As regards performance, the K-01 is something of a mixed bag. Start-up (ie - the time taken from switching the camera on to it being focused and ready to shoot) clocks in at around 2.5seconds, which isn’t particularly speedy but should be adequate for most people’s needs. Processing times aren’t too bad, although continuous shooting speeds are hampered somewhat by the K-01’s slow autofocus (more on that in a moment). In single-shot drive mode, we were able to shoot five frames inside ten seconds, which equates to 0.5fps. At this setting there is no upper limit on the number of consecutive shots you can take.
The K-01 offers a choice of two Continuous drive mode options; a 3fps ‘Lo’ setting and a 5fps ‘High’ one. While we were able to record 30 consecutive full-resolution JPEG images in the Low setting without any slowdown, the High setting isn’t able to maintain 5fps for more than about one second, after which it slows to nearer 2.5fps. Processing waits aren’t bad at all though, with the K-01’s processor pretty quick at clearing the backlog once you take your finger off the shutter button.
So far, so good. The main gripe we have with the K-01’s performance, however, is with the lacklustre speed and excessive noise of the K-01’s autofocus system. The 81-point contrast-detect AF is by no means the fastest we’ve seen on a camera of this type, and lags well behind all of its main competitors. Focus hunting (where the camera repeatedly zooms in and out trying to ascertain focus) is common too, even in good light and this can be really quite annoying thanks to the fact that the K-01’s AF system is one of the noisiest we’ve ever encountered.
Indeed, the highly audible whirrs and mechanical grinding sounds the K-01 makes as it attempts to gain focus are, in our opinion, the camera’s single biggest failing. The problem doesn’t appear to be specific to any particular lens either – we experienced exactly the same issue with both the 40mm f/2.8 XS and with an 18-55mm SMC Pentax kit zoom that our review sample came supplied with. Given this, we really can’t recommend the K-01 as a camera to shoot quiet occasions (weddings, christenings etc) with.
Thankfully, the problems with sluggish and noisy AF are somewhat offset by the high standard of overall image quality produced by the K-01’s 16.2MP sensor – the same (albeit Pentax modified) Sony-made chip that’s found inside the Sony NEX-5n and Nikon D7000, both of which also scored very highly in terms of overall image quality. Not only is this particular CMOS chip able to resolve plenty of fine detail at lower sensitivity settings, it also perform very well at higher sensitivities too, keeping noise under control well into the mid-range ISO settings. The K-01 also offers built-in image stabilisation technology in the shape of Pentax's propitiatory Shake Reduction and this works well, enabling you to get sharp shots at speeds and extended focal lengths that might otherwise come out blurred.
While Raw shooters are well catered for thanks to the storage of lossless files in the widely accessible Adobe .DNG format, JPEG shooters will also find that the K-01 offers plenty of scope to create your own look with thanks to the various Custom Image and Digital Filter options. Indeed, until you’ve explored them all fully it can sometimes be tricky to decide which one (or indeed combination of the two) will best suit your subject. Still, that’s not a bad dilemma to face – especially if you’re primarily a JPEG shooter looking for a camera that can produce interesting effects straight out of camera without the aid of any image editing software.
The tone and colour produced by the K-01 will vary depending on your choice of Custom Image setting. During our test we tended to stick with the ‘Bright’ Custom Image setting (with the digital filters switched off), which produces images with slightly more punch and clarity than the ‘Natural’ setting, but with less saturation than the ‘Vivid’ setting. We also developed a bit of a soft spot for the ‘Reversal Film’ setting that, as the name implies, mimics the feel and tone of old slide film. Of course, the beauty of having so many options to hand is that you can either find a setting you like and stick with it, or mix and match as the situation demands.
Metering options extend to a multi-segment, centre-weighted and spot options. Pentax doesn’t specify how many pixels the metering module employs, but when used on multi-segment mode we found it to be extremely reliable. The K-01 is able to capture a good dynamic range even with the Highlight and Shadow Correction tools switched off. Should you feel the need to use either of these tools then they are both quite good at what they do, although ultimately you’ll be better off shooting in Raw and processing the image yourself. In addition to these the K-01 also offers built-in software to correct fringing and lens distortion, and while they both work quite well they do prolong processing times quite dramatically. We didn’t encounter any problems of note with the K-01’s Automatic White Balance either, although there are of course options to set colour temperature yourself.
ISO performance is another area where the K-01’s CMOS sensor performs very well. At lower settings of ISO 100 to 400 noise isn’t at issue at all, with mid-range settings of ISO 800 to 1600 also exceptionally clean and free of image degrading noise too. Indeed, noise only starts to make a small impact at ISO 3200, with the setting still perfectly usable to make smaller sized images with. ISO 6400 is the cut-off point in terms of overall quality, with noise much more visible – even at smaller image sizes. This trend accelerates as you hit the top two settings of ISO 12,800 and 25,600 (the latter actually being an ‘extended’ setting). Overall though, the K-01 is undoubtedly one of the better cameras on the market in terms of controlling unsightly noise.
The Pentax K-01 is a relatively unique looking compact system camera that has already divided opinion over its bold styling. You’ll either love the look of it, or write it off as a bit of a brick. As this is really a matter of personal taste it’s not for us to say either way. Judged purely on its merits as a digital camera though the K-01 has much going for it but also comes with some fairly major flaws. On the plus side it’s undoubtedly a well featured and easy-to-use camera that’s capable of very good image quality. On the downside, however, the K-01 is pretty bulky for a CSC and the autofocus system is sluggish and far too noisy. All in all then, a brave move from Pentax, but one that requires some refinement before it’s fully worthy of a TrustedReviews ‘Recommended’ badge.