Mamiya 645DF: An "Open Platform" DSLR
It wouldn't be wrong to say many of today's pro, full frame 35mm-based DSLRs capture image files that rival or surpass the quality of medium-format film cameras. As for medium-format digital cameras... they've come quite a ways too. They've become quicker, more nimble and the image quality of the higher-res capture backs now approaches the image quality of larger-format film cameras, which brings us to the Mamiya 645DF.
Unlike 35mm-based DSLRs, in which the imaging sensor is permanently integrated into the camera body, Mamiya's 645DF ($5990.00) is modular in design, which means all of the components of the system—the camera, lenses and imaging sensor—can be updated individually as needed. For working pros, this is a plus.
And then you have the advantages of medium-format sensor size (56 x 41.5mm), which is about twice up from full-frame (24 x 36mm) "35mm" DSLRs. In terms of image quality, it's not a stretch to claim properly exposed "645" digital image files approach the image quality of a 4 x 5 transparency, especially when shot through premium Mamiya APO or ULD-series optics.
Mamiya's 645DF is billed as an "open platform" camera and marketing angles aside, this is an appropriately accurate way to describe the 645DF. The 645DF can be coupled to Mamiya DM-series capture backs, which are available in a choice of resolving powers (DM-22, DM-28 , DM-33 , DM-40 and DM-56. The 645DF also plays nicely with capture backs from Phase, Leaf and Sinar.
Note: Mamiya's 645DF is also backwards-compatible with many older-generation capture backs via software/firmware updates.
Though medium-format camera systems are traditionally perceived as being larger and heavier than Pro 35mm-based camera systems, that's no longer necessarily so. If anything, the size, weight and form factors of pro-end 35mm and medium-format DSLRs have become increasingly similar. According to the specs, the weight of the Mamiya's 645DF with a DM-series back (approximately 1480 g / 3.26 lb / 52.2 oz minus the battery) is only about 15% heavier than a Canon 1Ds Mark III (approx 1210 g / 2.66 lb / 42.6 oz minus the battery). And in terms of usability and overall handling, slower burst rates aside, the Mamiya 645DF isn't all that different to use than any of the "pro 35s."
Designed for use in both the studio as well as on the road, Mamiya's 645DF offers many of the same attributes found on 35mm-based DSLRs including a built-in grip and a bright optical system, both of which are molded in uni-body fashion. Camera controls and layout are also nearly parallel to the controls and layout found on 35mm DSLRs. If you're familiar with the workings of a 35mm DSLR, the learning curve of figuring out the Mamiya 645DF is near zip.
Depending on your particular needs or preferences, Mamiya offers a choice of three focusing screens—Matte (standard), Checker and a Microprism Type C, which is recommended when shooting with non-AF Mamiya M645 lenses.
The 645DF's electronic focal-plane shutter offers a full range of shutter speeds in both AE mode (30 seconds to 1/4000th, in 1/8th steps) and manual mode (30 seconds to 1/4000th, in 1/2 or 1/3 steps) and a top flash sync of 1/125th, which for studio and fill-flash shooters can put the kibosh on things when shooting flash under brighter ambient lighting conditions.
To address the issue, Mamiya introduced a trio of leaf shutter (LS) lenses — the Mamiya Sekor 55mm/f2.8 LS D (wide angle), Mamiya Sekor 80mm/f2.8 LS D (normal) and Mamiya Sekor 110mm/f2.8 LS D (short-telephoto / portrait), each of which enables flash sync speeds of up to 1/800th to 1/1600th of a second, depending on your choice of capture back.
Along with three leaf-shutter lenses, Mamiya also offers a choice of 15 Sekor AF optics including a choice of four wide angles (28mm/f4.5, 35mm/f3.5, 45mm/f2.8, and 55mm/f2.8), a 120mm/4 Macro, four telephotos (150mm/f2.8, 150mm/f3.5, 210mm/f4 ULD and 300mm/f4.5 APO), and three zooms (75-150mm/f4.5, 55-110mm/f4.5 and 105-210mm/f4.5 ULD).
A recently announced accessory that should make using the 645DF even slicker is the Mamiya V-Grip Air, which like the power winders we've all grown accustomed to on 35mm DSLRs, makes the 645DF easier to work with when shooting vertical images.
In addition to a second shutter release, front and rear control dials and AEL and AFL buttons, the Mamiya V-Grip Air also contains a built-in, 2.4GHz, 8-channel transmitter that allows wireless triggering of ProFoto D1, D4 and all Pro-8 power packs from a distance of up to 300m (984').
Mamiya's 645DF is powered by six AA batteries (alkaline-magnesium, lithium, nickel-hydride or nickel-cadmium rechargeable). You also have the option of plugging in a number of optional external power supplies.