Pentax K-5 II Digital Camera Review

Introduction

The new camera can be read in two completely different ways, depending on your perspective. If you're not a fan of the K-5, or of the brand, you can read it cynically: Pentax has nothing new to bring to the table. If you're a K-5 devotee, you can read the K-5 II optimistically: Pentax is so confident in the K-5's staying power that they've re-released it, pausing only to fix its one glaring flaw.

Which perspective you adhere to probably says more about you than it does about the camera, and the truth is probably somewhere in between. The K-5 was undeniably at the top of its class in 2010 and 2011, in large part due to its remarkable Sony-sourced sensor, but its class is now two years old. Re-releasing essentially the same camera smacks of weakness, but on the other hand, where's the competition?

Until a month ago, there wasn't any, but Nikon's announcement of the 24-megapixel D7100 changes everything. Comparable in terms of specs, build quality, and weatherproofing, it also boasts the same filterless sensor design as the K-5 IIs but ups the resolution considerably. The D7100 also outclasses the K-5 II in terms of autofocus points and tracking capability, and does so for only $100 more.

With this in mind, can the K-5 II hang with the current generation of APS-C system cameras, or is it a camera out of time?

Design & Handling

The K-5 II upholds Pentax's tradition of phenomenal ergonomic design and rugged weatherproofing.

We were deeply enamored of the Pentax K-5’s design when we reviewed it a couple years back, and we feel precisely the same way about the K-5 II. The ergonomics are still spectacular, the amount of physical controls still admirable, and the weather-proofing still highly desirable. In particular, the combination of the camera's compact, dense magnesium alloy frame and its perfectly sculpted grip makes it feel like a finely crafted weapon in your hand. The Nikon D5200 and Canon Rebel T3 are in the same ballpark size-wise, but feel far less substantial thanks to their primarily plastic construction.

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Inside, you’ll find the same 16.1-megapixel Sony-sourced, APS-C sized CMOS sensor, paired with the same PRIME II processor. The only new internal component is the vastly improved SAFOX X autofocus module, which claims accurate focus down to -3 EV (roughly equivalent to moonlight). Also improved is the rear LCD. Though still 3 inches and 921,000 dots with an IPS panel, it’s now a gapless design that Pentax says creates a brighter, sharper image. We found that it provided slightly better viewability in bright light, as well as better off-angle viewing.

Like the older model, the K-5 II features a magnesium alloy body and full weather resistance, with 77 individual seals. It's rated to operate in temperatures as low as 14 degrees Fahrenheit (-10 Celsius) and as high as 104F (40C). We expect it can exceed both of those limits, though battery life and LCD performance may take a hit in extreme cold. Pentax's weather sealing is the real deal, as this internet-famous video of an American soldier burying his K-5 in Afghan sand and washing it off in the shower handily demonstrates.

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Performance

The K-5 II's 16-megapixel CMOS sensor is still one of the best on the market, and now has an optionally removable AA filter.

The K-5 II's sensor and processing pipeline are essentially unchanged from the K-5, but that's not as much of a handicap as it may seem. The K-5's sensor was a benchmark for its class of APS-C DSLRs, and it still produces great image quality today.

In our testing, sharpness was outstanding when paired with quality lenses, though our DA 18-55mm WR kit lens proved to be relatively soft. The kit lens also produced significant distortion and chromatic aberration, though these can be addressed with in-camera JPEG processing options and post-processing editing suites. We were less than impressed by the value proposition of the filter-free K-5 IIs, but if ultimate sharpness is your goal, it might be worth ponying up. For all the details, check out our head-to-head sharpness comparison.

Dynamic range performance was admirable, particularly when recovering shadows in RAW files. As with the K-5, noise levels are manageable all the way up to ISO 12800, and even shots at ISO 25600 and 51200 are usable with a little post-processing and resizing. Chroma (splotchy color) noise was virtually nonexistent, giving high-ISO shots a more natural, film-like grain.

As usual, video quality is a serious problem for Pentax. The options here are unchanged from the K-5, and so is the performance—the best you can do is 1080/25p (an odd framerate for a camera sold in NTSC-land), and the camera still uses the bloated, outdated Motion JPEG compression protocol. In our tests, sharpness was fine if not outstanding and motion was fluid, but there was obvious trailing due to the low max framerate. Artifacting was kept to a minimum in good light, but there was significant frequency interference in the form of rolling shutter and moire.

Features

Stills shooters will be more than satisfied, but videographers should give the K-5 II a pass.

Compared to similarly-priced DSLRs, the K-5 II is feature-rich—at least for stills shooters. A bevy of enthusiast-oriented shooting modes, including a couple unique to Pentax, make it easy for experienced users to jump in and get their hands dirty. Manual controls for all major settings further enhance the camera's photographer-friendly credentials.

