1 - 10 min. frame with the SBIG ST-8300M (monochrome) CCD camera at -25C. 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: 24 dark frames; calibrated and DDP applied in ImagesPlus 3.75 (Auto Image Set Processing). Curves in Nebulosity2.

20100114_M81_600s_-25c-ddpcrv