cameras by the early 1950s. Coating lenses with up to a dozen different layers of chemicals to suppress reflections across the visual spectrum (instead of at only one compromise wavelength) was a logical progression.Ray, pp. 74–75, 108–109 1971 Asahi Pentax Electro Spotmatic (Japan; name shortened to Asahi Pentax ES in 1972; called Honeywell Pentax ES in USAWilliam P. Hansen, Hansen's Complete Guide Illustrated Guide to Cameras; Volume 1. Kennesaw, GA: Rochdale Publishing Company, 2003. . p. 17): first SLR with electronic aperture-priority (using stop-down TTL metering) autoexposure plus electronically controlled shutter."Modern Photography's Annual Guide to 47 Top Cameras: Honeywell Pentax ES," p. 99. Modern Photography, Volume 36, Number 12; December 1972. Earlier mechanical AE systems tended to be unreliable, but reliable and convenient AE systems (as well as other electronic control systems) that electronically set either the camera shutter speed or lens aperture from light meter readings once the other was manually set began with the Electro Spotmatic. Rival electronic AE SLRs included the Canon EF (1973; shutter priority),Shell, pp. 54–56 Minolta XE–7 (1975; aperture priority)William P. Hansen, Hansen's Complete Guide Illustrated Guide to Cameras; Volume 2. Kennesaw, GA: Rochdale Publishing Company, 2003. . p. 19 and Nikkormat EL (1972; aperture priority),B. Moose Peterson, Nikon Classic Cameras, Volume II; F2, FM, EM, FG, N2000 (F-301), N2020 (F-501), EL series. First Edition. Magic Lantern Guides. Rochester, NY: Silver Pixel Press, 1996. . pp. 50–65 all from Japan. Electronic AE came to most 35 mm SLRs by the late 1970s. The Japanese electronic AE SLR effectively ended the German camera industry when they failed to keep up with their Japanese counterparts. After ailing throughout the 1960s, such famous nameplates as Contax, Exakta, Leica, Rollei and Voigtländer went bankrupt, were sold off, contracted production to East Asia, or became boutique brands in the 1970s."Annual Guide to 54 Top Cameras: Contax RTS," p. 123. Modern Photography, Volume 40, Number 12; December 1976. Lothrop & Schneider. "The SLR Saga (part 2)," pp. 50–51, 64Schneider, "How The Japanese Camera Took Over." pp. 56–57, 78, 86 1971 Praktica LLC (East Germany)(really December 1969): first interchangeable lens camera with electric contact lens mount, first camera with electromechanical lens diaphragm stopdown control."Modern Photography's Annual Guide to 47 Top Cameras: Praktica LLC," p. 120. Modern Photography, Volume 36, Number 12; December 1972. Had M42 screw mount modified for open aperture metering. The M42 mount was a very popular interchangeable lens