http://en.wikipedia.org/wiki/T-mount http://en.wikipedia.org/wiki/T-mount T-mount beats F-mount by 2 years. It's not as elegant as F-mount, but it's very simpl

http://en.wikipedia.org/wiki/T-mount http://en.wikipedia.org/wiki/T-mount T-mount beats F-mount by 2 years. It's not as elegant as F-mount, but it's very simple - essentially a screw. I use it with adapter to attach my Nikon DSLR to a telescope.