Craig Dickson , Nov 28, 2010; 12:53 p.m.
The basic issue is that to have the lens focus to infinity while using an adapter that has no optics, the host camera's flange distance has to be less than the original Canon FD cameras (to leave room for the adapter). The only current digital cameras with interchangeable lenses that satisfy that criterion are the Four-Thirds, Micro Four-Thirds, and Sony NEX models. I've seen FD lenses used successfully on an Olympus E-P2 (Micro Four-Thirds). I don't know what adapter was used, though. The only cross-brand adapters I've used were to mount Nikon F and Pentax M42 lenses on Canon EOS cameras, and I found that Fotodiox adapters worked well. Novoflex is also well-regarded, but more expensive. There are also cheaper models, often with no brand name, that you can purchase through eBay, which are of inconsistent quality but work nicely if you get a good one.