Thanks, guys , for your helpful comments and suggestions! I have now looked up those utubes and a couple of pdf's (will have to re-look a few times). I will perservere with it for a bit longer, although I tried it out on Jupiter from my OSC, and came up with a HORRIBLE result! Omega Cen was a bit better, but so far no better than Star Tools!
I think I am about 1% along the learning curve


My wife hears me muttering to myself and wonders what I am up to, then I tell her "Oh,I'm just learning dynamic crop, histogram ,background calibration, curves transformation, morphology and cosmetic correction - I'm not quite mad yet, but beware............."