Olympus E-M10 III vs Pentax K-3 II
The Olympus OM-D E-M10 Mark III and the Pentax K-3 II are two digital cameras that were announced, respectively, in August 2017 and April 2015. The E-M10 III is a mirrorless interchangeable lens camera, while the K-3 II is a DSLR. The cameras are based on a Four Thirds (E-M10 III) and an APS-C (K-3 II) sensor. The Olympus has a resolution of 15.9 megapixels, whereas the Pentax provides 24.1 MP.
Below is an overview of the main specs of the two cameras as a starting point for the comparison.
Going beyond this snapshot of core features and characteristics, what are the differences between the Olympus OM-D E-M10 Mark III and the Pentax K-3 II? Which one should you buy? Read on to find out how these two cameras compare with respect to their body size, their imaging sensors, their shooting features, their input-output connections, and their reception by expert reviewers.
The physical size and weight of the Olympus E-M10 III and the Pentax K-3 II are illustrated in the side-by-side display below. The two cameras are presented according to their relative size. Three consecutive views from the front, the top, and the rear side are shown. All size dimensions are rounded to the nearest millimeter.
Both cameras are available in two different colors (black, silver).
If the front view area (width x height) of the cameras is taken as an aggregate measure of their size, the Pentax K-3 II is notably larger (28 percent) than the Olympus E-M10 III. Moreover, the K-3 II is substantially heavier (95 percent) than the E-M10 III. It is noteworthy in this context that the K-3 II is splash and dust-proof, while the E-M10 III does not feature any corresponding weather-sealing.
The above size and weight comparisons are to some extent incomplete since they do not consider the interchangeable lenses that both of these cameras require. Hence, you might want to study and compare the specifications of available lenses in order to get the full picture of the size and weight of the two camera systems.
The adjacent table lists the principal physical characteristics of the two cameras alongside a wider set of alternatives. In case you want to display and compare another camera duo, you can use the CAM-parator app to select your camera combination among a large number of options.
|1.||Olympus E-M10 III||122 mm||84 mm||50 mm||410 g||330||n||Aug 2017||649|
|2.||Pentax K-3 II||131 mm||100 mm||77 mm||800 g||720||Y||Apr 2015||1,099|
|3.||Olympus E-M10 IV||122 mm||84 mm||49 mm||383 g||360||n||Aug 2020||699|
|4.||Olympus E-PL10||117 mm||68 mm||39 mm||380 g||350||n||Oct 2019||599|
|5.||Olympus E-PL9||117 mm||68 mm||39 mm||380 g||350||n||Feb 2018||599|
|6.||Olympus E-PL8||115 mm||67 mm||38 mm||357 g||350||n||Sep 2016||549|
|7.||Olympus PEN-F||125 mm||72 mm||37 mm||427 g||330||n||Jan 2016||1,199|
|8.||Olympus E-M10 II||120 mm||83 mm||47 mm||390 g||320||n||Aug 2015||649|
|9.||Olympus E-M10||119 mm||82 mm||46 mm||396 g||320||n||Jan 2014||699|
|10.||Olympus E-PL7||115 mm||67 mm||38 mm||357 g||350||n||Aug 2014||599|
|11.||Olympus E-P5||122 mm||69 mm||37 mm||420 g||330||n||May 2013||999|
|12.||Panasonic GX80||122 mm||71 mm||44 mm||426 g||290||n||Apr 2016||799|
|13.||Pentax K-3 III||135 mm||104 mm||74 mm||820 g||800||Y||Mar 2021||1,999|
|14.||Pentax KP||132 mm||101 mm||76 mm||703 g||390||Y||Jan 2017||1,099|
|15.||Pentax K-70||126 mm||93 mm||74 mm||688 g||410||Y||Jun 2016||649|
|16.||Pentax K-3||131 mm||100 mm||77 mm||800 g||560||Y||Oct 2013||1,299|
|17.||Pentax K-5||131 mm||97 mm||73 mm||760 g||740||Y||Sep 2010||1,099|
|Notes: Measurements and pricing do not include easily detachable parts, such as add-on or interchangeable lenses or optional viewfinders.|
Any camera decision will naturally be influenced heavily by the price. The retail prices at the time of the camera’s release place the model in the market relative to other models in the producer’s line-up and the competition. The E-M10 III was launched at a markedly lower price (by 41 percent) than the K-3 II, which puts it into a different market segment. Usually, retail prices stay at first close to the launch price, but after several months, discounts become available. Later in the product cycle and, in particular, when the replacement model is about to appear, further discounting and stock clearance sales often push the camera price considerably down. Then, after the new model is out, very good deals can frequently be found on the pre-owned market.
