The Konica FM was the last of the Bayonet Mount I (aka "Early" or "F-Mount") SLR cameras. It was introduced in 1964. The next Konica, the Auto-Reflex, would have a larger diameter bayonet mount allowing the linkage for aperture control to be completely enclosed within it.
The Konica FM might have been the first Japanese 35mm SLR to have a cross-coupled, CdS-based meter built in. The meter was powered by a single 625 mercury cell (1.3V).
The FM continued use of the Copal Square shutter found in the F series predecessors and shared the same specifications as the FP and FS models.
By the time the FM went into production,Konishiroku was beginning to hit is stride in camera production with four years experience in the manufacturing of SLRs.
The FM are wonderful handling cameras. Currently,few can be found with accurate, working light meters. However, because the Konica FM is a fully-mechanical in operation, the camera is usable without the meter.