The Little Dumbbell in Perseus
This is a bicolor, with Ha mapped to red and OIII mapped to teal (hue 180).
Optics/Mount: CPC1100 with f6.3 Celestron reducer on a Milburn Wedge. Dec antibacklash set to 27/27. PEC on.
Exposure: 36.3 hours total. 58x20 min Ha, 51x20 min OIII, both bin 1x1.
Filters: Astrodon 5nm Ha, 3nm OIII
Date: 11 nights from July 25-26 to October 2-3, 2013
Imaging automation and capture: Sequence Generator Pro
Guiding Hardware: ASI120MM binned 2x2, Celestron off axis guider. Guiding scale 0.92 arcsec/pixel. 1 second guide exposures.
Focusing: Rigel Systems GCUSB/nStep on stock C11 focuser
Guiding Software: PHD. Aggressiveness 80, Hysteresis 0, Minimum Move 0.9, Max RA 1000, Max Dec 600. Dec set to auto/resist switching. Dithering set to Extreme with Settle < 1.2.
Guiding performance: HFR of subs about 1.2 arc seconds, RMS in PHD about 0.5 arcsecs.
Light pollution: Bortle 8 (white zone, NELM about mag 4.5)
Image scale: 0.6 arcsecs/pixel = f/5.7
Processing: Darks, bias, and flats. Stacked with Nebulosity 2, post-processed with Photoshop CS2 using AstraImage pluging for deconvolution.