Originally posted by: OffTopic
Spliting hairs:
Sharpness & colour reproduction is about equal from both manufactures, however the consumer standard 50mm Nikon is slightly sharper with slightly better barels control at the corners of the lens at wide open. However, closing down the aperature 1 or 2 stop both are equal in quality. The Nikon consumer 28-80mm also produce a bit better picture than the Canon 28-80 at wide open, but quality equal when stop down 1-2 stops. Some Nikon pro lenses are sharper than Canon pro lenses, however most Canon pro lenses are slightly sharper & better at colour reproduction than Nikon.
What make the 2 stand a part:
1. Canon USM motor is way faster than Nikon old pin drive focus system, however Nikon did license Canon first generation of USM (horseshoes motor) for their newer lenses (Canon is now at the third gen USM...it is slightly faster and lighter).
2. Canon ISM also is another technology that I haven't heard that Nikon have.
3. Canon tilt shift lenses are much better than the old Nikon shift lenses, because Canon is newer design that is sharper with both tilt & shift capabilities.
4. Canon eyes focus control.
5. Canon spend more money on R&D, therefore they have better & lighter long telephoto & super wide angle than Nikon.
6. Canon telephoto lenses tend to be slightly lighter than Nikon.
7. Nikon lenses & bodies tend to be better construction out of metal, and craftman ship (much nicer than Canon lenses, when use in manual focus mode).
8. Nikon old manual lenses can interchange with newer bodies (if you own lenses since the 70s, however the older lenses are not as sharp as the newer lenses).