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Pentax K-3 III Review

We review the new Pentax K-3 III DSLR from Ricoh Imaging and take an in-depth look at the camera's new features, as well as look at the image quality from the camera. Find out how the K-3 III performs.

|  Pentax K-3 III in Digital SLRs
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The Pentax K-3 III is the long-awaited update to the Pentax K-3 Mark II, released in 2015, Pentax's flagship APS-C sensor DSLR. The Pentax K-3 III is a 26mp DSLR, with a BSI CMOS sensor, and whilst the rest of the camera market has almost entirely switched to mirrorless cameras, Pentax believes "in the future of SLR photography" with the optical viewfinder being central to this experience.


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Pentax K-3 Mark III Features


Looking at the Pentax K-3 III website, the first main point to come up is the optical viewfinder, which offers a 100% field of view, and approx 1.05x magnification (0.7x equivalent), making it one of the largest you'll find in an APS-C DSLR, and an improvement over the K-3 II (with 0.95x magnification) - Pentax say there's also a 10% increase in brightness. There's an eye-sensor to detect when you have the camera held up to your eye, and this will automatically switch the screen off when needed.


"This viewfinder also provides an almost 10-percent increase in brightness, thanks to the improved reflectance of the pentaprism, while also assuring a nearly 100-percent field of view. By incorporating a distortion-compensating optical element and optimizing the lens coatings, it provides natural, true-to-life image rendition with high-magnification observations." - Pentax

Pentax K3 Iii Viewfinder |

Another key update to be found in the Pentax K-3 Mark III can be seen in the new autofocus (AF) system, which now features 101 AF Points (SAFOX 13) when using the OVF-AF system, of these there are 25 cross-type AF points, and you can select 41 individually. The focus system will work down to -4EV with an f/2.8 (or brighter) lens, in the central AF area.

The camera features a new 25.7megapixel BSI CMOS sensor, without an anti-aliasing (AA) filter, to give improved detail and resolution capture. This makes it one of only few APS-C cameras available with a 25.7mp BSI CMOS sensor, with only Fujifilm also using a BSI CMOS sensor.

The K-3 III, like other Pentax DSLR cameras, features a SHAKE REDUCTION (SR) mechanism, SRII, which is an In-Body Image Stabilisation system, which moves the camera sensor in 5-axis, to give up to 5.5stops of stabilisation, by moving the sensor and compensating for camera shake caused by horizontal and vertical shift, roll, pitch and yaw. There is an Auto mode, as well as a panning mode option.

Using the shake reduction system, and the camera's ability to move the sensor, the camera has a Pixel Shift Resolution System, designed to give full-colour information at each pixel, by capturing 4 images of the same scene, but with the sensor slightly shifted. This is designed to work with the camera mounted on a tripod, and ideally with still scenes. However, there is a Motion Compensation feature that can be turned on to help with any motion in the scene. This gives you a 26mp image, with better colour, detail, as well as improved noise control.

There's also an AA (anti-aliasing) filter simulator so that you can reduce moire and false colour if this is an issue in your shots.


There's a new PRIME V image engine (processor) and "second-generation accelerator unit" (processor) to give high-speed performance, and this is said to improve the Pentax Real-Time Scene Analysis System, and autofocus system. Along with the new image processing engines, the camera has a new generation "Fine Sharpness" function that is on by default and is designed to improve the reproduction of detail more naturally and sharply.

Pentax says that the noise reduction system is designed to reduce noise, whilst maintaining detail in the outline of subjects, with Pentax claiming that "even at the top sensitivity of ISO 1,600,000, it delivers a natural, well-defined image with a sharp subject outline and vivid colours." We'll have to have a look at the results to see if this is true.

There's a new RGBIr AE sensor with approximately 307,000 pixels (0.3mp), which detects the subject in greater detail than before, and Pentax says that this is also used to detect the subjects face and eyes in viewfinder shooting. The Real-time Scene Analysis System uses this to provide exposure control and automatic selection of the focus point. This is also used to provide more accurate tracking of subjects in motion.

