NGC 772 in Pisces

Optics: CPC1100 at f6 on a Milburn Wedge
Camera: QHY8
Image scale at capture: 0.9 arcsecs per pixel
Exposure: 49 x 10 minutes
Guiding: PHD Guiding, using a Meade DSI Pro II on a Taurus Tracker III off axis guider. Dithering performed with Nebulosity 2.
Date: November 7, 8 and 10, 2010
Processing: Stacked with Deep Sky Stacker, post-processed with Photoshop CS2 with maximum entropy deconvolution using a PS plugin from AstraImage. I did a little star shrinking by selecting the stars with the color range tool and using curves.

This was my first effort at using dithering, which is possible with the PHD/Nebulosity link, and it worked quite well. The kappa-sigma clipping setting in Deep Sky Stacker clipped all of the hot pixels, without the use of any darks or bad pixel mapping. I found that I had to set the kappa setting higher than the default of 2 or stack with auto adaptive weighted average, or else I wound up with rather noisy final images. This appears to be due to the heavy light pollution I shoot through, leading the kappa-sigma clipping to discard too many pixels when run at the default values.

This galaxy has been disrupted, presumably by the small elliptical above it. It has one bright blue arm, but the other arms are a real challenge to capture through the heavy light pollution at my site.