Taking on the DSLR Giants: Fstoppers Reviews the Pentax K-1 Camera

Taking on the DSLR Giants: Fstoppers Reviews the Pentax K-1 Camera

Earlier this year, Pentax released the K-1, its first foray into the digital full-frame market and a camera surrounded by a healthy dose of excitement and intrigue. I've had the chance to use it and some of the new system lenses for the past month. It's a fun and highly capable system that could be just the ticket for many photographers.

I'm just not a megapixel guy. Even for landscapes, 20 of them are good enough for me. I'll take noise performance, a fast frame rate, and good autofocus instead, please. However, if you give me a 36-megapixel camera with great noise performance, a decent frame rate, and good autofocus, I'm certainly not going to turn it down. Can the Pentax K-1 and its new lenses turn them in? Let's find out.

Key Specifications

Pentax K-1 Camera

  • 36.4 MP CMOS sensor with no AA filter, but with an AA filter simulation effect to eliminate moire
  • ISO sensitivity up to 204,800
  • Five-axis in-camera shake reduction, offering up to five stops of compensation
  • Pixel-shifting technology that shifts the sensor to create high-resolution images, complete with motion correction
  • Continuous shooting of up to 4.4 fps (17-shot raw buffer) in full-frame mode, or up to 6.5 fps (50-shot raw buffer) in APS-C mode
  • Dual SD slots
  • 33 AF points (25 cross-type), sensitive to EV -3, including an LED AF assist lamp
  • 100% coverage viewfinder with 0.70x magnification
  • Illuminated controls and lens mount
  • A 3.2-inch LCD display that can be tilted along multiple axes: 44° down, 90° up, 35° left and right
  • Weather and dust resistance
  • Built-in GPS and electronic compass
  • AstroTracer function that shifts the sensor to follow the motion of stars, enabling blur-free long exposures

Pentax D FA 15-30mm f/2.8 ED SDM WR Lens

  • f/2.8-22 aperture range
  • ED (extra-low dispersion) glass elements
  • Super Protect and HD Multi-Layer coatings
  • Supersonic Direct-Drive AF motor and Quick-Shift focus
  • Minimum focus distance: 11 in
  • Weather resistant
  • Nine-blade rounded diaphragm
  • Integrated hood

Pentax D FA 28-105mm f/3.5-5.6 ED DC WR Lens

  • f/3.5-5.6 to f/22-32 aperture range
  • ED glass elements
  • Super Protect and HD Multi-Layer coatings
  • Supersonic Direct-Drive AF motor and Quick-Shift focus
  • Minimum focus distance: 1.64 ft
  • Weather resistant
  • Nine-blade rounded diaphragm

Pentax D FA* 70-200mm f/2.8 ED DC AW Lens

  • f/2.8-22 aperture range
  • ED glass elements
  • HD, SP, and Aero Bright coatings
  • Direct Current AF motor and Quick-Shift focus
  • Minimum focus distance: 3.94 ft
  • Focal range limiter
  • Weather resistant
  • Detachable, rotatable tripod collar with click-in-place positioning
  • Nine-blade rounded diaphragm

Design and Handling

The design is a photography geek's dream. It's very light and comfy for a full-frame DSLR, but it's very solid too. It's ergonomic and comfortable in the hand and features 87 points of weather-sealing; it's clear Pentax intends this to be a rugged camera, and indeed it is: I had no problem taking it out in light rain showers or the like. There isn't a blank space on it; every bit is used for some kind of control. So impressive is the array that I barely was forced into the menu system, only using it maybe twice in a month to make changes I couldn't make externally. That being said, the menu system is perfectly well designed and thought out, and I never had an issue quickly finding and setting what I needed to with five main sections: shooting, movies, playback, setup, and custom settings. What I really love is the info menu on the screen, which is customizable, allowing the photographer to display the info they want where they want it. It's a simple touch that goes a long way. Speaking of another simple touch, the camera features lighting all over the body to assist in dark scenarios; it's an absolute lifesaver when you're trying to change a lens at 2 a.m. in the middle of a field on a moonless night. 

