[Intro for the non-astronomers]
This field covers a swath of one of the most interesting parts of the sky. At about 15 full moons wide, it stretches from Orion's sword at right through the Horsehead and Flame nebula at center, with all surrounded by huge swaths of hydrogen gas and dust. A great reminder that our galaxy is not just made of stars!
[Nerdy intro for the astro-folk]
After much agonizing time staring at my screen, I'm done with this mosaic. 2 frames, roughly 15% overlap, then cropped. (Can't imagine how guys like Rogelio do 20-frame mosaics!)
For the RGB, I used a combo of 90 minutes taken from home (new moon, but still badly light polluted) and some old DSLR data from 2 years ago taken under dark skies. Aligning the Ha and RGB was a pain due to this as well as slight field rotation in the Ha. Ha was blended with pseudo-Lum (from the RGB), then blended as Luminance in PS with the RGB. Please forgive the Blue haloes ... my filters are chronically haloed and this is exacerbated by the Ha as it has smaller stars.
Hydrogen-alpha-only version can be found here.
Hydrogen-alpha = Baader 7.5nm, 8 x 20 min (right panel has an extra 10
x 1 min Ha, layer masked over M42's core)
RGB = 18 x 5 min exposures each
Telescope = Takahashi FSQ-85EDX
Camera = STL-11000M
Mount = EQ6 Pro
Software = capture, stacking and alignment in MaximDL; mosaicking, levels and cropping in Photoshop
Date = Several nights in October and November 2010
Location = downtown Toronto, Canada