7 - 15 min. exposures with the SBIG ST-8300M (monochrome) CCD camera at -20C. Baader 2" UV/IR filter. Telescope configuration: TEC-140 (980mm, f/7) and no focal reducer, yielding an image scale of 1.14 arc-seconds/pixel; Astro-Tech 2" field flattener. Mount: Losmandy G11 w/Gemini. Focused using a Bahtinov focus mask. Post processing: bad pixel removal in Nebulosity2 using 20 dark frames (threshold 5240); calibrated using 16 bias frames, aligned, Min/Mix excl avg combined and DDP applied in ImagesPlus 3.82 (Auto Image Set Processing). Adaptive Richardson-Lucy deconvolution applied in ImagesPlus. Image cropped from original of 3352 x 2532 to 1280 x 960.

20100502_M51_CombExcAvg-ddpadjarl.tif