I recently purchased a RODENSTOCK RETINA-ROTELAR 135mm f/4 lens and while it has Retina printed on the front of the lens it would not fit on my Retina S camera. The lens mount is very similar to my other Retina lenses but it just doesn't fit all the way into the camera. I also have the Schneider-Kreuznach 135 f/4 and the two lenses look identical except the Rodenstock is about 5mm shorter. Do you know which camera this lens fits? Also, I have Ivor Matanle's "Collecting and Using Classic SLR's" and the only Rodenstock 135 f/4 bayonet mount lens listed fits the Retina cameras. This lens should be a Retina "S" mount but it just doesn't fit. Any ideas?