[gbeal]

Originally Posted by xelasnave

But thinking more a lot of problems can be fixed with a massive focal reducer.. so the first problem is what can we reduce the 12 inch effective f/l to?
alex

Forget ti, at f4 - f5 it is as "short" as you can go without major headaches. The Epsilons are f3.3 (in my case) or the latest are f2.8, but they employ a humungous corrector/reducer system to correct the optical problems.