To say the Pentax K-01 has unconventional looks would be an understatement. While most manufacturers are working hard to slim down their offerings, Pentax has gone in the opposite direction.
The K-01 has all the curves of a slightly rounded brick. It's fat, a little heavy, and looks more like a stylish toy than a £500 semi-pro camera, with its chunky buttons and switches and ends encased in ribbed rubber.
Pentax called on the services of designer Marc Newson to come up with the styling, which does exude a certain retro charm, but won't be to everyone's taste. There's a very good reason for its shape and size though, which I'll come to later.
Expect the Pentax K-01 with an 18-55mm to set you back £600, or as an 18-55mm and 50-200mm lens bundle for £700.
Stills tests
Whatever you think of its outward appearance, you can't argue with the quality of its shots.
I tested the K-01 using a 40mm prime lens with a maximum aperture size of f/2.8 and a minimum of f/22. I performed most of my tests with the camera set to aperture priority mode so I could control the depth of field, while allowing the camera to make all other decisions concerning exposure and sensitivity. I occasionally also switched to the full auto and refreshingly light-of-touch HDR mode, the latter of which avoids over-egging the effect and producing unattractive haloes around hard contrasts.

I shot raw (native Digital Negative DNG files in the case of the K-01) and JPEGs side by side and found that the K-01 performed consistently well.
Low light performance is excellent, with well controlled grain allowing for a high level of retained detail and very accurate colour reproduction. To shoot this image of a cat below, the K-01 was set to aperture priority and it self-selected a sensitivity setting of ISO 6,400. The fur is clearly rendered and easy to see and the stripes accurately placed. The catchlight in the cat's left eye is sharp and the noise pattern is a light, even grain, without any false colours and so doesn't distract from the subject.

In better lit conditions, where it could reduce the sensitivity, the results were very clean indeed. In the shot below, the subject's skin tones are realistic on both the lit and shaded sides of the face and the only blemishes on the entire frame are natural, not digital. The focus is spot-on with this lens, as is particularly clearly illustrated by the fidelity of the strands of hair that pass in front of the bokehed light at the back of the scene.

The performance you'll achieve will depend on which lens you use, but I found that the high-resolution APS-C-sized sensor delivered extraordinary levels of detail in all lighting conditions.
The air line in the shot below is a case in point. It's starting to show its age, with paint peeling from the gauge and dirt marks soiling its face. Even from a couple of metres away and using a lens with no zoom, the K-01 had no trouble picking these out, with sharp edges and a good, clean focus.

You might put this down to the fact that the dial sits close to the centre of the frame, but the level of focus and detail retention was pretty uniform right across each image in my tests.
In the shot below, the trees at the edges and encroaching into the corners of the frame are sharp and detailed. There's no evidence of them being smeared where the lens has had trouble focusing the light accurately on the sensor, at the points where light has had to be bent to the most extreme degree.
Neither is there any sign of chromatic aberration, which is an unwanted colour fringing effect caused by a lens not quite focusing each wavelength of light in unison with the rest of the visible spectrum. This earns the K-01 extra points for a very impressive performance overall.

Each of the scenes examined above has a fairly broad colour palette, but the K-01 does just as well when tasked with capturing more muted hues.

The shot above shows a carved wooden badge fixed to the front of a similarly coloured VW Camper Van. The clearly captured changes to luminance render both the badge and the paintwork of the van full of detail. The image below of a dragon roof adornment is similarly well handled, despite being dominated by a warmer orange palette.

