The Nikon S3, released in March 1958, was a simplified companion to the flagship SP rangefinder, with around 14,000 made before the Nikon F ended the rangefinder era - a body whose chassis and shutter the F itself inherited.
Its defining feature is the life-size finder with simultaneous 35/50/105mm framelines; it takes the S36 motor drive, and a black batch built for the 1964 Tokyo Olympics commands large premiums.
It represents the final flowering of Nikon's rangefinder era and is arguably more practical than the SP for the common lens trio, with added weight from its kinship with the F.
Used buying: torch-test the curtains, confirm all three framelines and patch contrast, verify infinity alignment, and check serials - the 2000 remake is easily conflated in listings at very different money; Olympic blacks need expert authentication.