As always, these objects are simple to find, being right next to bright Alnitak. And that’s the problem! I had nasty ghost images from Alnitak despite keeping the exposures to only 120 s, so I had to rotate the camera to keep them from being on top of the interesting parts of the image. I Photoshopped out the worst of them. I also had software problems; Nebulosity 3.1.3 kept crashing on download of the image after an extended exposure (it never did it with 1 s frame & focus images) so I had to revert to 3.1.2. CCD was around 0 °C throughout the run. I’ve still got significant differential flexure from my finder/guider, so I guess I need to put in a few more set screws to lock it in place.
The B revision used Nebulosity digital development, further stretching and noise reduction and Life:moderate in StarTools, and heavy layer masking in Photoshop to remove some stacking artifacts, the bad reflections, and a lot of the glow of Alnitak. This is kind of cheating! In C I just boosted the saturation a bit more.
Date: 4 Feb 2013
Subject: NGC 2024, Flame Nebula, IC 434, Horsehead Nebula
Scope: AT8IN+Antares 0.5x telereducer
Filter: None
Mount: CG-5 (Synta motors)
Guiding: 9x50 Finder/Guider + DSI Ic + PHD 1.14.0
Camera: DSI IIc (no chiller, T = 0 °C to -2 °C)
Acquisition: Nebulosity 3.1.2, no dither
Exposure: 117x120 s
Stacking: Neb 3, bad pixel map, bias included, normalize first, trans+rot align, 1.25 SD stack.
Processing: StarTools 1.3 Wipe, Develop, HDR
ptimize, Sharp, Deconvolute, Track, Magic:Shrink, Magic:Tighten, Magic:Core Expand, Life:Moderate. CS6 Gaussian blurred layer mask with Levels to remove a bad reflection, increase saturation, Astronomy Tools increase AstroFrame.
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