The RB67 Pro-S or Professional S as written on the body, was released in 1974, and is the most common RB67 camera. It was sold for over 15 years. It improved upon the previous model by having an orientation indicator for portrait or landscape mode on the rotating back. This was a feature on the original, but a majority of them did not include the printing. The focusing has been changed a bit with a new focusing knob lock. It is located below the left hand side focus knob. To use it move the lever forward towards the front of the camera. The shutter interlock system has also been revised slightly. On the Pro-S roll back the shutter cannot be released if the film is not advanced. That means the previous method of multiple exposure is changed. The film back now contains an additional multiple exposure lever, under the film advance lever. To use; rotate the lever to the front revealing the red indicator. Cover the red indicator to revert to normal. The waist level finder had been changed a bit. The magnifier can be raised by moving a small leaver on the inside top of the front finder. The magnifier now completely covers the opening of the finder. This reduces the amount of exterior light that enters the focusing screen. Closing the finder is much easier and requiring only pinching the sides to collapse. The original requires you to collapse all four sides independently.
Specs:
Type : 6x7cm lens shutter type , single lens reflex camera.
Lens mount : Bayonet mount ( with safety lock ring)
Viewfinder : Horizontal format index mark interlocks with revolution of revolving adapter.
Focusing hood : Single action open and closing.
Focusing screen : interchangeable.
Revolving adapter : only for use with Pro-S.
Focusing : Bellows extension system with rack pinions. ( max 46 mm extensions.)
Shutter and mirror cocking :Single action (75°) cocking by lever on camera body side.
Dimensions : 144 x 104 x 228mm.
Weight : 1850 grams.
Mamiya Sekor C 127mm F 3.8 Standard Lens
Focusing: Bellows extension system with rack and pinions.
Maximum extension: 46mm. With focusing knob fixing device.
Shutter and mirror cocking: Single-action (75°) cocking by lever on the side of the body.
Composition: 5 elements in 3 groups
Angle of view: 38°
Filter screw diameter: 77mm
Aperture: Full automatic diaphragm (with depth-of field preview lever). f/3.5 to 32 (with click stops for aperture settings).
Shutter: Seiko #1 shutter 1 to 1/400 second and T (Time) Flash synchronization: X contact
Other features: Mirror-up photography. Bulb (B) feature.
Dimensions : 94x70mm
Weight : 750 gram.