I'm seriously considering a major upgrade of my telescope to an AG Optical 10.5" iDK. Currently using a TPO 10" f/4 Newtonian and want a real step up to get away from the backfocus limits imposed by the coma corrector and the steel tube causing major focus shifts through the night.
AGO does not have a focal reducer. I've emailed with Dave Tandy who says that the Astrophysics 27TVPH might work. Having a focal reducer would allow me imaging at the native 1674mm (F6.7) or 1255mm (F5) with the reducer. This reducer would also have a decent amount of backfocus available.
Another one he mentioned is the Planewave 0.66x reducer but it has a horribly small backfocus of 48mm and I don't see how anyone with an OAG can get anywhere near that.
Does anyone have any experience with these or other focal reducers on corrected Dall-Kirkhams?