MAMIYA - Mamiya M645 Super Lens TechBulletin

This technical bulletin from MAMIYA provides essential guidance on lens compatibility and exposure metering with the M645 Super camera system. The document addresses a critical optical issue: the ultra-bright focusing screen of the M645 Super produces significantly brighter viewfinder images than standard M645 models, which can lead to overexposure when paired with the M645 Super AE Prism Finder N. A detailed compatibility reference table covers seven popular lenses—80mm F4 Macro, 150mm F3.5, 210mm F4, 105-210mm F4.5 Zoom, 145mm F4.5 Soft, 75-150mm F4.5 Zoom, and 500mm F5.6—along with their correct pairing to two compensative meter coupler types: Type A (P/N 0.524804181) and Type B (P/N 0.525204181). Technical diagrams illustrate the mechanical design and configuration differences between both coupler variants. A critical note specifies that the 300mm F5.6 lens requires exposure compensation between 1 and 1.6/3 stops when used with the AE Finder N, depending on lighting conditions. This service bulletin is an indispensable reference for M645 Super owners and technicians ensuring accurate metering across diverse lens configurations and maintaining proper exposure control throughout the system.