Pentax K-3 at a glance:
- 23.35-million-pixel, Sony-made CMOS sensor
- Unique anti-aliasing system
- 27-point AF (25 cross-type points)
- Fully weather-sealed, magnesium-alloy body
- Compatible with SD cards, Flucards and Eye-Fi cards
- ISO 100-51,200
- Street price £1,099 body only
- See product shots of the Pentax K-3
- See sample images taken with the Pentax K-3
Pentax K-3 review – Introduction
With company takeovers, mergers and job losses, it is not surprising that the past few years have seen Pentax lose its way a little. In 2009, two years after the company was bought by Hoya, Jessops made the decision to stop selling Pentax cameras altogether. However, the company returned to Jessops’ shelves some two years later, shortly before its purchase by Ricoh.
This takeover appears to have given Pentax a new lease of life. There are now five DSLRs in its line-up, including the new Pentax K-3, although it is a fair criticism to say that they are too alike, sharing the vast majority of their features.
However, the new Pentax K-3 breaks that mould. Rather than using a 16.2-million-pixel, APS-C-sized sensor, the new model steps forward with a 23.35-million-pixel, APS-C sensor manufactured by Sony. This drags the K-3 back into the DSLR market with an APS-C sensor matching the resolution of its Nikon and Sony counterparts, all of which offer a slightly higher resolution than the equivalent Canon DSLR.
However, don’t be fooled into thinking that the K-3 is all about megapixels. It is every bit the high-end enthusiast DSLR as its competitors, and in many ways even more so. It is a lot to ask of just one camera, but the K-3 looks as though it could be capable of taking on Nikon and Canon in this section of the DSLR market. At the very least, it would appear to be the DSLR Pentax users have been waiting for.
Image: Shown here 100% at 300dpi, the level of detail that the K-3’s 23.35-million-pixel sensor resolves can be clearly seen. Image shot at ISO 200
Pentax K-3 review – Features
The sensor in the new Pentax K-3 is a Sony-made, 23.35-million-pixel, APS-C-sized CMOS unit. This is presumably the same sensor that is used in the Sony NEX-7 and Alpha 77. With Pentax’s previous K-5, K-30, K-5 II and K-5 IIs DSLRs all using a 16-million-pixel sensor, the 23.35-million-pixel resolution is a significant increase.
Even better, Pentax has removed the optical low-pass (anti-aliasing) filter from in front of the sensor. This should allow the sensor to reach its full potential and resolve as much detail as possible, unhindered. For more on this, see Anti-Aliasing.
Combined with the K-3’s processing engine, the sensor can shoot at an equivalent sensitivity of ISO 100-51,200, with 14-bit raw capture and a very impressive 8.5fps shooting rate. As is standard for Pentax cameras, the K-3 can save raw files as either Pentax PEF or Adobe DNG files. Those who want to use their existing raw-conversion software, such as Adobe Camera Raw or Lightroom, without having to wait for the next upgrade, will really benefit from shoot in the universal DNG file format. In my opinion, DNG raw files are great and I wish more manufacturers gave the option of shooting in this universal format.
Another feature common to Pentax DSLRs is built-in sensor-shift stabilisation. This means that any lens mounted to the K-3 can be stabilised, regardless of age.
One new system installed in the Pentax K-3 is autofocus. This has been significantly upgraded and now features 27 AF points, 25 of which are cross-type. Although the number of AF points may pale a little in comparison to the 51-point system that Nikon has employed in its cameras for several years now, 27 points should be more than enough for most photographers.
Although the Pentax K-3 doesn’t have built-in Wi-Fi connectivity, it can use the new SD-compatible Pentax Flucards, which provide Wi-Fi connectivity. Unlike Eye-Fi cards, which only offer image transfer to a smart device, Flucards allow for full control of the camera’s exposure settings and focusing, as well as a mirrored live view display to a smartphone or tablet.
The Pentax K-3 is also compatible with standard Eye-Fi cards for those who just want to copy images via Wi-Fi. Getting images off the camera in a more conventional manner is made faster with the addition of a USB port on the side.
