Astrophotography Beginner Needs Help
I have been a semi pro photographer for over 35 years, so I know my way around photography and gear. I just recently decided to try and live my life long dream of doing some astrophotography. I have done a few wide angle shots of the Milky Way and Comet Neowise, but really want to get something of Andromeda Galaxy (m31) and eventually move on to other deep sky subjects. I am using good gear and have read as much as I can on the subject, but I am still failing miserably! The image below is the best I could do.
For M31 I am using the Sky Watcher Star Adventurer, with the balance weight, a Nikon D810 and either a Tamron 70-200 f2.8 or a Nikon 300 f4 PF. I am doing my best at aligning the Star Adventurer to Polaris and have tried various exposure times and ISO settings. Last night I used the 300 f4 PF lens at f4 and shot 15 frames at 2 minutes and ISO 2500. The files are all very bright and washed out, but I loaded them all onto Deep Sky Stacker with the "dark" "flat" and "bias" files I created earlier. The stack in DSS is still really bright white and washed out, but when I load the saved tiff into Photoshop and process it, I can get something that looks like M31 and it's sister galaxy. However, what I am getting is unacceptable and far worse than anything else I can find online, and even much worse than I have seen from people with lesser gear and no clock drive. I am at a loss as to what I am doing wrong and am really hoping that the people here can help me with this.
I live on a 2 acre property about 12 km outside of the city of Victoria (population about 400,000) so there is still a reasonable amount of light pollution here. Could that be my problem? I have seen pretty good samples online where people "say" they shot M31 from within a city and light pollution and I would be very happy to get something as good as they display. Do I need more frames or slower/faster exposures? What can I try next?
Any and all advice/help is greatly appreciated. :)