Hi, Anyone had any experience with the Zeiss Planar 135mm f3.5 lens when shooting wide open? Is it quite sharp? How old is it? How much would you expect to pay for this lens? Am also interested in the Xenotar 150mm 2.8 and the Xenotar 135 3.5? Same issues as stated above? I plan to buy one of them for portraits shot wide open. Thanks. Any information you could provide would be great.