The imaging sensor is at the core of digital cameras and its size is one of the main determining factors of image quality. A large sensor will generally have larger individual pixels that offer better low-light sensitivity, provide wider dynamic range, and have richer color-depth than smaller pixels in a sensor of the same technological generation. Moreover, a large sensor camera will give the photographer more control over depth-of-field in the image and, thus, the ability to better isolate a subject from the background. On the downside, larger sensors tend to be more expensive and lead to bigger and heavier cameras and lenses.
Of the two cameras under consideration, the Olympus E-M10 III features a Four Thirds sensor and the Pentax K-3 II an APS-C sensor. The sensor area in the K-3 II is 63 percent bigger. As a result of these sensor size differences, the cameras have a format factor of, respectively, 2.0 and 1.5. The sensor in the E-M10 III has a native 4:3 aspect ratio, while the one in the K-3 II offers a 3:2 aspect.
In terms of underlying technology, both cameras are build around CMOS sensors.
With 24.1MP, the K-3 II offers a higher resolution than the E-M10 III (15.9MP), but the K-3 II nevertheless has larger individual pixels (pixel pitch of 3.90μm versus 3.76μm for the E-M10 III) due to its larger sensor. However, the E-M10 III is a much more recent model (by 2 years and 4 months) than the K-3 II, and its sensor will have benefitted from technological advances during this time that enhance the light gathering capacity of its pixel-units. Coming back to sensor resolution, it should be mentioned that neither of the two cameras has an anti-alias filter installed, so they are able to capture all the detail the sensor resolves.
The resolution advantage of the Pentax K-3 II implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the K-3 II for good quality output (200 dots per inch) amounts to 30.1 x 20 inches or 76.4 x 50.8 cm, for very good quality (250 dpi) 24.1 x 16 inches or 61.1 x 40.6 cm, and for excellent quality (300 dpi) 20.1 x 13.3 inches or 50.9 x 33.9 cm. The corresponding values for the Olympus E-M10 III are 23 x 17.3 inches or 58.5 x 43.9 cm for good quality, 18.4 x 13.8 inches or 46.8 x 35.1 cm for very good quality, and 15.4 x 11.5 inches or 39 x 29.3 cm for excellent quality prints.
Unlike the E-M10 III, the K-3 II has the capacity to capture high quality composite images by combining multiple shots after shifting its sensor by miniscule distances. This multi-shot, pixel-shift mode is most suitable for photography of stationary objects (landscapes, studio scenes).
The Olympus OM-D E-M10 Mark III has a native sensitivity range from ISO 200 to ISO 25600, which can be extended to ISO 100-25600. The corresponding ISO settings for the Pentax K-3 II are ISO 100 to ISO 51200 (no boost).
Consistent information on actual sensor performance is available from DXO Mark for many cameras. This service assesses and scores the color depth ("DXO Portrait"), dynamic range ("DXO Landscape"), and low-light sensitivity ("DXO Sports") of camera sensors, and also publishes an overall camera score. The table below summarizes the physical sensor characteristics and sensor quality findings and compares them across a set of similar cameras.
