The area of sky around the star cluster Messier 35, at top in Gemini, with the supernova remnant IC 443 below, and the Monkeyhead Nebula, IC 2174, in Orion at bottom. This is with the 200mm Canon lens to frame a binocular field of view, and taken with the standard Canon 6D MkII camera at ISO 800, for a stack of 16 x 2-minute exposures and through the NISI Natural Night filter to help bring out the nebulas. On the iOptron Sky Guider Pro. Taken from home Feb 19, 2020. The stock camera did a pretty good job recording the red nebulas but not as good as the filter-modified Canon 5D MkII did on shots taken the next night for comparison.
Open cluster M35 in Gemini and nearby nebulosity IC 443 (Jellyfish Nebula) bottom left of cluster and NGC 2174 below cluster. This is a stack of 5 x 4 minute exposurs with Canon 5D MkII at ISO 800 and Canon 135mm lens at f/2.8. Taken January 6, 2011. Field of view simulates binocular field.
A portrait of various emission nebulas in southern Gemini and into northern Orion. At top is the bright star cluster Messier 35, with the small more distant open star cluster NGC 2158 below and to the right of it. Left of centre is the shell-like supernova remnant, IC 443, aka the Jellyfish Nebula. The small blue reflection nebula above and to the left of it is IC 444 amid a field of fainter emission nebulosity. The round and bright nebula at bottom is IC 2174 in Orion, aka the Monkeyhead Nebula. It is mostly an emission nebula but has some blue reflection components. The smaller round red nebula above it is Sharpless 2-247. It appears to be an ionized HII region, as a form of bubble, but is not a planetary nebula. So this is a field of various forms of nebulas: emission, reflection and supernova remnants. Missing is an obvious planetary nebula or dark nebula. The orange star to the right of the Jellyfish is Propus, or eta Geminorum. This is a stack and blend of filtered and unfiltered exposures, the latter set maintaining the natural star colours, and avoiding the haloes introduced by the filters, particularly the L-eXtreme. The image is a blend of: 10 x 6 minutes at ISO 800 without a filter + 8 x 12 minutes at ISO 1600 with an Optolong L-eNhance dual narrow-band filter + 6 x 16 minutes at ISO 3200 with the Optolong L-eXtreme vary narrowband filter, the latter set taken at the end of the sequence when the field was quite low. Through masking the L-eXtreme images contributed only some of the nebulosity, particularly the subtle cyan fringes on the leading edges of IC 443 — it is the Oxygen III cyans that the L-eXtreme is good at picking up. All were with the Canon EOS Ra camera and through the SharpStar 76mm triplet apo refractor with the EDPH reducer/flattener for f/4.5. Guiding was with the multi-star Lacerta MGEN3 stand-alone auto-guider, which also controlled the camera shutter and performed dithering between each frame to shift each exposure by a few pixels for noise reduction in stacking. All stacking, alignment and blending was with Photoshop v22.3. Some curves were applied with Lumenzia luminosity masks to selectively adjust the mids or dark-mid tones. Nik Collection ColorEFX ProContrast filter applied locally to the nebulas, plus a high pass sharpening, both to further enhance the nebulosity. No darks or LENR frames were employed or applied on this cool but pleasant and very clear and dry late winter night.
