I'm using a new Nikkor 85mm PC-E lens on an old F4. While the lens is manual focus, the camera's AF sensor still works the same as when you have an AF lens on the body (set to manual focus). So I like using that as a double-check on my manual focusing especially in low light (the small green dot in the viewfinder tells you you're in focus).

However the manual for the lens says you cannot use the camera's AF detector when the lens is tilted or shifted. Clearly that applies to tilt, but I'm not sure why it would apply to shifting (assuming no tilt). In large format, I've never really had focus change on me when only using rise/fall. A modern, slightly long focal length lens like this Nikkor PC-E should have a flat enough field to avoid focus shift when shifting the lens, especially at apertures smaller than wide open.

My assumption is that this is simply a flaw in the lens manual, since these things are gerenally badly written, and vague. When I focus this lens, either before or after shifting, and check the camera's focus indicator either before or after shifting, there appears to be no change.

So what do people think? Is it just a bad sentence in the manual as I suspect?