Pentax K-3 vs Nikon D7100 Comparison

October 8, 2013

Nikon D7100 and Pentax K-3 cameras on a metallic background

In this article I will compare the Pentax K-3 vs Nikon D7100 — two environmentally-sealed 24MP APS-C enthusiast DSLR cameras.  The Pentax K-3 is the newer model, announced on October 7th, 2013 — 7 months and 17 days after the D7100 was announced to be exact. Nikon D7100 has gotten high rating on almost all major camera review websites, including the well-regarded Gold Award. Pentax is still missing  a full frame DSLR, but the new K-3 DSLR certainly grabbed the attention of many enthusiast photographers when it was first announced. Will the Pentax K-3 convince you to make the switch from Canon or Nikon?

I assume that there are many photographers who will consider changing camps and buy the K-3 due to its excellent range of impressive features, including some innovative ones which are first seen in any DSLR camera.

OK, so without further ado, let’s jump straight into our comparison and see which camera comes on top.

Price Comparison: K-3 vs D7100

Before we start talking about the features of both cameras, let’s first take a look at the pricing first.

  • Pentax K-3
    $1299.00 (body only)
    $1649.00 (body + 18-135mm WR f/3.5-5.6 lens)
  • Nikon D7100
    $1146.95 (body only)
    $ $1446.95 (body + 18-105mm f/3.5-5.6 AF-S DX VR ED lens)

* prices as of October 8th, 2013 (visit for latest prices)

We can see that the K-3 is $152.05 more expensive than the D7100 — but we need to consider the fact that the D7100 is the older model. This means that both cameras sit in the same price range and aimed towards the enthusiast photographer.

Of course it doesn’t mean that everyone should debate between the two cameras. It really comes to personal preferences and one camera might be better than the other for specific uses. Some of you already have a wide selection of Nikkor or Pentax lenses, so you should think more than once before even considering changing sides — which means selling your current equipment.

So because the price difference shouldn’t be a part of your buying decision, we should take a closer look and compare the features, camera design and image output to fully understand which camera is best for your type of shooting style. If you don’t already own a DSLR camera or own only one or two lenses, it will be easier for you to make a decision. Other important aspects of a buying decision should be lens selection and lens availability, and those shouldn’t be ignored.

OK, now that we finished discussing the prices, let’s start examining both cameras in-depth. In each section I will discuss and compare different aspects of the cameras — we’ll start with the camera body design and construction.

Camera Design

The camera body plays a significant role for some photographers. You should pay attention to the body construction materials, ergonomics, size and weight,  buttons and dial layout, Viewfinder, LCD, etc.

Some photographers prefer buying a cheaper camera model, and spent more money on a better / secondary lens. Others find it a necessity to invest in the camera body. For example, for some photographers, having a weather-sealed body is crucial for getting their task done when shooting in harsh weather environments, like in the rain or in freezing temperatures. Without that weather-sealing protection, they wouldn’t able to get the photos they are after.  Another thing can be the camera’s high ISO performance or the sensor’s resolution for example.

Nikon D7100 and Pentax K-3 side by side

Nikon D7100 and Pentax K-3 side by side size comparison (via

Let’s take a look at the specs first:

Nikon D7100Pentax K-3
Dimensions135.5 x 106.5 x 76 mm131.5 x 100 x 77.5 mm
(inc. battery and card)
Constructionmagnesium alloy for the top and rear covers.full magnesium alloy
Weather SealingWeather and dust sealing (same as the D300s and D800)Dustproof, weather-resistant and cold-resistant construction.

92 sealing parts
Lowest Operating Temperature0°C-10°C
Official Weather Sealed battery groupYesYes
Shutter Durability150,000 cycles200,000 cycles
Top LCDYesYes
Rear LCD3.20 inches
Not touchscreen
3.20 inches
Not touchscreen
Eye-level ViewfinderPentaprism
100% coverage
0.94x magnification

-2 to +1 m-1 diopter adjustment
100% coverage
0.95x magnification

-2.5m to + 1.5m-1 diopter adjustment

We can see that the Pentax K-3 has the edge in some aspects: it’s a bit smaller (if you see this as an advantage), has full magnesium alloy body (D7100 has partial magnesium alloy construction), it can operate under lower temperatures, has more durable shutter and a slightly larger viewfinder. Pentax is well known for its top-notch durable DSLR bodies and the K-3 is no exception.

One of the questions that people ask me is whether or not it’s safe to shoot with a specific camera in the rain, without worrying water drops penetrating the camera body.

According to this official news page on website:

The magnesium alloy adopted for the top and rear covers of the D7100 ensures great strength, and sealing of individual components ensures a high level of water and dust resistance. “.

So the Nikon D7100 should withstand water drops, but it’s in no way a waterproof camera.

