So I went crazy last week and bought a bunch of lenses from Henry's Outlet Store, because they were clearing out manual focus lenses. This 100mm f4 macro was one of the many I bought. Before Micro 4/3 cameras came along, Canon FD mount lenses could only be used on old Canon FD mount film bodies, and prices for them were very low. The Micro 4/3 cameras give FD lenses, among others mounts, new life. If you work with telephoto or macro lenses a lot, this is even better because the Micro 4/3 cameras essentially make the focal length 2x longer. So this 100mm f4 macro lens becomes a 200mm lens. The slow f4 maximum aperture is not even a problem, as the Electronic View Finder will just make the view finder brighter to compensate.
The nFD 100mm f4 macro lens (I also have the older FD 100mm f4, which I will try later) is very sharp. Well, there are no bad macro lenses, but some may not perform as well at infinity as at macro. This particular lens is pretty decent at infinity. Too bad I haven't taken any macro shots yet, but a couple of sample below will give you some ideas.
Naked Tree -- Panasonic G1 & Canon nFD 100mm f4 Macro.
Hot Cross Buns -- Panasonic G1 & Canon nFD 100mm f4 Macro.