I know there are adaptors around for changing the mount of a Leica R lens to Nikon. And; I understand the job is not to difficult.
What I donīt know is what lenses can be used and why (or not) - does this have anything to do with 2-cam or 3-cam? The only cams I remember are those in car engines.
Iīm sniffing a tempting 2,8/180 tele-elmarit.