Pentax Ricoh  is marketing the K-3 as a durable and water-resistant camera. The camera is protected against water splashes, heavy humidity, snow, sand, dust, etc. The problem is that these cameras don’t get any IP liquid ingress protection rating, so we can’t compare and tell which one provided better protection. For some reason I feel safer to use the K-3 in the rain, rather than the D7100, but both should provide somewhat around the same degree of protection — except that the K-3 can work in freezing temperatures as low as -15 degrees Celsius.

Both cameras come with lots of buttons and dials which provide fast-access to frequently used camera settings and functions. In the D7100 Nikon introduced a new “i” button to recall recent settings. You have buttons for fast access to ISO speed, white balance, light metering settings, autofocus mode, etc. I also liked the D7100 dual dial at the front and back to change different settings with different dials, instead of needing to toggle the dial functionality to change two different settings via the menu system.

Most of the K-3′s buttons are placed on the right side, and it seems that the K-3 was designed to provide a convenient single-hand control, compare to the D7100 which have its button spread on both sides. The K-3 like the D7100 has a dual dial (front/rear) to control different camera settings.

Grip size comparison: Nikon D7100 and Pentax K-3

Grip size comparison: Nikon D7100 and Pentax K-3

The Nikon D7100 has a more rounded group which some people prefer. Both provide a deep and comfortable grip. Having said that, some of you might prefer buying the battery grip in order to get more room to put your pinkie, especially if you have large hands. A vertical battery grip better stabilizes the camera weight when you mount heavy and long lenses, as well as provide a place to insert an extra battery — allows you to shoot more photos and videos without changing the battery.

Both the D7100 and K-3 feature a large 100% coverage pentaprism viewfinder, with Pentax always pushes to provide photographers a larger and better in every new model.

  • Pentax K-3: 0.95x magnification
  • Pentax K-5 IIs: 0.92x
  • Pentax K-5: 0.92x
  • Pentax K-30: 0.92x
  • Pentax K-x: 0.85x
  • Pentax K-r: 0.85x

0.95x magnification is certainly a great feature to have in a new Pentax flagship DSLR camera. Furthermore, the K-3 glass prism is treated with a new coating to improve reflectance for a much brighter image.

Both cameras feature a 3.2″ fixed high-res LCD display but not touchscreen functionality on neither devices. The K-3 also enjoys a more durable (50K cycles more) shutter durability which adds to its professionalism and gives the camera an added value.

Summary: I give my top score to the K-3 for extra durability, larger viewfinder, full magnesium-alloy constructing. Both cameras have a dual-memory card slot.

Sensor, Image Stabilization and Performance

AA Filter – With or Without? (Maybe both)

The Pentax K-3 features a newly-developed 24MP (effective) APS-C CMOS sensor and a newly developed PRIME III image processor. The K-3 features a unique and innovative selectable anti-aliasing filter technology. This technology allows photographers to choose whether to shoot with the anti-aliasing filter on or off. This allows photographers to gain more control over the image output, and toggling the AA filter when they found fit for a specific shooting scenario.

As some of you might already know, by removing the AA filter, the camera can capture an image with more details (at some degree), but it’s more prone to moiré effect. Cameras like the Nikon D800e, Leica M9, Sigma’s Foveon-based DSLRs. Fujifilm X100 and all medium format camera’s digital backs lack this AA filter, which is also referred to as optical low pass filter (OLPF).

Nikon D7100 also lacks that optical low pass filter as well — but unlike the Nikon D7100, you can’t toggle the AA filter effect on or off. However many reviews have shown that there isn’t any practical advantage to removing the AA filter. You can check out this page of the Nikon D7100 review on dpreview. You can see that there is a difference, but it’s very small, and visible only if you look at the image at 100% scale. So it seems that the non-AA filter advantage was exaggerated by camera manufacturers, and there isn’t any big substantial benefit from having non-AA based camera. On the other hand, there isn’t any big downside either. Some photographers who care about every tiny bit of detail might find it tempting to get a model without the AA.

Pentax K-3 actually solved us the headache for deciding between a non-AA based DSLR and one with AA filter by allowing us to toggle between the two.

So how that anti-aliasing simulator toggle function actually work? — Well, according to Pentax, the sensor itself lacks the optical low pass filter. In order to achieve the same effect that you get with an AA filter, the K-3 uses the SR sensor vibration technology and applies microscopic vibrations which moves the image sensor at a sub-pixel accuracy and simulates the effect of an AA filter. Also worth mentioning that this is the first time ever what such an anti-aliasing simulator function is used with any digital camera. Furthermore, K-3 allows you to adjust the level of the AA simulation effect as well.

The next video wasn’t shot with either the K-3 or D7100, but it gives you a good idea of the effect of an Anti-moiré / anti-aliasing filter.

