The Petri Penta is the first of a series of 35mm SLR cameras made in the late 1950s and early '60s by Kuribayashi/Petri (the company changed its legal name to Petri in 1962, while this series of cameras was current; they all bear the name Petri on the front of the prism). Some of the series were sold in the USA (and perhaps other markets) as the Petri Flex V, and some examples are badged Petri Flex (with no 'V'); note however that the Petri Flex 7 is not one of this series.
Petri Penta (1959). The first model in the series was Kuribayashi's first 35mm SLR camera, made in 1959.
- 42mm screw lens mount.
- Manual aperture stop-down (that is, the camera does not stop the lens down during exposure; the user must do this manually).
- Focal-plane shutter with cloth blinds, giving speeds from 1/2 to 1/500 second, plus 'B'.
- PC socket, and flash synchronisation switchable between X and FP, but no flash shoe. A clip-on cold shoe was available as an accessory.
- No self-timer.
Petri Penta Automatic/Petri Penta V (1960). Improved version of the Penta.
- Lens mount is now a breech-lock type bayonet.
- Automatic stop-down of preset-aperture lenses.
- Shutter now 1/2 to 1/1000 second, plus 'B'.
Petri Penta V2/Petri Flex V (1961). Almost identical to the Penta Automatic/Penta V.
- Fastest shutter speed returned to 1/500 second.
- Petri Penta Junior (1961). Simplified version of the Penta V2, but returned to the specification of the original model (no automatic stop-down or self-timer). According to McKeown, supplied with an f/3.5 35mm lens.