Pentax K-3 review

It might be playing third-fiddle to Canon and Nikon, but Pentax - now part of Ricoh Imaging - is a venerable name in the field of photography. Its long history means that its DSLRs, like the now-top-spec K-3, can more than hold their own. The company not only has years of experience to draw upon, but an extensive back catalogue of lenses that can rival the market leaders. It isn’t shy to innovate, either.

The K-3 isn't that dip into a larger, full-frame sensor that some had been hoping for, but the model doe introduce the highest resolution we've yet seen from the company. If the 24-megapixel sensor sounds similar to the Sony Alpha A77 or A65 then it's for good reason: it's the very same base sensor. But Pentax has a certain way with its image processing and, typically, we've found the company to get the utmost out of raw hardware. Can the K-3 succeed in continuing this success and does it stand out beyond its Canon and Nikon peers?

Do the shake

The Pentax K-3's new sensor also has another trick up its sleeve: it does away with the low pass filter. This filter is traditionally used to blur the incoming light slightly in an effort to avoid jagged-edges and the effects of moire on the image, where fine detail in the source material lines up with the grid layout on the sensor.

Instead of the filter, the K-3 applies microscopic shakes to the sensor at the point of exposure to achieve the same result. Pentax calls the hardware option "advanced anti-moire". The primary benefit of this approach is down to choice. Because with it switched off certain subjects will benefit from the absence of the low-pass filter, while others, such as pin-stripe suits with their closely-aligned lines, would fall into issues. Or not, as is the case here, as the option of on or off isn't something any other manufacturer has tackled.

Rugged construction

When it comes to build quality the Pentax K-3 nothing short of excellent. The stainless steel chassis is very sturdy, and you won’t worry about it getting a bump or two if you have it slung over your shoulder while you’re out for a hike.

It’s been designed for use in more demanding surroundings than your average DSLR, with 92 weather-sealed points to keep out the damp and dust, and it should have no problems with the polar vortex that's been plaguing the UK over the winter: Pentax claims that it will keep on shooting right down to -10 degrees Celsius. We've not quite hit that temperature, fortunately, but shooting outside has been no problem whatsoever.

Despite this, it’s comfortable to hold for extended periods because of a decent notched grip, but it's slightly heavy at 715g for the body alone - but that's the price to pay for a tougher steel construction. Around the back the buttons are responsive, and the smooth clicks in the thumbwheel make it easy to dial in the exact settings you’re after. Even the mode dial comes with a wonderfully simple but ace feature: a lock dial that clicks in and out of position. Again it's all about choice, to cater for different users.

The menus are clear and well thought-out, and the 3.2in rear display, which supplements the top-plate LCD to display your current settings, flips its contents as you turn the camera from landscape to portrait. An optical viewfinder with 100 per cent field-of-view also makes for accurate framing - an essential for a DSLR such as this.

Pentax isn't shy of pro features in its cameras either. With a shutter speed that runs from 1/8000th second all the way down to 30 seconds, it’s ripe for everything from sports to long-exposure night shots. It can write up to 60 JPEG and 23 raw files at 8.3fps should the need arise too, while at the opposite end of the scale the Bulb mode lets you hold open the shutter for longer night-time shots. It's the availability of that super-fast shutter that we liked the most though, as this is often reserved for pricier top-spec DSLR models.

Raw power

That new sensor also claims to be better in low light conditions. Specifications such as a maximum sensitivity up to an impressive ISO 51,200 - and exposure compensation of five stops in either direction - might sound impressive, but it's a numbers game really. What the Pentax K-3 is the king of is at the other end of this sensitivity range.

The K-3 shoots both JPEG and raw files, the latter offering Adobe DNG (Digital Negative Format) and Pentax’s own format. The camera has dual SD card slots too so you can set it to write to both for backup purposes, use card two as an overflow, or send your JPEG files to one and the raw files to the other.

Pentax K-3 review - sample image at ISO 3200 - click for full size JPEG crop

At middling sensitivities up to and around the ISO 400 mark we found the results are crisp and grain-free, allowing for reliable indoor shooting using natural light. However, when heading outside and shooting in muted woodland surroundings, where the decreased light caused the K-3 to hike the sensitivity to a more ambitious ISO 3200, looking back at the results at 100 per cent scale revealed considerable levels of grain in the image.

