Product Review: Pentax K-5

February 3, 2011

By Dan Havlik

Pentax hasn't tinkered much with the body of the K-5 from the previous model—which is a good thing—but it has made some changes under the hood to help it capture better images in larger bursts.

If there’s been a true underdog’s story in the photo industry in the last few years, it belongs to Pentax. After the company survived a messy merger with the Hoya Corporation in the late 2000s during which it was rumored Pentax’s camera division would be sold off, Pentax Imaging kept chugging along, churning out digital SLRs that frequently received better reviews than its bigger money rivals.
Case in point is the 14.3-megapixel K-7, a camera we liked so much we named it Prosumer DSLR of the Year in 2009. Now, along with launching the medium-format, 40-megapixel Pentax 645D (which we hope to review soon), Pentax has released the 16.3-megapixel K-5, a follow-up to the K-7, which doesn’t look a lot different from its predecessor but has some significant changes under the hood.
For starters, Pentax has aimed to improve the K-5’s low-light shooting capabilities—a bugaboo with the K-7—by boosting the maximum expanded ISO to 51,200. The company says the new APS-C-sized, CMOS sensor in the camera features improved noise performance thanks to the ability to do A/D conversion right on the chip. Meanwhile, the revamped SAFOX IX + autofocus system (no, that’s still not a good name) features a dedicated light-sensing chip to zero in on subjects in dim conditions.
Shooting speed has been boosted to 7 frames per second—from just over 5 fps on the previous model-making this a seemingly very capable sports camera. The HD video functionality on the K-5 has been improved as well, with the camera able to capture 1080p HD at 25fps.

And this is, actually, just scraping the surface of what has been added to the K-5. There are tons of little tweaks here and there that advance the camera’s overall functionality. So if this is an improvement on the K-7 and is that camera’s successor, what’s with the step down in model name to K-5?
Leave it to the underdog Pentax to be just a little bit left of center. Let’s take a look at the company’s latest surprising DSLR.

Pentax came up with such a good design with the tough K-7—compared to its predecessor, the bigger and bulkier K20D—it decided to stick with it for the K-5. The only small change I noticed is a good one: the mode dial sits higher on the K-5’s left (facing) shoulder, making it easier to turn without getting hung up with the locking system. (I mildly complained about the tight locking mode dial in my review of the K-7.)
Now the dial is easier to adjust while still protecting against accidental switches. (Incidentally, Canon has also adopted a locking mode dial system for some of its DSLRs and is now offering to retrofit older cameras with a locking dial—for a fee.)

Other than being slightly lighter, the K-5 looks and feels like its predecessor, which is a good thing. The camera has a rock solid, professional build and is weather resistant, dustproof, and coldproof (14º F, -10º C). The 26.1-ounce body (when loaded with the rechargeable lithium-ion battery) wraps a shell of magnesium alloy around a stainless steel chassis. In a word, the K-5 is rugged.

The camera’s built-in dust reduction system uses supersonic vibration on the low pass filter to shake off specks. The K5 also has a Shake Reduction (SR) system built into its body, which works to stabilize any Pentax lens you put on it. Overall, I’ve found Pentax’s in-body system to be effective and reliable, though I prefer lens-based image stabilization because it allows you to see the anti-shake effect as you compose your shot. (That’s a minor quibble.)

The K-5 retains the sweet 3-inch LCD with 921,000 dots of resolution from the previous camera and offers an external stereo mic jack and an HDMI port for transferring high def videos and images directly to an HDTV.

Speaking of video capture, the K-5 has the same awkward recording configuration as its predecessor, forcing you to turn the mode dial to the movie camera icon and then press the shutter to start shooting video. (Most HD-DSLRs use a single-button video record set-up.) If you’re in a rush to capture that perfect moment in HD, you may miss your shot.
One small but helpful change on the K-5 is converting the dedicated RAW button on the front left of the camera—which makes it easy to switch between RAW and JPEG image shooting on the fly—into a programmable RAW/Fx BUTTON, giving it a wider range of functionality.

The camera’s electronic level now adds a tilt angle reading along with side-to-side level indicators. You can only see the live tilt level using the display on back, not on the top LCD panel, which just shows side-to-side roll. A recent firmware update now allows the K-5 to use larger capacity SDXC cards in the camera.

Since the K-5 looks so much like the previous model I was pleasantly surprised to find some revved up changes under the hood. For one, the upgrade to the 7fps shooting speed is significant.

I used the K-5—which boasts a maximum 1/8000th second shutter speed— to shoot a basketball game and while it was no match for Canon’s flagship sports camera, the 1D Mark IV, it more than held its own and costs less than half what that model does. (The K-5 retails for $1,599, body only, vs. the 1D Mark IV, which lists for $4,999.)
Don’t get me wrong, if you’re looking for the serious professional sports camera, I’d stick to Canon’s 1D models or Nikon’s D3 series, because of the faster shooting bursts, quicker autofocus and more rugged bodies, but the K-5 is certainly no slouch. It’s own autofocus system—the 11-point SAFOX IX+ – is superb, especially for a camera in this price range.

