Since taking these lights, I have redone darks, flats and bias frames and done a reworking of the NB images of M17.
Taking on board the comments about controlling the green of the Ha channel, I have tried, in this rendition, to emphasise the shock fronts (which seem to be mainly SII) and the blue reflection nebulosity much more.
The image is a 50% (or thereabouts crop) and comes from 45 unbinned minutes in each of the usual NB filters (Astronomic 12nm) with an ATIK 4000 on a WO FLT110ED at F7.
I would be glad to hear comments.
Peter
