Japanese medium-format SLR (edit)
6×9 Rittreck (6×9)
6×8 Fujifilm GX680
Japanese TLR and pseudo TLR ->
Other Japanese 6×6, 4.5×6, 3×4 and 4×4 ->

The Mamiya M645 is the first series of 4.5×6 SLRs made by Mamiya. The finder and screens are interchangeable, but there is no magazine back, only preloadable film inserts. All the M645 models share the same accessories (finders, screens, lenses, grips and inserts). The lenses and inserts can also be attached on the later Mamiya 645 models.

The original M645 appeared in 1975. It has knob advance and shutter speeds from 8s to 1/500. It supports a mirror lockup and double exposure lever. Flash sync is 1/60 sec.

Original M645 Specifications[]

  • Manufactured by Mamiya Camera Co.,Ltd., Tokyo, Japan
  • Produced between 1975-87
  • Medium format SLR film camera
  • Film 120 / 220 roll, picture size 6x4.5 cm
  • Lens: Mamiya-Sekor C 80mm f/2.8, (standard lens), Automatic diaphragm, with AE meter coupler
    • Auto / Manual diaphragm setting lever
    • M645 bayonet mount,
    • Aperture: f/2.8 - f/22
    • Focus range: 0.7-30m +inf
  • Lens release: by the small silver knob, on the front-left side of the camera
  • Focusing: Fresnel matte screen, with centered microprism with a fine focusing collar; Screen is interchangeable with 5 different screens
  • Shutter: electronically controlled cloth focal plane shutter, does not work without a battery; Speeds: 8-1/500, +B, (a red dot is for the AE finder)
  • Shutter release: Two shutter release buttons, one on front of the camera with safety lock collar, and the other is on top of the body; Shutter locks when no film is in the camera
  • Multiple exposure lever: setting to ME unlocks the shutter
  • Mirror lockup lever
  • Viewfinder: SLR pentaprism, type FH, with hot-shoe connections; Interchangeable with metered and waist level finders
  • Flash PC sockets: two, on the left side of the camera, X and FP; Flash sync 1/60 sec. (red on the speed dial)
  • Back cover: hinged, opens by pressing the memo holder and moving the latch to the right
  • Film loading: follow the drawings in the film insert part, (somewhat difficult, try to learn with a used film or paper)
  • Film insert: special vertical type; interchangeable with 220 film insert,
  • Others: Hot-shoe; Memory holder; Tripod socket 1/4 inch; Strap buttons; Battery check button
  • Body: metal; Weight: 1580g with standard lens
  • Battery: 6v Silver oxide, alkalines like 476A or 4LR44 are okay

M645 1000S[]

The M645 1000S (1976) adds the 1/1000 top speed, a selftimer, a depth of field preview button and other details.

M645 J[]

The M645 J (1979) is like the original model with shutter speeds from 1s to 1/500 but with the mirror lockup feature removed. It also lacks the upper shutter-release button of the other M645 models. It was only made for export.



General links[]

In French :

In Spanish :

In Japanese:

In English

In Italian

Documentation and manuals[]