Mamiya 645J

Name: Mamiya 645J
Brand: Mamiya

The Mamiya 645J is the budget, stripped-down version of the original Mamiya 645 (1975) and the 645 1000s (1976). The "J" stands for Junior. It's a medium format 6×4.5cm SLR that shoots 15 frames on a roll of 120 film (16 if you count the 6×4.5 format strictly, though most users report 15). The body is a focal-plane shutter design, fully manual, with no built-in light meter as standard. For metering you fit the optional metered prism viewfinder.

The cut that hit the budget price was mirror lock-up, which is handy for tripod work but otherwise rarely used. The camera still takes the full Mamiya 645 lens mount, so the extensive Sekor C lens lineup fits. Typical kits shipped with a waist-level finder and an 80mm f/2.8 C lens.

Documentation on this specific variant is thin. The fact sheet shows conflicting maximum shutter speed figures (1/500 vs 1/1000s) that can't be resolved from the available sources, so that spec is omitted. No production years, original price or dimensions are confirmed for the J specifically either. Listings and owner reports do agree on one thing: it's a small, well-built camera that handles comfortably. One owner picked one up on Lomography for around £160 complete with the 80mm lens. Another user on a photo forum was weighing a $500 purchase that included the body, 80mm f/2.8 lens, and both AE and waist-level finders. Several eBay and shopgoodwill listings appear "NOT TESTED," so condition is very much a gamble.

Known specs:

Medium format SLR, 6×4.5cm on 120 roll film
Fully manual exposure; no built-in meter (optional metered prism finder available)
Interchangeable Mamiya 645 mount lenses (Sekor C series)
Electronically controlled shutter, battery required
Multiple exposure capability
Waist-level finder standard; mirror lock-up omitted