| DXO |
|1.||Olympus E-M10 III||Four Thirds||15.9||4608||3456||4K/30p||..||..||..||..|
|2.||Pentax K-3 II||APS-C||24.1||6016||4000||1080/60i||23.6||13.6||1106||80|
|3.||Olympus E-M10 IV||Four Thirds||20.2||5184||3888||4K/30p||..||..||..||..|
|4.||Olympus E-PL10||Four Thirds||15.9||4608||3456||4K/30p||..||..||..||..|
|5.||Olympus E-PL9||Four Thirds||15.9||4608||3456||4K/30p||..||..||..||..|
|6.||Olympus E-PL8||Four Thirds||15.9||4608||3456||1080/30p||..||..||..||..|
|7.||Olympus PEN-F||Four Thirds||20.2||5184||3888||1080/60p||23.1||12.4||894||74|
|8.||Olympus E-M10 II||Four Thirds||15.9||4608||3456||1080/60p||23.1||12.5||842||73|
|9.||Olympus E-M10||Four Thirds||15.9||4608||3456||1080/30p||22.8||12.3||884||72|
|10.||Olympus E-PL7||Four Thirds||15.9||4608||3456||1080/30p||22.7||12.4||873||72|
|11.||Olympus E-P5||Four Thirds||15.9||4608||3456||1080/30p||22.8||12.4||895||72|
|12.||Panasonic GX80||Four Thirds||15.8||4592||3448||4K/30p||22.9||12.6||662||71|
|13.||Pentax K-3 III||APS-C||25.6||6192||4128||4K/30p||..||..||..||..|
Many modern cameras are not only capable of taking still images, but also of capturing video footage. Both cameras under consideration have a sensor with sufficiently fast read-out times for moving pictures, but the E-M10 III provides a higher video resolution than the K-3 II. It can shoot video footage at 4K/30p, while the Pentax is limited to 1080/60i.
Apart from body and sensor, cameras can and do differ across a variety of features. For example, the E-M10 III has an electronic viewfinder (2360k dots), while the K-3 II has an optical one. Both systems have their advantages, with the electronic viewfinder making it possible to project supplementary shooting information into the framing view, whereas the optical viewfinder offers lag-free viewing and a very clear framing image. The viewfinders of both cameras offer the same field of view (100%), but the viewfinder of the K-3 II has a higher magnification than the one of the E-M10 III (0.63x vs 0.62x), so that the size of the image transmitted appears closer to the size seen with the naked human eye. The table below summarizes some of the other core capabilities of the Olympus E-M10 III and Pentax K-3 II in connection with corresponding information for a sample of similar cameras.
|1.||Olympus E-M10 III||2360||n||3.0||1040||tilting||Y||1/4000s||8.6||Y||Y|
|2.||Pentax K-3 II||optical||Y||3.2||1037||fixed||n||1/8000s||8.3||n||Y|
|3.||Olympus E-M10 IV||2360||n||3.0||1040||tilting||Y||1/4000s||15.0||Y||Y|
|8.||Olympus E-M10 II||2360||n||3.0||1040||tilting||Y||1/4000s||8.0||Y||Y|
|13.||Pentax K-3 III||optical||Y||3.2||1620||fixed||Y||1/8000s||12.0||n||Y|
One difference between the cameras concerns the presence of an on-board flash. The E-M10 III has one, while the K-3 II does not. While the built-in flash of the E-M10 III is not very powerful, it can at times be useful as a fill-in light.
The reported shutter speed information refers to the use of the mechanical shutter. Yet, some cameras only have an electronic shutter, while others have an electronic shutter in addition to a mechanical one. In fact, the E-M10 III is one of those camera that have an additional electronic shutter, which makes completely silent shooting possible. However, this mode is less suitable for photographing moving objects (risk of rolling shutter) or shooting under artificial light sources (risk of flickering).
The Olympus E-M10 III and the Pentax K-3 II both have an intervalometer built-in. This enables the photographer to capture time lapse sequences, such as flower blooming, a sunset or moon rise, without purchasing an external camera trigger and related software.
Concerning the storage of imaging data, both the E-M10 III and the K-3 II write their files to SDXC cards. The K-3 II features dual card slots, which can be very useful in case a memory card fails. In contrast, the E-M10 III only has one slot. The E-M10 III supports UHS-II cards (Ultra High Speed data transfer of up to 312 MB/s), while the K-3 II can use UHS-I cards (up to 104 MB/s).
