Sorry Sinwen, but that's actually a misconception. You are partly right in that people tend to prefer Leica lenses, but the reason you don't see any other SLR lenses being used on Leica R is because Leica R has the longest flange to focal distance of common 35mm SLR's. It is possible to put a Leica R lens on almost any other mount with an adapter, but to put any other maker on Leica R would require a glass element in order to achieve infinity focus. But I do expect people to put other lenses on the S2, precisely because it is so expensive. If you use a certain lens only occasionally, would you want to pay 6000 dollars for it when you could just buy an adapter and use a mamiya, contax or Hasselblad lens? It will depend on the flange to focal distance, but I imagine the S2 is much narrower than the other medium format camera, so I doubt it will be a problem.