Pentax K3 Field Test Part I

Initial thoughts

Posted: 12/26/2013

I shot the Pentax K-3 alongside my own K-5, to get a feel for how image quality and handling is changed. Click the image above for the high-res shot from the K-3, and click here to see the result from the K-5.

Before I get down to my thoughts on the Pentax K-3, a little background would probably be appropriate. When I'm reviewing cameras, I'm pretty brand-agnostic: What the camera can do for me is far more important than the badge on the front. I can't afford to own everything I get to review, though, or to keep changing allegiance to a new lens mount. For the last few years, I've used Pentax's flagship DSLRs as my daily shooters, after the original Pentax K-7 brought me into the fold back in 2009. A couple of years later, I upgraded to the K-5, but I skipped the subsequent K-5 II, as it was a fairly modest update.

When I first heard news of the Pentax K-3, I was thrilled. There's a lot I love about my K-5, but there are areas in which I wanted to see the company make some improvements -- especially autofocus -- and with the K-3, it seems to have done so. As well as the new AF system, I also found the prospect of better metering, dual flash card slots, a better and wider-aspect LCD monitor, and a brighter viewfinder to be particularly appealing. And the promise of greater all-around performance doesn't hurt, either.

So this review will be serving a dual purpose. In large part, it's obviously to help you to decide if the K-3 is the camera for you, whether you're upgrading from an existing Pentax SLR, or making the jump from another mount. (Or perhaps you're planning on stepping up from a fixed-lens camera.) But it's also an exercise in determining whether it's time for me to upgrade my own camera, as well, and so I'll be making some side-by-side comparisons with my K-5.

Still quite compact. In our walkaround above, we noted that the K-3 has grown just slightly in size and weight since the K-5. Having spent some time shooting the two cameras side by side, I have to say that it's not even slightly noticeable, however. If the K-7 and K-5 / K-5 II fit your hand well, then the same will be true of the K-3. The subtly reprofiled handgrip of the K-3 makes it even more comfortable in hand, though. (And that's saying something; despite their relatively compact size for an enthusiast-grade DSLRs, the earlier K-series flagships have already been among my favorites in terms of comfort.)

I used both cameras exclusively at ISO 3200 and above on this late afternoon shoot, to get a feel for high ISO noise characteristics, as well as the in-camera JPEG noise processing. Click here to see a shot with the exact same exposure variables on the Pentax K-5.

The portrait grip dilemma. Among the first accessories I picked up for my Pentax K-7 was the optional D-BG4 portrait / battery grip. I'm a big fan of this add-on, for three reasons: it doubles the (already great) battery life of the camera, lets you use standard AA cells in a pinch, and adds a second set of controls for portrait shooting. I was a bit disappointed to find that -- after following me from the K-7 to the K-5, and (if I'd chosen to upgrade again), to the K-5 II -- my battery grip won't work with the K-3.

Instead, I'll have to buy the new D-BG5 if I upgrade to the K-3. New buy or not, I'd still recommend picking up the updated grip -- it's nicely built, weather-sealed, and makes portrait shooting a much more comfortable experience. Functionally, it's almost identical to the earlier grip, and in fact, it can even accept the same insert trays. The only changes are that it's been reprofiled to fit the new K-3 body, and that Pentax has switched around the positions of the Green and AF buttons, to better match those on the camera body.

Thankfully, my other Pentax accessories will still work with the K-3. (I highly recommend picking up the waterproof remote control, by the way.)

As the sun went down, the sensitivity went up. This shot is at ISO 6400; click here for the Pentax K-5's version of the same scene.

Ergonomic tweaks. Although it's grown a little and its insides are almost completely new, the Pentax K-3 feels very familiar indeed, coming from the K-7 and K-5. Many controls are unchanged, and those which have been tweaked have mostly changed for the better. The new Metering and Autofocus Mode buttons are easier to change than the slightly fiddly switches found on the earlier cameras, and the addition of a switch that makes the Mode dial locking button optional is a great feature. (Personally, I love locking mode dials, but some of my colleagues at Imaging Resource find them frustrating -- now we can both be happy with a single design.)

