Pentax K-3 Review – Can the Pentax K-3 enthusiast DSLR offer some competition to Nikon and Canon? Find out in the full What Digital Camera Pentax K-3 review
Breaking from the 16.2 million-pixel sensor used in the last few Pentax DLSR cameras, the new Pentax K-3 has an impressive 23.35 million pixel APS-C sensor, manufactured by Sony. On paper at least, the K-3 looks like the DSLR that many Pentax users have been waiting to upgrade to.
Pentax K-3 Review – Features
As stated, the new Pentax K-3 uses a Sony 23.35-million-pixel APS-C size CMOS sensor. This presumably is the same Sony sensor that is used in the Sony NEX-7 and Alpha 77, except the lower resolution accounts for Pentax’s in-camera image stabilisation system. All K mount lenses are stabilised on the K-3, even older manual focus lenses. The stabilisation motors can also be used to move or rotate the sensor slightly when composing very precise images, such as close-up or macro shots.
The same principle is also used with the Pentax O-GPS1 unit, to work the AstroTracer feature. This feature shifts the sensor when taking long exposure astro photographs, to prevent star trails.
But back to the sensor itself, the previous the K-5, K-30, K-5 II and K-5 IIS Pentax DSLR cameras all using a 16 million pixel sensor, so new 23.35-million-pixel resolution is a significant increase. Even better is the fact that Pentax has no optical low pass, or anti-aliasing, filter in front of the sensor. This should allow the sensor to reach its full potential, unhindered by the slight blur the anti-aliasing filter creates.
Should you wish to reproduce the effect of an anti-aliasing filter, once again, the sensor shift motors are used. By shifting the sensor by distance of less than a pixel during the exposure enough blur is created to reduce any moire patterning. It’s a really clever feature that offers photographers the best of both worlds.
Combined with the K-3′s processing engine, the sensor can shoot with an equivalent sensitivity of ISO 100-51,200, with 14-bit raw capture and a very impressive 8.5fps-shooting rate. As standard for Pentax cameras, the K-3 can save raw files as either Pentax PEF or the universal Adobe DNG raw files, which is useful for those who don’t have the very latest raw editing software.
One new system installed in the K-3 is the AF system, which 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 a number of years, 27 points should be more than enough for most photographers.
With no built-in Wifi connectivity, the K-3 relies on the new Pentax Flucards, which enable the Pentax K-3 to have 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 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 3.0 port on the side.
Pentax K-3 Review – Design
The Pentax K-3 is built to a very high standard. The magnesium alloy body is fully weather sealed, and I didn’t once feel that the camera would be compromised by taking it out in the rain. Indeed, the K-3 showed no ill effects of shooting in wet conditions.
Pentax also has a growing range of Pentax WR (weather-resistant) lenses, which allow the K-3 to be used in all weather conditions. As a standard kit the Pentax 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.
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 video resolution.
All of the main shooting and exposure features have dedicated buttons on the rear of the camera, and the cameras LCD top plate means that the basic exposure settings are all clearly displayed. I found that I ended up switching the rear status screen off as I had all the information I needed on the top display, and it helped to save batter life a little.
As usual with Pentax there is an absolute wealth of custom options, 27 to be precise. These include 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 – Performance
Of the lenses I used during testing of the Pentax K-3, I found that the Pentax 40mm f/2.8 was the fastest to focus, whilst the kit lens performed as you would expect it to – it is quite slow, but I wouldn’t go quite as far as to say it is sluggish. Switching to the 60-250mm f/4 lens and the performance is again, steady without being snappy.
Photographing wildlife using continuous AF the K-3 was able to keep up with trotting deer, though there were a few shots where the focus was slightly off.
As usual with Pentax DSLR cameras the AF is quite noisy, which gives the impression that the AF is slower than it actually is. Perhaps the best summary of the AF system is that it isn’t sleek. Whilst 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, though it is possible to get shots in focus, don’t expect a high success rate.