Pentax K-3 review – Anti-aliasing
Like many recent cameras, Pentax has opted to not use an anti-aliasing filter in the K-3. For those who have managed to miss the coverage of how these filters work, they are designed to minutely blur the light reaching the sensor to help reduce moiré pattering. The result is a slight blur in the final digital image. By not using this filter, images are crisper and resolve more detail, but they are also prone to suffering from more moiré patterning when photographing close-knit patterns, such as distant netting or brickwork, or more obviously patterned clothing.
To combat this, Pentax has come up with an ingenious solution. The same motors that move the sensor slightly when stabilising it are employed to shift the sensor the width of a pixel or two during an exposure. There are actually two settings in the K-3’s menu controlling the anti-aliasing filter effect. The first of these moves the sensor back and forth along one axis, while the other moves the sensor in a more circular fashion. The second of these settings produces a greater anti-aliasing effect, although obviously this reduces detail more.
As the anti-aliasing feature is applied electronically, via the sensor motors, it means that photographers have the advantage of choosing whether to employ the anti-aliasing feature depending on the subject they are photographing. For example, when shooting portraits or fashion images, you might want to apply the filter effect to prevent any moiré patterning emerging in fabrics; landscape photographers, on the other hand, might leave it switched off to reveal every last detail in a scene.
To test the anti-aliasing filter effect, I photographed a pair of jeans turned inside out, as the fabric weave is usually ideal for demonstrating moiré patterning. Surprisingly, to create any moiré patterning, I had to stand around 4m away from the jeans and use an 18mm focal length. If I stood any closer, the high resolution of the camera meant that all the weave of the fabric was clearly visible with no artefacts.
Using the anti-aliasing filter effect did indeed remove the moiré patterning, although this was at the expense of detail. Given the resolution of the K-3, I would suggest that most photographers could quite happily leave the anti-aliasing feature turned off unless they are specifically aware of something in the scene that may cause moiré. For example, if you are photographing portraits or, say, fabrics with repetitive patterns (like those you might find in a Moroccan souk), then you would be wise to switch the anti-aliasing feature on.
Pentax K-3 review – Build and handling
One of the strong points of Pentax enthusiast-level DSLRs has always been the build of the body, and the K-3 is no exception. With a fully weather-sealed, magnesium-alloy body, the K-3 is a very robust camera, certainly capable of withstanding inclement or rough conditions. Much of the time spent testing the K-3 was in the wind and rain, and I didn’t once feel that the camera would be compromised.
However, it isn’t just the camera itself that needs to be weather-resistant; there are also the lens and accessories to consider. Thankfully, Pentax has a growing range of WR (weather-resistant) lenses. As a standard kit, the K-3 comes with the 18-55mm f/3.5-5.6 WR kit lens, so the camera and lens are weatherproof straight out of the box. A weather-sealed battery grip and two weather-sealed flashguns are also available.
Making the K-3 even more attractive to demanding photographers is the durability of the shutter, which has been tested up to 200,000 actuations. This will be particularly appealing to those photographers keen to take advantage of the K-3’s ability to create time-lapse videos at a 4K video resolution.
As you’d expect, there is a good array of buttons and dials, and most of them are placed fairly logically. However, I was confused by the handling of the K-3 when the rear status screen was turned on.
The rear status display does not allow for the individual settings to be highlighted and then changed via the directional control. However, a number of times I instinctively went to use the directional control to move or change a setting on the rear display. In fact, all the settings on this screen are controlled via direct button presses. To change other settings, a press of the info button brings up an on-screen menu that reveals all the other key image settings. This can be changed via the directional button.
Resolving this was straightforward. I simply turned the rear status display off and used a completely blank rear screen, relying on the physical buttons and the camera’s top LCD panel to know which settings I had the camera on. Of course, the quick menu is still available at the press of a button for changing image settings, but the camera handled far more intuitively with less information displayed.
As usual with Pentax, there is a wealth of custom options – 27 to be precise. These include a standard AF fine-tune feature, one-push exposure bracketing, and whether you want the exposure linked to the AF point in use. You really can make the K-3 behave as you want it to.
