A couple weeks ago, I was at a Bortle 4 site and captured the North America and Pelican nebula (image here on CN) using the gear in my signature. Seeing was very good that night and overall I'm pretty pleased with the results.
That said, looking at the guiding log, I'm hope to figure out what it is telling me and how what I can do to improve.
- Setup balanced before imaging and all clutches were tight. HEQ5 is unmodified (ie no belt mod) and I have no idea if it has ever been tuned (I'm at least the 3rd owner).
- Guiding exposure was 3s
- Polar alignment was within 2' as determined by ASIAIR PA routine.
- A meridian flip occurred slightly more than half way through the session. Guiding seems to have gotten worse afterwards
- Looking at the log, guiding star HFD grew from 3.9 to 4.69 after the flip which surprised me.
- Guiding parameters were not changed during the night but after the flip, guiding degraded from .88 to .97. RA stayed roughly the same pre- and post- but DEC was noticeably worse post (.44 vs. 61) - why?
- Both pre and post flip, RA shows a roughly 12 minute sinusoidal cycle where guiding constantly pulsing one way, then the other. Is this PEC or a result of poor polar alignment?
I've attached PHD2 log viewer graphs of pre and post flip. The log itself is in my Dropbox as it was too big to attach.
Appreciate any insights from anyone who has a few minutes to ponder this.