Pentax K-5 Review: Pentax shows with the K-5 its new DSLR “semi-professional” flagship

Pentax introduced the K-r, a new mid-range DSLR. Now, the upper-range DSLR K-5 will follow, which will complement the K-7 – making it Pentax’ new flagship model. It is based on the K-7, but offers a higher resolution sensor with 16.3 megapixels, which is no longer from Samsung. It is also possible to record FullHD videos. Pentax has also worked on many other details.

Brief assessment

Pros

• Very good ergonomics with many possibilities for customization
• Many clever details
• Very good image quality with even, unobtrusive image processing
• Solid, splash-proof housing

Cons

• Gaps in the lens program (e.g. fast (super) telezooms and telemacro)
• Knob for autofocus selection (multi, point selection and spot) too slow and small
• SD card somewhat difficult to remove for “gross motorists
• Slightly overloaded menus due to the high level of features and the possibility of customization

If the K-7 with outstanding processing and broad equipment extent was so far the DSLR top model of Pentax with outstanding processing and broad equipment extent however critical image quality, it is to be out-trumped now by the K-5. Pentax does not only want to improve the image quality, but has also incorporated numerous, partly hidden improvements in detail. Most importantly, the new 16-megapixel CMOS sensor is expected to exhibit significantly better noise performance at higher resolution, which also improves the dynamic range. We took a close look at the K-5 in the test to highlight the improvements in detail.

The CMOS sensor from Sony comes with A/D converters directly on the CMOS chip, i.e. an external converter with noise-sensitive signal lines as still used in the K-7 is not necessary. But the new sensor not only offers a higher resolution, but together with the powerful signal processor PRIME II also a high continuous shooting rate of 7 fps (the K-7 needed it “only” to 5.2). Thus the K-5 is also recommended for action photography. The storage formats used are JPEG (in four compression levels) or RAW, optionally as PEF or DNG. You can save to an SD or SDHC memory card. The autofocus is also said to have become more powerful, which underlines the camera’s suitability for action. The SAFOX IX+ module with 11 sensors, 9 of which are high-quality cross sensors that react to horizontal and vertical structures, comes from Pentax’s professional range – the 645D digital medium format camera. Although the new module is not more light sensitive, it should enable higher speed. A green auxiliary light beam is available in dark environments.

Just like the K-7, the K-5 has a LiveView function with contrast autofocus, face recognition, magnifying glass function, various types of fade-in grids, live histogram, etc. The oscillating mirror doesn’t have to fold down again before triggering, as with most other DSLRs. This not only enables quiet and quick release, but also reduces vibrations, especially during bracketing or continuous shooting. The live image is displayed on the rear 3″ (7.6 cm) screen with a resolution of 921,000 pixels, which has a wide viewing angle of 170° and whose display glass is anti-reflective and protected against scratches by a special AR coating. The SLR viewfinder is also a real joy to use: A high-quality pentaprism provides a bright image, the viewfinder matte plate is interchangeable and the field of view is 100%, i.e. it corresponds exactly to the subject detected by the sensor. The magnification is 0.92x, a dioptre correction is also built in. In addition, accessories can be connected, such as the 1.2x viewfinder magnifying glass from Pentax, which magnifies the viewfinder image even more, but reduces the suitability for spectacle wearers (reduced exit pupil).

Other areas benefit from the new image sensor, such as the video function: it achieves FullHD resolution with 1,920 x 1,080 pixels at 25 fps. The sound can be recorded in stereo quality via an external microphone. Of course, the aperture is manually adjustable to work with depth of field. A second benefit of the new sensor is the light sensitivity: it ranges from ISO 100 to 12,800, but can even be manually adjusted in the range of ISO 80 to 51,200 – more than any digital Pentax before. The noise reduction can be individually adjusted for each sensitivity range. The sensor position for lens adjustment is also adjustable. An electronic spirit level, on the other hand, shows in the viewfinder and on the screen how crooked or straight you are holding the camera. Due to the movable and even rotatable image sensor, an inclined horizon can be automatically adjusted within certain limits during image acquisition. Otherwise, the movably mounted and opto-magnetically displaceable sensor serves for image stabilization of up to 4 f-stops. It is antistatically coated to prevent dust adhesion and has an ultrasonic cleaning mode.

