The Asahi Pentax 6×7 is what I call an SLR on steroids. It looks like a regular SLR for 35 mm film has been pumped up in size to use 120 roll film. Negative size is 6 x 7 cm giving the camera it’s name.
The Pentax 6×7 was launched by Tokyo-based Asahi Optical Co. in 1969. In 1979 it was replaced by an improved model with mirror lock-up. There were two more follow-ups. In 1989 the Pentax 67 was released, major change was the shutter timing being fully electromechanically controlled for improved accuracy (in difference to the partly mechanical timer in the 6×7). The last model of the series was the Pentax 67 II, released in 1998. This was a complete redesign of the camera which was now fully computerized and featured auto-exposure and matrix metering through the new AE pentaprism.
The set of interchangeable lenses available for the Pentax 6×7/67 is quite amazing, with focal length ranging from 45 mm to 1000 mm (this corresponds to a range of 22 mm to 500 mm in the world of 35mm film). For the photographer in need of faster flash-sync times than the 1/30 sec. of the Pentax 67, there is a range of leaf-shutter lenses which will allow you to do flash-sync of up to 1/500 sec.
The Pentax 6×7 is designed as a field camera for handheld shooting, versatile and built like a tank. If fires off like a canon because of it’s big mirror which also causes some vibrations. So for handheld shooting you need a shutter speed of 1/250 or above which usally requires fast film with 400 ISO or more. Besides that you handle the Pentax like any 40 years old 35 mm SLR. This and the wide range of affordable lenses makes the camera one of my favorite medium format cameras.