Hi Les
Good work, i prefer the M17 shot, the colour and focus looks a bit better, than M42.
Forgive me for saying, but you appear to me to be at a stage where you are at a crossroads, and that means guiding. Stacking exposures will increase the signal over noise, but there is no real substitute for detail over exposure. i to stayed up late on Saturday (4.30am) and took some shots of M42, even a 3 min guided shot was overkill on it. Have you thought about getting a little guide camera? it seems to be the direction you heading in ...
that said, good work all round
