As part of astro photography study, I spent a couple of weeks running through and testing permutations of flip mirrors, lenses and adapters to do positive and negative projection. This was for three fix-focal length scopes that I own: a 10 inch 1100mm fl Newt, a 1290mm fl 5 1/4 inch refractor and a PST. I still plan to get out an do the Ealing as the fourth scope (direct projection only, no projection). The general idea was to have a negative barlow and positive projection cookbook. This is a phamplet of 10-15 designs that I can refer to when I want to slap something on a scope, i.e. - assemble the adapters and roll the tube focuser tube back a pre-determined distance with confidence that I will be close to focus. Although I assume that most of you imagers here have moved on to variable focal-length SCTs (where getting your camera to prime focus is easier), is this typical for your own experience with fixed focal length scopes? Or do you just get one or two barlowed projection setups to work and stick with what you are comfortable with? - Kurt _______________________________________________ Sent via CSolutions - http://www.csolutions.net