Boris, you can mount MTO 500 and 1100mm on Nikon (Or any other SLR body) with infinity focus if you simply swap original lens mount with T2 mount. MTO lens mount is identical as "outer" T2 mount. You do not have to use standard internal T2 ring with 42x0.75mm thread. I did it to my MTO 500 almost 25 years ago and also did it with MTO 1100 when I had one. It works!