The K-3 Mark III camera has P, Sv, Tv, Av, TAv, M shooting modes, giving you full manual controls, along with B (Bulb), X (X-sync), 5 User modes, and Auto. The lag between shutter release and image capture has been improved, compared to the K-3 II, and the mirror and shutter drive mechanisms have also been upgraded. There's said to be minimised mirror bounce, and reduced weight of the main mirror unit, which reduces collision energy, and a new damper mechanism.

The K-3 III offers improved compatibility with classic lenses, saving the aperture value as Exif data when you set the aperture using the electronic dial, and you can set the focal length of the lens to make the most of Shake Reduction (SR). It also allows AE photography with the aperture closed-down for M-series lenses.

For continuous shooting, the camera offers 12fps continuous shooting (AF-S), and up to 11fps with continuous AF.

Custom Image control lets you choose from 13 different colour profiles, with options to adjust saturation, hue, high/low key adjustment, contrast, contrast (highlight), contrast (shadow), and fine sharpness.

The camera body features a 3.2inch touch-screen, that is fixed, and does not tilt. There are dual SD card slots, with one of these supporting UHS-II.

Wireless connectivity supports image transfer to a smartphone, and low-power Bluetooth can be used to transfer GPS data to the camera so that images are tagged with GPS location data.

The camera records 4K UHD video at 30 or 24fps, and FullHD video at 60, 30, 24fps, there is no 50/25fps option. When recording video the camera benefits from the shake reduction system, which will help stabilise video. There are mic and headphone sockets, and you can adjust the microphone level (or leave it on Auto), and adjust the headphone volume. You can use the touch-screen to set the focus point, and there are a number of other settings that can be adjusted using the touch-screen.

The camera supports the ASTROTRACER function, with an optional GPS unit. This lets you take astrophotographs, where the camera will move the sensor when needed for long exposure photographs.


Key Features

  • 25.7mp APS-C BSI CMOS sensor
  • Pentax K bayonet
  • In-Body Shake Reduction system, SR II (IBIS)
  • 3.2inch touch-screen, with 1.62m dots
  • 1.05x magnification TTL prism optical viewfinder, with 100%
  • 101 AF Points (SAFOX 13), 25 cross-type
  • 12fps continuous shooting (AF-S), 11fps AF-C
  • ISO100 to ISO1600000 available
  • Shutter life rating of 300,000 shots
  • 4K video recording, UHD, 30 or 24fps
  • FullHD video recording at 60,30,24fps
  • Weather sealed magnesium alloy body
  • Wi-Fi and Bluetooth built-in
  • Available in Black or Silver

Pentax K-3 Mark III Handling


For those who like the feeling of holding a Digital SLR, the Pentax K-3 III has excellent ergonomics, with the grip being particularly comfortable and pleasing to hold. It has the same shutter release button mechanism as the Pentax K-1, using a leaf switch, and the shutter release button feels really nice to use

The body is made from magnesium-alloy, and this includes the top, bottom, front and rear panels. The camera is weather-sealed, and when an AW (All-Weather) or WR (Weather Resistant) lens is mounted, you have a completely weather-sealed camera system.

The top LCD panel provides you with the shutter, aperture, ISO speeds as well as additional information so you can quickly see the cameras settings, battery status, and memory card information, as well as AF information.

The top LCD screen is backlit, and on default settings, this illuminates when you switch the camera on, and when you press the shutter release button. It automatically switches off the illumination (on Auto settings), after a short period of inaction. You can set the screen to manual, and then set one of the custom buttons to switch it on and off when needed, or you can set it to be off at all times. It's unfortunate that there's not a button already dedicated to switch the illumination on and off. However, as there are 10 customisable buttons this is easily resolved.