The camera housing is extremely robust, and is almost like the K-7’s body. The only changes were the slightly higher and more grippy program dial in the K-5 and the AF switch, which is now easier to operate with gloves. The camera body of the Pentax K-5 is made of a magnesium alloy and is protected against splash water and dust by 77 seals. Matching this, the battery handle with portrait format shutter release is also protected against environmental influences. In addition, Pentax specifies a temperature working range down to -10 °C – so the K-5 is a camera especially for outdoor enthusiasts. Especially the compactness of the case (131 x 97 x 73 mm) and the relatively low weight (750 g with battery and memory card but without lens) make the K-5 ideal for applications where luggage size and weight play a major role (such as trekking tours on foot or by bike). Pentax offers a wide range of splash-proof lenses to match. The DA* series of high quality lenses includes six models, the somewhat cheaper WR series already counts four models with the 18-135mm introduced today. This covers a focal length range of 16-300 mm at a light intensity of up to F1.4. Of course, all “normal” Pentax lenses (and compatible ones) fit the K-5 as well.

But the K-5 not only has a lot to offer in terms of hardware, but also in terms of software: Thus, the HDR function has been upgraded by not only superimposing and calculating the three differently exposed photos, but also aligning them before. Thus, unlike the K-7, this function can be used not only from the tripod but also from the hand. In addition, 16 digital filters provide various effects such as retro, miniature effect (as in telecom advertising), fish-eye etc. Exposure is controlled by the standard programs Program Auto, Shutter Priority, Aperture Priority and Manual Exposure, but the “innovative” programs Sv and TAv are also available. The former is a program automatic with ISO sensitivity set by a dial, while the latter has a fixed aperture and exposure time and controls the exposure only by the ISO automatic. This is useful, for example, in sports photography when the photographer wants to control the depth of field via the aperture and the motion blur and camera shake via the exposure time, but needs a variable exposure setting. Also available are a bulb exposure mode, the exposure time can then be extended to over 30 s, an X-sync mode, the exposure time is then fixed at the flash sync speed of 1/180 s (without flash, the K-5 exposes up to 1/8,000 s fast), a green single-auto, a video mode and a user memory.

With the K-5, Pentax has a total of four DSLR models on the market by 2011. The K-5 was launched on the market at the end of 2010, and its price was 1,460 EUR when it was launched, much more than ten years ago. As a set with the 18-55mm WR lens, the price rises to 1,550 EUR. A bundle with the 18-135mm WR lens introduced today is also planned, the price should then be just under 2,000 EUR – still about 250 EUR below the retail price.

Ergonomics and Workmanship

At first sight, the Pentax K-5 of the K-7 seems to resemble each other like an egg. But if you take a closer look, you can see few differences. The magnesium body is as solid as ever and protected against splash water, which by the way also applies to the standard 18-55mm WR zoom and all other Pentax lenses with DA* or WR in the name. The SD/SDHC card compartment and the battery compartment (D-LI90 for 740 shots according to CIPA) are also sealed. The metal tripod thread is in the optical axis and sufficiently far away from the battery compartment, and the likewise sealed portrait handle not only improves ergonomics but also doubles the battery life – it also allows the use of AA cells. For a flagship model, the K-5 is surprisingly compact, which is very comfortable for the luggage and the photo bag, only photographers with big paws might wish for a larger housing. With almost 750 g the K-5 is quite heavy and looks as solid as it is. Even the 3″ screen is protected against scratches by a coating.

Ergonomically, the case is extremely good despite its compactness. The handle is pronounced and there is a recess for the middle finger, the non-slip rubber applications do the rest. It is very practical with Pentax that one can operate the lens release with the ring finger of the grip hand, thus one does not have to grasp around and can remove the lens with the left side. One of the detail improvements compared to the K-7 is the switch from single to tracking and manual focus, which can now be operated better “blind”. The good ergonomics include the many operating elements on the housing, almost all of which can be operated without having to reach around, and to a large extent can even be freely assigned. For example, the front and rear control dials, the OK button, and the RAW button, with which you don’t necessarily have to switch between JPEG and RAW, but you can use them for other purposes.