Pentax K-3 review – Autofocus
The K-3 is equipped with a respectable 27-point AF system, and 25 of these are the more sensitive cross-type points. The number of AF points is reasonable, with all of them placed around the centre of the frame. Naturally, I used the camera with a few different lenses. Of these I found that the Pentax 40mm f/2.8 Limited lens was the fastest to focus. It was fairly snappy in single-shot spot AF mode. However, as we have seen, or should I say heard before, the AF is quite noisy with Pentax DSLRs, particularly when using the kit lens.
Although quite fast, the AF feels a little slower than it actually is due to the process being fairly audible. Although the action of focusing appears to happen in one motion, the noise emitted from the motors tells us that the lens seems to roughly focus and then fine-tune.
The 18-55mm f/3.5-5.6 kit lens isn’t especially fast, but is a satisfactory accompaniment for those starting off with the camera, especially given that it is waterproof. Switching to the 60-250mm f/4 lens, the performance is again steady without being snappy. Photographing wildlife using continuous AF, the K-3 was able to keep up with trotting deer, although with a few shots where the focus was slightly off.
Perhaps the best summary of the AF system is that it isn’t sleek. While in good light it finds focus quickly, it is not blazingly fast and in dim light it does slow down. Those wanting to shoot wildlife or fast-moving subjects will find the AF speed a little frustrating. While it is possible to get shots in focus, don’t expect a high success rate.
Pentax K-3 review – Metering
With an 86,000-pixel RGB metering sensor, you would expect the K-3 to get perfect exposures every time. However, as we have seen from other metering sensors, a high specification isn’t everything. In fact, I noticed little difference between the metering system of the K-3 and other Pentax DSLRs I have tested and used over the years.
As with previous models, the K-3 has a tendency to underexpose, particularly in overcast light. I found myself having to add around 1-1.3EV to many exposures in dull light, while in good light a +0.3-1EV adjustment was needed. This did mean that I had a few issues with burnt-out highlight details.
Another positive of the K-3’s metering system is its consistency. As I have commented before with other Pentax cameras, you quickly get a feeling for how the metering system is going to behave in certain conditions, and as no metering system is infallible, predictability is important. However, for very tricky scenes with a high-contrast range, spot and centreweighted metering, along with an AE-L button, are on hand to ensure very precise results.
Pentax K-3 review – Dynamic range
Image: The dynamic range of the camera is good with a fair amount of detail and, importantly, colour is recoverable from highlights and shadows. However, there is some noise as a result
When we tested the Pentax K-3, we found it to have a dynamic range of 11.97EV. This is about on a par with the Sony cameras that also use this sensor.
With the metering tending to underexpose, highlight retention is not really an issue. However, this does mean that shadow areas tend to be darker than they should be. I found that I could increase the exposure of the DNG raw files in Adobe Camera Raw quite significantly, and what looked on screen like a dark expanse actually revealed a surprising amount of detail.
That said, at all but the very lowest sensitivities there is quite a lot of luminance noise in lightened shadow areas, although colour noise is not a real concern. Even the default Camera Raw colour noise-reduction setting managed to a remove nearly all colour noise.
Increase the sensitivity above ISO 400 and there is an increase in luminance noise in shadow areas, but it was only really noticeable when I was making adjustments greater than +1EV.
Pentax K-3 review – Noise, resolution and sensitivity
Image: Shown at 100% at 300ppi, the pull-up shows the fine detail that the K-3 can capture, although at ISO 400 a little luminance noise is visible if you look very closely
You would expect a 23.35-million-pixel sensor with no anti-aliasing filter to produce fantastically detailed images, and the K-3 doesn’t disappoint. The camera comes close to scoring a perfect 40 on our lens chart, which is something that, so far, only the Nikon D800/E and digital medium-format cameras have achieved. In fact, it is possible to make out all the individual lines at the end of the chart. However, there is moiré patterning and some slight, possibly consequent, artefacts, and that stops the K-3 producing a perfect result. As it stands, the K-3 falls just short, reaching 36 on the chart, rather than the perfect score of 40. That said, it is important to remember that this moiré patterning is visible from around 28 onwards, although this will, of course, only be an issue if you happen to photograph fine linear patterns – or indeed, test charts.
