Yeah, it looks more like a non-metered S-mount 'tax... Seems rather interesting how both Pentax and Nikon made their early '80s pro bodies about the size of their '60s consumer models. An F3 is the same overall dimensions and weight as a Nikkormat FTn. Was rather amazed to see that I could fit a Nikon F3 body into a Nikkormat CTM eveready case. Sure, the tripod screw for the case was in the wrong spot, but the camera slid right in, even though the camera has the built-in handgrip.