Canon Lens - Compatable with Nikon?

[deckcadet]

Paul pretty much covered it. Nikon lenses fit Nikon Cameras, Canon lenses fit Canon cameras. Some third parties like sigma and Tamron make lenses for both.

Your D40X will only autofocus with AF-S or AF-I Nikon lenses, or Sigma lenses with HSM. In your case, the only lens in the segment you're looking for that will have full functionality with your d40x is the Nikon 70-300mm AF-S VR ED, which is superb optically.

[JSPhoto]

No, Canon to Nikon won't work.... BUT

YES, there ARE adaptors that will allow the use of Nikon lenses on Canon EOS bodies. I have seen them used by several former Nikon shooters who wanted save $$ when changing over to Canon 1D bodies.
The issue is the "Canon cameras have a shorter distance between the lens flange and film plane than Nikon". The adaptor is $200 according to this site: http://www.kenrockwell.com/tech/nikcan.htm

Having seen them used the setup does work, and in some cases the Nikon manual focus lenses actually work better on the Canon bodies... check it out.

JS