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.

Pentax 645D review – click for sample image gallery

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.