I am beginning to explore the FD lenses and need an FD lens to EOS camera adapter. I see the following kinds out there on ebay etc.: 1. Aluminium ones without glass element (small opening): My understanding is these won't allow infinity focus. I would like infinity focus so they are out of question. 2. Cheap glass elements allowing infinity focus (with smaller opening and glass element): my understanding is they will allow infinity focus but may not work for macro lenses. 3. Apparently there is a variation on #1 above that may work for macro lenses (larger opening), allowing for shorter focusing distances. 4. There is another type that has a glass element but allows that element to be removed if would like. Could you guys please guide me or provide pointers to which one(s) should I be looking to buy. Currently, I may be looking to get a 200mm (macro), 400m and 50mm FD lenses. Thanks!