The camera menus are on the one hand clearly structured and modern in design, but on the other hand the K-5 offers such a wide range of settings that you can lose track when looking for a specific function – a kind of favorites menu would certainly be helpful here. After all, if desired, the K-5 can jump to the last used menu item when the menu button is pressed again. The screen itself is a feast for the eyes, it has a very fine resolution of 921,000 pixels and is coated against reflections and scratches. When you activate the LiveView, you immediately notice the very quiet and well damped mirror beat, it can only be heard in quiet environments and remains pleasant there. To release the shutter, however, the mirror doesn’t have to fold down again, unlike other DSLRs. Thus, you only hear the short noise of the also very quiet shutter that we would wish for in a mirrorless system camera from Samsung, Panasonic, Olympus or Sony, which all release louder than the Pentax K-5. By the way, Pentax has also improved the contrast autofocus. Not only is it significantly faster than the K-7, but the focus field is automatically enlarged, giving you excellent visual focus control. After focusing, you can see the entire image section again.

But it’s not only the screen and LiveView that makes you go into raptures, the viewfinder is also extremely good. Like the LiveView function, it covers 100 % of the later image, magnifies 0.92 times and is pleasantly bright thanks to its high-quality prism construction. The lower viewfinder bar displays the necessary shooting information – just like the LC display on the back of the camera and, if desired, on the rear TFT screen. Aperture, exposure time, ISO and even the camera orientation (spirit level) are always in view. Thanks to the replaceable viewfinder matte screen, a grid is also available, for example, which is digitally displayed on the screen in LiveView.

Equipment

The function list of the K-5 is so long that it would probably be shorter to list what it cannot do. For example, all subject programs are missing, and the program selector, which has a useful lock button, is designed for more demanding users. Instead of subject programs, you can adjust the program curve in the menu, for example for fast shutter speeds, shallow depth of field or the optimum aperture for the lens. User memories allow individual shooting settings to be compiled, stored and recalled at lightning speed, allowing the photographer to adapt optimally to different shooting situations.

The sensitivity range goes from ISO 100 to 25,600, or even from ISO 80 to incredible ISO 51,200 after enabling it in the user menu – areas that were previously unthinkable, especially in that range. Not only can the user precisely control the sensitivity in 1/3 EV increments, but he can also adjust the ISO automatic to his needs by limiting the control range both upwards and downwards. In the TAv program, it is even possible to set aperture and exposure time and to let the camera control the exposure only via the sensitivity. For each sensitivity (or, in the case of a 1/3 step setting, for always three together), the photographer can determine how much noise reduction should apply. In addition to “Off”, there are three strength settings; so you can choose between low noise and rich detail at any sensitivity.

The flash folds out nicely high, but then makes a not quite so robust impression compared to the camera body. But it is sufficiently powerful and nothing is missing in the settings. External flashes can be controlled via the TTL system hot shoe, via sync cable or even via wireless TTL, leaving nothing to be desired. If you know the less reliable flash exposure from the *ist D or K10D, you will be thrilled with the K-5, it is much safer and more reliable, even the exposure without flash is flawless.

In addition, Pentax shows that there is more to white balance than five presets. There is a fixed default value for virtually every important lighting situation; in the case of incandescent lamp white balance, you can even set the automatic mode to be warmer or more neutral. Moreover, there is a fine correction on two axes as also the possibility to preset three different Kelvin values for the colour temperature, also for the manual measurements there are three memories, whereby one can also take any already taken photo as a reference. The change in white balance can be simulated directly on any image. However, the photographer has far-reaching influence not only on the white balance, but also on other areas of image processing such as sharpness, tone and color value curve or contrasts. There are numerous storage options for the settings. And if you’re still not satisfied with this, there are digital creative filters for black-and-white images in sepia or other colours, a cross-filter or even a toy effect.

The video function has drilled Pentax to the FullHD format (1,920 x 1,080 pixels). This is possible at 25 fps, with lower resolutions also optionally 30 fps. For playing with the depth of field, the aperture can be set manually, focus has to be set before taking the picture, because during this time the autofocus is deactivated. The sound is transferred to the memory card either via the built-in mono microphone or, better, via an externally connected stereo microphone. The mechanical image stabilizer can also be used in video, but it produces noise that is mainly picked up by the internal microphone. Apropos image stabilizer: It does not only stabilize each attached lens but can also be used for the sensor adjustment. Not only is a slight shift effect possible, but the camera can even align a tilted horizon automatically within limits if desired. Back to the video function: As contemporary as the resolution is, the Motion-JPEG video format is totally outdated. The video recording length is theoretically limited to 25 minutes anyway, but the maximum file size of 4 GBytes is reached at high resolution long before that. With MP4, twice as long video recordings would be possible compared to Motion-JPEG.

