Pentax K-r at a glance:
- 12.4-million-pixel stabilised CMOS sensor
- Prime II image engine processor
- Pentax K mount
- SAFOX IX 11-point AF system
- 3in, 921,000-dot LCD
- 16-segment TTL metering
- 720p HD video capture
- Street price around £510 with 18-55mm lens
Pentax K-r review – Introduction
Pentax had quite a prolific 2010, bolstering its DSLR range with three new cameras at a time when most manufacturers struggled to update more than two models apiece in their ranges. The new K-5 and K-r have doubled Pentax’s existing DSLR range, while the 645D created a new medium-format DSLR category to cater for the high-end or professional photographer.
This expansion has been a welcome sign for Pentax users as it has reinforced the company’s commitment to the DSLR market and gives users confidence in the future of the brand. It also makes the Pentax K-mount system more appealing to new users, as there is now a wide range of models for them to choose from and upgrade to.
The Pentax K-r sits as a mid-level model in the range, above the entry-level K-x but below the K-7 and flagship K-5. It has a compact body, much like the K-x, and yet it offers a more advanced feature set so it stands apart. With a street price of around £510, the Pentax K-r is competing with many competitors’ entry-level offerings, and this could be its strength.
It brings some strong features from higher in the range, such as the SAFOX IX 11-point autofocus system and a large, high-resolution LCD monitor, as well as an innovative new battery compartment that can house either a dedicated rechargeable unit or four standard AA batteries with an adapter.
It also offers the second highest ISO sensitivity in the Pentax range, with a maximum expanded ISO equivalent of 25,600. This all sounds encouraging, although the Pentax K-r does retain the same 12.4-million-pixel sensor and 16-segment metering of the earlier K-x, which is likely to show as a significant weakness against the competition.
The sensor in the K-r is a high-sensitivity CMOS unit with an effective 12.4-million-pixel resolution. It is APS-C-sized with a crop factor of 1.5x on the field of view. This gives an output of 4288×2428 pixels at full resolution in JPEG and raw file formats. At a standard 300ppi size, this equates roughly to an 8x14in print without interpolation.
JPEG files can also be output in 10MP, 6MP and 2MP sizes and with three levels of compression. Raw files remain at full resolution, but can be saved as either a native PEF file or the generic Adobe DNG file type. Video can be captured in 720p HD (1080×720 pixels) in AVI motion JPEG format, with mono sound. The lens mount is a Pentax KAF2 bayonet fitting compatible with KAF3, KAF2, KAF and KA lenses.
The Prime II (Pentax Real Image Engine) processor is the same as that featured across the whole Pentax DSLR range, including the medium-format model. With the K-r this allows a standard ISO range of 200-12,800, expandable to ISO 100-25,600.
The full range can also be selected automatically by the camera and be limited at the top end by any amount, down to ISO 200.
As with previous Pentax DSLRs, the sensor is on a moving bracket to allow for sensor-shift shake reduction when using any Pentax lens to an equivalent of up to 4 stops. This also provides dust removal by shaking the sensor on start-up. Additionally, an SP (Super Protection) coating repels dust and a dust alert function detects particles on the sensor.
The 16-segment TTL metering is coupled with lens and AF information, and although this seems a little basic it is the same system used in the flagship K-5 model, rather than the 77-segment metering of the K-7. This also offers centreweighted and spot-metering options and exposure compensation in 1/2 or 1/3 intervals to ±3EV. Exposure bracketing is available for three frames, also to a maximum of ±3EV.
Autofocusing benefits from Pentax’s latest SAFOX IX AF system, which uses the same 11 points as the SAFOX VIII but boasts quicker and more accurate focusing, and now illuminates the active focus point. The contrast-detection AF has also been improved and now features an automatic zoom to the selected focus area when the shutter is half-pressed to check that focus has been achieved. There’s a choice of single, continuous and auto settings for the focusing as well as manual, and an AF illuminator lamp for low-light shooting.
Exposure modes include the standard array of creative settings, with program, aperture and shutter priority, and full manual. There is also Pentax’s ‘Sv’ (sensitivity value) mode for ISO priority, and green auto picture mode.
These are accompanied by six scene modes and a further 11 via a sub-menu. The K-r also has a range of features and effects that can be added to the image before and after taking the shot. The colour modes give nine colour variations, ranging from black & white to reversal film, for a slide film effect. There are cross-processing settings that can be preset or set to random, and HDR capture options when shooting in JPEG. The digital filters can be applied pre- or post-capture, although pre-capture is available for JPEG only and has fewer options.
