So, taking this a bit down to the wire, hoping for more than one night of data. I finally got that second session last night, which netted some interesting experimental data, along with more on this month's Challenge as well. What I ended up with is a bit of a "Frankenstein" in its content, due in part to that experiment. (I guess you mono imagers call this "normal process" )
The first night, 4-March, was a "get something in the can" event, just to learn a bit about the target. I'd never imaged it before, and it's the first of this type with the cooled CMOS camera. So, no filters, just grab the image. In that first session I managed 1hr 24 min of 4 minute subs, and got an OK image; nothing great. After playing with different stacking methods in DSS, I tried stacking the data with ASTAP, and got a significantly better treatment to the background noise. Unexpected, but welcomed. Good enough to post, I suppose, if that's all I could get. Then we got weather, and the Moon and weather together.
Last night the weather cleared, and the Moon was full, but in a different enough part of the sky that I thought it might work. With the contingency image in hand, let's experiment! I threw on the Astronomik UHC-2 filter, to see how well it did with the Nebula's structure in the presence of the Moon. Surprisingly, I didn't have to change the exposure from my "regular" settings. That probably means something worth understanding, but I haven't had a chance to digest it.
Due to some technical issues (I'm still fighting with the USB 3.0 Hub killing off my imaging camera), I only got 32 minutes with the filter. Processed alone, they weren't half bad, comparing favorably in some regards to the longer-integration no-filter image. Taking both sessions into DSS for stacking (it does a good job at organizing multiple sessions), the results were different than the base image; better in some ways but worse in others. Throwing caution to the wind (er, stars?), I threw everything into ASTAP's stacking page. All the Lights were lumped together, as were both pairs of Flat / Dark-flat sessions. No clue what it would do with the motley mix, but somehow the results were better than either single night, and what was done with DSS' carefully organized tabs. StarTools processing brought out the added deep red that I never got with my old Nikon, likely enhanced by the additional integration time with the UHC filter. Attached, below.
Final experiments included grabbing about a dozen images binned 1x1 instead of my usual 2x2 in-camera. After processing (including a software 2x2 bin), the result was about the same as the pre-binned image, confirming that the savings in space, and the shorter download time is a net benefit to binning in the camera.
Finally, this is another it-barely-fit image (only cropped for very slight stacking artifacts), suggesting that my next upgrade (after Galaxy season) should be a reducer / flattener.
IC443, Jellyfish Nebula, Imaged 3-4-2021 and 3-28-2021
Telescope: Stellarvue SVA130EDT, at its native 130mm f/7
Camera: ASI2600MC-Pro. Gain 300, offset 50, cooled to -5C. In-camera 2x2 binning.
Mount: Celestron AVX
Guider: ZWO 60mm f/4.6 scope, ASI174mm Mini camera
At-mount software: CCDciel, ASTAP, PHD2 on a 4gb Raspberry Pi 4B with Astroberry distro
Lights: 21 x 240 seconds no filter; 8 x 240 seconds with Astronomik UHC-2 (1hr 56min total)
Calibration frames: 20 x Darks, 2 sets of 20 Flats, Dark-Flats; no Bias frames used.
Stacked with ASTAP on Linux PC (not the Raspberry Pi!), processed with StarTools