Hi folks,
Ok, first off, I'm amazed at the variety of image interpretations so far. Very creative crew out there.
Second, the field of view of my telescope is a bit narrow for an object this size, so this is a bit zoomed in compared to the rest. It's basically the Pelican's upper body. I didn't realize the poor framing during the imaging, as it is too dark an image to see anything in the individual subs on the camera. So, I was imaging on faith that the plate solve using the guide scope was close enough for the imaging scope. Seemed to work, though I would frame the head region if I were to do it over.
The image was processed differently than what I've done in the past. Instead of using Deep Sky Stacker, I used Sequator. It's not nearly as full featured / optioned as DSS, but Sequator appears to work perfectly on my Linux PC under Wine. It's also much faster, very clean, very easy to use. The stack here took about 25 minutes; a similar stack in DSS 4.1.1 took 10 hours. That said, there is a new version of DSS 4.2 that is known to be a lot faster, but I haven't tried it as yet. And there's still the Linux/wine issue.
Sequator, for some reason, seemed to produce a stack with smaller stars, and less walking / pattern noise than DSS. Instead of being blobby, the noise looks more stringy, almost creating an embroidery sort of pattern. Sequator doesn't seem to have a place for Dark-Flats, so they weren't used. My guess is that this raised the black level, so the blobs don't show. No idea how they do the pixel math. I'm still playing with the settings, but so far, it looks like a tool worth exercising a bit more. Not sure if it can be made to handle LRGB, however, but this is from my DSLR.
Remaining processing was done in StarTools, beginning with the Contrast tool instead of Develop, due to the high dark level. Seemed to handle it well.
Taken 8/25/2019
Telescope: Celestron 8" f/5 Newtonian (f/5.6 with coma corrector); 1,150 mm net focal length
Mount: Celestron AVX
Guider: Celestron 80mm f/7.5 scope, ASI174mm Mini camera; PHD2 on a Raspberry Pi 3B
Camera: Unmodified Nikon D3200; exposures 20 seconds at ISO 12,800
294 Lights (98 minutes integration), taken 8/25/2019
20 Darks
20 Flats
Stacked in Sequator, Processed in StarTools 1.3
Enjoy,
Greg