I think I have started something here!
What I will do is turn off the noise reduction and take dedicated darks at the time of the lights. The trick will be to stack the darks and make a master dark first then apply that. as far as flats are concerned I'll tackle that one next!
I found this too which may be of use ...
http://www.covingtoninnovations.com/...300Dastro.html
Will see how I go.
Its an interesting topic.
Will thank Humayun...now! thanks mate and thanks to everyone for your comments
Will post some second light pics to show the difference. It will be interesting to compare them with my first light pics where I had the noise reduction turned on.
Its a huge learning curve!