Dynamic range performance
In our dynamic range test we found that the Pentax K-3 we found it to have a dynamic range of 11.97EV. Although the dynamic range may not be quite as good as some of the 16 million pixel sensors we have seen, including that used in the Pentax K-5 series, it is still very good. 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 of black, actually revealed a surprising amount of detail, though noise can be an issue if the brightness is increased too much.
Looking through the viewfinder of the Pentax K-3 is a real pleasure. It offers 100% field of view and is as bright and clear as that of any offer APS-C sensor DSLR I have tested.
The 3.2in, 1.037-million-dot screen has no air gap between the LCD panel and the protective glass, which means that reflections are reduced, and contrast increased. With a viewfinder and a simple monochrome top LCD, the K-3 can be comfortably used in bright sunlight.
For video enthusiasts the K-3 also has a good specification, with it being able to capture full 1920x1080p video at a rate of 24,25 or 30fps. A external microphone socket, as well as a headphone socket for audio monitoring is also available.
Pentax K-3 Review – Image Quality
White Balance and Colour
As well as AWB and various preset white balance settings, there is also the ability to work in a range, meaning that you can rely on the K-3 to get great results, even, for example, if the colour of the daylight varies over the course of a day. Overall the colours produced by the K-3 are great, and there are a good selection of image styles, including the excellent black and white mode and the interesting Bleach Bypass effect. Greens in particular look good, which should be good news for landscape photographers.
Despite having an impressive 86k pixel RGB metering sensor, I did find that the K-3 produces exposures that all tend to be slightly on the dark side. I found myself having to add around 1-1.3EV to many exposures, particularly in dull light, whilst in good light a +0.3-1EV adjustment was needed. However, this did mean that I had few issues with burnt out highlight details, and the metering is at least consistent, so you know how the camera will be behave and can quickly compensate accordingly.
With a 23.35 million-pixel sensor and no anti-aliasing filter the Pentax K-3 produces fantastically detailed images, and it doesn’t disappoint. The camera comes close to out resolving our lens chart, at a resolution of 38lp/pm, almost matching the Nikon D800/E , which did out-resolve our chart. There is some slight artefacting that looks like it has been the result of moiré patterning, that stops the K-3 producing a perfect result.
In real life situations, the K-3 can resolve all manner of fine details with great clarity, though to get the best from it you need good light and tripod to really push the cameras potential to its limits. Also you must be shooting raw files. The JPEG images don’t resolve as much detail, only reaching around 30 on our test chart, which is still a very impressive resolution.
With such a high resolution it was actually difficult to shoot a subject and see moire patterning. I would suggest that unless you are photographing very fine fabrics the anti-aliasing effect feature should be left switched off by default.
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, though 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.
Pentax K-3 Review – Verdict
The fantastic body and excellent image quality are the two main reasons to buy the Pentax K-3. It really is a great camera, though it does have its quirks.
The autofocusing isn’t as fast as its competitors from Canon and Nikon, and whilst it isn’t bad, wildlife and sports photographers will probably find it is too slow for there needs. Those more keen on landscape and travel photography have more to look forward to in the K-3.
The rugged body and it weather seals give you the confidence to take it anywhere, though it could weigh a little less, but the high resolution is certainly backed up with the great colours that the camera can produce.
You do have to spend some time with the camera learning how to get the best from the metering, but a simple +1EV exposure compensation adjustment is often the simplest way to get better results. I found that the K-3 is a real photographers camera. It is a tool and you have to learn how to use it, but once you have mastered it, it produces excellent images.
Sample Image Gallery
These are just a small selection of images captured with the Pentax K-3. For a wider range, including a full set of ISO test shots, head on over to the Pentax K-3 review sample image gallery.
The Pentax K-3, an interchangeable lens DSLR, is the new flagship model of the K-series, combining existing traits of the previous models in the series with a hefty number of new features.
Chief among the improvements is the new CMOS sensor, manufactured by Sony, which offers 24 effective megapixels of resolution.
One unique feature of the camera is its original new shake reduction (SR) mechanism, which uses an SR-dedicated servo controller to compensate for camera-shake when used in conjunction with any Pentax lens.