The SAFOX X focusing system is a huge leap forward for Pentax, fixing long-standing problems with low-light focus accuracy and taking a big step ahead of much of the competition with -3 EV focusing capability. Subject tracking could still stand to be improved and we'd like to see more focusing points with a wider spread, but the new module is a great improvement overall. Continuous shooting speed is unchanged from the original K-5 at 7 fps, still very good for the class. That said, we'd still recommend other makes for sports shooters, mostly due to the tracking deficiencies.

As usual for a high-end Pentax DSLR, the K-5 II's ruggedness is beyond reproach. Its magnesium alloy build and 77 weather seals mean you can shoot in the rain, the snow, or even a sandstorm without worry. In-body image stabilization means every lens you mount on the camera enjoys up to four stops of shake reduction, even legacy manual focus glass.

Serious videographers will almost certainly want to take a miss on the K-5 II. While the camera feints at video-friendliness with its mic jack, it offers extremely limited video recording options and absolutely no audio control. Full-HD recording is limited to 1080/25p in the outmoded Motion JPEG compression format.

Conclusion

The K-5 II is the best DSLR Pentax has ever produced, but it may have trouble attracting the unconverted.

When it was announced at Photokina 2012, the K-5 II was an immediate disappointment for some die-hard Pentaxians, who had been primed by the photo rumor mill for a true follow-up to the K-5. They had hoped for a full-frame K-3, or at least a 24-megapixel APS-C body. What they got instead was a warmed-over K-5, with only a new LCD and improved autofocus.

Others, however, were quick to recognize the K-5 II as a smart tactical move. The K-5 had excellent staying power in an APS-C market starved of new high-end models, and the new camera addresses its predecessor's one notable failing: unreliable autofocus accuracy. The K-5 II attacks the focusing problem in style, too: The new SAFOX X AF module can find a focus lock in light as dim as -3EV, and in our experience it was extremely quick and accurate under all conditions.

While we can see the merits of both positions, we find ourselves firmly in the latter camp. Sure, we'd love a K-3, and we always love to see a smaller player beat the big two to the punch, but the K-5 II is a stellar APS-C DSLR regardless of the age of its design. Along with Sony's Alpha A77 SLT, the K-5 II is one of our favorite full-sized APS-C system cameras on the market today, and a particularly great option for street and landscape photographers. That said, it's bound to face some serious competition from Nikon's immensely impressive-on-paper D7100.

The D7100 is set to launch at $1,199.95, body only—just $100 more than the K-5 II and dead even with the K-5 IIs. Nikon's new top APS-C camera matches the IIs step for step in weatherproofing and low-pass filterectomy, but goes further with 51-point autofocus and a 24-megapixel sensor. Obviously, unaffiliated photographers buying their first top-tier DSLR will have a tough choice ahead, but Pentaxians are likely to stick with the home team. If you're looking to upgrade from a K-7, K20D, or K-x and don't require stellar autofocus performance in low light or with fast primes (brighter than f/2.8), the K-5 is a great choice and a real money-saver. But if you just love shallow depth of field and need the flexibility to shoot in the dark, the K-5 II is your answer.

Introduction

Inheriting as it does the bulk of the K-5's internals, we expected to get very similar lab testing results out of the K-5 II. For the most part, our expectations were borne out by the data. The K-5 II produces near-identical sharpness, dynamic range, and color results, though its JPEG noise reduction algorithm appears to have been tweaked to apply a more gradual curve across the range of ISO sensitivity settings.

Resolution

The sensor is capable of great sharpness, but our kit lens wasn't up to the task.

Your sensor is only half of the equation when it comes to sharpness—you need a sharp lens, too. Unfortunately, the kit lens our Pentax K-5 II was paired with wasn't a stellar performer. We've seen better results from Pentax 18-55s in the past, so we have to assume we just got a sub-optimal copy here. (In comparison, it seems our K-5 kit lens was a great sample.) As you'd expect, the sharpest results came at middle apertures, and the longest focal lengths were the softest.

We also tested the filterless K-5 IIs with the same lens and same focal lengths, and found it consistently produced sharper images. In our testing, the K-5 IIs was about 8% sharper (in terms of line widths per picture height at MTF50) than the K-5 II when using the same lens at the same focal length and aperture. This advantage held with three different lenses (the DA 18-55mm kit lens, the FA 77mm f/1.8 Limited, and the DA 35mm f/2.4). We didn't notice issues with moiré when testing the K-5 IIs for stills in the lab, but check out our head-to-head comparison for some real-world samples.

The K-5 II shows admirable restraint when it comes to sharpening its JPEGs, at least when you're shooting with the Natural color mode. Other color modes that use higher sharpness settings may display more haloing around high-contrast edges (typically this appears as a dark outline), but we didn't encounter any in our testing.

Noise Reduction

Pentax has tinkered with its noise reduction formula, but the results are still excellent.

