Olympus Pen F Lenses

Olympus Pen F half-frame SLR mount, 1960s-1970s | Half-frame 35 mm film

Olympus Pen F is the mount for the original half-frame film SLR system, not the later digital PEN-F camera. The cameras expose 18 x 24 mm frames on 35 mm film, doubling the number of vertical-format exposures compared with standard 24 x 36 mm photography.

The smaller frame let Olympus build a remarkably compact SLR system with dedicated Zuiko lenses. The cameras used an unusual optical and mechanical layout, including a sideways mirror/prism path and rotary shutter, which helped keep the bodies slim.

In catalog comparisons, Pen F lenses are useful because they show high-quality SLR design scaled to half-frame. They cover less field than full-frame 35 mm lenses, so image-format metadata is essential when comparing their field, aberrations, and physical size.