BRONICA - Zenzanon S to PS Lenses

This comprehensive technical study examines the significant evolution between Zenzanon S and PS lenses for Zenza Bronica SQ medium-format cameras. The document traces the transition from the S lens family, introduced in October 1980, to the PS family launched in 1986, following the company's relocation to a state-of-the-art manufacturing facility. It provides in-depth analysis of optical refinements, including multicoated lens elements across different groups, alongside critical mechanical redesigns of the shutter cocking transmission system that eliminated the "Sloppy Lens Syndrome" problem. The service documentation includes aesthetic improvements such as the removal of barrel side screws and presents a detailed case study of the 150mm lens redesign, which demonstrates the shift from a simple aluminum disk mechanism to a more rigid dual ball-bearing cylinder design with internal light-absorbing coatings. Comprehensive specification tables compare all S and PS lens models with complete technical data covering apertures, minimum focus distances, filter sizes, dimensions, weights, and 35mm equivalencies. Detailed photographs of internal components and mechanical assemblies support the content, making it an essential workshop reference for technicians servicing or maintaining these Bronica lens systems.