I understand that Pentax fans will hate me for this post, so I think it's important to emphasize that I am, in fact, really partial to Pentax. When I was younger I used to borrow my father's Canons, but the first SLR I bought with my own money was a Pentax. I was a Pentax user for several years and I was always fascinated by the quality of their lenses and their non-standard approach to camera design. I still think that Pentax has simply the best lens line-up for serious amateur shooters wanting the highest possible image quality without the excessive bulk and weight associated with full-frame cameras.
However, they were late to the mirrorless party and their first entry — the Q — was nothing more than a glorified point-and-shoot selling for a ridiculous price. (I think it's worth to remember that Pentax was late to the DSLR party as well, and this delay contributed significantly to the company's decline.) Finally, almost a year later, they launched what can be considered the first REAL Pentax mirrorless — the K-01. This time Pentax wisely judged that they don't have enough resources to support yet another lens mount and made the K-01 fully compatible with the company's venerable K-mount, making it a compelling option (on paper, at least) for existing owners of Pentax lenses, both modern and legacy. What's more, the camera has the same excellent sensor as the flagship Pentax K-5, which makes it even more attractive.
Body and design
Pentax hired famous designer Mark Newson to create the body of the K-01, and the final result is highly controversial. I think the K-01 is the most frequently bashed camera in the world simply because it looks different to other cameras. As for me, I quite like its boxy appearance, especially the bumblebee-colored version. And the camera feels very well made, too. Its body is entirely covered in metal with some rubber parts. All the switches and dials have a very solid feeling to them.
The K-01 is quite big. In its thickest part it's certainly thicker than the Panasonic GH2, which previously held the title of the biggest mirrorless camera in the world. Compared to the diminutive Panasonic GF2, the K-01 looks almost comically huge. The camera is also heavy for a mirrorless design: it weighs just 10 grams (about 1/3 oz) less than the company's entry level DSLR, the K-r.
As nice as the K-01 body is, I have 2 problems with it. First of all, it has almost no handgrip. I have fairly large hands, but for me the smaller Panasonic GH2 is more comfortable to hold than the Pentax K-01. The second problem is that the rubber flap that covers the ports on the right-hand side of the camera is awful. Once opened, it's rather difficult to close, and it also manages to work itself loose every time I get the camera from my bag. Needless to say, this is quite annoying.
The screen is the same VGA TFT panel used in the Pentax K-r. It's nice and sharp, but it has severe problems with visibility in broad daylight, even at the maximum brightness. Many of the photos I took with the K-01 featured uneven horizon or suboptimal composition simply because I could not see what exactly I am photographing.
The kit lens
The K-01 is sold with the SMC-DA 40mm f/2.8 XS (eXtra Small?) lens, which is probably the most 'pancakish' pancake lens ever. It's absurdly thin and looks more like a body cap. Optically it's identical to the highly-regarded DA40 Limited lens. I can't say that I'm enamored with its focal length (the 60mm FOV is rather weird) or F-number (f/2.8 is not that fast by any standard), but at least this lens manages to disguise the true size of the camera. Oh, by the way, the rubber lens cap is as annoying as the aforementioned rubber flap on the camera itself.
And, of course, the moment you mount any zoom lens on the camera, it becomes really huge.
Controls and menus
The menus and controls of the K-01 are essentially identical to those of the K-r. They are nicely done, all buttons are comfortable to reach. (Hint for Kai Wong of DigitalRev: don't try to press the green button with your index finger, use your thumb instead.) Compared to the Panasonic GH2 and even to the GF2, the menus are a bit sparse (meaning that the K-01 doesn't have as many options), but everything important is there.
Shooting with the Pentax K-01
I hate to admit it, but shooting with the Pentax K-01 is an exercise in frustration. No, the camera is not as clumsy as Sigma DP series (after all, Pentax is a much more mature camera company), but in many respects it is one of the worst cameras I have ever used.
Let's start with the AF performance. I have only two words to describe it, and those two words are 'pain' and 'misery.' According to Imaging-Resource.com, focus acquisition times in most cases are close to a full second, and I'd say this is most certainly true. In low light the camera focuses even slower. Another problem is that the smallest size of the AF area is not small at all, and the camera happily focuses on anything that falls within the AF frame — just not on the object you want it to focus on. Another thing to consider: if you're shooting near the minimum focusing distance of the lens, the AF system sometimes produces false positives. The camera beeps and the AF frame turns green, but the image is visibly misfocused. And finally, most Pentax lenses (including all DA and FA Limiteds) don't have built-in focusing motors and are driven mechanically from the camera body. Such lenses make really scary sounds when they are focusing.