There are only really two changes to the K-3's control layout that concern me. Most notably, I'm not a fan of the new AE Lock button placement, as it's uncomfortable to reach above the thumb grip, especially when shooting single-handed. Other than perhaps the Playback and Green buttons, the AE Lock button is probably my most commonly-used control. I can see why it was moved, to accommodate the new (and well-considered) Movie / Still switch, but I find myself wishing that Pentax had simply placed the AF button in the center of that switch, as it did with the AF button and Focus Mode switch of the K-7 and K-5. Obviously we're stuck with the new button positions, but perhaps Pentax could consider allowing me to reverse the functions of the AF and AE-L buttons via a firmware update? I shall cross my fingers for such an occurrence.

The only other control which bothered me is the new Focus Point Selection button, and that's largely because previous Pentax flagships have so deeply ingrained in me that I switch to focus point selection with the OK button in the center of the Four-way Controller pad. Even after shooting with the K-3 for some time, I find it hard to remember the new button, and face momentary confusion when I can't access point selection... at least for a few seconds, until my memory catches up. I'll get used to it eventually, but for K-7 and K-5 / K-5 II owners making the move to the K-3, expect to find it similarly difficult to remember for the first short while.

...and UI tweaks. The Pentax K-3 also sports an updated user interface, in part to accomodate its new, wider-aspect monitor. I'm a big fan of most of the changes, which go some way to making things more logical. For example, switching between PEF and DNG raw file formats was previously accomplished with an option that sat in a completely different menu tab to all other file type options. Now they sit together in a single, logical screen. Other similarly thoughtful changes abound.

This was the only scene where I thought the K-5's auto white balance did a better job than did the K-3, under a complex mixture of artificial light and partial sunset. You can see more noise in the K-3's rendition at 1:1 on-screen, and it's a bit blotchier than that from the K-5, but it cleans up pretty easily. Click here for the K-5 version.

But there's one change I confess that I find infuriating: the new popup menu when changing display modes. This would be a logical feature on a camera with a touch screen, as it would allow you to shortcut straight to your chosen display type. Thing is, there's no touch screen here, and so all the popup does is add one extra button press before you can get to your display type of choice, since there's no way to skip the intermediate display types. I've heard from other Pentaxians who also find this change frustrating, and hopefully Pentax will either revert to the old method, or make the new one optional.

Another high-sensitivity shot at ISO 12,800. Interestingly, the K-3 correctly locked focus on the Soccertaco sign, where I set the autofocus point. The K-5 locked focus on the fence in the foreground, even though I'd selected an AF point directly over the sign. Click here for the K-5 shot.

It's also a little confusing, since you can now access Movie capture regardless of the Mode dial position and shoot with Program, Priority, or Manual exposure, that the Mode dial has no effect on the Movie exposure mode. Instead, you must select this through the menu system. I'd like to see an option added to simply abide by the Mode dial setting when shooting movies, with any modes that wouldn't make sense for movie capture (such as Bulb or X-sync) reverting to Program auto exposure.

With those slight quirks aside, though, I'm pretty happy with the physical and interface changes Pentax has made between the K-3 and its predecessors.

What really matters: The shooting! I couldn't wait to get out and shoot with the Pentax K-3, once it cleared our lab testing, and so I didn't hang around when it arrived. Sadly, it came accompanied by a couple of weeks of absolutely shocking weather here in Knoxville, Tennessee, with the sun making brief appearances only whenever I was too busy to leave the office. After entirely too long bemoaning my luck, I was blessed with a sunny afternoon a few days before Christmas -- and almost ran for the door.

Side-by-side comparison. The first thing I wanted to get to grips with was the K-3's low light / high ISO behavior, as I'd heard some griping from early adopters about an increase in noise levels versus the K-5 and K-5 II. Hence, I aimed to shoot around (and for a couple of hours after) sunset, as I gradually lost the light and ended up shooting merely by street lighting. And I left my flash strobes at home, to ensure I relied on available light. Both cameras were mounted with identical 18-135mm lenses for this shoot, since that's the kit lens sold with the K-3. (I've done some shooting with more exciting glass -- my Limited primes -- in part two of my Field Test.)

