so are you saying you use a 58mm reverse adapter for a 50mm lens. Is that something you can do with any lens? What about focusing distance? how is that affected?
That's what I have been using - 50 f/1.4 reversed. The focusing distance is a few feet. The smaller the focal length of the lens, the closer you can get with higher magnification.
I just received an adapter for my 135l, so I may try that tonight and see what that does to magnification/focal length. I'm definitely not an expert on the subject so maybe others can chime in. I like the results thus far.