A 35mm SLR system developed and manufactured by the Japanese company Cosina based on the M42 screw mount with fully automatic aperture and TTL stop-down exposure metering. Both cameras and lenses belonging to this system were also produced under various names for Vivitar and other distributors of photographic equipment.
NOTE: During the transition period, the lenses were produced not only with the M42 screw mount, but also with the Pentax K bayonet mount, and some of the lenses even with the Canon FD and Minolta SR bayonet mounts.
NOTE: The following Cosinon lenses were also mentioned in the Hi-Lite EC instruction manual: 300/5.5, 400/6.3, 500/8, 800/8, 1000/8, 90-230/4.5, but we cannot record them in the database because we do not have basic manufacturer data for them.
NOTE: The year of production of a particular Auto Cosinon lens can be easily determined by the first two digits of the serial number, which is located on the front ring.