West Veil Nebula (NGC 6960, Farm III)

In addition to just absolutely enjoying the chance to get back out in the field, it was rewarding to see my setup doing everything that I asked of it. I am not expecting a lot from my images, because I wasn’t on my A game, and didn’t ask everything of my setup that I should have. Although every aspect of running the equipment has been rehearsed and tweaked over the past couple of months, the Jim part of making it all happen correctly in the field was new, and I didn’t execute as well as I could have. I did learn a lot and am looking forward to getting out under a dark sky again soon.

Start up

At the outset, I got behind my solar schedule (not being ready to start polar alignment at sunset +40m), and that was partly due to dealing with the tent (because I didn’t remember as much as I thought that I had about how to set it up) and partly waiting for clouds to clear. Since I was maybe forty-five minutes late in being ready to polar align, I elected to go off script (i.e., not follow my work plan step by step), and rely upon my frequent practice session of late. Given similar circumstances again, I would go off script again.

Conditions were not perfect, but reasonable throughout the night. It was hot upon arrival but started getting chilly pretty quickly. I started in shorts and a t-shirt, switched to long pants and long sleeve shirt right after sundown, and put on a medium coat not long after that. There were lingering clouds to the north that were obscuring Polaris as it got dark, and they cleared by about 2230. Dew started forming as soon as it got dark. It wasn’t as bad as I have seen it. I noticed fog at about 3am.

My setup was the lightweight tripod, G11, NP101, and ASI6200 with ASI290/OAG guiding. There were no equipment issues, and I was able to get through setup and start up fairly easily.


My imaging strategy was shaped by my late start and having just three hours of imaging time before beginning of twilight. I needed 480s per sub exposure time to get histogram separation, and wanting at least eight subframes with each filter, the math worked out to 1 hour with each RGB filter and would need to forego the L filter.

The first place that memory failed me as I was working off script was in the camera rotation angle. I had consulted Stellarium before leaving home and determined that I wanted the long axis of the target to align with the long axis of the image frame. Looking at my pre-departure notes, I wrote down that the way to get this alignment was with the camera rotation at 90 degrees. Working off script my incorrect memory was that I needed 0 degrees rotation, so that is how I set the camera. The first test image came back with the target aligned with the short axis of the center. The Broom was well-contained in the frame, and already running behind, I didn’t want to devote more time to targeting or to risk making the situation worse. I accepted the alignment and moved on.

The next deviation from what I had intended to do was related to how I take care of myself during the night when imaging at home vs. what I did in the field. At home and after making sure that an imaging session correctly running, I set an alarm and nap once or twice. The last time I wake up is for the final check and to capture Flats. I had envisioned brief chair naps in the field so that I could function better as the night wore on. I didn’t nap and that caused two problems. First is that I was extremely fatigued, and gave up on the B filter after just 4 subs. Second is that I didn’t even attempt to take Flats.

Wrap up:

One obvious place for improvement is to practice setting up the tent the day before. Not only will this help my recall for how to set it up, I will also have an opportunity to correct deficiencies like a broken bungee.

One 33AH battery lasted the whole night with power to spare. The dew strap was turned up to about 25%. I did notice some dew formation on the front lens. I think that turning up the dew heater just a bit above 25% will help that.

Being disciplined about brief chair naps and making sure that I start early enough that I can stick to my work plan will help me get better data next time.

Witches Broom (NGC6960) - 2022-06-30
West Veil Nebula

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