Contax 645AF System
enlarge image (645 body and 140mm f/2.8).
Review coming. It's such an amazing system I can't bring myself to review it and raise the prices; you can get them cheap today compared to the completely insane prices they commanded new.
The Contax 645 is the world's most advanced medium-format camera system. It has backs for 120 and 220 and even vacuum backs for 220, and today it's among the world's most popular pro cameras for use with medium format backs.