The external controls really steal the show, though. I rarely read the manual simply because I feel it's a good test of the intuitiveness of a piece of equipment if I can pick it up and use it without instruction. The K-1 passed this test with flying colors, which is impressive given its myriad of buttons, dials, and switches. 

The left side of the camera features the USB, HDMI, and DC power connections. As for controls, it also features the camera lock, which prevents unintended operation; the Fx1 button, which is a customizable function button; and the AF mode and AF/MF controls, which are in an intuitive place, making them easy to use without taking one's eye from the viewfinder.

The top of the camera is quite interesting. As you can see, there are five user customizable slots, quite a bit more than the normal two or three slots on most cameras. While I didn't use them all, I won't complain about having them available. The rest are the standard modes, save for Sv, which varies aperture and shutter speed in response to a user-selected ISO setting. I didn't use this mode, but it's there. Moving to the right, you can see the GPS button. The GPS is used for geotagging and the Astrotracer function, and it worked well without issue. The right side of the top panel is where the camera travels off the beaten path. The top info panel is very small compared to even most APS-C models, and it only displays the three exposure parameters, card-writing status, and a battery level indicator. This is to make room for the multifunction dial you see above it, which allows you to quickly access most any major camera function you would want to. Coming from Canon land, this took me a little while to get used to, but I quickly enjoyed it; although I wished for AF mode info up there, the tradeoff for being able to quickly jump into bracketing, crop mode, exposure compensation, and more was pretty awesome. If you shoot things like sports and need AF information and WB settings for JPEGs at hand, this might not be a great setup, but then again, this isn't a sports camera. Pentax's clever design really comes into play here; the second dial (under the backlight button) is generally linked to whatever function is selected on the multifunction dial, so you can quickly and intuitively move through different settings without having to remember different button combinations. In fact, most settings and shooting scenarios are controlled by the three dials: the one in front of the shutter button, the aforementioned dial, and the one just below the screen on the top panel.

Starting on the top left, we have the live view switch and the metering selection button. Next is the dial that helps control shooting functions and zoom during playback, followed by the autofocus button and autoexposure lock button. The green button is like a default switch: it resets whatever parameter you're adjusting. The bottom cluster is where my only real gripe about the camera controls comes in. While they work perfectly fine for drive mode, white balance, display control, and more, you'll notice that there's no dedicated AF joystick. You can change the default behavior to selecting AF points first, then using the AF select button to switch to labeled functions, but it was still cumbersome to use the four way pad to change points and rather error-prone with the camera to my face and my thumb mashing the buttons. While this may sound like a minor inconvenience, being able to quickly select your AF point can make the difference between getting or missing a shot. I would have gladly traded the green button for a joystick. 

Last are the viewfinder and screen, which are a joy. The screen is bright, vibrant, and full of info. It also features an outdoors boost setting, which ups the brightness to compensate for the sun, a setting I ended up using quite a bit. I also adored the articulating screen. Some people consider it a gimmick, but being able to hold the camera above your head for a crowd shot or down low for a flower macro is awesome. The viewfinder is pretty standard for a full-frame DSLR; it's plenty bright, sports all the shooting info you need, and will overlay a grid or crop rectangle if so desired. 

Autofocus

This is far and away the weakest part of the system. Unfortunately, the system is just not of the level we expect in 2016. While this is a landscape-oriented camera, its 4.4 FPS continuous shooting rate (6.5 FPS in crop mode) place it essentially on par with the Canon 5D Mark III and Nikon D810, both of which are formidable wedding cameras, and with the image quality and new line of lenses, the K-1 could be a great third option. As mentioned, the AF system consists of 33 points (25 cross-type). 33 is a little on the low side for a full-frame DSLR, though not tragically so. 

Single Shot Performance

In AF-S mode, results were generally accurate and precise. There was a smidgen of hesitation, but if you're shooting in single shot mode, you're probably not in a fast-paced scenario. Nonetheless, the hesitation is a bit more worrisome in continuous mode. Moreover, as lighting gets worse, the hesitation gets longer, often to an unacceptable point. Good AF point sensitivity doesn't mean much if the speed isn't reasonable. Nonetheless, when the camera did eventually focus, it rarely missed. 