Post-capture, there are options to resize, crop and convert files from raw to JPEG. There’s even the option to retrieve the raw information of the last image shot in JPEG and resave as a raw file. The K-r’s IrSimple infrared transmission also means you can share images between two cameras, and even play image-based games with another K-r user.
The built-in flash offers a guide number of 12m @ ISO 100 and provides a range of slow sync and redeye reduction options. It also has the ability to fire external flash devices (AF540FGZ or AF360FGZ) through wireless connectivity. In addition to the self-timer and remote firing functionality, the K-r also features an interval timer that can be set to fire up to 999 shots over periods ranging from one second to 24 hours apart. The camera uses SD card storage and is compatible with SDHC high-capacity cards, although not the newer SDXC cards as yet. In burst mode, the K-r can shoot continuously at up to six frames per second. Using an 8GB SanDisk Extreme III SDHC memory card, write times are around 1/2sec for a JPEG, 1sec for a raw file and just under 2secs for raw+JPEG. When shooting continuously at 6fps, the camera shot either ten raw+JPEG, 13 raw or 35 JPEG files before slowing down.
Dual Battery choice
Perhaps the most interesting feature of the K-r is its ability to take both a dedicated Li-Ion rechargeable battery and standard AA-type batteries.
This is relatively common in additional battery grips, and although we’ve seen AA batteries in a DSLR before, this is the first time there has been the choice of dedicated Li-Ion or AA in the body. The thought process is simple: if your rechargeable battery runs out unexpectedly or you can’t charge your battery for a long time, you can easily buy some new AA batteries – or keep some in your bag – and carry on shooting.
The one downside to this setup is that to use AA batteries the camera needs a special holder that must be bought separately for an additional £30, which seems a little miserly for such a useful addition to the camera.
Also, as a separate holder is required, it must be carried separately to the camera, ready for use. It seems a shame that the battery holder couldn’t have been designed to hold the AA batteries without a holder, although there obviously needs to be space to fit the square Li-Ion battery.
Interestingly, the included rechargeable battery is expected to give less than half the number of shots that a set of AA batteries would: roughly 470 per charge as opposed to 1,000 with AA units. Perhaps the answer is for a more unusually shaped rechargeable unit to fit the AA space, like those on professional DSLRs. That said, if buying the K-r, it is definitely worth adding the battery holder to your shopping basket.
Build and Handling
The K-r is not much bigger than the K-x and looks almost identical. It is lightweight and compact, making it ideal for the entry-level market – regardless of the fact that it is not the lowest in Pentax’s range. Despite its small frame, it has a sizeable grip that is deeper and longer than most at this price point, and it means that I can (just about) keep all four fingers around it.
The body feels like a polycarbonate construction and isn’t weather-sealed so is suited more for the fair-weather shooter. It does feel solid, though, and the only rattle comes from the sensor motors, which really shake the camera when set for dust reduction on start-up.
Having the stabilisation in the body means that lenses can remain small, and even the pancake models can be stabilised. The only downside is that the image in the viewfinder is not stabilised, making composing trickier with longer lenses.
The layout of the K-r is functional, with buttons and dials kept to a minimum to appeal to the non-technical user. This, on the whole, is not an issue: by using the info button the display on the rear screen allows you access to the majority of functions, while the rest are accessed via the main menu or the four directional buttons.
The problem is that these directional buttons also double as the AF selection when in manual point selection. To switch between these two functions requires you to hold down the central OK button, which is far from obvious and a little fiddly. The shooting mode dial is also quite light, which makes it easy to knock and change mode, which it often did when placing the camera in a coat pocket.
The rear LCD hosts a graphical display of shooting information, which is clear and functional, if perhaps not overly stylish.
The main menu takes the same approach, with items divided into four main sections and scrolled across in subsections. This again is functional rather than sleek, but functions that have a quick access button – such as white balance and ISO – have been left off the main menu, when it might have been handy to have both options available. Without an eye sensor above the screen the display remains on until the shutter is half-pressed or turned off, which you may need to do when working in dark conditions.
White balance and Colour
Image: Colours are bright and zingy from the K-r while remaining natural in their appearance
For white balance the K-r offers ten presets, including four types of fluorescent light plus Pentax’s unique CTE setting to enhance dominant colours in the scene, which is ideal for the likes of sunsets. All the presets can be fine-tuned on a blue/amber, magenta/green scale, although there is no white balance bracketing.
Auto and manual settings are also included, which take a reading when the shutter is pressed. In auto white balance, there is the option in the custom menu to leave tungsten light with a natural warm glow or to neutralise it altogether, depending on your preference.