Video test
The video mode shoots Full HD (1,920x1,080 pixels) at 30, 25 or 24 frames per second. It also sports options for 1,920x720 pixels and 640x480 pixels at the same frame rates, each at three different quality settings. I used Full HD, 30fps at maximum quality in my test.
The results were a little mixed. In most instances the K-01 performed very well indeed, with an extremely fast and very smooth response to changing light levels and a brilliantly recorded soundtrack. However, when shooting while walking, there was some degradation in the quality of the captured video.
Sweeping across the scene caused a slight ripple effect where the footage appeared to shimmer slightly, while walking through a narrow passage, such as an alley or between two hedges, as shown in the scene below, caused the picture to lose clarity.
Handling and build
Chunky chassis aside, the K-01 is well laid out, with the controls very logically arranged. Every time you change modes, it displays a couple of lines of help at the bottom of the screen that explain what the various buttons and dials do in that mode. This is very helpful and aids you in getting to know the camera better more quickly.
There's a comprehensive quick menu through which you can tweak the most common settings, where they're all arranged on a flat grid rather than a multi-tabbed list. You can step through these using the four-way controller and adjust each one with the wheel that's otherwise used to adjust aperture and shutter speed.

There's direct access to sensitivity (ISO 100 to 25,600, with the option to cap it on a narrower band if you want to avoid graininess), and exposure compensation (+/-3EV in 1/3 EV steps) outside of the main menus. There's a neat set of graphs to explain the differences your settings will make to the overall colour balance in your images. Set it to portrait and you'll see that saturation is increased across the board, but pick landscape and it illustrates that the greatest boost is applied to the yellows and blues. This lets you see at a glance how your results will be balanced.
The screen is vibrant, clear and easy to use in bright sunlight, but its habit of boosting the contrast when fixing focus makes for an ugly preview. Unless you turn off the menu option to display a start-up screen, it takes close to 2 seconds to wake up from sleep mode, so you risk missing a shot. Disable it and it's ready to shoot in less than a second.

The sensor is a 16-megapixel chip producing 4,928x3,264-pixel images. In front of this sits the K-mount lens attachment, which is the camera's main draw, as this particular mount gives you access to several dozen legacy lenses. This enormously enhances the appeal of the K-01, particularly when compared to rival compact system cameras (CSCs) -- many of which only offer a small number of compatible lenses.
The question though is whether that legacy lens library is sufficient enticement to buy into a bulky body design when you could bag yourself a more sculpted and comfortable dSLR with a similar number of lenses to choose from for close to the same price.
It's the use of the K-mount that's to blame for the camera's size, as the glass needs to be a particular distance from the sensor, as evidenced by the empty box you'll find if you twist off the lens and take a look inside. Starting again from scratch, as it did with the Pentax Q, would have allowed the company to build something that competed more directly with its near rivals in terms of size and design.
Conclusion
The real appeal of compact system cameras is, well, compactness. This isn't fulfilled by the Pentax K-01's design. However good its output might be, that ultimately reduces its appeal in this class of shooters.
For that reason, I've marked it four out of five. If its mechanics were pulled out and housed in a smaller, lighter body, while somehow still having access to the K-mount lens system, it would garner top marks. But for all its retro geek appeal, the K-01 is a little too large to be comfortable, or to compete effectively against such rivals as the Panasonic Lumix GF5 or the sleek Samsung NX range.
I love what this camera does. I just don't love using it -- not in the wild. If I was looking for a dedicated studio snapper that I'd predominantly leave on a tripod for still-life use, then bulk and a boxy design would be less of an issue. In such a scenario, the K-01 would be close to the top of my studio shortlist, if not number one.

User reviews2
Add your review
Benjamin Kanarek 12 August 2012
Good: Amazing Video and Still output
Bad: Would be nicer with a pivotable screen
Comment: I love this camera. Especially for Video's. We used this for our last behind the scenes video's for VOGUE & Harper's BAZAAR. As good as the output from a Nikon 7000 or Pentax K5... and NO they did not pay me for this endorsement! :-)
sfdgoz 28 June 2012
Good: It looks brilliant
Bad: Nothing that I can see
Comment: I really have to say this looks stunning as a camera and is refreshingly different, I don't really care about weight to much so its pretty much perfect!!! I have a Pentax Optio S12 at home and know and trust the Pentax brand which is another incentive for me to buy it!!! (£500 is a good price!!!)
See all 2 user reviews