Continuous Autofocus

This is where things got frustrating. I took the K-1 to a hunter derby, a type of horse jumping competition. Horse shows are a great autofocus test; the horses move at around 15-25 mph with a bit of bounce and vertical motion, but they generally move smoothly in terms of quick lateral changes and average forward speed. It's also typically during the day, meaning lighting is good, making for a very reasonable, not overly difficult test. Unfortunately, out of about 480 images, 350 were entirely out of focus, 90 missed enough to be throwaways, and about 40 were acceptable. There didn't seem to be much consistency either: I would frequently lock on a subject, only to watch the autofocus evaporate even when the subject did nothing sudden. What's frustrating is that there's little in the way of customizability in the menu system. Options like telling the camera to ignore closer subjects that suddenly pop into the frame aren't there. This is frustrating, as by the end of the derby, I could predictably tell where the camera would lose autofocus as I panned across a closer jump while following a rider and horse. It's a shame, because when the camera did nail focus, the results were nice. 

For some reason, as I followed horses up to this jump (a simple straight-on approach of about eight strides), the camera would do one of two things: not quite keep up, or randomly go completely out of focus, despite me stubbornly keeping the AF point on the horse. This was one of 3 riders (out of 25) that I successfully got a shot of. 

Lateral motion presented similar issues. Out of 11 shots in this series, only 2 were in focus, including the one above. What's frustrating is that the horse was traveling unobstructed almost perpendicularly to me, meaning the focal distance was changing very little, but again, the focus would often go wildly out of whack, or just fail to keep up, even with Pentax's newest glass attached.

Things did get a bit better when the horses slowed to a walk. So, for the wedding crowd, not all hope is lost. Nonetheless, I couldn't trust the camera's continuous autofocus; it's slow and mercurial. That being said, each lens performed about the same in terms of both accuracy and speed. 

Image Quality

General Points

The files that come out of the K-1 are gorgeous. They're full of detail, contrast, and saturation, and the post-processing latitude is tremendous. The colors are particularly notable; they're rich, earthy, and transition beautifully between each other. This really makes subjects pop.

Dynamic Range

Dynamic range is, as expected, extremely good. What makes it better is that the camera is very close to being ISO invariant, meaning you can vastly underexpose files and recover them with very little loss in image quality as compared to properly exposing in camera. This has a multitude of uses, the biggest of which is protecting highlights. Check out the below example, which was pushed five stops in Lightroom:

Of course, the situations in which one will underexpose by that much are very few and far between. What's great about the dynamic range, though, is that it makes scenes with extreme ranges easier to capture. One can get away with exposure-blending less. In a more practical example, check out these shots below, all of which were captured in one exposure, with the landscapes showing the most impressive dynamic range:

Let's take a quick aside to note something about the above images. They were shot on all three of the lenses used in this review: the 15-30mm, the 70-200mm, and the 28-105mm, the third of which is a walk-around lens and decidedly less expensive than the former two. There's an impressive consistency in image quality: drawing, sharpness, contrast, bokeh, and color are all quite nice out of all three lenses, even the walk-around, which was used for the third shot (wide open). This is quite commendable and can lend your images a very consistent quality, which is of course important for any portfolio. 

Resolution and Details

With 36 MP, there's lots of resolution to work with and plenty of room to crop in post. Coupled with the high-quality optics of all three lenses, this makes the files full of detail, so long as the autofocus does its job. 

