Pentax 50mm f/2 SMC M Manual Focus K-Mount Lens

The Pentax 50mm f/2 SMC M Manual Focus K-Mount Lens is a compact, manual-focus standard prime lens built for Pentax K-mount 35mm film SLR cameras, produced from 1979 to 1985 as part of Pentax’s respected M-series lineup. The M-series designation reflects a compact, lightweight design philosophy, making this one of the more elegant 50mm lenses of its era, prized among photographers for its classic standard perspective across portraits, street photography, and everyday shooting.

Optically, the lens offers a 50mm focal length with a maximum aperture of f/2, delivering strong low-light performance along with pleasing background separation for a lens of its class. The simple 5-element, 5-group optical design is complemented by Pentax’s renowned Super Multi Coating (SMC), which reduces flare and ghosting while producing rich contrast and faithful color reproduction, a hallmark of Pentax lenses from this era. A 6-blade automatic diaphragm contributes to the lens’s background rendering.

As a fully manual lens, both focus and aperture are controlled directly on the lens barrel, with no autofocus motor or electronic communication to the camera body; the lens includes a traditional aperture ring (without an “A” automatic setting) for direct exposure control. On native Pentax K-mount DSLRs such as the K-1 or K-3, the lens mounts and communicates as intended for metering purposes, and it can also be adapted to other mirrorless camera systems via a K-mount adapter for manual-focus use.

Build quality reflects early M-series construction, generally all-metal, though some plastic components were introduced after the later Pentax-A lens line’s release. The lens has a minimum focusing distance of approximately 0.45m, measures approximately 63 x 42mm, and weighs approximately 180g, with a 49mm filter thread.

As a full-frame-compatible K-mount lens, the Pentax 50mm f/2 SMC M covers a full 35mm image circle, delivering its full field of view on both film SLR bodies and modern full-frame Pentax K-mount DSLRs, as well as an effective narrower field of view on Pentax’s APS-C format digital bodies.

Key Features
– 50mm f/2 standard prime lens for Pentax K-mount
– 5 elements in 5 groups optical construction
– Super Multi Coating (SMC)
– 6-blade automatic diaphragm
– Manual aperture ring (no “A” setting)
– Fully manual focus and aperture control
– Minimum focusing distance of approximately 0.45m
– 49mm filter thread
– Compact, lightweight construction (approximately 180g)
– Compatible with Pentax K-mount film and digital SLR cameras (adaptable to mirrorless systems)