Pentax's classic M-series standard prime — compact 50mm f/1.7 for the miniaturised M system.
The Pentax SMC Pentax-M 50mm f/1.7 is a compact manual-focus standard prime from Pentax's M-series lens line, designed for the Pentax K-mount 35mm SLR cameras of the late 1970s and 1980s. A widely used kit lens for its era. Pentax K mount.
f/1.7 maximum aperture. 50mm focal length. SMC (Super Multi Coating) anti-reflection treatment. Manual focus only. Six elements in five groups. 49mm filter thread. At approximately 150g. Pentax K mount.
The M-series designation indicates the compact, lighter lens design generation for Pentax MX and ME series bodies. SMC coating reduces flare and improves contrast versus uncoated glass. At 150g, the 50mm f/1.7 M is among the lightest fast normal primes for any SLR system. Fully compatible with current Pentax K-mount DSLRs in manual focus mode.
On the used market the Pentax SMC Pentax-M 50mm f/1.7 is an affordable compact manual-focus prime for Pentax K-mount cameras. Condition checks: SMC coating condition, front element for haze or fungus (common in 40-year-old optics), aperture blade smoothness and oil-on-blades, focus ring smoothness.