Metallica II

Some articles on metallica:

Pentax Cameras - The Screw Mount Cameras - Other Prototypes
... they also showed another SLR prototype which they called the Metallica ... The Metallica gave a glimpse into the future direction of Pentax cameras it featured a prototype bayonet lens mount, a vertical-traveling, metallic Copal-type focal ... While Asahi Optical didn't put the Metallica into production, the concepts of a bayonet lens mount and a metal focal plane shutter were already being discussed internally at ...