What really counts is the performance of the K-3 in the field. Here it is excellent at resolving all manner of fine details, which is particularly apparent when photographing landscape images. To make the most of the K-3’s sensor you must shoot raw files: JPEG images don’t resolve as much detail, only reaching around 32 on our test chart. Don’t get me wrong, this is still a very impressive figure, but it is only really what you would expect of a camera of this resolution – as we have seen, by not having an anti-aliasing filter, the camera is capable of far more. It would appear that the JPEG images have some anti-moiré effect applied, as there is only the merest hint of it when shooting JPEGs.
In terms of noise, the K-3 starts to show some signs of luminance noise in the shadow areas at around ISO 400, which shouldn’t be of any concern. At ISO 800, slight magenta/green colour noise can just be seen, although this is kept under control and it doesn’t actually get any worse until ISO 12,800 is reached. At the two sensitivities above this, slight banding is also visible in shadow areas.
Overall, sticking to the ISO 100-800 sensitivity range and shooting raw files produces highly detailed images with very little noise, particularly if images are well exposed. At the lowest sensitivities, the K-3 produces some of the most detailed images we have seen from a DSLR.
These images show 72ppi (100% on a computer screen) sections of images of a resolution chart, captured using the Sigma 105mm f/2.8 macro lens set to f/8 . We show the section of the resolution chart where the camera starts to fail to reproduce the lines separately. The higher the number visible in these images, the better the camera’s detail resolution is at the specified sensitivity setting.
Pentax K-3 review – White balance and colour
Image: Once again, the colours produced by the K-3’s sensor are excellent. This image was taken using the vibrant setting, which is perfect for rich autumn colours
As well as the usual range of different white balance settings, the K-3 has a couple of interesting options tucked away in the custom menu. The first of these we have seen on other cameras: a choice of whether to keep tungsten light or produce a completely neutral tone when using the AWB lighting setting. The other option is one that allows each of the default white balance settings to work with a range of colour temperatures, rather than a single setting. For example, rather than have a single value for a tungsten setting, say 2,900K, the camera can work with a range of 2,700K-3,100K, which will allow for more precise correction. Obviously, the same principle will work for the daylight setting, which is most useful as the colour of daylight can change throughout the day.
Like the Pentax K-50 (which I tested in AP 24 August), the colours produced by the K-3 are great. There is a good selection of presets, with the black & white setting with red filter effect applied being a particular favourite. For those who like to experiment with colour settings, there is also a cross-process option, which can produce a variety of different effects. However, aside from the standard natural, portrait, landscape and vibrant settings, it is the bleach bypass filter effect that I enjoyed using the most.
When sticking to the standard settings, I found that the colours produced by the K-3 looked very natural. Greens in particular look excellent, making the K-3 great for landscape photographers.
Image: This unedited JPEG image shows why landscape photographers will appreciate the way the K-3 renders green colours
Pentax K-3 review – Viewfinder, LCD, live view and video
Looking through the viewfinder is a real pleasure. It offers a 100% field of view and is as bright and as clear as I have tested on any APS-C-format DSLR. Manual focusing is possible, with a focus indicator on the viewfinder LCD panel reassuringly indicating when the camera also feels that the focus point (the last to be used) is in focus.
The 3.2in, 1.037-million-dot screen has no air between the LCD panel and the protective glass, so reflections are reduced and contrast increased. The result is that the screen is fine to use in all but the very brightest conditions. However, with a viewfinder and a top LCD panel, you don’t need to use the rear screen too much except for reviewing images and occasionally changing settings. Live view is available and the dual-axis image-level indicators and live histogram will no doubt prove useful for landscape photographers. For those working on very exact images, there is also the option to slightly adjust the image composition by shifting the sensor slightly. This can be a real benefit for those shooting still life or macro images when working on a tripod, because without a micro-adjustment plate it can be difficult to make tiny, precise corrections.