Noise Performance

Noise performance is generally quite good. Files are generally devoid of easily noticeable grain through about ISO 1600. At ISO 3200 and 6400, the noise is definitely there, but it's not bothersome and with 36 MP, downsizing cleans it up nicely. Even at ISO 12800, noise doesn't overwhelm the picture, and I would have no problem using those files for web or small prints. Color noise starts to seep in at ISO 25600, but again, with a little cleaning up, the files are usable. It's not until ISO 51200 that a marked downturn in quality and deviation from the generally linear trend of ISO level vs. image degradation occurs. By ISO 102400 and 204800, files are dominated by noise, leaving these levels to be used only in emergencies. The GIF below shows ISO levels 100-204800 in one-stop increments.

pentax-k-1-ISO-performance

Other Features

Pixel Shift

Pixel Shift is one of the marquee features of the K-1. By taking four shots in which the sensor shifts one pixel each shot, both dynamic range and resolution are improved. While you don't get a file bigger than 36 MP, the resolution within that file is markedly better. Unfortunately, Adobe Camera Raw does not handle Pixel Shift files well at the moment, particularly those with motion correction turned on, but Pentax includes bundled software to import them. In practice, I noticed the best dynamic range improvements in the shadows, where transitions were noticeably smoother. The resolution improvement was modest, though definitely noticeable upon close inspection. Unfortunately, the motion correction did not work well; notice the artifacts from the boat on the river.

Pixel Shift off.

Pixel Shift on.

Altogether, Pixel Shift does offer an improvement in dynamic range and resolution if you're looking for the absolute best. However, your subject needs to be essentially motionless, you need to use Pentax's somewhat cumbersome and rather slow software to see the benefits, and you likely won't notice the difference at all but the largest sizes. Whether it's worth it is up to you. Lastly, if you're thinking of using this feature in studio, keep in mind that it doesn't work with flash (continuous lighting is fine).

AstroTracer

AstroTracer takes advantage of the sensor's ability to yaw and pitch by allowing it to rotate with the Earth, effectively eliminating star trails and allowing blur-free exposures of up to five minutes, which is great, considering how crucial gathering as much light as possible is in astrophotography. One should note that terrestrial objects will be blurred because of the motion during the exposure. In theory, it's a simply concept; in practice, it's a smidgen involved. 

Setting it up is a bit involved, but not really tricky. One first turns on the GPS, then enables AstroTracer in the menu system, performs a calibration that involves rotating the camera in multiple directions, then switches to bulb mode and sets the exposure time. Of course, a shutter timer and mirror lockup are a good idea as well. Shown below is a 210-second exposure at 15mm, f/2.8, and ISO 200. Unfortunately, clouds were in and out both nights at the dark park, making life a bit difficult, but the performance of the function is still impressive; note how the stars are kept as point sources.

The only issue is that the camera seems to have difficulty when this function is used in a vertical orientation. That being said, the results are still much better than if the feature is turned off. Shown below is a 150-second exposure at 15mm, f/2.8, and ISO 400 for the sky blended with a 10-second, ISO 6400 exposure for the ground.

Altogether, AstroTracer is a fun and relatively easy to use feature (especially compared to lugging around an equatorial mount). While it won't replace a dedicated device, it can give you an extra step up that should satisfy a lot of landscape photographers who don't specialize in astrophotography, but do want a bump in quality.

Image Stabilization

Pentax uses in-body image stabilization ("Shake Reduction") that shifts the sensor and offers up to five stops of compensation. In practice, it was quite good. Shooting golden hour portraits, I could eke out more time as the light got dimmer without bumping the ISO; I had no problem shooting 1/50 s at 200mm. It was also helpful for spur-of-the-moment landscape shots in which I simply wanted to jump out of my car, snap a picture, and get back in without going through the hassle of using a tripod. It just works, and it works well, which is all I ask of image stabilization.

Buffer

Buffer depth is a bit below what I'd prefer; I frequently filled the buffer within 8-13 shots shooting double raws (duplicating on both cards), though I occasionally made it to about 15 and around 40 in crop mode. I wouldn't care as much if the camera didn't slow so noticeably, with shooting essentially stopping for 3-10 seconds as the buffer cleared. That's a little on the low side for shooting events. 

Battery Life

Battery life is rated for 760 shots, which is about what I got in normal use. While a bit low for a DSLR, it's not terrible, and it certainly bests mirrorless options. 

