Introduced in 1976 as an economy totally mechanical camera with features that are adequate in every way to make it a very desirable "students' camera", the Pentax K1000 became one of the longest lived basic mechanical cameras of all time. With a full array of features including an extended range CdS TTL metering system and manually settable completely mechanical shutter speeds 1 second to 1/1000th and availed of AOC's (Asahi Optical Co) superb full array of lenses. About the only important creative tool that is omitted from the K1000 is a DOF (Depth of Field) preview button. The lack of a self timer is a much less significant omission. It also has no mirror lock up.

The K1000 is largely a cheapened and bayonet mount version of the SM Spotmatic II. There are many economies of fabrication that were progressively adopted during its extremely long total production run(s). Its internal parts mechanisms are stamped, not machined. When production moved to China (later to Hong Kong) the chromed base metal top and bottom covers were replaced with metalized plastic that is chrome plated. It was rumored by company insiders that Pentax had long wanted to cease producing this unprofitable but very popular (especially with students) financial albatross. It finally ceased production in 1997.

The Pentax K mount was introduced as an "OPEN" mount much like the precedent M42 Screw mount or the analogous nearly contemporaneous IBM open PC computer architecture. Using this "OPEN" mount architecture were such camera companies as Ricoh, Chinon and Cosina as well as derivative brand. users such as Sears, J C Penneys and Vivitar.