The K-3’s specification is also good for video enthusiasts, with it being able to capture full HD, 1920×1080-pixel video at a rate of 24fps, 25fps or 30fps. An external microphone socket, as well as a headphone socket for audio monitoring, is also available.
Pentax K-3 review – The competition
The Pentax K-3 will no doubt find itself pitched against the Nikon D7100, which also features a 23.35-million-pixel APS-C sensor. However, you would expect the K-3’s anti-aliasing filter to produce slightly more detailed images. The K-3 also has excellent weatherproofing and a magnesium-alloy body, compared to the polycarbonate body of the D7100. The new Nikon D5300 is aimed at the less-advanced photographer, but it does feature the 23.35-million-pixel sensor without the AA filter.
Further competition comes from the Canon EOS 70D. Its resolution is lower at 20.2 million pixels, although it does have fast phase-detection AF in live view. Those concerned about weatherproofing should also look at the 16.2-million-pixel, micro four thirds Olympus OM-D E-M5.
Pentax K-3 review – Our verdict
Based on image quality alone, the Pentax K-3 is one of the best enthusiast DSLRs we have tested. Images are full of detail and there are more than enough colour settings to satisfy most photographers. The metering is a little on the dark side, although this does have the benefit of preserving highlights, and the AF could be faster. However, the camera handles well, once you have set it up according to how you wish to use it, and the weather-sealed body means you needn’t fear the British winter weather. It is a little heavy though, particularly in a world where we are getting used to small and light compact system cameras.
Once again, Pentax has come up with a camera that photographers should really enjoy using. It is a pleasant experience, and there is something about the K-3 that feels more tactile than many other cameras.
Enthusiasts looking to break away from Nikon or Canon could do far worse than the K-3, although expect to have to put in a little more legwork to get the results you want.
Pentax K-3 – Key features
Mode dial lock
The mode dial can be locked in place to prevent it moving, or it can be left unlocked to allow quick adjustment.
Dual SD card slots
Under the panel at the side of the camera is a pair of SD card slots. This means that a Flucard, for Wi-Fi connectivity, can sit alongside a standard SD card for image storage.
Sturdy rubber doors protect the sockets on the side of the camera from water and dust ingress.
The K-3 has a 3.2in, 1.037-million-dot screen that is also sealed to allow its use in the rain.
AF point selection
This button allows the AF point to be switched by using the directional controls.
Pentax K-3 at a glance:
- 23.35-million-pixel, Sony-made CMOS sensor
- 27-point AF (25 cross-type points)
- Fully weather-sealed, magnesium-alloy body
- Compatible with SD cards, Flucards and Eye-Fi cards
- ISO 100-51,200
- Price £1,099.99 body only
Pentax K-3 – Introduction
Despite Pentax releasing a number of excellent DSLR cameras over the past few years, there has often been little variation or any real standout features that would warrant existing Pentax users upgrading to the latest DSLR. The exception to this is the K-5 IIS, which has an increased resolution due to the decision to remove the anti-aliasing filter in front of the camera’s 16.3-million-pixel sensor.
The new Pentax K-3 is very different. Significantly, the camera uses a Sony 23.35-million-pixel CMOS sensor, which is presumably the same sensor as that used in a number of other popular cameras, including the Sony NEX-7 and Alpha 77. The 23.35-million-pixel resolution is a big increase from the last four Pentax DSLRs – the K-5, K-30, K-5 II and K-5 IIS – which are all 16-million-pixel models.
Like the K-5 IIS, Pentax has opted not to have an anti-aliasing filter in front of the sensor in the K-3, which means it should have greater resolving power than we might expect from a 23.35-million-pixel sensor. For some users moiré patterning may be a concern, but Pentax has developed an ingenious anti-aliasing effect that utilises the on-sensor image stabilisation. When activated, the sensor moves during the exposure by just enough to blur the image by a pixel or two, which Pentax claims produces the same effect as an anti-aliasing filter.
