I've been playing with an old Orion 4" F6 achromat. I'd originally planned to do NB (because it is not the best from the point of view of colour correction) with it but my old ST7 died on me and so I have fallen back on a 350D and have reconfigured the rig to do OSC via a WO flattener/reducer which gives me a resolution of 2.56 as/p and a FOV of 1.75 x 2.4 degrees. Not being cooled, I wasn't expecting much from this rig but we had one brief night of clear skies here on Monday and so I gave it a whirl on the obvious target - M42/43. This is a mix of 6 x 1 minute and 6 x 5 minute subs at ISO800 with darks only applied and some layer masking and a touchup in PS to finish. I'm surprised by the result. It's better than I had expected by a long shot. Hope you agree.