In extreme low-light conditions while testing the camera’s new ISO 51,200 (yes, it’s noisy) setting, the dedicated AF assist lamp and light-sensing sensor helped me lock in on a subject and record the shot. (Most competing models in this price range would typically rack in and out while searching for a focus point in ultra-dim conditions.)
The one big knock against the K-5 when it came out late last year was its sludgy buffer when shooting RAW images. Prior to a recent firmware update, the camera could only capture a sequence of eight 14-bit RAW images before seizing up for a minute or so. That’s changed with the new firmware, allowing the camera to shoot 20 RAWs before clearing the buffer. (Incidentally, the K-5, like the K-7, lets you shoot your RAW images in either Pentax’s .PEF format or Adobe’s DNG, giving you great flexibility.)
In case Pentax is listening, I’d like to see the 22 JPEG buffer improved in future firmware updates as well.
It’s hard to say what’s given the K-5 its new burst speed since the camera uses the same image processor as the previous model. Whatever’s been added to the guts of this camera, it’s working overtime since the K-5 also adds the ability to record 14-bit RAW files, capture images up to ISO 51,200, and shoot full 1080p HD video.
While that kind of performance is all well and good, what about the image quality? Funny you should ask.

While I liked the K-7, I found it struggled at ISO 3200 and produced baseline JPEGs that were slightly oversaturated, particularly in the green channel. I was also disappointed that the camera peaked at 720p for recording HD.
Pentax has improved both of those areas with the K-5. The K-5’s new 16.3-megapixel CMOS sensor, while offering more resolution than the previous model, does a bang-up job of keeping noise levels low all the way to ISO 6400. An even a bigger surprise was that I got very usable images at 12,800—my plug-ins in Photoshop were able to easily remove the excess luminance noise—out of the K-5 though the crunchy 51,200 ISO setting is not recommended.
Like the Nikon D7000, which was our 2010 Camera of the Year, the K-5 has been able to reduce noise while increasing resolution on an APS-C sized chip. That’s no small feat and I’d like to know how they were able to do it without excessively softening the image via in-camera processing. Whether it’s from the A/D conversion happening right on the chip or some magic pixie dust Pentax has sprinkled inside the camera, it’s a welcome change.
HD video has also improved with the K-5. Along with capturing beautiful 1080P video at 25fps with the camera, some of that pixie dust must’ve been used to improve the rolling shutter “jell-o” effect I experienced while shooting video with the K-7. Rolling shutter distortions are common from any camera that uses a CMOS sensor to record video but Pentax and other HD-DSLR companies have done well to reduce the effect.
Like the K-7, the K-5 has no full manual control over movie recording but it does let you control aperture. Otherwise, it’s mostly on autopilot when shooting HD, giving you a lot less creative control when compared to some multi-tasking models in Canon’s lineup such as the 60D, which I reviewed last month.
You can, however, employ the K-5’s built-in software filters to HD video recording if you want to add Cross Processing, Toy Camera or other cute but canned looks to your footage, though in certain instances they effect the video frame rate. The K-5 also lets you do some basic in-camera movie editing if you don’t want to be bothered with working on your clips in Final Cut.


In addition to the many useful features carried over from the K-7— copyright image embedding, self-leveling sensor functionality, an excellent 77-segment metering system—the K-5 further improves the in-camera HDR function that debuted in the K-7. (To our knowledge, the K-7 was the first DSLR on the market to offer such a feature. Now several competing models have similar features.)
Where the HDR function in the K-7 was dodgy at best—you needed to use a tripod to get a decent effect since any shift in the camera would throw off the multi image capture—the revamped feature is more versatile. Now, thanks to better HDR blending modes with improved alignment, you can get a pretty decent multi-shot combination while handholding the K-5.
There are also now five HDR settings: Standard, Auto, and three levels of HDR strength. None of these are going to give you nearly the same effect as you’d get from running your shots through good HDR software on your computer but they work fine in a pinch.

Everyone’s favorite camera underdog, Pentax, is back with another winner: the K-5, an excellent if not earth-shattering follow-up to the K-7, which was our Prosumer DSLR of the Year in 2009. Cosmetically, the 16.3-megapixel K-5 is virtually identical to the K-7, but there are many significant changes internally in the new model that improve its top-line specs including faster burst speed; better noise control; higher ISO shooting; full HD 1080p capture, and a host of other revamped functions. If there’s any area where I’d knock this camera is that it’s not adventurous enough. From a pro photography perspective, I’d love to see Pentax take the advances it has made in the K-5 and K-7 and put them into an even more robust camera body with a full frame sensor. Now that would be something that might make Canon and Nikon quake in their boots.

Pentax K-5

Pros: Faster 7fps burst rate; full 1080p HD shooting; higher ISO shooting options, better noise control at high ISOs; improved in-camera HDR feature

Cons: Would love to see this model with a full-frame sensor; only 22 JPEG buffer at time of this review; slow configuration for switching into HD video shooting mode

Price: $1,599 (body only)