For some imaging applications, the extent to which a camera can communicate with its environment can be an important aspect in the camera decision process. The table below provides an overview of the connectivity of the Olympus OM-D E-M10 Mark III and Pentax K-3 II and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.
| WiFi |
| NFC |
|1.||Olympus E-M10 III||Y||stereo||mono||-||-||micro||2.0||Y||-||-|
|2.||Pentax K-3 II||Y||mono||mono||Y||Y||mini||3.0||-||-||-|
|3.||Olympus E-M10 IV||Y||stereo||mono||-||-||micro||2.0||Y||-||Y|
|8.||Olympus E-M10 II||Y||stereo||mono||-||-||micro||2.0||Y||-||-|
|13.||Pentax K-3 III||Y||stereo||mono||Y||Y||micro||3.2||Y||-||Y|
It is notable that the E-M10 III offers wifi support, while the K-3 II does not. Wifi can be a very convenient means to transfer image data to an off-camera location.
Studio photographers will appreciate that the Pentax K-3 II (unlike the E-M10 III) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.
Travel and landscape photographers will find it useful that the K-3 II has an internal geolocalization sensor and can record GPS coordinates in its EXIF data.
Both the E-M10 III and the K-3 II have been discontinued, but can regularly be found used on eBay. The K-3 II was replaced by the Pentax K-3 III, while the E-M10 III was followed by the Olympus E-M10 IV. Further information on the two cameras (e.g. user guides, manuals), as well as related accessories, can be found on the official Olympus and Pentax websites.
So what is the bottom line? Which of the two cameras – the Olympus E-M10 III or the Pentax K-3 II – has the upper hand? Is one clearly better than the other? Below is a summary of the relative strengths of each of the two contestants.
Advantages of the Olympus OM-D E-M10 Mark III:
- Better video: Provides higher definition movie capture (4K/30p vs 1080/60i).
- More framing info: Has an electronic viewfinder that displays shooting data.
- More flexible LCD: Has a tilting screen for odd-angle shots in landscape orientation.
- Fewer buttons to press: Is equipped with a touch-sensitive rear screen to facilitate handling.
- Less disturbing: Has an electronic shutter option for completely silent shooting.
- More compact: Is smaller (122x84mm vs 131x100mm) and thus needs less room in the bag.
- Less heavy: Is lighter (by 390g or 49 percent) and hence easier to carry around.
- More legacy lens friendly: Can take a broad range of non-native lenses via adapters.
- Easier fill-in: Is equipped with a small onboard flash to brighten deep shadow areas.
- Easier file upload: Has wifi built in for automatic backup or image transfer to the web.
- Faster buffer clearing: Supports a more advanced SD data transfer standard (UHS-II vs UHS-I).
- More affordable: Was introduced into a lower priced category (41 percent cheaper at launch).
- More modern: Reflects 2 years and 4 months of technical progress since the K-3 II launch.
Reasons to prefer the Pentax K-3 II:
- More detail: Has more megapixels (24.1 vs 15.9MP), which boosts linear resolution by 25%.
- High quality composites: Can combine several shots after pixel-shifting its sensor.
- Better image quality: Features bigger pixels on a larger sensor for higher quality imaging.
- Richer colors: The pixel size advantage translates into images with better, more accurate colors.
- More dynamic range: Larger pixels capture a wider spectrum of light and dark details.
- Better low-light sensitivity: Larger pixels means good image quality even under poor lighting.
- Better sound: Can connect to an external microphone for higher quality sound recording.
- Better sound control: Has a headphone port that enables audio monitoring while recording.
- Brighter framing: Features an optical viewfinder for clear, lag-free composition.
- Larger viewfinder image: Features a viewfinder with a higher magnification (0.63x vs 0.62x).
- Easier setting verification: Features a control panel on top to check shooting parameters.
- Larger screen: Has a bigger rear LCD (3.2" vs 3.0") for image review and settings control.
- Faster shutter: Has higher mechanical shutter speed (1/8000s vs 1/4000s) to freeze action.
- Longer lasting: Gets more shots (720 versus 330) out of a single battery charge.
- Better sealing: Is splash and dust sealed for shooting in inclement weather conditions.
- Easier geotagging: Features an internal GPS sensor to log localization data.