I've seen an argument that the AF performance should be better with CDAF-optimized lenses. This is probably true, but the ugly truth is that Pentax currently has 0 (zero) CDAF-optimized lenses, nobody knows when such lenses will be announced and how many of them (if any) we will see during the lifetime of the camera.
Manual focus has its share of problems as well. The camera has both 'focus peaking' and on-screen magnification. However, there is one big gotcha: in bright light the camera randomly stops down the aperture (probably to maintain a well-exposed live view image) making it difficult to assess both focus and depth of field.
Another problem with the K-01 is the speed of continuous shooting, or lack thereof. As a RAW shooter, I was unpleasantly surprised by 1 (one) fps continuous shooting speed.
I was also not pleased by the K-01's exposure meter. It's simply not consistent enough to be reliable: the camera both over- and underexposes as it sees fit. On more than one occasion I got shots like this:
I can also say with confidence that my own Panasonic GH2, while not having the awesome dynamic range of the K-01, consistently did a much better job of squeezing tough scenes into the dynamic range of its sensor, which speaks volumes about how unreliable the metering of the Pentax K-01 is. This is a bigger issue than it should be partly because the screen is so difficult to see in the sunlight.
Ok, enough grumbling, let's say something positive for a change.
The K-01 uses the same battery as K-5 and K-7. This battery is very big and has almost twice the capacity of the Panasonic GH2 battery. In my experience, battery life of the K-01 is awesome. The camera easily has the longest battery life of all the mirrorless cameras out there.
Another nice touch is the shutter sound. It's very soft, much softer and nicer than the shutter sound of the Panasonic GH2.
As frustrating as the K-01 is, its image quality is nothing short of spectacular. DNG files produced by this camera show exquisite color and very smooth tonal gradation. The richness and delicacy of the images is truly remarkable.
Surprisingly, while the high ISO performance (ISO 3200 and higher) is better than the GH2, the difference is only about half a stop which is less than I expected. It's at the lower ISOs (100-800) where the K-01 is miles ahead of the GH2, let alone the GF2.
Interestingly, the images from the K-01 (both DNGs and JPEGs) require an ungodly amount of sharpening before actually looking sharp. But once properly sharpened, they really shine.
Some sample images from the K-01 (mostly shot on my recent trip to Istanbul):
Full size: http://photo.torba.com/images/pavel.urusov/f/UmeQrKuf1vMcSKoznpwr.jpg
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Full size: http://photo.torba.com/images/pavel.urusov/f/HMm94NqpURpAoI0B6lEd.jpg
Full size: http://photo.torba.com/images/pavel.urusov/f/yvmEDxKSW0Wn7jnHwNEg.jpg
Full size: http://photo.torba.com/images/pavel.urusov/f/pDHKBbkHbQOYmQrt8SHN.jpg
Full size: http://photo.torba.com/images/pavel.urusov/f/D5rpaQDAX5tXwoSQOdLv.jpg
Full size: http://photo.torba.com/images/pavel.urusov/f/lHaaB35253IjklDr7L5W.jpg
Full size: http://photo.torba.com/images/pavel.urusov/f/oxz5cbXtIy2F7UxuW4vg.jpg
The Pentax K-01 is a very controversial camera. I like its unusual appearance and love its image quality, but shooting with it proved to be frustrating. Compared to modern mirrorless cameras from Panasonic, Olympus, Sony, Nikon or Samsung the K-01 is slow and clunky. It feels unnecessarily crude, almost like something from the Stone Age.
It is also worth noting that the K-01 does not have the flexibility of other mirrorless cameras in terms of compatibility with legacy lenses. The only lenses you can mount on the K-01 are either K-mount or M42 (aka Pentax Screw Mount) ones. Which is a pity because the K-01 would make a great camera for legacy glass.
In the end I don't know who should buy this camera. Existing Pentax users will be better served by one of Pentax DSLRs, and for everybody else the Sony NEX-5N will provide the same great image quality, but with fast and silent AF and in a package twice as small.
That said, there is no doubt that after I became accustomed to quirks and limitations of the K-01, I could take pictures with it just fine (unless I was shooting moving subjects). If it was my camera, I'd add something like Hoodman Hoodloupe to the kit (to mitigate the absence of the viewfinder) and use mostly legacy glass, simply because the AF performance of the K-01 is abysmal and manual focusing with legacy lenses is really good. In such configuration, it will make a great camera for landscapes, macro and even portraiture.