Lens Adapters

One thing to note is that Pentax is not new to the full-frame game, only to the digital full-frame game. This means their massive library of K-mount lenses all work natively on the K-1, including autofocus for those that have it. DA lenses also work on the camera in crop mode, though a few will cover the entire sensor with their image circle and thus will work in full-frame mode. M42 and M37 lenses work with a simple adapter. You can even adapt 645 and 6x7 lenses, though they'll need to have an aperture ring. Much like using 35mm lenses on a crop sensor, you can expect great optical quality from those lenses as the 35mm sensor is only using the center of the medium format image circle. That being said, don't expect every old lens to be up to par on that 36 MP sensor.

Video

The inclusion of video on the K-1 is a bit of an afterthought; however, given Pentax's customer base, I'm ok with that, especially if it helped keep the camera at its impressively competitive price point. Nonetheless, should you wish, the K-1 can shoot 1080p at 30 fps (or 1080i at 60 fps) for up to approximately 25 minutes per file. However, focus peaking and the ability to zoom to check focus are not available while recording, leaving only the slow contrast-detect autofocus or manual focusing without the ability to zoom. It'll work in a pinch, but anyone who does serious work with video will want to look at another option.

Summary

The Pentax K-1 and accompanying lenses are an excellent option for those looking for top-notch image quality, rugged build, and all those little features that set it apart from other systems and make a photography geek's shooting experience better. The only real hindrance to the system is its autofocus, which lags behind this generation's DSLRs. If your subject matter and shooting style are less demanding, you simply won't be disappointed by the quality, versatility, and price point of this camera and its lenses. If Pentax can improve AF quality via a firmware upgrade, they'll have a camera that can not only hang with the best of landscape shooters, but can also compete handily in the wedding market. 

What I Liked

  • Fabulous sensor with great resolution and dynamic range
  • In-body stabilization
  • Pixel-shifting adds even more resolution and dynamic range
  • Dual card slots
  • Large, bright viewfinder
  • Lighted controls and lens mount
  • Crisp, bright LCD screen with great articulation
  • Rugged but ergonomic build quality
  • AstroTracer function
  • Customizable info screen
  • Plethora of external controls
  • Multi-function dial enables quick access to most major shooting parameters and scenarios
  • Great file latitude
  • Good noise performance
  • All lenses are sharp and contrasty with melty and unintrusive bokeh
  • ​Ability to use extensive library of older lenses
  • Extremely good price point

What I Didn't Like

  • No dedicated AF point selector
  • Autofocus tracking is slow, finicky, and frequently misses
  • AF customization is lacking
  • Small buffer depth and low operability during buffer clearing
  • Currently limited selection of more modernized lenses, specifically primes
  • Pixel Shift requires using proprietary and slow software

Ordering

At $1796.95 for a full-frame camera of this caliber and feature set, the Pentax K-1 is truly a steal. Its complement of lenses keep up with its spectacular sensor admirably and would make a great kit for almost landscape shooter or general shooter. Order yours below.

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18 Comments

Ryan Mense's picture

Ever since I reviewed the K-3 II I've been interested in hearing about the K-1. Now I can finally stop hounding you about it! These Pentax bodies are my favorite as far as feeling in the hand and controls at your fingertips. Pixel shift with this bigger sensor looks so good! I'd totally rock either of these two cameras full time.

Alex Cooke's picture

Glad I could deliver a review! I totally agree; the ergonomics and controls are absolutely spectacular. I'd be more than happy to have this in my bag.

Spy Black's picture

It's a shame about the AF, this camera has so much going for it. I wonder if Ricoh can improve the AF through a firmware update.

Tony Northrup's picture

"Currently limited selection of more modernized lenses, specifically primes"

*braces*

The range is not hopeless, by any means - we have the 200, 300 and 560 primes that work on FF and are optimised for digital. And have you tried the FA 31, 43 and 77 Limiteds? They may be film era lenses but they are spectacular on the K-1. We do need some fast wide angle primes, though: a 20mm and/or 24 mm would hit my sweet spot nicely!