How good is the DA 18-135mm F3.5-5.6 ED AL [IF] DC WR kit lens?
Click here to see our test results for this optional optic.

ISO 6400 was plenty for handheld shooting under city street lighting. Click here for the K-5's rendition of this scene.

And both cameras were set to their defaults as I always do when shooting review cameras, with the exception of JPEG+raw file formats, and bracketed exposures. I'd typically shoot raw only in DNG format for my own personal enjoyment, but since Pentax's PEF format is the default, that's what I went with here. And on the rare occasions when I shoot in-camera JPEGs I typically use the more realistic Natural image mode, rather than the snappier, more saturated Bright mode which is the default, but my JPEG shots here are with the latter.

Improved autofocus. Straight away, I noticed that the Pentax K-3 has a noticeable advantage in the autofocus department. And I'm not just talking about the much denser array of autofocus points, although these are great to have. (I had to reframe images far less often with the K-3, simply because there was more frequently an autofocus point already right over the critical portion of my subject.)

What I noticed was that, while shooting with identical setup and the same lens, the K-3 would confidently lock focus even in very dim light, where my K-5 would require me to at least get it in the ballpark manually, before letting autofocus do its thing. (For info on how autofocus performs with screw-drive lenses, and with tracking active, look at part three of my Field Test.)

Better auto white balance. Another difference I picked up on straight away is that Auto white balance on the K-3 has a warmer rendering under late afternoon sunlight than does my K-5. Almost all of my shots with the K-3 looked more like what I saw in person, in terms of color balance, although I did have one or two shots under very mixed lighting where I thought the K-5 did a better job.

Even after dark the K-3's auto white balance tended to produce a somewhat warmer result than the K-5, under the exact same conditions. Again, I prefer the K-3's result here. Click here to see what the K-5 yielded.

A bug in exposure bracketing? I haven't yet noticed a lot of difference in metering between the two cameras, but that's not surprising, as I've yet to shoot any particularly difficult-to-meter subjects. I did, however, pick up on what seems to be a bug in the Pentax K-3's firmware, which I'd updated to the current version 1.01 right before my afternoon's shooting. Several times -- but not every time -- I found that two shots in the bracketed sequence, set to vary between shots by 0.7 EV, and taken just fractions of a second apart, actually had an identical exposure. Shutter speed, aperture, and ISO sensitivity were the same. I'll have a fiddle and see if I can find anything in particular which triggers this behavior; I've never seen my K-5 or K-7 do the same.

So... What did I think of the K-5's high ISO performance? Rather than taking my word for it, you can judge for yourself from the samples here -- for each image, I shot with both the K-3 and K-5, seconds apart and with similar (albeit handheld) framing. But in a nutshell, I don't think there's a whole lot in it.

High ISO verdict. Yes, seen at 1:1, the K-3's images are definitely noisier than the K-5, which I believe is what some early K-3 owners took issue with. The K-3's grain pattern is also rather blotchier and less film-like, seen 1:1. However, that's hardly a realistic scenario for most of us -- how often do you print your images large enough to match 1:1 onscreen viewing, and then look at them from a typical monitor viewing distance? I tried downsampling some of my K-3 images to the same resolution as K-5 images shot at the same time, and the difference in noise levels was much less noticeable.

Want to know how the Pentax K-3 deals with image noise at higher sensitivities?
View the IR Lab's comprehensive K-3 noise reduction series by clicking here.

And not only that, but I ran the K-3's images through DxO Optics Pro 9, the latest version of one of my favorite raw image processors. DxO Labs recently added support for the Pentax K-3 in Optics Pro (as did Adobe in Photoshop Lightroom), and the new PRIME denoising engine in Optics Pro can do some truly amazing things with high ISO photos. The way it does this is simple: throw boatloads of processing power at the problem, rather than trying to process in near-real time. Once they'd taken a trip through Optics Pro 9, I was quite happy with the quality even of images shot at ISO 12,800 with the Pentax K-3. Above that threshold, I did find it hard to get convincing results even with Optics Pro, as removing the noise left images looking plastic and artificial, but even then I reckon I'd be happy with shots at the highest ISOs for smaller prints.


Editor's Picks