Just want to add that the Pentax K-3 uses DR II (Dust Removal II) dust removal mechanism that utilizes a UV/IR-cut filter, absorption-type IR-cut glass, Piezoelectric element which sits above the CMOS image sensor, including a dust alert system.

Image Stabilization

Pentax K-3 features a built-in sensor-shift image stabilization mechanism, the Nikon D7100 like all Nikon DSLRs, does not. This unique image stabilization ‘SR’ (Shake Reduction) unit supports various features of the K-3, including auto level compensation, image-compensation adjustment, Astro Tracer and of course the basic image stabilization feature to reduce the occurrence of blurry images when shooting handheld and in slow shutter speeds.

This in-body SR mechanism works with any Pentax lens you attach to the camera. Pentax also improved this mechanism compare to the older version by using a dedicated servo controller and increased the magnetic force that drives the IS unit to provide a more effective mechanism.

This means that you no longer need to worry about whether you can afford buying a specific image stabilized lens due to higher cost — every non image stabilized lens that you mount on the K-3 will be stabilized. A great feature that is both very useful for low-light photography and when shooting with telephoto / telephoto-zoom lens and one that can save you quite a lot of money (image stabilized lenses cost more, sometimes much more!).

So this is another advantage that the Pentax K-3 has over the D7100, and an important one too I have to say.

The next video was shot with the Pentax K-r. First part of the video was shot with the Shake Reduction (SR) turned off, and the second part of the video was shot with the SR turned ‘On’. You can clearly see the effect that it has when shooting videos — but the same applies to stills.

Light Metering and AF Module

Let’s take a look at the specs first:

  • Pentax K-3
    - Newly designed SAFOX 11 AF with 27 AF points (25 are cross-type)
    - Center and two points below and above the center are compatible with AF at F2.8
    - AF working range as low as -3EV (up to +18EV)
    - 86,000 pixel RGB light-metering sensor with Real-time scene analysis and improved algorithms
  • Nikon D7100
    - 51-point (15 are cross-type) Multi-CAM 3500DX AF Sensor Module (covers the entire area in the 1.3x crop of DX mode)
    - Center AF point is compatible with AF at f/8
    - AF working range as low as -2EV
    - 3D Color Matrix Metering II 2,016-pixel RGB sensor

Pentax really gives Nikon a good run for the money.  The Pentax K-3 has less AF points, but has center point that provided more accurate focusing with fast-aperture lenses, more sensitive AF working range, more cross-type AF points and high-resolution light-metering sensor to further enhance the light-metering accuracy, which also contribute to improve AF performance and proper white balance.

The Nikon D7100 as already tested by many camera reviewers and found to be extremely fast an accurate. I am skeptical whether Pentax can outperform the D7100, but we need to wait for some field tests to see whether the K-3 can achieve the same great performance that we’ve seen from the D7100.

Continuous Shooting Speed

The Pentax K-3 can shoot at 8.3 fps in continuous shooting mode and has a generous buffer that allows 22 images in RAW and up to 60 images in JPEG format. Let’s not forget that we are talking about a 24MP resolution image. We finally get a high-resolution APS-C camera that provided a high burst speed — which also makes the K-3 a good camera for the fast-action shooter in general and sports photography in particular.

The K-3 uses various technologies, including a mechanism to regular the shutter, mirror and diaphragm independently and a mechanism to reduce the mirror shock when it flips up and down.

Nikon D7100 can shoot full-res image at approx. 6 fps for up to 100 frames. The next video does a good job explaining about the D7100 continuous shooting mode speeds.

The Nikon has a larger buffer but the Pentax shoots quicker. I was really impressed when I first read that the K-3 has such a  high resolution and still enjoy such a high burst speed — excellent job Pentax (or should I say Ricoh).

Video Recording

Pentax K-3 can record Full HD videos at 60i, 30p and 25p (NTSC) or 60p, 30p and 24p in HD resolution. It has a built-on monaural microphone but comes with a mic input which you can use to connect a high-quality external stereo microphone to improve the video audio quality.

Pentax also included a headphone input for monitoring the audio. Certainly a good range of features that puts Pentax at the same level of other movie-oriented DSLR cameras, although it lacks an articulating LCD display.

Pentax K-3 can also record 4K-resolution image clips (3840 x 2160 pixels) at a fixed interval which is useful for time-lapse videos.

Pentax K-3 also feature a USB 3.0 socket — which makes it the first DSLR camera to support USB 3.0 SuperSpeed data connection (correct me if I am wrong). USB 3.0 provided backward compatibility.

Nikon D7100 can shoot full HD videos with its D-Movie in 30p or 60i or change to 720p60 to enjoy smooth video with high quality progressive frames. One cool feature that the D7100 has is the ability called 1.3x crop which provides an even narrower FOV. So instead of 1.5x of the lens focal length, you get 2x of the lens focal length, allowing you to get closer to your subject without any impact on image quality.

