Well, it's official. There is absolutely no way I can get any of my Nikon lenses to come to infinity focus with my FW in place. Even without the OAG the smallest backfocus i can get is ~50mm, 5mm too long and *so close* but not enough. So might just consider a small (< 70mm) refractor, unless if anyone else has managed to get a Mono + FW combo working!
**Edit**
It appears it is possible -
http://ukastroimaging.co.uk/forums/i...?topic=54566.0
I suppose I need much thinner adapters. Hmmm