OH! Those are very nice taken. Enjoy the process of the astrophotography is the mostly important.
I like the tone of your M42, very soft natural. For the core of the M42, have you done the layer mask with the shorter exposure to maintain the details?
Thanks Eric. Yes, for M42 I've used layer mask to improve the details in the centre, and I delibrately did not sharpen too much to keep a more natural feel.