Orion Nebula region with NGC1973-7. Stack of two 10-minute exposures + stack of 30s and 1min exposure for retaining bright core deail. Blended with Normal @ 85% but erasing all of short exposure layer except for core. With Canon 20Da, at f/6 with 5-inch AP apo refractor, ISO400, and Long Exposure Nosie Reduction ON in camera. Ambient temp was about -3° C. Taken Dec. 29, 2005.
M42 amd M43, Orion Nebula, with 92mm TMB Apo refractor and Borg 0.85x flattener/reducer for f/4.7, with Canon 20Da camera at ISO400 for stack of 4x 12 minutes, 4x4 minutes, 4x80 seconds and 4x20 seconds (for core). Bright area in upper layer selected, feathered, inverted selection, copied, the lower layer selected and Mask created, making a dark hole in the shape of the bright area for shorter exposure content to shine through.
The Orion Nebula complex consisting of M42, M43 and the reflection nebula area known as the Running Man Nebula, NGC 1973-5-7. NGC 1981 is the blue star cluster at top north edge. North is up, though in the sky from Australia where this was shot the object appeared upside down compared to this northern-centric view. This is a 3-exposure stack to preserve details in the bright core while bringing out the faint outlying parts. It is a stack of 4 x 1 minute + 4 x 5 minutes + 4 x 15 minutes, all at ISO 400 with the Canon 5D MkII (filter-modified) and Astro-Physics Traveler 105mm apo refractor at f/5.8 with the 6x7 field flattener. Images were aligned and masked in Photoshop CS6 using Refine Mask. An HDR stack did not work and produced odd artifacts. Images had to be manally stacked and masked. Shot from Timor Cottage, Coonabarabran, Australia, December 12/13, 2012.