Medium Format

In photography, the term Medium Format has traditionally been applied to film and digital cameras that record images on media larger than 24 by 36mm (full-frame), but smaller than 4 by 5 inches (which is considered to be large-format photography).
Most reasonably priced mirrorless and DSLR cameras come with sensors much smaller than full frame (24mm x 36mm). That doesn’t mean that those sensors don’t come with a ridiculous number of pixels, those pixels are just much smaller. Generally, a bigger sensor is better, allowing to record more light with less noise and that’s why photographers gravitate to full frame cameras when capturing the “money shots.”
As you can see in this graphic however, full-frame is not the end and Medium Format describes a bigger, much bigger sensor than full-frame:

In the film world, medium format has moved from being the most widely used film size (1900s through 1950s), to a niche, used by professionals and some amateur enthusiasts. I’m not at all getting nostalgic here, I’m just saying that there is a lot of medium format equipment available that with a little imagination can be used with a full-frame or even an APS-C camera.

This is the a Mamiya 645 Super in a basic configuration, a medium-format SLR cameras made in Japan by Mamiya from December 1985 to 1993. The M645 series was replaced with the auto-focus 645 AF series from late 1999.

We have also now reached a point, where creating a bigger than FF sized digital sensor is possible and depending on your budget might even be affordable. The Fujifilm GFX 50S mirrorless camera for instance, comes with a 44 x 33mm, 51 megapixels sensor and is available for about $6,500.

Medium Format Lenses

The Mamiya – Sekor C 80mm f/2.8 N is a classical manual focus medium format prime for Mamiya’s 645 series. The lens was designed as an entry level standard angle prime and often bundled with starter kits. When used on the native medium format body, the lens has the field of view, equivalent to a 50mm lens on a regular 35mm camera. When adapted to a full frame camera, the lens has the field of view resembling that of a 80mm prime, while when adapted to an APS-C camera, its field of view will be similar to that of a 128mm telephoto lens.

Specification

  • Focal Length: 80mm
  • Aperture Maximum: f2.8
  • Aperture Minimum: f22
  • Blades: 6
  • Format Compatibility: 6×4.5cm
  • Minimum Focus Distance: 2.2′ (.7m)
  • Elements/Groups: 6/5
  • Angle of View: 47°
  • Filter Thread: 58mm
  • Dimensions: 43.5x70mm
  • Weight: 235g

BH-Photography for instance, has a lot of good things to say about this Mamiya lens:

The Mamiya 80mm f/2.8 is a compact, lightweight standard focal length lens.
Mamiya lenses are quality controlled at all stages. They are engineered for professional use. Mamiya manufactures its own glass and coats the lens elements using Mamiya’s proprietary multi-coating process, increasing light transmission, dramatically reducing flare, and ensuring crisp, clean whites and vibrant natural colors.

Lens Adapter

Adapting a lens to a non-native camera body not only means to mechanically (and sometimes also electronically) connect the two pieces, but also to create the exact distance between the lens and the camera sensor, the lens was design for. This unique distance is also called the Flange Focal Distance, and varies between manufactures and series:

Flange Focal Distance

  • Fujifilm X-mount: 17.7 mm
  • Nikon F-mount: 17.7 mm
  • Canon EF-M-mount: 18 mm
  • Sony E-mount: 18 mm
  • Micro Four Thirds System: 19.25 mm
  • Nikon S-mount: 34.85 mm
  • Canon FL-mount 42 mm
  • Canon FD-mount: 42 mm
  • Canon EF-mount 44 mm
  • Canon EF-S-mount 44 mm
  • Mamiya 645: 63.30 mm


Obviously lens-adaption becomes an issue, when the lens was designed with a smaller Flange Focal Distance, than its new camera system. One reason, why I replaced the lens-mount on the old FD lens, instead of using an adapter.
Adapting Mamiya lenses (which expect a 63.30mm distance to the sensor) to the Canon EF-mount (natively providing 44mm distance) is not an issue however and just requires the equivalent of 19.3mm long extension tube.

Kipon Mamiya 645 Lens to Canon EOS Camera Lens Adapter


The KIPON M645-EOS adapter mounts Mamiya 645 series lenses on Canon EOS EF series camera bodies.
The Mamiya 80mm f/2.8 adapted to the Canon EOS 6D

Comparison

Old Mamiya 80mm f/2.8 [left] vs. Canon 85mm f/1.8 [right]

1/800 sec at f/2.8 ISO 100

1/400 sec at f/4.0 ISO 100

1/125 sec at f/8.0 ISO 100

Old Mamiya 80mm f/2.8 [top] vs. Canon 85mm f/1.8 [bottom]

1/50 sec at f/2.8 ISO 100