Though the hardware is identical between the K-5 and the new K-5 II, our results show that Pentax has fiddled with its software noise reduction algorithm. Where the original didn't apply a ton of noise reduction at base ISO, but piled it on in force around ISO 3200, the follow-up uses a steadier NR curve.

With NR off (imagine "off" in air quotes, because it seems clear that noise reduction is still being applied at this setting), noise levels start at 0.63% at the base ISO 100 and don't break the 1% threshold until ISO 800. From there, noise climbs steadily to hit 2.32% at ISO 6400, 3.19% at ISO 25600, and 4.04% at the maximum extended sensitivity of ISO 51200. At ISO 6400 to 12800 there's a slight plateau, but otherwise the noise levels follow a steady, fairly predictable curve.

This result differs drastically from the behavior of the K-5, which started at 1% noise at ISO 100 and rose steadily to 2.99% at ISO 1600, then never got up to that level again, hovering between 2.6% and 2.9% all the way to ISO 25600.

The same curve applies when using the K-5 II's low, medium, and high NR levels. When set to NR Low, the K-5 II produces 0.52% noise at ISO 100 and hits 3.9% at ISO 51200. Medium produces a noise spectrum of 0.46% to 3.09%, while High returns values of 0.38% to 2.28%. As you can imagine, a lot of detail is lost when using the Medium and High NR settings. With NR Off or set to Low, the results are quite pleasing. Images have a film-like grain without visible chroma (splotchy color) noise, and plenty of detail is retained.

Dynamic Range

The K-5 II doesn't score as well as the K-5 in the lab, but real world results are identical.

Thanks to the Pentax K-5 II's revised noise reduction algorithm, its dynamic range score suffered slightly in our tests. At low ISO settings, where it produces less noise than its predecessor, the K-5 II actually outdoes the K-5, maxing out at 7.36 stops of high-quality dynamic range (meaning that it's measured with a signal-to-noise threshold of 10:1). At higher sensitivities, the less aggressive noise reduction leads to more noise and lower dynamic range. Where the original K-5 produced 3.7 stops of high-quality DR at ISO 12800, the K-5 II can only manage 2.4 stops.

But that's all in the lab. Out in the real world, we found the output to be indistinguishable. Just like the K-5, the K-5 II has incredible room for shadow recovery. Shadows can be boosted by a remarkable 4-5 stops in post-production (when shooting RAW) without too much damage to image quality. Highlights are a bit dicier; our advice is to avoid overexposure whenever possible, since you'll have a lot less headroom there.

Video Quality

The K-5 II's video mode is stuck in 2010, having learned nothing from the K-30 and K-01.

Like the K-5 before it, the K-5 II renders motion quite fluidly in its maximum resolution format of 1080/25p, though obviously not as smoothly as those that can record at 1080/30p or 1080/60p. There is remarkably little artifacting, but trailing can be an issue, primarily due to the low maximum framerate of only 25 frames per second. Still, this is only a problem in video stills; generally, the image looks quite beautiful in motion.

Frequency interference in the form of rolling shutter is a serious problem when panning left and right, as it has been for virtually all CMOS-based cameras. Recent models from other manufacturers have made some headway in dealing with this problem, but the K-5 II's 2010-era video implementation is predictably inept. Another byproduct of that aged video implementation is huge file sizes; the K-5 II uses the extremely inefficient Motion JPEG codec, which means a 3:50 video, for instance, will take up 2.26gb of memory card space.

Video sharpness is acceptable but not stellar. In bright light, we recorded horizontal sharpness of 625 lp/ph at MTF50, while vertical sharpness was a bit higher at 650 lp/ph at MTF50. However, moire was a serious problem even with this mediocre sharpness. Garish, colorful pattern interference could be seen all over our test chart, and while it wasn't as much of a problem in real-world shooting, the issue was still observable. Sharpness dipped slightly in our 60 lux low-light test, to 600 lp/ph horizontal and 625 lp/ph vertical. The sharpness loss was mostly down to increased artifacting. Moire was still an issue, as well.

In our low-light video sensitivity test, we try to find the minimum ambient lux level at which each camera can produce an image that hits 50 IRE (a broadcast standard for acceptable image brightness). The K-5 II managed this feat at 11 lux. That's a pretty good achievement, and it's worth bearing in mind that the camera was probably limited in part by the kit lens, which has a relatively narrow maximum aperture. Still, we've seen some cameras pull it off with less than 1 lux of illumination, so if low-light video shooting is your favorite hobby, you can probably cross the K-5 II off the list.

Meet the tester

Ben Keough

Contributor

@ben_keough

Ben is an experienced industry journalist who formerly served as Senior Editor of News and Features at Reviewed. He now contributes as a freelance writer and editor. Most recently hailing from the vast wilds of the American southwest, he is an avid photographer who is deeply disturbed by the lack of wide open landscapes in Boston.

See all of Ben Keough's reviews