Pentax 67: An Obsolete Mount That Refuses to Disappear
The Pentax 67 mount is technically obsolete, but calling it irrelevant would be a mistake. The system was created in 1969 for the large Pentax 6×7 film camera, later renamed Pentax 67, and it remained in production until the early 2000s. Pentax eventually ended development when digital photography overtook medium-format film systems, and no modern digital camera bodies use the Pentax 67 mount natively. In that strict sense the mount belongs to a discontinued ecosystem.
Yet the interesting twist comes from the mirrorless era. When Pentax designed the system, the lenses had to sit far away from the film plane because the camera was essentially a giant SLR with a large mirror box. That long flange distance, which once seemed like a limitation, turned out decades later to be perfect for adapting the lenses to modern mirrorless cameras. Canon RF, Sony E, Nikon Z and similar mounts all have extremely short flange distances, so an adapter ring can easily bridge the gap without affecting focus. Infinity focus works normally, and the lens behaves as if it were designed for the camera.
Because of that, Pentax 67 lenses have actually gained a second life among photographers experimenting with adapted optics. The lenses were built to cover a huge 6×7 film frame, far larger than full frame or APS-C sensors. When mounted on a modern digital camera, the sensor uses only the central portion of the lens’s image circle. This often produces very clean images with minimal vignetting and strong edge performance. In other words, the digital sensor is sampling the best part of the optics.
Another reason these lenses continue to circulate actively is their rendering style. Many Pentax 67 lenses, especially classics like the 105mm f/2.4 or the 200mm f/4 you asked about earlier, produce a smooth tonal transition and background compression that many photographers still appreciate. Modern lenses are often optimized for extreme sharpness and correction, while these older medium-format lenses sometimes produce a more gradual and organic look.
The only real limitations are practical ones. Everything is manual: focus, aperture, and no electronic communication with the camera. The lenses are also physically large because they were designed for a medium-format system the size of a small brick. On a compact mirrorless body like the Canon R100 the combination can look almost comically unbalanced, though it works perfectly well.
So in a strict historical sense the Pentax 67 mount is obsolete because the camera system itself no longer exists. But in practical photographic terms it is very much alive. Mirrorless cameras unexpectedly revived many older lens systems, and the Pentax 67 mount turned out to be one of the easiest and most rewarding medium-format mounts to adapt to modern digital cameras.