Pentax's 6x7 SLR — 35mm-style handling, focal-plane shutter, 67 mount, 1969.
The Pentax 6x7 is a 1969 medium-format SLR from Asahi Optical, built to handle like an oversized 35mm SLR. Rather than a modular studio system with interchangeable backs, it uses a fixed body with a bayonet lens mount, aiming to make the large 6x7 frame accessible to photographers used to 35mm handling.
It is a medium-format (6x7) SLR producing a 56x70mm frame on 120 or 220 film in a fixed, non-interchangeable film chamber. Unlike leaf-shutter medium-format systems, the Pentax 6x7 uses a body focal-plane shutter, so it does not sync flash at all speeds. It takes interchangeable prism or waist-level finders and focusing screens and mounts Pentax 67 bayonet lenses; a TTL metering prism was available. The shutter is electronically controlled and battery-dependent.
The 35mm-style handling and large 6x7 negative made it a choice for landscape, portrait, and location photographers who wanted big film without a modular studio rig. It is heavy and the mirror slap is pronounced, so a firm tripod and mirror-up help sharpness, but it can be used handheld more readily than a bellows studio camera.
Because the shutter is electronic, confirm the body fires on a fresh battery, as it will not operate with a dead cell. Test the focal-plane shutter for accurate speeds, and check the mirror, screen, and any metering prism against the correct battery. Inspect the fixed film-chamber seals and the finder for haze, and confirm the mirror-up and self-timer functions work.