Being past film shooter who went digital. I figured to use one of my el-Nikkors on my 6300, so I bought what I figured would be easy adapter with helicoil movement so I could focus the lens, Lens is for enlarge, and has no focus. Well, the el-Nikkor is a LTM mount, and figured all I needed was LTM adapter that had ability to move or focus. I found one on eBay and, I thought. But, it appears the adapter is a Leica M to e-mount. I figure if I can locate adapter M to e-mount, it should work. I did not know M mounts came in a variety of sizes... The thread diameter of the M mount is 31mm, Is such an adapter available? Thanks.