Hi,

Has anyone used PemPro to find root causes of
non-periodic problems? Mechanical ringing on the mount axes? Wind? Differential flexure? Floppy imaging or guiding trains? (I use another OTA as a guide scope.)

I have a VMC-260 on a 1200gto. In the past, I have sometimes
gotten 15 minute exposures and good images.
But for the last month, I have mostly not.

Last night, after a straightforward PemPro run, I had an incredible 0.6 arc seconds total PE. (There was a weird harmonic at about 0.4 worm cycles. Wot de hey?) The night before, I spent 2 hours drift aligning using my imaging CCD and MaxIM v5 guiding unplugged. I didn't check it with PemPro, but it looked about 12 pixels in 30 minutes.

In prior weekends, I replaced the felt in my Parallax rings with hard polyurethane/rubber, and tightened every screw and bolt I could lay my hands on.

Yet tonight, I'm about 1 for 10 on 15 minute exposures. I'm beginning to get really curious about what might be causing this.

Thanks,
Steve

Steve,

PEMPro V2 was not designed to do that kind of modeling/analysis. You should consider trying TPoint or MaxPoint. Also, the upcoming Astro-Physics Command Center will also be able to do telescope modeling/analysis.

-Ray