For the type of imaging you are doing Alex I recon this is a fine shot, I have never been a noise-a-phobe unless it is terrible, the colours match your reference image nicely too. Imaging this way ie big aperture and lots of short exposures is much more productive than the way I and many others do it
. If you get the focus and other quirks down pat you can image plenty the way you do aaaaand your scope is easily turned into an amazing visual instrument to boot
Of course you may have issues if you were to try and image with a camera and chip like mine
Mike