Nikon’s first single lens reflex camera and the first Japanese SLR to have interchangeable focusing screens. It was designed to meet professional demands. Its features include an interchangeable viewfinder, titanium focal plane shutter, mirror lock, rapid-return mirror, a removable back to allow to allow attachment of an F-36 or F-250 motor drive, safety lock and rewind mark on the shutter release collar, film reminder dial for 20 or 36 exposure films, self-timer lever with a start button, a depth of field preview button and an especially reinforced tripod socket. This was the first SLR with 100% image visible in the viewfinder, in other words what is seen in the viewfinder is what appears on the slide or negative. Electronic flash is synchronised at 1/60th sec. It swiftly became the must-have camera for professional photographers worldwide.