Joseph Drago's picture

My biggest complaint about the Pentax 645Z seem to run in the K-3's veins as well. No prime lenses under 35mm and the autofocus is seriously lagging behind anything I have ever used...ever. No tilt shifts for architectural photographers either although the 35mm prime has ver little distortion. I would love to see Pentax step down the ISO range to 50 or even go further to 25 instead of the seemingly unnecessary upper limits. The lenses have a hard enough time focusing in ideal light so unless you plan on manual focusing in dark conditions, good luck!

I can't say I know much about the 645Z (it's out of my price range currently, I do own an original film one though) but the K series does have a few primes under 35mm, the DA14, DA15 limited, DA21 limited, and FA31 Limited, all of which are in production. You can find several others like the FA24 and FA28 and several manual focus ones that are out of production if you are willing to go back that far. Even sigma has a few good ones.

Besides the Pentax lenses there are the Samyang/ Rokinin lenses and the ones from Sigma that are under 35mn including the Sigma 15 mm f/2.8, 20mm f1.8, 24mm f1.8 and 28mm f1.8. There are enough lenses now with more to come.

Some people don't like Pentax for whatever reasons and never will. The fact is Pentax is giving a lot more value for the money spent than anyone else competing with the 645Z, the K-3/K-3ii or K-1. The cameras may not be for everyone, but they are refreshingly innovative, aggressively priced, weatherproof, and dependable.

Anonymous's picture

I'm just curious ... does anyone need more that 33 AF points for landscape photography? I'm using 1 (one).
It's possible however that I've missunderstood something so correct me if I'm wrong :/

I shoot portraiture and just use one point as well....maybe the extra points come into play with action photography, but this isn't exactly the camera for that.

Roberto Duran's picture

Agree.... 98% of the time I use only 1 AF point.. for action photography it helps ( i guess ), for other kind of shoots neeehh..

Paul Watt's picture

Or 0 AF points for landscape shots sometimes!

Jon Wolding's picture

In regards to buffer size/speed... I read elsewhere that each slot has a max bus speed of 104 MB/s, figured that'd be helpful to note here.

1. What speed were your SD cards rated for?
2. Were you writing to both SD cards simultaneously when shooting bursts?
3. Was any specific camera setting/mode(s) slower or faster than another?

I rented the K-1 for a few days and found the continuous autofocus acceptable. Pentax gives much more bang for the $ spent than anyone else out there, with the shortcoming only coming into play for dedicated sports photographers or professional videographers. Everyone else receives 30% - 50% more value for the money spent.

Re: Autofocus. Most of the time I know where a person or object will be for an action shot and use pre-focus to get the shot every time. (well almost every time) For landscapes I generally use a manually adjusted hyper-focal distance. Really have little need for auto-focus after all. ;-) The K-1 is on my 'get it next' list.

Benjamin Kanarek's picture

I used to be an avid Pentax user and was at one time sponsored by them. In fact we still use the Pentax K3 for most of our video recordings as our Director Frederique Renaut loves the compactness. However, I left Pentax for their endemic AF issues. I was interested in the K1, but after seeing how cluttered the AF points are in the centre, it would be problematic to focus on an eye and reframing the subject, especially as I shoot more often than not at maximum aperture when shooting outdoors. The focus needs to be spot on and refocussing would render the accuracy rather useless. That is why I love the Nikon D800/810's, as I am able to set up the 5/4 crop ratio, which replicates 90% of all of the magazine formats I work for , i.e. VOGUE, BAZAAR, ELLE, etc and get very close to or spot on the part of the face I want to focus on, without having that pesky re-crop issue. I still get 30.2 megapixels with a framing that replicates Medium Format crop ratios.

Thanks for the clear and unbiased article. (I don't understand why there's such manic bias against Pentax from some so called reviewers).
Just an extra point; you made good mention of the compatibility with older Pentax lenses; the SR function works just as well on those too - so all lenses, despite age, are effectively image stabilised.

Oliver Kmia's picture

Great review Alex. Thanks for covering the Astro part. I totally missed it.