Croc's Eye Galaxy, M94

3 May 2014.  I chose this target because I was not very happy with last year’s image (it was quite noisy).  Conditions were again pretty good, though there was a bit of breeze.  I located M94 using the PicGoto starting from Cor Caroli; I have become completely spoiled by the ability of the PicGoto to find things easily.  I had guiding issues, especially early, because I didn’t carefully balance and weight-bias the mount.  After doing a meridian flip, I paid attention to balance (I tried west-weighting again) and guiding was much better.  However, I had nearly 6 hours of subframes, from which I selected the best 200 minutes to stack.  Processing this stack was more difficult than usual; the core of M94 is quite bright, so the dynamic range between the core and the outer ring is very high and required some fiddling.  Still, in the end I like this image better than the overprocessed one I took last year.

Date: 2 May 2014

Subject: M94, Croc’s Eye Galaxy

Scope: AT8IN + HPS Coma Corrector

Filter: None

Mount: CG-5 (Synta motors, PicGoto Simplificado)

Guiding: 9x50 Finder/Guider + DSI Ic + PHD 2.2.2 (Win 7 ASCOM)

Camera: DSI IIc no chiller T = 15 °C)

Acquisition: Nebulosity 3.2.0, no dither

Exposure: 40x300 s

Stacking: Neb 3, bad pixel map, bias included, normalize first, trans+rot align, 1.5 SD stack.

Processing: StarTools 1.3.5.279 Crop; Develop 81.72%; Color:Scientific, 200% sat.; Wipe, 75%; Develop 84.41%; Color: Scientific, 250%; Deconvolute auto mask 3.0 pix; HDR:Reveal core; Sharpen; Life:Moderate; Track RNC 6.37%; Magic:Shrink 1. CS6 Astronomy Tools Gradient Xterminator with layer mask; increase star color; Healing brush; Deep space noise reduction; Space noise reduction; Less crunch more fuzzy; layer mask the denoising; Astro Frame.