I decided to give the North American Nebula a try with my new APO.
First setup was my unmodified EOS M3 with the 480 mm APO and the flattener from my light polluted garden. The nebula was close to the zenith which makes the sky a little bit darker. Total integration time was about hour.
The signal was really weak. Below is the result after pulling all my post processing skills.
Next night I tried it with my Baader H-alpha filter. As my current setup for the APO does not work with flattener AND filter, I had to make the pictures without the flattener which is painfully visible at stars in the corners.
The image below has almost 2 hours of integration time.
Again it shows the bad sensitivity of the unmodified EOS M3 to H-alpha frequencies.
I'm now really considering getting one of the dedicated CCD cameras, even if you've to sell your house to get one.