Olympus's 1969 E.Zuiko Auto-S 38mm f/2.8 — the slim pancake standard for the Pen F half-frame SLR.
Olympus made the E.Zuiko Auto-S 38mm f/2.8 for its Pen F half-frame SLR system, fitting the Pen F, FT and FV bodies. Introduced around 1969, the pancake was the slimmest lens in the range and, on the half-frame format, gave a field of view close to a 55mm standard lens on full-frame 35mm.
The optical design uses five elements in four groups, the 'E' in E.Zuiko denoting five elements. It measures only about 21mm long, weighs roughly 72g, takes 43mm filters and uses a five-bladed diaphragm stopping to f/16. It mounts on the Olympus Pen F rotary bayonet, a mount unique to the half-frame system and distinct from the later OM mount.
The lens renders sharply within the small half-frame image circle but falls off dramatically toward the edges when adapted to larger sensors, producing a soft, swirling effect prized by digital adapters. On its native format it is a crisp, pocketable everyday optic.
Sought after by both Pen F shooters and mirrorless adapters chasing its character. Check the tiny helicoid for smooth focus, the blades for oil and the coating for cleaning marks. Confirm the correct Pen F bayonet rather than the later OM mount. Dedicated Pen-F-to-mirrorless adapters are readily available.