For the Pentax DSLR user, the increased resolution alone is probably enough to warrant an upgrade, but the K-3 has so much more to it than an improved sensor.
Pentax K-3 – Key features
I look forward to testing the full capabilities of the K-3’s 23.35-million-pixel sensor, particularly how much detail it can resolve and whether the anti-aliasing sensor’s shift feature works in real-world tests. With a maximum sensitivity of ISO 51,200, 14-bit raw capture and a very impressive 8.5fps shooting rate, enthusiast photographers are well catered for.
Thanks to the K-3’s built-in sensor-based image stabilisation, all lenses used on the K-3 are stabilised, regardless of whether they are brand new or a 30-year-old manual-focus K-mount lens. The AF system is another new feature. The system now has 27 AF points, 25 of which are cross-type. The centre points are sensitive down to f/2.8, which allows for better focusing speed and accuracy in low light with f/2.8 lenses. Although the number of AF points may pale a little in comparison to the 51-point system that Nikon has employed in its cameras for a number of years, 27 points should be more than enough for most photographers.
Pentax K-3 – Build quality
One of the things we like about Pentax DSLRs is their rugged nature. The K-3 is no exception, as it has a fully weather-sealed magnesium-alloy body. More importantly, the range of Pentax WR (weather-resistant) lenses is growing, and the K-3 can be bought with a variety of weather-sealed lenses, including the standard 18-55mm f/3.5-5.6 WR kit lens. A weather-sealed battery grip and two weather-sealed flashguns are also available.
Also making the Pentax K-3 attractive to demanding photographers is the durability of the shutter, which has been tested up to 200,000 actuations. This will be particularly appealing to those photographers keen to take advantage of the K-3’s ability to create time-lapse videos at a 4K resolution – and just in time for the new 4K high-definition televisions that have arrived in shops recently.
In the hand, the K-3 feels tough and strong. It has a reassuring weight to it, without being overly large and heavy. All the buttons are in logical places, and the camera should feel familiar to most DSLR photographers, not just Pentax users.
Like other recent Pentax DSLR cameras, the K-3 has a 100% optical viewfinder and an equally impressive screen. The 3.2in, 1.037-million-dot screen is gapless, meaning there is no air gap between the LCD panel and the protective glass. The result is a screen that has reduced reflection, and one that is bright, with rich colours and a good range of contrast. It looked stunning in the pre-production sample of the camera that we saw.
Pentax K-3 – Data and connectivity
The Pentax K-3 has dual SD card slots for storing images and to enable Pentax Flucards to be used. These SD-compatible cards essentially give the Pentax K-3 Wi-Fi connectivity. Unlike Eye-Fi cards, which only offer image transfer to a smart device, Flucards allow for full control of the camera’s exposure settings and focusing, as well as a mirrored live view display from a smartphone or tablet. The final specification of what will be compatible with the Flucards has yet to be finalised, although Android and iOS should both be supported. The images we saw of a device operating the K-3 also showed a web-browser window, suggesting that remote control via a web-based interface may be possible, although this will most likely be via an ad-hoc connection rather than being able to control the camera from anywhere in the world via a computer.
The K-3 is also compatible with standard Eye-Fi cards for those who just want to copy images via Wi-Fi. Getting images off the camera in a more conventional manner is made faster with the addition of a USB port on the side.
Pentax K-3 – First impressions
Pentax now has a full line-up of DSLR cameras, from the K-50 and K-500, to the K-5 II and K-5 II S, with the new K-3 increasing its range. Yet what is different is that the K-3 offers a real alternative, not only in terms of resolution but also in its feature set, which wouldn’t look out of place on a professional DSLR camera.
If the resolution and image quality match what we have seen from other cameras containing the Sony sensor, the K-3 could be a real prospect for Pentax. It could help rebuild its DSLR brand, and provide a real alternative to rival Canon and Nikon. The K-3 seems to be a camera that will allow Pentax to compete with them on the same level. I’m really looking forward to testing this camera in the next couple of months.
The Pentax K-3 will be available in November, priced £1,099.99 body only.