The Whirlpool Galaxy

Optics/Mount: CPC1100 with f6.3 Celestron reducer on a Milburn Wedge. Dec antibacklash set to 27/27.
Camera: QHY8
Exposure: 27 x 10 minutes
Date: March 27 and 28, 2011
Conditions: Seeing 2/5, Transparency 3-4/5. No wind.
Light pollution: Bortle white zone
Filter: Orion Skyglow Imaging Filter

Image scale at capture: 0.94 arcsec/pixel = f/6.1
Scale of presentation: Full scale; frame cropped to eliminate coma in corners
Capture software: Sequence Generator and Nebulosity 2.
Guiding: DSI II Pro, Taurus Tracker III off axis guider. Guiding scale 1 arcsec/pixel.
Guiding Software: PHD. Aggressiveness 90, Hysteresis 0, Minimum Move 0.6, Max RA 1000, Max Dec 350. Dec set to auto/resist switching. Dithering set to Extreme with Settle < 0.5.
Guiding performance: FWHM 4.4 arc seconds. RMS 0.52 arc seconds, OSC 0.45. Calibration steps 11 x 9.
Processing: Stacked with Nebulosity 2, post-processed with Photoshop CS2.