaging worse.
Other than that, general good-to-do-to-help-tracking stuff:
- Balance your scope and camera East-Heavy / Camera-heavy
- Tripod legs down
- Gears adjusted for close mesh without binding, in both axes.
- Belts adjusted snug and tracking down the middle of the small pulley, in both axes.
Hope this helps!
Edited by Devonshire, 31 October 2019 - 04:48 PM.