The SR unit also functions as the world’s first anti-aliasing simulator, designed to reduce moiré effect at the same level as an anti-aliasing filter. It works by applying microscopic (sub-pixel level) vibrations to the image sensor during exposure.
This means that, unlike an anti-aliasing filter, it can be switched on and off and its level can be altered, allowing the user to increase the intensity of the compensation when shooting a moiré-prone subject such as striped clothing.
The K-3 also sports a new Prime III imaging engine, a newly designed optical viewfinder with a near-100% field of view, and a new SAFOX 11 AF module.
The new SAFOX 11, the successor to the SAFOX X, expands its coverage by increasing the number of AF points to 27. The central sensors are designed to detect the light flux of an f/2.8 lens, which will streamline focusing when used with a wide-aperture lens.
Image: The Pentax K-3 top controls, including AF mode-select
The AF system also sports zone-focusing, whcih selects the best focal point within a nine-sensor zone, and a face detection system that is capable of identifying as many as 16 faces simultaneously.
The K-3 is fast too, capable of high-speed continuous shooting of 8.3 images-per-second. The startup time lag is approximately 0.3 seconds.
A new RGB light-metering sensor with approximately 86,000 dots allows for what Pentax is calling a ‘Real-Time Scene Analysis System’. This system uses data gathered by the light metering sensor to refine accuracy of auto-exposure and white balance. Pentax says this system will also be able to distinguish more accuartely between main subject and background and thus provide more accurate flash discharge.
The K-3 comes with a high-resolution 3.2-inch LCD monitor with approximately 1,030,000 dots of resolution. The LCD screen is non-articulated and is not touchscreen-enabled. Pentax says this was to keep both the bulk and cost of the camera down to manageable levels.
Image: The rear screen and controls of the K-3
Movie shooting has been upgraded for the K-3. The camera records MPEG-4 AVC/H.264 movies and 4k-resolution movie clips in Motion JPEG (format AVI). Exposure settings can be adjusted during movie recording, and AF can be altered mid-recording by simply tapping the AF button.
Pentax has also released some new accessories that are specifically compatible with the K-3: the exclusive D-BG5 battery grip featuring an extra set of buttons, the O-ST1401 camera strap and the O-FC1 Flu Card for Pentax 16GB.
The O-FC1 is a memory card to connect camera and smartphone. When placed in the second of the camera’s dual slots, the card’s wi-fi connectivity allows the user use a phone to see the live-view, control shutter release, adjust focus, set aperture and view captured images.
The camera retains the solid build of the K-5, with a lightweight
magnesium alloy and 92 sealing parts for weather and dust-proofing. Pentax says the camera will be able to operate in temperatures as low as -10ºC. A limited premium silver edition will also be released in addition to the standard black model.
Image: Just 2000 units of the silver edition are set to be produced and released. Its specs are the same as the black model
The K-3 is set for release in November, priced at £999.99 body-only, £1099.99 with a Pentax-DAL 18-55 f/3.5-5.6 WR lens and £1349.99 with a Pentax-DA 18-135mm f/3.5-5.6 WR lens. The OFC-1 card is coming soon, though a firm date is yet to be announced.
Auto; 9 presets
SD; SDHC; SDXC
+/- 5EV at 1/3 / 1/2 EV steps
Best; Better; Good
Optical pentaprism, 0.95x magnification
6016 x 4000
3.2in, 1,037k dot TFT LCD
1920 x 1080p, full HD
24MP APS-C CMOS sensor
Multi; Center-weighted; Spot
Auto (Green), P, A (Av), S (Tv), TAv, M, Bulb
Li-ion D-LI90 rechargable, approx 560 shots
USB 3; HDMI mini
Raw (PEF / DNG); JPEG;
30 – 1/8000 sec
Auto; Multi-area; Center; Selective single-point; Tracking; Face detect; Live view
131 x 100 x 77mm
Single; Continuous; Remote; Self-timer
sRGB; Adobe RGB