Fortunately such imperfections in a physically large image are harder to spot when the image was zoomed back out to fill a display, so if you’re planning on using your results with care and not printing at giant scales or cropping right into the shot then it's not something you’ll have to worry about too much.

Pentax K-3 review - sample image at ISO 1600 - click for full size JPEG crop

In many ways we like Pentax's honesty. Its processing doesn't over-work JPEG images and render them soft, it allies itself on the side that's truer to the original raw capture. The ISO 1600 example above being a prime example of how much detail can be maintainedstraight from camera.

The one problem we did have was underexposure, but then this is typical of Pentax metering and just a case of something to get used to. However, it did mean bumping exposure in post-production a number of times - so we'd recommend relying on raw capture as a backup.

Pentax's pinnacle performance?

Pentax has been a champion around the 16-megapixel mark in our opinion, and it seems the push in resolution in the K-3 pushes things both forwards and backwards. It's a bit of a tug-o-war depending on whether you need to shoot predominantly in low-light or not.

Pentax K-3 review - sample image at ISO 400 - click for full size JPEG crop

Because elsewhere images are rather glorious. Colour fidelity is second to none, with warm reds and yellow, and rich greens and blues. Where similar tones come together, such as the green of a drake’s head against a foliage background, they’re clearly distinguished, and in shots displaying only minor tonal variation, such as a plaster frieze, the play of light on the sculpted curves is accurately reproduced with no loss of detail.

There was some very slight colour fringing (chromatic aberration) in some sample shots, although that comes down to optics. And we've been using the K-3 with the basic 18-135mm lens - there are some far superior Pentax lenses out there, although it's nowhere nearly as easy to obtain them as it is with the competitor brands.

Pentax K-3 review - sample image at ISO 1600 - click for full size JPEG crop 

The K-3 delivers a 27 focus point system, known as SAFOX 11, complete with 25-cross-type sensors for precision performance in either portrait or landscape orientation. The autofocus points cover the central part of the frame, so it’s easy to get a fix on your subject, and the 18 - 135mm lens we were using produced some impressive shallow depth of field shots with a quick fall-off in the level of focus around the sweet spot and an attractive bokeh to the background.

In short Pentax has only got better and better in recent years and this latest autofocus system shows that. SAFOX 11's arrangement is similar to that found in the K-5 model - it's a central rectangular arrangement with two line points to the side - but there are now more points for improved tracking AF and a greater detail when it comes to autofocus. It gives wider scope for tracking and shooting all manner of subjects. In the viewfinder the AF points light-up red to make clear where focus has been attained, which is bright, clear and quick to respond.

Video performance

Then there's movie mode, an area where Pentax has typically lagged behind the competition. But then we don't mind that, as this is a stills camera after all. Movie mode shoots Full HD at 60 or 50 frames per second, but outputs as 1080i interlaced which isn't nearly up to current standard. It is 1080p if shooting at 30, 25 or 24fps though.

The internal microphone is mono, but plug in an external mic and you can record stereo along with your images. You can set the volume manually or leave it set to auto, but there’s no option to filter wind noise.

Video image quality is good, and it handles the transition from light to dark settings and back again smoothly, with no stepping in the level of exposure. However, walking around while shooting, which naturally means that the composition of the scene is constantly changing, leaves a lot of background noise on the soundtrack as you can hear the K-3 and attached lens fiddling with the autofocus mechanics to compensate. Making a more significant change, such as sweeping from a close point of focus to a more distant one, causes it to make more significant corrections, which results in a very obvious snapping sound on the audio track.

Verdict

Pentax’s years of experience shine through in the K-3's well thought-out construction, which puts all of your most commonly used controls in convenient, easy to find locations. The innovation and user choice behind features such as advanced anti-moire and simple things such as a mode dial lock make this a camera that's looking to please everyone. And please it does, as using the K-3 is a bit of a treat.

Video performance still isn't the best out there, but then this is a stills camera - and still image quality is where it really counts in a DSLR. That's exactly where the K-3 makes it count too, by putting in a good performance at regular sensitivities, even if it introduces a fair amount of grain at the upper end. It's not the best of the best Pentax quality we've seen, but it's still impressive and will give its closest competitors a run for their money.

But the thing that gives the K-3 considerable appeal is that it’s extremely keenly priced, which makes it a very tempting buy indeed. But it's not a price that comes at the expense of build or function. Nope, Pentax has got everything nailed down and it all works wonderfully.