I'm well aware that FD lenses can be used on EOS bodies with an image correcting lens adaptor. From what I've read this is effectively a tele-converter to correct for the different mount lengths in FD vs. EF. Since the low end DSLR bodies have a 1.6x crop, is it really necessary to us the standard FD to eos adaptor, or would a simple mount converter (like an eos to Nikon adaptor) with no optics work? This would effectively be the same as a macro extension tube of a few mm. Would this lose infinity focus?