(Pocket-lint) - There are camera and then there are cameras. Ricoh Pentax has just announced a wedge of camera gear that firmly sits in the latter category: the medium format Pentax 645Z.

An update to the earlier Pentax 645D, the Z is the second model in the company's medium format range. It features a 50-megapixel CMOS sensor (51.4-megapixels at full count), which we had first heard about when Hasselblad announced the H5D-50C, thus strengthening our prediction that we would see other manufacturers make use of the latest CMOS tech.

READ: Hasselblad reveals first medium format CMOS sensor, opening the door for other photography brands?

Targeted at professional photographers, the 645Z is a sturdy construction that's both water-resistant and dust-proof just like the original 645D.

But it's got a lot more on offer than the earlier model. The 3.2-inch, 1,037k-dot LCD is higher resolution than before and mounted on a tilt-angle bracket to make light work of waist-level work. There's also a built-in optical viewfinder with 98 per cent field-of-view.

The 645Z's sensor does not feature a low-pass filter for the sharpest possible results, and is paired with the latest Prime III imaging engine to counteract any potential image issues as a result of this filter's absence.

The 645Z's sensor does not feature a low-pass filter for the sharpest possible results, and is paired with the latest Prime III imaging engine to counteract any potential image issues as a result of this filter's absence.

Sensitivity also sees a significant boost, with ISO 204,800 available for ultra low-light shooting. We doubt it will be many photographers' staple setting, but when the earlier 645D maxed out at ISO 1000 (with ISO 1600 an extended option) there's a whole different focus in the later model.

Burst shooting has been upped to 3fps, which is largely unheard of in medium format territory, particularly at such high resolution. And while it's not going to be the ideal camera for shooting fast action on account of its size, those extra frames in quick succession might be the difference between bagging the studio shot and missing out. Pentax claims up to 10 raw shots can be captured in succession at this sustained burst rate.

The 645Z also incorporates a new Safox 11 phase-matching autofocus module with 27 sensor points that can shoot in low-light thanks to its -3EV sensitivity. That's more than most pro DSLR cameras offer. And if you want live view, you've got live view: particularly useful for when using the LCD screen for image preview.

There are many more specification details, highlights of which include 1080p movie capture (imagine cinema quality from that giant sensor) and dual SD card slots.

The £6,800 body-only asking price might sound gob-smackingly huge, but then for a medium format camera with such a specification it's a bit of a steal. You will need 645AF2-mount lenses, though, which cost a pretty penny themselves. And if you want time to save then no such luck as the Pentax 645Z will go on sale in May.

Writing by Mike Lowe.