M42 Orion Nebula with Astrotech AT65EDQ and Nikon D7000

M42 Orion Nebula with Astrotech AT65EDQ and Nikon D7000

Got a "clear" (as in no clouds, but plenty of haze/poor visibility thanks to our lovely inversion in Salt Lake City) night last night, decided to pack up my gear and drive up to the top of a canyon near my house. Still a bortle 6/7 zone so lots of light pollution that’s made worse thanks to the snow on the ground and the haze in the air this time of year. Decided to go for the "layup" in terms of night sky targets, M42, since the skies weren’t great and I probably wouldn’t have been able to image much else. Just wanted more practice setting up, imaging, dithering, and breaking down this new gear. I think I’ve nailed the polar alignment process with sharpcap, guiding has been going well (usually around 1 arc-sec total RMS), dithering is something I need to figure out how to automate better though.

Acquisition details:
Shot with Astrotech AT65EDQ and Nikon D7000 (full spectrum mod with UV/IR Cut filter)
Orion Sirius EQ-G mount with Rowan Belt Mod and ADM Losmandy saddle
Orion 50mm mini guide scope and ToupTek guide cam, polar aligned with Sharpcap, guiding and dithering with PHD2
36 x 5 minute exposures at ISO 800
25 x 45 second exposures at ISO 800
100 x bias frames, 41 x flat frames

Editing steps:
created master bias, corrected flat frames with master bias and then created master flat, then calibrated light frames with master bias and master flat in PixInsight
cosmetic correction to remove hot pixels in PI
BatchDebayer to debayer all light frames
StarAlignment for image registration, then stacking (5 minute exposures separate from 45 second exposures), then drizzle integration
Dynamic Crop to crop off edges
Extract luminence channel, then separate RGB channels, LinearFit RGB channels to luminence channel and then channel combination to combine RGB channels
Dynamic Background Extraction to remove gradient
Color calibration with white and dark reference points
Noise reduction with MultiScaleLinearTransform
Screen Transfer Function for the 5 minute exposure stack, masked stretch for the 45 second exposure stack
Open stacks in Photoshop, align as layers, then mask in the 45 second exposure stack for the core of the nebula.
Flatten image and do a smart sharpen
Select brighter stars with astro actions tool, then expand selection several pixels, feather by half as many pixels.
Minimum filter to reduce star size
Curves and levels to add contrast
Open in lightroom so I can resize and export with watermark for web upload

It’s pretty overprocessed, the stacking didn’t remove some artifacts like the geosynch satellite trails, there was also some horizontal banding that I think was caused by cars driving by illuminating the haze in the air. Not an overly great edit, but it was more about getting more practice with the equipment and just trying this target with this scope for the first time.

Posted by Utah Astrophotography on 2017-01-19 05:25:48

Tagged: , Astrometrydotnet:id=nova1910500 , Astrometrydotnet:status=solved


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