The Pentax K-3 III features the expected front and rear control dials, plus a third, additional control dial (E-Dial) on the top. This can be used to change settings, such as AF type, or ISO speed, and this can be selected using the S.Fn (Smart Function) button on top of the camera. When you press this button you get to set what the third dial does, from a choice of 5 different things, and these 5 functions can be customised from 22 options. If you do use the E-Dial for ISO control, then it takes the camera out of Auto ISO, as expected, but trying to get back into Auto ISO can take a while - you can either press the ISO button and then the green button, or you can go back into the S.Fn button and switch to Auto ISO there - rather than being able to scroll through to Auto ISO like on other cameras.

It can take a little while to get used to the three control dials, and it's easy to accidentally use the third E-dial accidentally. You can set it so that it's switched off completely (in the menus), so this could be an option for those looking to simplify camera operation, however, it would be nice if you could set up the Smart Function so that you had say 4 options available, and a 5th option where the E-Dial was switched off.


Now for some Q&A: What's in the box?

There is no external battery charger provided - these are available separately, however, if you're upgrading from an earlier Pentax, it's likely you already have one. A USB power adapter and USB cable is provided in the box so that you can charge the battery in the camera.

Q&A: Where can I find the manual?

If there's no printed manual in the box with your camera (depending on region), here's where you can find the manual to download from Ricoh / Pentax.

Q&A: Where can I find the software to use with the Pentax K-3 Mark III?

The provided software “Digital Camera Utility 5” is stored in the internal memory of the camera, and you can access this when you connect the camera to your computer and switch it on, however, make sure you've set the access to CD-ROM in the settings menus. Here are the instructions you'll need to follow:

The software can be installed by following the procedure below.

  1. Set [USB Setting] to [CD-ROM] in the D4 menu.
  2. Turn the camera off.
  3. Connect the camera to a computer using a USB cable.
  4. Turn the camera on. The camera is recognized as CD-ROM [S-SW177].
  5. Open [S-SW177] on the computer. The [Win] or [Mac] folder appears.
  6. Open the [Win] or [Mac] folder.
  7. Double-click [setup32.exe] or [setup64.exe] for Windows, or [INSTPUT5.pkg] for Mac.For subsequent steps, follow the on-screen instructions.
  8. Return [USB Setting] to [MTP] in the D4 menu.
  9. Turn the camera off and back on.The [USB Setting] setting switches to [MTP].

With “Digital Camera Utility 5”, you can develop RAW images, make colour adjustments, or check shooting information on the computer.

You'll find this vital piece of information in the full manual (or above, on this page), it would be nice if this information was provided on a piece of paper in the box, or alternatively why not just let users download it from the Pentax website? In answer to our own question, you can download it from Pentax's website, however, it informs you that you have to install the (original) software before installing the update on the Pentax website. We ignored this and installed the software from the website without any problems.

Pentax K 3 III Silkypix Digital Camera Utility 5
Pentax K-3 III - Digital Camera Utility 5

Q&A: Is Digital Camera Utility 5 the same as SilkyPix?

No, but it's based on SilkyPix software, so the interface and controls will be familiar to anyone who has used SilkyPix.

Q&A: Do I have to use Digital Camera Utility 5 / SilkyPix?

No, you can use any photo software compatible with Pentax K-3 III PEF raw files, or switch the camera to shoot AdobeDNG raw files, and then this will make it possible to open raw files on older software.


There are 101 AF points, vastly more than the 27 found on the K-3 II. You can select 41 of these points, and 25 are cross-type sensors (found in the central area of the image). You can select Auto area, Zone select, Select, Expanded select area, Select and Spot, and the joystick on the back lets you set the focus point more quickly. Focus works down to -4 EV, when using an f/2.8 lens. The 307,000 pixel RGBIr image sensor is used to provide tracking of subjects, includes faces and birds, to help the camera focus more accurately.

