most medium format digital cameras are cropped sensors, smaller than a 6×4.5 film size, thus wide angle shots become problematic.
apart from the Leica S, the diagonal is commonly 1.7x that of 35mm full frame which in effect a gives these cameras a 0.79x crop factor
the traditional medium format cameras are SLR cameras with mirrors and have removable digital backs containing the sensor which allows one to upgrade the sensor by buying a new digital back
have either 72mm (120mm & 180mm lenses) or 82mm (35mm & 70mm lenses) filter threads
Leica S2:
16bit, 37.5mp, 6 micron photosites, 1.5 fps x 8 RAW DNG, ISO 80-1250, 1.4kg body
460,000 dot LCD, in-camera jpegs (most medium format do dot have this option)
single central cross-hair AF sensor point, lenses have full time MF
HSS flash to 1/4000th sec; 96% viewfinder coverage
A special micro-lens pattern allows complete capture of angled light rays on the image periphery for optimal use of available light.
no anti-alias filter for higher resolution while Moiré effects are detected and eliminated by the camera's internal signal processing, thus taking full advantage of the system's high-resolution lenses.
Metz SCA-3002 interface
dual shutter system:
in-body metal focal plane shutter for fast lenses - flash sync 1/125th sec
in-lens leaf shutters (the CS lenses) for high flash sync speeds to 1/500th sec
dual shutter system allows you to choose between the integral focal plane shutter and the leaf shutter when using one of the 3 leaf lenses (the Sekor AF 55mm f/2.8 LS D, Sekor AF 80mm f/2.8 LS D, and the Sekor AF 110mm f/2.8 LS D)
aperture-priority AE, shutter-priority AE, programmed AE (PH, PL setting possible), and manual TTL metering, center-weighted average (AV), spot (S), and variable ratio (A-S auto) exposure modes, auto-bracketing, and it uses the TTL phase difference detection method for autofocus
Mamiya Leaf Credo range of digital backs
announced April 2012
work seamlessly with the Mamiya 645DF camera - which offers shutter speeds up to 1/4000 of a second and sync speeds of up to 1/1600 of a second with Schneider-Kreuznach designed Leaf shutter lenses
open platform philosophy enables compatibility with other medium format camera bodies, such as:
ALPA, Arca-Swiss, Cambo, Horseman, Linhof, Rollei X-Act 2, Sinar, Toyo and other 4×5” & 6×9 via Leaf Graflok or 3rd party adapter
Bronica ETRSi/ SQA/ SQAi, Fuji GX680I/II via 3rd party adapter
optimized for shooting with Capture One software
large, high resolution (1.15 megapixel), multi-touch screen with excellent rendition of 16 million colors for quick and easy verification of focus and tonal accuracy
fast, new dual-core microprocessor enables powerful performance for the fastest available image viewing, focusing and editing
new, intuitive graphical user interface (GUI) offers easy navigation and extends the touch screen beyond the LCD area – letting you navigate and click outside the image area
FireWire 800 and USB 3.0 support delivers fastest image transfer speeds
1/10,000th sec shortest shutter to 60sec exposure (120sec on Credo 80)
16bit color depth with 12.5 f-stops dynamic range
CF storage
Li-ion battery
Leaf Credo 80
80mp CCD sensor 53.7 x 40.4 mm (645 full frame) at 5.2 micron photosites with ISO 35-800 at up to 0.7fps, $38,995
Leaf Credo 60
60mp CCD sensor 53.0 x 40.4 mm (645 full frame) at 6 micron photosites with ISO 50-800 at up to 1fps, $32,495
Leaf Credo 40
40mp CCD sensor 43.9 x 32.9 mm (1.3 crop factor for 645) at 6 micron photosites with ISO 50-800 at up to 1.2fps, $19,495
Sinar / Leaf / Rollei Hy6 system
discontinued Sinar / Leaf / Rollei Hy6 system:
6×6 (56mm square) camera
uses Rollei lens mount so MF & AF lenses for the Rollei 6008 will fit.
built in shift (up to 25mm) for wide angle photography with digital backs or film backs - RRP $US11000 excl. dig. back.
other
Linhof M679cs:
a medium format view camera designed for 6×9 images on 120/220 film but also designed to take 645 digital backs.
being a view camera and able to utilise the new large format lenses designed for digital which have the large image circle to allow for lens shift/tilt while having a superior resolution which better matches the high end digital backs makes this camera potentially the best future-proof for very high end digital photography requiring shift/tilt lenses.
for a 21mm equivalent wide angle view, the Rodenstock HR 35mm f/5 Apo-Sironar matches well.
HR lenses are actually specified by Rodenstock as surpassing the resolution capabilities of digital sensors with pixel dimensions down to 5 microns, but as they have a reduced image circle of 70mm (cw 150mm on non-HR lenses), there is limited rise/shift available.
a used Hasselblad A12 magazine and a V series adaptor plate is all that's needed to turn the 679cs into a backup film camera.
6×6 camera with Phase One db20p 16mpixel digital back $US16,000; 1.5kg without lens
compatible with Rollei 6000 lenses
Pentax
Pentax 645 digital (late 2006):
18.8mpixel; 9x9um pitch; ?45x34mm sensor (1.3x crop of 645 lens)
Bronica
Silvestri adapters but will cost 650 Euro for the SQ version which essentially converts the camera back to Hasselblad V digital back compatibility
Kapture Group used to sell an adapter that allows digital backs designed for Hasselblad V-series to be used but the adaptors cost $US895/$A1700 (2005) and require use of a one shot cable release $US395 with certain backs.
the adapter plate is different for ETRS vs SQ series cameras!
there are potential issues with soft focus due to the adapter.
Fuji GX 680
Kapture Group sell an adapter that allows digital backs designed for Hasselblad V-series to be used. In addition they sell an adapter to allow stitching of 2 digital images.