Surprisingly there was a clear sky for a few hours last night over Innsbruck. Moon was half up, but otherwise it was as good as it can get in city conditions.
I wanted to try a few things. First use my very cheap Skywatcher StarTraveler 80mm refractor to make a wide image of M31. Second I wanted also to check out my new Astronomik CLS filter to reduce these pesky city lights. And thirdly I wanted to use off axis guiding through the scope.
With the off axis guiding I failed miserably. I have to try to get focus and light during day. I fell back to use my 9x50 finder as guiding scope.
The Astronomik CLS filter is a mixed bag. I seem to get a little more contrast with it (which is needed because of the short focal length of 400mm). On the other hand you get blueish images with almost no red channel in it. I took 12x5 min 1600 ISO subs and still there was almost no information there.
The StarTravel ST80 is amazing for the amount of money it costs. Of course there are distortions off center, purple fringe effects are very visible around stars and focus is not really clear cut on the full frame. But for 100 euro it is still amazing.
So here's the final image 12x5 min ISO 1600 subs with an EOS M3. No dark frames, no flats, noise reduction was completely done in Photoshop.