- Faster data transfer: Supports a more advanced USB protocol (3.0 vs 2.0).
- Better studio light control: Has a PC Sync socket to connect to professional strobe lights.
- Greater peace of mind: Features a second card slot as a backup in case of memory card failure.
- More heavily discounted: Has been around for much longer (launched in April 2015).
If the count of individual advantages (bullet points above) is taken as a guide, the K-3 II is the clear winner of the contest (20 : 13 points). However, the relative importance of the various individual camera aspects will vary according to personal preferences and needs, so that you might like to apply corresponding weights to the particular features before making a decision on a new camera. A professional sports photographer will view the differences between cameras in a way that diverges from the perspective of a street photog, and a person interested in family portraits has distinct needs from a landscape shooter. Hence, the decision which camera is best and worth buying is often a very personal one.
How about other alternatives? Do the specifications of the Olympus E-M10 III and the Pentax K-3 II place the cameras among the top in their class? Find out in the latest Best Mirrorless Interchangeable Lens Camera and Best DSLR Camera listings whether the two cameras rank among the cream of the crop.
In any case, while the comparison of technical specifications can provide a useful overview of the capabilities of different cameras, it remains partial and cannot reveal, for example, the shooting experience and imaging performance when actually working with the E-M10 III or the K-3 II. User reviews, such as those found at amazon, can sometimes inform about these issues, but such feedback is often incomplete, inconsistent, and biased.
This is why expert reviews are important. The following table reports the overall ratings of the cameras as published by some of the major camera review sites (amateurphotographer [AP], cameralabs [CL], dpreview [DPR], ephotozine [EPZ], photographyblog [PB]). As can be seen, the professional reviewers agree in many cases on the quality of different cameras, but sometimes their assessments diverge, reinforcing the earlier point that a camera decision is often a very personal choice.
|1.||Olympus E-M10 III||..||+||80/100||4.5/5||4.5/5||Aug 2017||649|
|2.||Pentax K-3 II||4.5/5||..||..||5/5||5/5||Apr 2015||1,099|
|3.||Olympus E-M10 IV||4.5/5||..||81/100||4.5/5||4.5/5||Aug 2020||699|
|4.||Olympus E-PL10||..||..||77/100||..||4/5||Oct 2019||599|
|5.||Olympus E-PL9||..||+||..||4.5/5||4/5||Feb 2018||599|
|6.||Olympus E-PL8||..||..||..||4.5/5||4/5||Sep 2016||549|
|7.||Olympus PEN-F||..||..||82/100||4.5/5||5/5||Jan 2016||1,199|
|8.||Olympus E-M10 II||4.5/5||+ +||80/100||5/5||5/5||Aug 2015||649|
|9.||Olympus E-M10||4/5||..||80/100||5/5||5/5||Jan 2014||699|
|10.||Olympus E-PL7||4/5||+||..||5/5||4/5||Aug 2014||599|
|11.||Olympus E-P5||5/5||+ +||78/100||4.5/5||5/5||May 2013||999|
|12.||Panasonic GX80||4.5/5||+ +||82/100||5/5||5/5||Apr 2016||799|
|13.||Pentax K-3 III||..||..||..||..||..||Mar 2021||1,999|
|14.||Pentax KP||4/5||..||82/100||5/5||4.5/5||Jan 2017||1,099|
|15.||Pentax K-70||4.5/5||..||79/100||4.5/5||4.5/5||Jun 2016||649|
|16.||Pentax K-3||4/5||..||83/100||5/5||5/5||Oct 2013||1,299|
|17.||Pentax K-5||4/5||..||83/100||5/5||4.5/5||Sep 2010||1,099|
|Notes: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.|
The above review scores should be interpreted with care, though. The ratings were established in reference to similarly priced cameras that were available in the market at the time of the review. Hence, a score should always be seen in the context of the camera's market launch date and its price, and comparisons of ratings among very different cameras or across long time periods have little meaning. Also, please note that some of the review sites have changed their methodology and reporting over time.
Other camera comparisons
Did this review help to inform your camera decision process? In case you are interested in seeing how other cameras pair up, just make a corresponding selection in the search boxes below. There is also a set of direct links to comparison reviews that other users of the CAM-parator app explored.
