. "it is just a pain in the neck because you either have to eyeball it, or you have to take the mount plate off the lens.Not that it is hard to do, but you never know what a manufacturer has put under that plate, and all kinds of springs and stuff can come flying out when you least expect it.So far this one has worked great, I just need to go out somewhere and shoot some serious shots and see what is up" . . . .