The great globular cluster and galactic nucleus remnant Omega Centauri, NGC 5139, with two galaxies in the field: Centarus A or NGC 5128, the Hamburger Galaxy, at top; and NGC 4945 at right. Ther field simulates a binocular field of view. This is a stack of 4 x 2-minute exposures with the 200mm telephoto at f/2.8 and Canon 5D MkII at ISO 2500.
A widefield view of Orion's Belt and Sword showing the complex of nebulosity in the area. The three Belt stars are at top (L to R): Alnitak, Alnilam and Mintaka, with the dark Horsehead Nebula (B33) below Alnitak. Above Alnitak is the pinkish Flame Nebula, NGC 2024. At bottom are Messiers 42 and 43, making up the Orion Nebula, with the bluish Running Man Nebula above it, aka NGC 1973-5-7. Above it is the star cluster NGC 1981. Messier 78 is just on frame at upper left. Numerous other bits of emission and reflection nebulas populate the field amid a backdrop of faint emission nebulosity. The stars around the Belt belong to the large star cluster Collinder 70. This is a blend of two stacks of images: 15 x 8 minutes through an IDAS NBX dual narrowband filter to bring out the faint nebulosity, and 15 x 4-minutes with no filter for the more natural star colours and colours of the Orion, Flame and Horsehead (IC 434) Nebulas. So a total of 3 hours of exposure time. I did not take shorter exposures for the Orion Nebula core. All were with the William Optics RedCat 51mm astrograph at f/4.9 and filter-modified (by AstroGear) Canon EOS R at ISO 3200 for the filtered shots and ISO 800 for the unfiltered shots. Taken from home January 22, 2023 on a rare clear winter night. Autoguided and dithered with the Lacerta MGEN3 autoguider. No darks or LENR employed. All stacking, alignment and masking in Photoshop. Luminosity masks with Lumenzia helped bring out the nebulosity, as did a mild application of the Nebula FIlter action in the PhotoKemi StarTools Actions set. Noise reduction with RC-Astro Noise XTerminator. The filtered set has had all the stars removed using RC-Astro Star XTerminator, so it contributed just the nebulosity, Stars come from the unfiltered set for tighter stars with more natural colours.
A mosaic of the Belt and Sword region of Orion the Hunter, revealing the diverse and colourful array of nebulas in the area, all a part of a vast star-formation complex. The Orion Nebula itself, Messier 42, is below centre, overexposed here. But also visible are the large red Barnard’s Loop, at left, and the blue Witchhead Nebula, IC 2118, at right, illuminated by the bright star Rigel. The Horsehead Nebula is visible below the left start of the Belt of Orion. Above it is the pinkish Flame Nebula, NGC 2024, and above it the bluish M78 reflection nebula complex. This is a 4-panel mosaic shot Jan 1, 2016 from home on a very clear night, though with some sky gradients. Each panel is a stack of 5 x 3-minute exposures at f/2.8 with the Canon L-Series 135mm lens, on the filter-modified Canon 5D MkII at ISO 1000. The camera was tracking but unguided on the AP Mach One mount. Orion was on the meridian but even so there was a lot of difference in sky brightness between panel segments. Also, trails from geostationary satellites appeared in each frame, as Orion was then near the opposition point, due south at midnight. I eliminated these with a Median combine stack mode for each panel segment. Plus from my latitude southern Orion tends to sit in brighter sky gradients, so the lower panels were brighter and more sky fogged than the upper panels. All stacking and stitching in Photoshop CC 2015.
