Originally posted by ChrisTrevino I think I'll order a fotodiox one for now. When I get it I'll ask for instructions on how to ensure it doesn't cost me hundreds by getting stuck.
That's easy. Remove the screw and clip, and it won't get stuck.
I have a lens-mount test-bed. It's simple and inexpensive: a set of the cheapest PK macro tubes, about US$8 shipped from Shanghai to USA. The tubes come in several sections, including mount sections. When I have a questionable lens or adapter, I put in the female mount section, and look at what's happening with everything that protrudes from lens and mount. It's like getting a view from inside the camera. I can see how the lens would interact mechanically with the camera, without touching the camera. Is a lifesaver sometimes.