The Nikon FM is a mechanically operated, interchangeable lens, 35 mm film, single-lens reflex (SLR) camera. It was manufactured in Japan between 1977 and 1982 by Nippon Kogaku K. K. (now Nikon Corporation). History The FM was the replacement for Nikkormat FT3, which had been introduced only a few months prior. It introduced an entirely new compact, but rugged, copper-aluminum alloy (duralumin) chassis that would become the basis for Nikon's highly successful range of compact semi-professional SLR cameras. These cameras were intended to provide a more reasonably priced alternative to Nikon's professional F-series cameras, which at the time was the Nikon F2. They were all-new successors to the Nikkormat F- and EL-series of amateur-level SLRs, but despite the lower price-point they continued Nikon's reputation for high-quality construction, impressive durability and measured technical innovation. The FM has proven to be a remarkably long-lived and reliable camera. Nippon Kogaku would over the next twenty-nine years use the same chassis (but with some modifications) and basic design philosophy for the FE (introduced in 1978), FM2 (1982), FE2 (1983), FA (1983) and the limited production FM3A of 2001. Design and construction The FM is constructed almost entirely from metal and uses a mechanical shutter. It is manual-focus-only, with manual exposure control. Being mechanical, the FM needs no batteries to operate (though two 1.5 volt 357 or 76A or LR44 or SR44 cells are required to operate the light meter). The metering system comprises a gallium photodiode (with 60/40% center-weighting) that meters through-the-lens at maximum aperture. Its reading is displayed by a "center-the-LED" system using vertically arranged light-emitting diodes (LEDs) next to +/O/- markers on the right side of the viewfinder that indicate overexposure, correct, or underexposure, respectively. The photographer adjusts the aperture or shutter-speed until the "O" LED illuminated to indicate correct exposure. This system can be traced back to the Nikkormat FT of 1965 and its "center-the-needle" system. The succeeding Nikon FM2 uses an improved center-the-LED system. For its time, the FM used a modern titanium-bladed, vertical-travel focal plane shutter capable of speeds from 1 second to 1/1000 of a second, plus bulb. Flash X-sync was at speeds up to 1/125th second. The body has dimensions of 89.5 mm height, 142 mm width, 60.5 mm depth and 590 g weight. It was available in two finishes; silver with black trim and all black. Lens compatibility The FM accepts all Nikon F bayonet mount