The Pentax 645D: is Pentax’s first digital medium format camera with a massive 40MP resolution. So what does £10k of medium format camera buy you? The What Digital Camera Pentax 645D review finds out...
Pentax 645D review
Medium and large format cameras are the last bastions of the analogue world, and though digital versions have been around for quite some time, prices have been sky-high and users slow to convert. Medium format sensors principally have a size advantage over their full-frame (35mm) cousins. Not only is the resolution increased but so is each of the physical sensor nodes, allowing for greater detail and tone capture.
What the Pentax 645D sets to offer is a more friendly medium format experience, with much of the handling being brought across from the K-7 DSLR model. This makes it ideal for those in the field, or those looking to enter the medium format market for the first time. Existing users of the Pentax 645 system will feel just as at home.
However, the up to date Pentax system utilises a vertical-run shutter much like a DSLR, so the newer lenses won’t offer the higher flash sync that’s possible with leaf shutters found in some competitor cameras. This may limit more complex lighting setups (unless using older LS-series lenses), though Pentax’s 645D offering is more firmly targeted at the landscape photographer looking for super-high resolution.
Pentax 645D review – Features
The Pentax 645D uses a Kodak 40MP CCD sensor, which outputs at 7264×5440 pixels in 14-bit Raw (PEF or Adobe DNG) or JPEG. At 44x33mm in size it’s smaller than a true 6×4.5cm frame but still 1.7 times larger than a full-frame (35mm) sensor. This means its new lenses have a 0.79x crop factor.
The processor is the Prime Engine II, which also features in Pentax DSLRs, from the K-x up to the K-5. It provides a conservative ISO 100-1600 range, though of little issue as medium format has traditionally been for use in controlled studio environments or landscape scenarios.
Metering is a 77-segment system that appears to have been taken straight from the Pentax K-7 DSLR model. There’s a choice of Evaluative, Spot and Partial modes, and an exposure compensation of +/-5EV. Autofocus comes in the form of the new SAFOX IX+ thas provides 11 selectable AF points with all but two being cross-type sensors. White balance features a large number of presets, plus manual and colour temperature settings, all with fine-tuning. The shooting mode dial offers a familiar array of options for regular Pentax users, with the PSAM accompanied by Sensitivity (Sv), Shutter & Aperture (TAv), a Bulb mode, Flash sync (X), and User setting. There is even the familiar Green button on the rear for quick auto setting with a single press. From the menus you can access in-camera HDR and Dynamic Range expansion settings, plus a series of digital filters.
The Pentax 645D’s viewfinder is much larger than on a DSLR, making it easier to manually focus. Despite this, it offers only a 98% field of view, which seems unusual for such a professional product (though is better than the 92-93% FoV on older film models). The rear screen is a 3in LCD with a 921k-dot resolution and displays shooting info or a digital level.
Design, Performance & Image Quality
Pentax 645D review – Design
Made from a magnesium alloy casing and die cast aluminium chassis for strength, the 645D is weather-sealed against dust and moisture, and is designed to work in temperatures of down to -10ºC. The camera certainly feels solid in the hand and, though fairly weighty, is only around 150-200g more than a Nikon D3X or Canon 1Ds with battery. It also benefits from a substantial right-hand grip that allows you to feel fully in control. In addition to the regular tripod mount on the base of the camera, there is a second on the side for a more traditional portrait-orientation.
The large shooting mode dial is heavily rubberised for easy grip but also has a centre lock button to avoid accidental mode changes. A four-way d-pad control is used for the main navigation, allowing menu access as well as AF-point selection. Underneath the LCD screen there are further quick access buttons for flash, colour, drive and white balance. All the controls and buttons are chunky and positive to press, making the operation easy and instinctive, so even in gloves the majority of features can be easily accessed. The whole layout looks and feels like the K-7 DSLR model, scaled up to fit the body.
However, as the body is a single unit, there’s no modular construction, meaning no possibility of a traditional waist-level finder option and the sensor cannot be detached as a back for use in conjunction with view camera bodies.
Pentax 645D review – Performance
In poor lighting or low contrast scenes the camera does struggle to find focus and there is no AF illumination. In regular light however it performs without a quibble, locking on to the subject with ease. In manual focus there is an AF confirmation light in the viewfinder however.
The 77-segment multi-pattern metering has already proved successful in the K-7 but here it really seems to excel. Evaluative metering tended to underexpose by between a half and a full stop, though this ensured all highlights were retained.
The write time is around 7secs for JPEG, 8secs for Raw, or 11secs Raw+JPEG. Thankfully the camera doesn’t lock up during this time leaving you free to keep shooting. If you want to review the image, however, you must wait up to 5secs for it to display, which can slow shooting. The continuous shooting mode gives a burst speed of around 1.1fps for up to 19 shots in JPEG, or 15 in Raw+JPEG.
No live view is available (no medium format camera offers this feature however), though the current lack of tethered shooting is a downside.
Pentax 645D review – Image Quality
For outdoor shots the Auto White Balance produces a nice rich set of colours, though did require a manual setting in the studio. Colours from the JPEG as default are rich and punchy without over-saturation.
The detail that can be obtained from a 40 million-pixel sensor of this size is truly breathtaking, and the difference even when compared to shots taken on Nikon’s 24MP D3x was starkly obvious.
There are subtle signs of image noise in the shadow areas from ISO 400 upwards but this appears more like a slight texture right up to ISO 1000. At ISO 1600 it does show some colour noise but this is still minimal.
Value & Verdict
Pentax 645D review – Value
Hasselblad’s latest H4D-31 offers the same sensor size and, with its modular design, is aimed more at studio work. The 645D’s weather-sealed body will be a big pull for those working in the field. The other real competition comes from high-end pro DSLRs, such as the Nikon D3x, that offer around half the resolution for about half the price.
Pentax 645D review – Verdict
The 645D will no doubt attract a niche audience, though its almost-£10k price tag is firmly out of reach for the majority. The experience of using a medium format digital camera is very different from a DSLR and has many advantages, especially for landscape photographers. To be clear: the 645D is less of a studio camera than its competition, but its weather-sealed single body design firmly fixes it as one to use in the field or where large, resolute files are a must. However the vertical run shutter, non-customisable construction and no tethered shooting ability may pose issues for certain users. However its handling is a winner and easy to pick up. For general use a pro-level DSLR still has more versatility but, so long as speed’s no issue, the Pentax 645D is a pleasure to use.