Guiding Problem Solved? M106

2 May 2014.  I think maybe I’ve finally figured out why my guiding is always bad after a meridian flip!  I decided to image M106 because conditions looked very good and my attempt at M106 from last year is pretty noisy.  Once again, finding M106 with the PicGoto was just a matter of centering a bright star (in this case Phad) and pressing the "goto" button.  Conditions were excellent, but once again I had nasty guiding issues, especially after performing the meridian flip.  Things would go along smoothly for a while, then it seemed as if the RA tracking would just stop for a while, then start up again.  After thinking about this and fighting it late into the wee hours, it finally occurred to me that what is probably happening is that the mount guides fine until it bumps the legs after passing the meridian.  At that point I go out and do a meridian flip, but in the process of bumping I'm driving the mount against the tripod leg and that loosens up the clutches (thank goodness; otherwise I'd strip everything!).  The loose clutches then result in erratic behavior after the flip.  Once I tightened everything up last night, the guiding was excellent.  I was trying the unorthodox approach of making the scope west-heavy rather than the usual east-heavy, and it seemed to help.  I backed off from the 600 s subframes I have been taking lately and went with 300 s.  That seemed to work fine, and I probably had to throw out fewer subframes this way.  I need to take a new set of darks and a new set of bias frames, but I’ll do that when it is cloudy or there’s lots of moonlight.   

Date: 1 May 2014

Subject: M106

Scope: AT8IN + HPS Coma Corrector

Filter: None

Mount: CG-5 (Synta motors, PicGoto Simplificado)

Guiding: 9x50 Finder/Guider + DSI Ic + PHD 2.2.2 (Win 7 ASCOM)

Camera: DSI IIc no chiller T = 13 °C)

Acquisition: Nebulosity 3.2.0, no dither

Exposure: 49x300 s

Stacking: Neb 3, bad pixel map, bias included, normalize first, trans+rot align, 1.5 SD stack.

Processing: StarTools 1.3.5.279 Crop; Wipe 75%; Develop 87.1%; HDR:Reveal core; Color:Scientific, 300% sat., cap green to brown; Deconvolute auto mask 2.1 pix; Life:Moderate; Track RNC 49.51%; Magic:Shrink 1. CS6 Astronomy Tools increase star color; Healing brush; Deep space noise reduction; Space noise reduction; Less crunchy more fuzzy; layer mask the denoising; Astro Frame.  I could probably make the dust lanes stand out more with an unsharp mask, but I elected not to.
Here's what it looks like with a different set of processing choices, mostly designed to further sharpen the core. I think I like this version better. I've done similar processing as above except I used "cap green to yellow" instead of "brown", I've deconvoluted more (2.5 pixels), I've done one pass with wavelet sharpening, and I've used an unsharp mask with a layer mask in Photoshop to bring out the dust lanes.