I will reply in case you are waiting for an answer. I am in no way an expert but i'll throw in my 2c. Probably time of day causes the lack of replies. mpcc = coma corrector (Most SW ED80s have a little coma near the edge of the image) but I have seen a lot worse than in your image.
Autoguiding - IMO the cheapest way would be a QHY5 autoguider (around $400 with postage) or the Orion which I suspect may be a little dearer but others may know better. I use PHD as guiding s/ware or alternatively guidemaster I hear is good both are free to down load. A few cables and a cheap achro guidescope and a way to mount it and you are away. It sure beats staring in an illuminated reticule.
That's a good start! Looks similar to my efforts so far, but with far better polar alignment. Well done. Out of curiousity, what were the exposure times and number of subs?
subs = shots. So, your first shot was a single sub. You can take multiple shots and then stack them to improve the shot(s) even more, using something like Deep Sky Stacker or Iris. I prefer DSS far more intuitive to use. Both are free downloads.
Nice one Les, Unguided WOW. Think what you will achieve with guiding and longer exposures. M42 is not an easy target with everything in your favour. The dynamic range is huge.
Well done, look forward to more.
