Tokina 400mm and some questions (1 Viewer)

First I heard the nikon D40 doesn't have an internal drive motor. Does that mean you need special auto focus lenses to auto focus? But if you have a Nikon D50 or D70 with an internal motor can you auto focus with a manual lens?
I also found the Tokina 400mm but I heard it doesn't work on some cameras, I'm most likely going to buy a canon rebel Xt, nikon D50, or a D70 which camera does it work the best on and does anyone have any experience with this?

Thanks

Hi,
You are correct in your statement about the D40. Autofocus is only possible with a Nikon lens that has the af-s designation or a Sigma lens with the HSM designation (except the 80-400 os, which is not HSM, but does have its own af drive motor). This is because the D40 does not have an af drive motor of its own, in an attempt i think, to keep the weight & cost down.
Im sorry but i cant help you with the Tokina, but can tell you that the D50, D70,D80,
D100 & D200 all have screw drive af motors fitted, so will af with any af lens.