In article <4f6b8v$nfb@news.csus.edu>, karant@gallium says...

>Angelo Provera (A.Provera@agora.stm.it) wrote:
>: Does anyone knows if the lens "system" of the Contaflex (Pro Tessar
>: 35,50,85,115) has some optical quality or is only a "strange" idea for an
>: economical camera?

>I assume you mean the system used in the Contaflex whereby there were
>lens elements/groups fixed into the body, and only part of the lens
>elements/groups actually changed with a change of "lens"; contrast
>this with the Contarex system which changed the entire lens (as with
>current Nikon, Canon, Minolta, Leica, ... , SLRs). If this is what
>you mean, the reason was cost and compactness (but primarily cost):
>Contaflex units were much less expensive than equivalent Contarex
>units.

The Contaflex used a leaf shutter in the lens which made it impractical
to have interchangeable lens rear sections, since that would have meant
that each lens would have needed a shutter - which would have been too
complicated, costly, and probably unreliable and bulky for this fine
little early SLR gem.
Hope This Helps