Pentax ME F1981

History

Pentax announced the ME F alongside the SMC Pentax-AF 35-70/2.8 zoom in 1981, beating Minolta's Maxxum 7000 to market by four years and competing directly with the Polaroid/Nikon AF collaboration and early Contax RTS AF experiments. The lens-based AF architecture reflected the engineering constraints of the era - miniaturizing a fast, reliable AF motor and processor to fit inside a camera body was not yet practical. Pentax's approach placed the costly electronics in the lens, keeping the body price manageable. The system was commercially limited by the single-lens constraint, and when Minolta launched the Maxxum 7000 in 1985 with body-resident AF and a broad new lens lineup, the ME F's architecture was rendered obsolete. The Super-A (1983) provided the upgrade path for the K-mount system but did not extend the AF system.

Why It Matters

The ME F's place in camera history is secure as one of the earliest practical phase-detection autofocus SLRs. Phase-detect AF - splitting incoming light to detect front- or back-focus directly rather than hunting by contrast - is the fundamental technology that still underlies fast DSLR and mirrorless AF today. Pentax's implementation was constrained by 1981 technology but the optical architecture of the system is recognizable in modern lenses. For historians of camera technology, the ME F and the concurrent Polaroid/Nikon SLR AF experiments are the direct ancestors of all subsequent SLR autofocus development. The ME F also demonstrates that Pentax was an innovator rather than a follower at this critical technological juncture - a fact often overlooked because the Maxxum 7000 later dominated the public narrative.

Lenses & Accessories

Pentax KA mount. All K, KA, KAF, and later Pentax K-mount lenses mount and function in aperture-priority AE. Only the dedicated SMC Pentax-AF 35-70/2.8 zoom lens enables autofocus on the ME F; this lens contains the AF motor, phase-detect module, and drive electronics. Manual focus works normally with any K-mount lens. The ME F accepts the ME Winder II for motorized film advance.

Sample Photographers / Notable Use

• Primarily a Japanese and European market camera; not widely distributed in North America.
• Featured in Japanese camera press (Camera Mainichi, Asahi Camera) at launch as a milestone product.
• Cited in histories of autofocus development as a key early data point in phase-detect AF commercialization.

References

• Camera-Wiki: Pentax ME F
• Pentax Forums: Pentax ME F