Quote Originally Posted by ShutterbugJohan


That is a common misunderstanding. The f3.5-6.3 zooms I've used focused fine along their entire range. I'm not sure why though--maybe they are chipped to tell the camera f/5.6?


Thanks for correcting me! It would make sense that the lens is chipped to give 'false' or no information on maximum aperture to the body (similar to the 'tape-the-pins' trick that can allow AF on too-slow Canon combinations like a teleconverter with a lens that's already f/5.6). That also makes Bryan's warning about current 3rd party lenses possibly not working with future Canon bodies very relevant, I would think.