>>3438411ok guys, i built this out of an old camera strap and a lens cap. it works very well, but i'm not sure if i can trust it. when the lens is screwed in tight it holds just fine, but when you twist it just a little it can fall. the problem is that there is no lock mechanism like the camera lens mount has.
now i'll try to find an extension tube, or much more likely, a teleconverter with a lock mechanism and build the same thing with that.