The Nikon EM formed the base of the new line. On introduction it was the smallest and cheapest Nikon SLR ever made. It was an electromechanically controlled, manual-focus camera powered by
button batteries. The EM featured a lightweight, compact copper-aluminum alloy body and fiberglass-reinforced
polycarbonate plastic top and bottom covers, plus aperture priority semiautomatic exposure control governed by a built-in 60/40 percent centerweighted, silicon photodiode
light meter. A left side viewfinder galvanometer needle pointer indicated the exposure on a shutter speed scale. The viewfinder also had Nikon's standard 3 mm split image rangefinder and 1 mm microprism collar focusing aids, but the focus screen was fixed. The viewfinder is dimmer than those in the semi-professional Nikons since the expensive prisms of the latter were not used. The camera is also fitted with a low-light exposure warning in the form of an audible 'beep'. Accessories for the EM included a highly automated dedicated electronic flash unit, the
Nikon SB-E (guide number 56/17 (feet/meters) at ASA 100) and a very small power winder, the
Nikon MD-E (motorized film advance at 2 frames per second). There was also a new Nikon Series E range of lenses. The Series E lens line up in 1980 included a 28 mm ƒ/2.8 wide angle, a 35 mm ƒ/2.5 semi-wide angle, a 50 mm ƒ/1.8 normal, a 100 mm ƒ/2.8 short telephoto and a 75–150 mm ƒ/3.5
zoom, with the subsequent addition of a 70–210 mm ƒ/4 zoom, and a 135 mm ƒ/2.8 medium telephoto. These lenses were intended to enhance the EM's appeal to new users, as inexpensive but good quality alternatives to expensive Nikkor-branded lenses. The EM also had one very rare feature for an electronically controlled camera. Nippon Kogaku's philosophy that a camera must always work when called upon resulted in the EM's backup ability to operate without batteries, albeit in a limited fashion: mechanical control with one available fixed shutter speed (1/90 second, marked "M90") or fully-manual, operator-controlled open-shutter duration marked "B" for "Bulb", and without the light meter. A little-known feature of the EM is that when the battery is removed, the "Auto" setting produces a shutter speed of approximately 1/1000 sec. This is documented in the factory repair manual. The EM and its E-system accessories were Nippon Kogaku's first attempt to reach the low end of the SLR market. the EM was designed to provide style, with its exterior contours designed Italian automobile stylist
Giorgetto Giugiaro); convenience with a system of dedicated accessories; as much ease of use and automation as was possible in 1979; low cost by dint of a simplified manufacturing process, and the prestige of the Nikon name prominently displayed on the pentaprism housing. Although the Series E lenses were unpopular with Nikon buyers, several of the Series E lenses exhibited excellent performance, particularly the 50 mm ƒ/1.8, the 100 mm ƒ/2.8, and the 75–150 mm ƒ/3.5 zoom. ==Further reading==