Canon, however, discarded the notion of camera-based motors and went to lens-based AF motors 20 years ago with the introduction of the EOS system and EF mount. Needless to say, this created howls from the Canonites with old glass they wanted to use on their new EOS cameras. Unlike Nikon, Canon changed the mount when shifting to the EF autofocus system, so old lenses weren't compatible. Some oldtimers still haven't forgiven Canon. With the D40, Nikon chips away at its famous backward compatibility. But I think reasonably so, since few D40 buyers have old Nikon lenses, and future lenses are likely to be AF-S Nikkors.