This is the most desired and popular lenses for the Pentax 67 camera. For portraits, it is really hard to beat.
Takumar is the name that Asahi Optical gave to its lenses, notably but not exclusively those for its own SLR cameras. Named after the Japanese-American portrait painter, Takuma Kajiwara, whose brother Kumao Kajiwara founded Asahi Optical. The name adorned its lenses until 1975, when Asahi switched from the M42 Screw Mount to the bayonet K-mount. K-mount lenses were simply named "SMC Pentax".