Quote Originally Posted by BradS View Post
I don't know about the specifics of the Rollei market but in large format lenses, Tessars are, generally speaking, older, command lower prices and are considerd to not perform as well as the (generally) newer Xenars. One way of understanding this is that Schneider "modernized" the basic 4/3 design. They made improvements in design, materials and manufacturing.

Personally, I greatly prefer the Xenars to the Tessars...
That's because Schneider stayed in the large format lens business longer than Zeiss. The Zeiss Tessars for MF were tweaked and reformulated as well, for instance the Tessar used on the Rollei 3.5 T models used rare earth glass and was a stellar performer, better than the Xenars of that era.