The long break was because I was gone for over half of September on work trips, and before that I was busy and the weather wasn’t good.
I took some 220 pictures of the Dumbbell Nebula, but several things were not in my favor.
· All of the good nebulae – Omega, Trifid, Lagoon, Eagle, etc. – are setting pretty early now, and since that puts them in the southwest, the direction of the town or city that is causing all the light in that part of the sky, imaging them yields not-very-good results.
· The camera cable got jiggled at some point, so over half the pictures were in JPEG before I realized it and reset that setting back to raw. (The camera-control program I was using, digiCamControl, automatically sets the image to JPEG every time the camera is plugged in. And no, I can’t edit the default settings.)
· The Dumbbell Nebula was pretty high in the sky, up in the 60°-altitude range (part of the reason I picked it – somewhat less light and much less atmosphere), but that gets into the range where the tracking is poor for alt-az mounts. So not only did it drift a lot, but the majority of the photos wad periodic tracking error. So, out of 220, only 7 came out, since many were lost to JPEG and the rest to periodic error.
The picture didn’t turn out too badly, actually. It is pretty grainy though. And, of course, I always want more light.
M27 Dumbbell Nebula
Nikon D3100 on my C8, 7x30s, ISO-3200
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