Image quality

Whether Pentax has made the expected progress in image quality by switching to the Sony sensor in the K-5, which also resolves 16 instead of 14 megapixels, the software test should show.

Especially the noise is smoothed out excellently, up to ISO 3,200 the camera can be used without restrictions. Also ISO 6.400 and 12.800 are still acceptable, even with the noise at ISO 25.600 you can still live with it, only ISO 51.200 should be used only in emergencies. Up to ISO 12.800, the noise has a quite natural character, even fine image details are not affected too much by the noise reduction. This impression is underlined by the good input dynamics, which oscillate around 8.5 f-stops up to and including ISO 800. The best value is achieved at ISO 100 with 8.6 f-stops, i.e. at ISO 80 the sensor is slightly oversaturated, which costs some dynamic range. At ISO 1,600 and 3,200, a good 8 aperture stops are still achieved. Even beyond this, the dynamic range decreases only slowly and is remarkable in view of the high sensitivity; even at ISO 25,600 the K-5 can cope with over 7 aperture stops. This means that Pentax is getting top marks here. The tone curve is very neutral, only the shadows are a little softer. The black level is slightly increased, i.e. the output dynamic range is not used to 100%, but does not necessarily need to be corrected.

A more differentiated picture emerges with the resolution measurement. The absolute resolution is at a relatively low level, but very uniform. Whether you use fade-in or fade-out, wide angle or telephoto, even with the 18-55mm standard zoom, it only plays a minor role. But this is due to the very defensive detail processing of the K-5, i.e. even in JPEG there is still a great potential for image post-processing. Artefacts on fine structures are practically impossible to detect; in this respect, the competition always scores bad marks. Also the sharpening is so restrained that no negative effects are visible. In practice, however, the potential of the image details shows where the respective lenses have their weaknesses.

The 18-55mm shows very typical standard zoom values for both distortion and vignetting, i.e. more edge darkening at open aperture and stronger at wide angle (with a maximum of 1.5 f-stops, which is in the green range) than at telephoto. However, the course is gentle enough not to attract negative attention. In addition, a visible barrel distortion is visible at wide angle, and a slightly cushion-shaped distortion at telephoto. But also here the K-5 offers an optional correction in the menus, it is only disabled by default, as the complex calculations make the camera slower when saving. Pentax underlines the good post-processing potential with a restrained JPEG compression. There are four levels to choose from, with the best quality compressed less than 1:5. This means larger images, but less compression loss. With 1:6 and 1:12, however, the next steps are still within the usable range; other cameras only start at 1:12 as the best quality.

Conclusion

Pentax brings limited Silver Edition of the K-5

Pentax launches the K-5 Silver Edition, a strictly limited, silver version of the K-5 DSLR. Although 1,500 sets are to be sold worldwide, it might be hard to get hold of one of them. The silver K-5 comes in a set with a silver 40mm-XS lens, the world’s thinnest pancake, which was recently introduced together with the mirrorless system camera K-01. The lens is hardly more bulky than a plastic bayonet cap, yet at F2.8 it is still quite fast with a normal focal length of 60 millimeters, corresponding to a 35 mm image. The K-5 Silver Edition is said to cost 1,500 EUR.

Pentax K-5 [Photo: Pentax]

Firmware update 1.12 for the Pentax K-5 

Pentax provides a new firmware version 1.12 for the K-5. The update only affects users of the GPS attachment O-GPS1. In connection with this accessory, starry sky recordings were subject to unwanted green noise, which is now to be reduced with the firmware update. The special feature of the O-GPS1 is the possibility to use the image stabilisation of the camera for image tracking when shooting star images from a tripod. This compensates for the rotation of the earth during longer exposure times. The update can be downloaded and installed by the user, Pentax provides an update manual in English language as PDF. If you still do not feel confident about the update, you should contact your dealer or the Pentax Service.

Pentax O-GPS1 [Photo: Pentax]

Pentax K-5 Datasheet