Bronica's early 6x6 SLR — focal-plane shutter, interchangeable backs and lenses, 1961.
The Bronica S is an early-1960s medium-format SLR from the Japanese maker Zenza Bronica, part of the company's first square-format system. It was built as a modular 6x6 camera with interchangeable backs and lenses, offered as a competitor to the established European medium-format systems of the period.
It is a medium-format (6x6) SLR producing a 56x56mm square frame on 120 film through interchangeable film backs. Unlike the later leaf-shutter Bronica systems, the S line uses a body focal-plane shutter, and it has a distinctive downward-travelling instant-return mirror. It takes interchangeable finders and focusing screens and mounts Bronica S-series bayonet lenses, with Nikkor-branded optics supplied for early models. There is no built-in meter.
The focal-plane shutter allowed a wide lens range without a shutter in each lens, and the square frame with waist-level finder suited studio and portrait work. It is a mechanical, deliberate camera; the downward mirror design and modular construction make it distinctive among 6x6 SLRs of its era.
The complex mirror-and-shutter mechanism is the main used check: confirm the focal-plane curtain and the downward mirror operate smoothly, as these bodies can develop faults with age. Inspect film-back seals and the dark slide, focusing screen, and finder mirror. Verify lens and body compatibility within the S series, since mounts changed across the line.