Specifications: Olympus E-M10 III vs Pentax K-3 II
Below is a side-by-side comparison of the specs of the two cameras to facilitate a quick review of their differences and common features.
|Camera Model||Olympus E-M10 III||Pentax K-3 II|
|Camera Type||Mirrorless system camera||Digital single lens reflex|
|Camera Lens||Micro Four Thirds lenses||Pentax K mount lenses|
|Launch Date||August 2017||April 2015|
|Launch Price||USD 649||USD 1,099|
|Sensor Specs||Olympus E-M10 III||Pentax K-3 II|
|Sensor Format||Four Thirds Sensor||APS-C Sensor|
|Sensor Size||17.3 x 13.0 mm||23.5 x 15.6 mm|
|Sensor Area||224.9 mm2||366.6 mm2|
|Sensor Diagonal||21.6 mm||28.2 mm|
|Sensor Resolution||15.9 Megapixels||24.1 Megapixels|
|Image Resolution||4608 x 3456 pixels||6016 x 4000 pixels|
|Pixel Pitch||3.76 μm||3.90 μm|
|Pixel Density||7.08 MP/cm2||6.56 MP/cm2|
|Moiré control||no AA filter||no AA filter|
|Movie Capability||4K/30p Video||1080/60i Video|
|ISO Setting||200 - 25,600 ISO||100 - 51,200 ISO|
|ISO Boost||100 - 25,600 ISO||no Enhancement|
|Image Processor||TruePic VIII||PRIME III|
|DXO Sensor Quality (score)||..||80|
|DXO Color Depth (bits)||..||23.6|
|DXO Dynamic Range (EV)||..||13.6|
|DXO Low Light (ISO)||..||1106|
|Screen Specs||Olympus E-M10 III||Pentax K-3 II|
|Viewfinder Type||Electronic viewfinder||Optical viewfinder|
|Viewfinder Field of View||100%||100%|
|Viewfinder Resolution||2360k dots|
|Top-Level Screen||no Top Display||Control Panel|
|LCD Framing||Live View||Live View|
|Rear LCD Size||3.0inch||3.2inch|
|LCD Resolution||1040k dots||1037k dots|
|LCD Attachment||Tilting screen||Fixed screen|
|Touch Input||Touchscreen||no Touchscreen|
|Shooting Specs||Olympus E-M10 III||Pentax K-3 II|
|Focus System||Contrast-detect AF||Phase-detect AF|
|Manual Focusing Aid||Focus Peaking||Focus Peaking|
|Max Shutter Speed (mechanical)||1/4000s||1/8000s|
|Continuous Shooting||8.6 shutter flaps/s||8.3 shutter flaps/s|
|Electronic Shutter||up to 1/16000s||no E-Shutter|
|Time-Lapse Photography||Intervalometer built-in||Intervalometer built-in|
|Image Stabilization||In-body stabilization||In-body stabilization|
|Fill Flash||Built-in Flash||no On-Board Flash|
|Storage Medium||SDXC cards||SDXC cards|
|Second Storage Option||Single card slot||Dual card slots|
|UHS card support||UHS-II||UHS-I|
|Connectivity Specs||Olympus E-M10 III||Pentax K-3 II|
|Studio Flash||no PC Sync||PC Sync socket|
|USB Connector||USB 2.0||USB 3.0|
|HDMI Port||micro HDMI||mini HDMI|
|Microphone Port||no MIC socket||External MIC port|
|Headphone Socket||no Headphone port||Headphone port|
|Wifi Support||Wifi built-in||no Wifi|
|Geotagging||no internal GPS||GPS built-in|
|Body Specs||Olympus E-M10 III||Pentax K-3 II|
|Environmental Sealing||not weather sealed||Weathersealed body|
|Battery Life (CIPA)||330 shots per charge||720 shots per charge|
122 x 84 x 50 mm
(4.8 x 3.3 x 2.0 in)
131 x 100 x 77 mm
(5.2 x 3.9 x 3.0 in)
|Camera Weight||410 g (14.5 oz)||800 g (28.2 oz)|
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