i recently was able to borrow a friend's Mamiya RZ67 and we've agreed that he's going to sell it to me. the lens he has for it is a 140mm macro and while this is a wonderful lens, its a bit long for some of the work i do. i'm looking at buying a good quality used 90mm f/3.5 from KEH.
the thing that's confusing me is that some of them are listed as:
90 F3.5 (77) MEDIUM FORMAT SLR MANUAL FOCUS STANDARD ANGLE LENS
and others are listed as:
90 F3.5 W (77) MEDIUM FORMAT SLR MANUAL FOCUS STANDARD ANGLE LENS
The W means that it is slightly newer than the non-w. The W is the current version, IIRC, it was introduced along with the RZ67 Pro II. There is no optical difference, besides maybe slightly revised coatings, if anything.