One of the real advantages of the mirrorless cameras, like my little EOS-M, is the ability to mount just about any lens. The small cameras have very shallow back focus requirements, the distance from the lens mount to the sensor. With the correct adapter they can mount the old Canon FD, Nikon, Leica, anything! I find myself unpacking my old photo gear, and wondering about the possibilities.
I do have some really good old Canon and Nikon primes around, lenses from the manual focus days. When I assembled an EOS-M to FD adapter, an extension tube, and a 50mm f/1.4 lens onto the front of the camera it resulted in a rather odd looking setup. Odd looking, but it works, providing an impressive macro capability. With better than 1:1 magnification I was able to keep a reasonable depth of field in the test shots. I need try some tests with the 100mm f/2.8 lens, for even higher magnification.
Aside from the FD to EOS-M adapter this is all gear I had sitting about unused. I never used it much in my film days. Digital is different, the ability to examine the result immediately and the elimination of per frame costs enables an ease of experimentation that was not there before. I am going to play with this a bit!