PEN F

The culmination of the PEN Series was the half-frame SLR PEN F System.
This was a full-blown professional SLR camera system that was almost as versatile as the OM System that was launched nine years later in 1972.
The PEN F camera bodies were masterpieces of camera design by Maitani featuring an ingenious porro prism instead of a pentaprism, which allowed the bodies to be built as flat as the viewfinder PEN models, and a rotary shutter that allowed electronic flash synchronization at all shutter speeds.
The Pen F and FV bodies didn't have a built-in meter. Instead an accessory meter could be clamped onto the shutter speed dial at the front.
The FT body did have a built-in CDS meter. New versions of the System lenses were released for this model. There were also two special microscope versions (F based and FT based) with a photomicroscopic focusing screen.
There were 17 Zuiko Pen F lenses available:
20mm/F3.5, 25mm/F2.8, 25mm/F4.0, 38mm/F3.5 Macro, 38mm/F2.8, 38mm/F1.8, 40mm/F1.4, 42mm/F1.2, 50-90mm/F3.5 Zoom, 60mm/F1.5, 70mm/F2.0, 100mm/F3.5, 100-200mm/F5.0 Zoom, 150mm/F4.0, 250mm/F5.0, 400mm/F6.3, 800mm/F8 Reflex.