In article
>OK, so the F4 focusing screens fit under the F3 viewfinder, but do
>they give a 100% view of the image? I could easily imagine that the
>F4 focusing screen is slightly different, and thus give another view,
>eg. 95%, 105% or something else. And another thing: Is the distance
>between the focusing screen and the mirror exactly the same for F3 and
>F4-type screens? If not, you will get pictures that are slighly out
>of focus with F4 focusing screens on the F3.
In all of the "F" series Nikon bodies, the framing and GG plane placement
is determined by the (moveable) frame in the camera body that the screen
rests on when installed, so there is no problem with screen exchanges
(except that above-the-screen meter calibration may need changing to
account for different screen brightness [the F3 meter is below the screen,
so this is not a problem when making screen exchanges in the F3]).
Hope This Helps