Still playing with my "new" ASI2600MC (I had to send my old faithful ASI294MM back to China under RMA as it started acting up last week). It's not particularly new as I got it last Xmas, but it found little use save with my Hyperstar(s), and I wanted to see how it performed with a bit more focal length.
Target: NGC 891, aka Caldwell 23
When: November 19, 2023, around 10pm
Where: Cévennes range, south of France, Bortle 4.
Conditions: some high clouds, FWHM around 3.6 arcsec, 40% moon
Setup: C6 SCT, RST-135 guided, Starizona Corrector IV, ASI2600MC bin1 (should probably have used bin2 instead), 180s exposures, darks, flats
Here's the save as seen, cropped and resized for posting. That livestack not particularly well defined: on the right of the dark dust lane, there's a slightly oblong yellow-orange star that should be resolved into what it is in reality: a double star with a separation of almost 3.7 arcsec. Seeing killed me on this one. That said, I still got some nice detail in the dust lane proper. Also, numerous small background galaxies around mag 17 in that narrow field, and even a quasar!
I spent a very long time fine tuning the color channels to get something as neutral as possible, which meant bumping up reds and blues to overcome the camera's tendency to paint everything green. Sharpcap's keyboard shortcuts helped a lot here (click on the color handle, then fine movements can be done with the up/down arrows)
Very nice! I had never known about the double star before, but now I can see it in other images. Without more than a brief digression, I hope, did you find the vignetting serious with the Starizona corrector on the C6?