Pentax SMC Pentax 67 75mm f/2.8 AL

Faster aspherical alternative to the SMC Pentax 67 75mm f/4.5, released during the Pentax 67II era. The AL designation marks the use of an aspherical element — corrects spherical aberration at wide apertures more effectively than the all-spherical f/4.5 design and enables the faster f/2.8 maximum aperture without unacceptable corner softness.

In 35mm-equivalent terms, 75mm on 6×7 corresponds to roughly 38mm full-frame — a moderate wide-normal popular for environmental portraits, available-light reportage, and landscape work where the 105mm normal feels too tight. The full stop of additional speed over the f/4.5 (and the accompanying shallower depth-of-field) is the buying argument; the practical cost is meaningfully larger size and weight plus a noticeable price premium.

Mounts on the inner bayonet; 82mm filter thread (larger than the 67mm common on most Pentax 67 lenses, reflecting the larger front element). Among the last lenses Pentax developed for the 67 system before discontinuation in 2009.