Overall, the auto setting performs very well, although I found low-light scenes look overly warm at times with the default subtle correction, while indoors it gives a more natural-looking effect than the strong setting, which results in images closer to the tungsten setting.
Images from the K-r don’t suffer from over-brightening or unreal levels of contrast. Both JPEG and raw files are natural and well coloured without appearing muted or lacklustre.
I have always found that Pentax DSLRs give pleasant colours and the K-r is no exception. If you’re looking for more extreme effects, however, there is a collection of options available, ranging from the colour settings to effects such as monochrome, vibrant and reversal film, through to cross-processing and digital filters for more extreme effects.
Image: Although this image was taken in near darkness using a tripod and low ISO, the results are crisp and clean
The 16-segment metering system is certainly no slacker, as we have seen in both the K-5 and 645D models, and in general conditions it gives a nice even midtone.
Given a wider range of exposures, the multi-segment metering tends to favour the highlights and can often underexpose a scene to avoid losing any bright detail. For those shooting in raw mode this is ideal, as you are easily able to pull more detail out of the shadows in processing.
When shooting in JPEG, however, I sometimes needed to adjust the exposure compensation by up to 2 stops to produce my required exposure. The information on the image review screen offers a choice of either singular or multiple histograms for RGB values, allowing you to check your tone range instantly.
There are also options for both highlight and shadow correction, to boost the camera’s range. There is even an in-camera HDR function that takes three images in quick succession and combines them for a wider dynamic range.
Image: Skin tones remain natural, even when using fill-in flash to add catchlights
The SAFOX IX autofocus system is a definite improvement on previous Pentax AF systems like the SAFOX VIII, and focusing is reliably faster.
The company’s other new DSLRs – the K-5 and the 645D – feature the ‘plus’ version of the SAFOX IX system, whereas the K-r has the standard version. The difference between the two is subtle: both feature an 11-point selection, with nine cross-type sensors in the centre area.
The SAFOX IX+ system does seem to have increased accuracy over the standard version, though, which is most noticeable in low-contrast scenes. The K-r’s AF is still very good, however, and competes admirably in its market.
For close subjects in low light, the K-r has an AF illuminator lamp to assist focusing. This is something increasingly being replaced by flash on many entry-level cameras, and its inclusion is a welcome sight.
The contrast-detection AF system, used when the camera is in Live View mode, has also had an overhaul for the K-r; the new algorithms have improved the speed of focusing, although it still struggles slightly in low light compared to the phase-detection system. The Live View focusing benefits from a fully flexible AF selection point, to all but the very edges of the frame.
The screen then zooms into the selected area while focusing to allow you to check that focus has been achieved. This is a really useful feature for Live View focusing and one that may well take off in future models. Manual focus can still be used in Live View and benefits from up to a 10x magnification that can be scrolled around to fine-tune the focusing for a specific area of the scene.
Noise, Resolution and Sensitivity
Image: While noise levels remain minimal at ISO 1600, the highest setting of 25,600 is best avoided for critical use
The 12.4-million-pixel sensor in the K-r is sparse in terms of pixel count when compared with much of its competition and will leave it at an immediate disadvantage on the shop floor against the 14 and 15-million-pixel models. That said, being less densely populated should allow the sensor to perform better in terms of noise, and the pixel count is more than adequate in terms of resolution for most potential users. On our resolution chart the K-r achieved an impressive 24 from the raw file and 20 from the JPEG.
By the top standard ISO of 12,800, both the raw file and the JPEG had slipped to just 18, and at the maximum ISO 25,600 the raw was still on 18, while the JPEG reached 16 due to the noise reduction. Images at up to ISO 6400 are free of any colour noise and feature only subtle artefacts. Even at ISO 12,800, images are very usable and can be well controlled with some post-processing. The maximum ISO of 25,600 does show heavy amounts of noise and is best avoided for critical work, but with a monotone conversion it can still produce a pleasant ‘grainy’ effect.
Resolution charts: These images show 72ppi (100% on a computer screen) sections of images of a resolution chart, captured using a Pentax 18-55mm f/3.5-5.6 AL lens. 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.
Image: Snow scene with +1.7EV
The K-r has been recorded as having a score of 12.5EV from DxO labs, which puts it ahead of much of its direct competition. This is in part thanks to the more sparsely populated sensor, and makes it a sensible choice for landscape fans.
Similar scores were achieved by the older K-x, which is to be expected as both cameras use an almost identical sensor. The dynamic range can be extended further using the highlight and shadow correction, or by employing the HDR function.