The rather obscure emission nebula catalogued as Sharpless 2-261, at top, but commonly known as Lower’s Nebula after the father and son team of amateur astronomers, Harold and Charles Lower, who in 1939 built an 8-inch Schmidt camera astrograph, one of the first, and used red sensitive plates and red filters to record these kinds of red nebulas. They noted this object on their plates, in northern Orion. They were certainly pioneers of this type of filtered astrophotography. At bottom is the small star cluster NGC 2169, also known as the X-Y Cluster or Number 37 Cluster as its two clumps of stars, just resolved here, resemble those letters or numbers with a little imagination at the eyepiece. At bottom left is the small emission nebula Sh2-269. The larger fainter patch above it is Sh2-267. The small nebula at the left edge might be Sh2-266 but charts are unclear and contradictory. This is a stack of 5 x 8-minute exposures unfiltered at ISO 800 with a stack of 6 x 10-minute exposures at ISO 1600 shot through an Optolong L-Enhance filter to bring out the nebulas, all with the old Hutech filter-modified Canon 5D MkII DSLR and the SharpStar HNT150 Hyperbolic Newtonian astrograph at f/2.8. What the Lowers would have given to have such technology in their day! Taken with some haze in the sky toward the end of the shoot for the unfiltered shots, adding the star glows. Taken from home February 22, 2020.
A telephoto lens image of the globular cluster Messier 3 in Canes Venatici. This is shot to simulate the field of view of binoculars for illustration purposes. The faint globular cluster NGC 5466 is at far left. This is a stack of 6 x 1-minute exposures with the 200mm lens at f/2.8 and Canon 6D MkII at ISO 800, tracked but unguided on the Mach 1 mount, on April 28, 2019.
M4 (at right) and NGC 6144 (upper) globular clusters with Antares. Taken with 4-inch AP Traveler apo refractor at f/4.5 with Canon 20Da camera at ISO 800 for stack of 4 x 5 minute exposures. Taken from Coonabarabran, NSW, March 27, 2007.
