Since a short while I have been playing with an old MF Ai 50mm f/1.4 (here's one recent post with it: https://www.nikoncafe.com/vforums/showthread.php?t=57900 ). Now I've been shooting some portraits from a much shorter distance and with large aperture. I notice that the lens back focuses, without question. Observations: - I have good eyes and I focus dead-on where I want the focus point. - back focus is quite a bit when I focus by eyesight: portraits are way off - when I focus and trust the "in-focus light" in the viewfinder, the portrait is perfect(!) - the (D1x) camera's focus system is dead-on with my AF lenses (some very demanding long focal fast lenses - no problem). So, in conclusion, if I were to focus with the image appearing OOF in the viewfinder, but with the "in-focus" light on, I get a perfect image. If I focus by eyesight in the viewfinder: no good, big time back focus. Comments??