Adapters to mount older fd mount canon lenses onto the newer eos cameras have been around for a while. There are some problems to solve. Because of the focal length, the fd lens could no longer focus to inifity and lose brightness(an f-stop). Rodolfo Novak modded his canon 55mm f1.2 fd lens for the eos mount by removing some vital parts(the attachment ring and the aperture ring). ?Now that the lens was closer, both infinite focus and the f-stop are back. He’s a bit short on the details, but it becomes clear if you look at an unmodified lens. Of course, to get the focus indicator working on a digital eos like my 350d, you need to add an af lens emulator circuit. If you don’t care about infinite focus, you could go a less invasive adapter.