The optical viewfinder (OVF) overlay is a little difficult to see at times, indoors and outdoors mostly, and the focus points that light up red, are also quite dull, and disappear quickly. You'll also find that there isn't much of a protrusion, and we'd prefer it if the OVF extended further back out of the camera, so that your nose isn't so close to the camera body and camera screen. The camera settings such as shutter speed, aperture, ISO speed and other camera settings are shown clearly at the bottom of the OVF.

You can use the 3.2inch touch-screen to change settings and options, as well as scroll through the menus. When using the screen, there were often times when photos look overexposed on the rear screen, and in live-view images look brighter and whiter than they actually are, so if you're shooting product shots, the white background will look correctly corrected, and white, however, when you look at them on your computer, you'll find they will have a yellow tone (depending on your white balance settings).

If you're using live-view or video recording, then the lack of a tilting screen can be frustrating, and for the most part, you may want to use the optical viewfinder. However, if you're used to a fixed screen, then this may not be an issue for you.


Menus - The menu system found on the K3 III has been updated. You can choose the colour theme, we went for blue, however, the camera is also set up so that every section uses this colour theme, so the photo menus, the playback menus, the custom settings menus, and the setup menus are all the same colour. We much prefer different sections to have different colours, so you can quickly see where you are in the menus. If you're used to using an earlier Pentax camera, then it may take a while to get used to the new menu system. One really nice feature of the new menus is the built-in help system, which explains functions, options and settings in an easy to understand manner.


Battery life - Battery life is rated at 800 shots according to Pentax / CIPA test results, which is quite good but is likely to be less when using live view. The camera takes the same battery as previous Pentax cameras but does not include an external charger in the box. The battery is therefore charged in-camera using the USB Type-C connection, you can also use the camera whilst powering it over USB. There's an optional D-BG8 battery grip available.

Whilst you can shoot at up to 12fps, the number of shots is fairly low, with 36 JPEG (SF) shots / 27 RAW+JPEG shots possible, before slowdown/stopping. The camera has 2 SD card slots, however, only the first one is UHS-II.

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Photographs taken using the Pentax K-3 III

TurnstoneScarborough HarbourFlamborough HeadCormorantFolk SingerWhitbyNot a Barn Owl....Tractor Engine AbstractRoebuckRed AdmiralJust a Single..Rock Pool AbstractJapanese AnemoneSpeckled WoodYoung Robin

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28 Jul 2021 5:51PM
Interesting review. Having used mine for the last 2-3 months I'd like make the following points about the camera and the review.
1. There seems to be quite a bit of nit picking in the review. Hardly anything comes with a printed manual these days. It hardly affects the quality of the camera. Same applies to software. It's quite clearly identified in the downloaded manual (pages 97/98), so why waste time, effort and space in the review?
2. You failed to mention the new (for Pentax) highlight exposure mode which is, IMO, is very useful when there is strong sunlight on the subject.
3. You made a lot about not providing an external battery charger with the camera but failed to mention that a charger and lead are provided for charging the battery in the camera. Again, IMO, this is a plus, not a negative. It's far easier than having to take the battery out every time it needs charging. Plus it takes up less space and weight when you are travelling.
4. I've tried using the camera on continuous to tog the Gannets at Bempton and have personally not had an issue with buffering when using a UHS-II card. It was a problem when I tried it with the other, UHS-I, card. If I'd have kept my finger on the button much longer I'd have probably been better using the video mode.
5. Again, with or without my glasses on, I couldn't see what your issue is with the viewfinder relief
6. I've found the camera to be far heavier on battery use than my K1. I put this down to using Bluetooth for recording GPS data from my phone.
7. For me the lack of a tilting screen is not a problem. Again this is a personal preference, but I don't think it should be noted as a con or as a pro.
8. It's definitely an improvement on the K3-II
9. As for the price/value for money, could it be that Pentax are taking advantage of the fact the big boys appear to be losing interest in dSLRs and Pentax are positioning themselves for when dSLRs are a niche market product?

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