Nikon D7100 comes with a built-in stereo microphone, stereo mic input and a headphone terminal. D7100 is also capable of shooting time-lapse videos (see page 145 in the manual). Nikon refers to it in the manual as “Interval timer Photography“. You choose the starting time, the interval and number of intervals.

Check this gorgeous time Lapse video of the Milky Way shot by Harley Grady.

Pentax K-3 – The Ultimate APS-C Camera?

The Pentax K-3 is a very impressive DSLR camera which drives innovation in times where it seems that camera manufacturers just not innovating enough smaller field of view.
So what I liked about the Pentax K-3: It’s (relatively) compact design, superb durability and body construction, the toggleable AA filter, built-in SR (shake reduction), big viewfinder, fast 8.7 fps burst, advanced AF and light metering system, 4K video clip recording, dual SD card slot, USB 3.0 and native ISO 51200 sensitivity.

When we compare the K-3 to the Nikon D7100 we can see that the D7100 has several advantages, including: built-in stereo mic, more AF points, 1.3x DX mode for video recording, 1/250 sec flash x sync speed (compare to 1/180 Sec of the K-3), bigger burst buffer and excellent 950 shots battery life (compared to the K-3′s 560 images CIPA – 50% flash used).

It seems that Pentax is a bit late to the party, and I am skeptical whether it can still some of Nikon’s or Canon’s loyal customers, even with such a good camera. I also still think that Pentax should release a full frame DSLR camera, Many photographers are moving to compact system cameras, and it seems that the future of DSLR cameras belongs to FF cameras, not APS-C cameras.
On the other hand, I have no doubt that there will be many photographers who already frustrated with Canon and Nikon lack of innovation, and they already made their mind buying the K-3.  If Pentax can innovate that much, I think we’ll soon see a new Pentax FF camera.

Pentax improved the mirror-bounce damper mechanism, it’s image stabilization, increased the burst buffer to support up to 60 image capacity, introduced a newly developed image processor, light metering sensor and AF module. It employed a new scene analysis system, improved the camera’s durability, added auto level compensation and multiple exposure function  (up to 2000 frames), improved the ergonomics and button layout of the camera, added 4K-compatible interval movie shooting, bump up the size and improved the viewfinder, improved the dust removal mechanism (DR II), etc.. etc.

In my opinion, Pentax one of the most innovative companies currently in the DSLR market. As this market shrinks in favor of compact system cameras, it’s important to deliver high-quality products. I think that now, more than ever, people are less loyal to a specific company, and it means that people will think less moving to using equipment of another company — and Pentax seems the shiniest one at this moment.

Personally, I had enough seeing those slight changes in Nikon and Canon each year, and I am happy for Pentax for investing in such a great camera and I hope it will extend its customer base after this release.

If you are searching to buy a new APS-C DSLR camera, I highly recommend checking the K-3 out. We still need to wait for some sample images to compare the K-3 against its rivals.  The official K-3 sample images look very impressive, an I mean — VERY impressive (check this image for example). So did the K-3 convinced you to switch from your Canon or Nikon DSLR? — Share your thoughts in the comment section below.

If I needed to purchase a DSLR right now, I would certainly put the K-3 at the top of my list — and I recommend you to do so too.

Buy Pentax K-3 from B&H Photo Store

Buy Pentax D7100 from B&H Photo Store

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  • Dave Rearwin

    You gave the Nikon D7100 burst depth as 100 frames (you didn’t say if this was RAW or JPEG or both.)
    According to ImagingResource:
    “at full resolution, according to Nikon the D7100 can shoot just eight 14-bit raw or 33 JPEG fine frames in a burst. (We measured lower buffer numbers in the lab.) Enable the crop [which lowers the resolution], and that jumps to 14 raw or 73 JPEG frames.”
    So who has the correct numbers?

  • Frederic Boehli

    pentax k3 is far superior in buffer, you re absolutely not objective.
    it s a better build camera with a lot of of better things :
    - weather sealing
    - all metalic body
    - better buffer
    - faster processor
    - cel adjustment
    - frame rate
    - as fast and precise focus, better cross sensors etc…

  • Geoff

    I’m a Nikon D7000 owner, and I have to admit, the K3 looks pretty good on paper. I’m curious, though, to see the AF performance compared to the D7100. K3 has more cross type AF points, but 27 total AF on the K3 compared to 51 on the D7100 is quite a difference. I love that the K3 has IBIS though. I wish Nikon would do that. If I didn’t have so many Nikon lenses I might consider switching.

  • alpaslan menese

    I am planning to buy a DSLR and thinking about K-3 seriously. But, I have read several comments about AF issues for still and continuous shooting. On the other hand, I have just read that with new firmware update these issues resolved. The bad thing is that almost all the reviews of K-3 belongs to pre release dates. Is there any new updated reviews around published in 2014?