MAMIYA RB67 PRO-S

The Mamiya RB67 Pro-S is a modular medium format single-lens reflex (SLR) camera introduced in 1974 as an upgrade to the original RB67. It was built for studio and field use. It shoots 6×7 cm negatives on 120 or 220 roll film and is known for a rugged build, interchangeable components and excellent image quality.

Overview

Mamiya released the Pro-S in 1974 for professional photographers who needed a reliable, high-precision medium format system camera. It succeeded the original RB67 and served as the foundation for later models, including the RZ67. The "Pro-S" name marked significant refinements over its predecessor, particularly in the film back mechanism and environmental sealing. It was aimed mainly at studio portrait, commercial and fashion photographers. It offered modularity, bellows focusing and a rotating film back. The rotating back let you shoot vertical or horizontal compositions without repositioning the whole camera.

The 6×7 cm negative is larger than 35mm and larger than some other medium format sizes, which gives better resolution and tonal gradation. The design is modular. Lenses, viewfinders, focusing screens, film backs and even finders with metering prisms all interchange. Add the all-metal construction and precise mechanical operation, and professionals who put image quality and system adaptability ahead of portability favored it.

Mamiya positioned the RB67 Pro-S as its flagship medium format SLR. It sat between the more compact but less flexible Hasselblad 500 series and the bulkier, studio-bound view cameras. It stayed in production until 1990. The electronically controlled RZ67 eventually succeeded it, but the Pro-S kept a loyal user base thanks to its fully mechanical operation and compatibility with a wide range of accessories.

Specifications

Key Features

• Rotating Film Back: The film back rotates 90° via a locking knob, allowing quick switching between horizontal and vertical formats without moving the camera—ideal for studio tripod work.
• Modular Design: Fully interchangeable lenses, viewfinders, focusing screens, and film backs enable rapid configuration changes for different shooting scenarios.
• Bellows Focusing: Provides precise macro and close-up capabilities with minimal lens extension, maintaining consistent image quality and enabling fine focus adjustments.
• Leaf Shutters in Lenses: Each lens contains its own leaf shutter, enabling flash sync at all speeds and reducing vibration compared to focal-plane shutters.
• Improved Seals and Durability: The Pro-S features enhanced light seals and a more robust back-locking mechanism compared to the original RB67, reducing film fogging and improving reliability.

Historical Context

The RB67 Pro-S arrived when medium format was the standard for professional studio and commercial work. Its main competitors were the Hasselblad 500C/M and the Bronica SQ series. It set itself apart with the larger 6×7 format, the rotating back and superior close-focusing ability. The Hasselblad was more compact and had a mature ecosystem. The Pro-S gave portrait and product photographers more flexibility when they needed format rotation and macro capability.

Reception was highly favorable, particularly in North America and Japan, where studio photographers embraced its ruggedness and precision. The shutter needs no batteries, so electronic failure was not a worry in demanding environments. Fashion and advertising photographers also took to it because it produced high-resolution negatives suitable for large-format printing. It is heavy and bulky, but its image quality and system expandability ensured strong sales throughout the 1970s and 1980s.

Collectibility & Value

Today the RB67 Pro-S is still sought after by film photographers, collectors and working professionals who shoot medium format. Used bodies typically sell between $300 and $600, depending on condition. Complete kits with lenses, backs and finders go for $800 to $1,500. Durability, extensive accessory support and compatibility with later RB67 Pro-SD components keep the value up.

Before buying an RB67 Pro-S, inspect the film back for light leaks, check the rotating mechanism and make sure the dark slide moves smoothly. Common problems are deteriorated light seals (which should be replaced), stiff focusing knobs and shutter inaccuracies in older lenses. The camera is fully mechanical and needs no batteries, but some metered prisms (like the AE Prism Finder) take a PX625 or equivalent 1.35V mercury battery. Those are now obsolete, and modern substitutes may need voltage adjustment.

Similar Cameras

• Hasselblad 500C/M – 6×6 cm format, modular, iconic Swedish design, widely used in professional photography.
• Bronica SQ-Ai – 6×6 cm SLR with interchangeable backs and lenses, more compact but less flexible than the RB67.
• Pentax 6×7 – Fixed back, non-rotating 6×7 SLR with excellent optics and strong following in portrait photography.
• Mamiya RZ67 – Electronic successor to the RB67, with improved automation and faster operation.
• Contax 645 – Later 6×4.5 cm system camera with autofocus and electronic integration, aimed at transitioning professionals to medium format digital.

Repair & Maintenance

The RB67 Pro-S needs no batteries for the shutter or any mechanical operation, which makes it highly reliable in the field. The optional metered viewfinder prisms (e.g., AE Prism Finder) use a 1.35V mercury PX625 battery. A modern 1.5V battery can stand in with an adapter or voltage regulator, which prevents meter inaccuracy. Regular maintenance means replacing light seals every 10-15 years, lubricating the focusing mechanism and checking shutter speeds on lenses with a calibrated tester.

Common repair issues include sticky shutters in older lenses, misaligned film backs and worn dark slide rails. The leaf shutter lenses and precision mechanics are complex, so repairs should go to technicians experienced with medium format systems. Replacement parts are still available through specialized camera repair shops and the secondhand market. With proper care, an RB67 Pro-S can stay fully functional for decades.

eBay Listings

Mamiya RB67 Pro-S Medium Format Film kit

$500

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