Olympus E-M10 III vs Sony A9 II
The Olympus OM-D E-M10 Mark III and the Sony Alpha A9 II are two digital cameras that were revealed to the public, respectively, in August 2017 and October 2019. Both the E-M10 III and the A9 II are mirrorless interchangeable lens cameras that are based on a Four Thirds (E-M10 III) and a full frame (A9 II) sensor. The Olympus has a resolution of 15.9 megapixels, whereas the Sony provides 24 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 Sony Alpha A9 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 Sony A9 II are illustrated in the side-by-side display below. The two cameras are presented according to their relative size. Three successive views from the front, the top, and the rear are shown. All size dimensions are rounded to the nearest millimeter.
The E-M10 III can be obtained in two different colors (black, silver), while the A9 II is only available in black.
If the front view area (width x height) of the cameras is taken as an aggregate measure of their size, the Sony A9 II is notably larger (21 percent) than the Olympus E-M10 III. Moreover, the A9 II is substantially heavier (65 percent) than the E-M10 III. It is noteworthy in this context that the A9 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. A larger imaging sensor will tend to go along with bigger and heavier lenses, although exceptions exist. You can compare the optics available for the two cameras in the Micro Four Thirds Lens Catalog (E-M10 III) and the Sony FE Lens Catalog (A9 II). Mirrorless cameras, such as the two under consideration, have the additional advantage of having a short flange to focal plane distance, which makes it possible to mount many lenses from other systems onto the camera via adapters.
Concerning battery life, the E-M10 III gets 330 shots out of its BLS-50 battery, while the A9 II can take 690 images on a single charge of its NP-FZ100 power pack. The power pack in the A9 II can be charged via the USB port, which can be very convenient when travelling.
The adjacent table lists the principal physical characteristics of the two cameras alongside a wider set of alternatives. If you would like to visualize and compare a different camera combination, you can navigate to the CAM-parator app and make your selection from a broad list of cameras there.
|1.||Olympus E-M10 III||122 mm||84 mm||50 mm||410 g||330||n||Aug 2017||649|
|2.||Sony A9 II||129 mm||96 mm||76 mm||678 g||690||Y||Oct 2019||4,499|
|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.||Sony A7S III||127 mm||97 mm||81 mm||699 g||600||Y||Jul 2020||3,499|
|14.||Sony A7C||124 mm||71 mm||60 mm||509 g||740||Y||Sep 2020||1,799|
|15.||Sony A7R IV||129 mm||96 mm||78 mm||665 g||670||Y||Jul 2019||3,499|
|16.||Sony A7 III||127 mm||96 mm||74 mm||650 g||610||Y||Feb 2018||1,999|
|17.||Sony A9||127 mm||96 mm||63 mm||673 g||650||Y||Apr 2017||4,499|
|Notes: Measurements and pricing do not include easily detachable parts, such as add-on or interchangeable lenses or optional viewfinders.|
The price is, of course, an important factor in any camera decision. 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 86 percent) than the A9 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 size of the imaging sensor is a crucial determinant of image quality. All other things equal, a large sensor will have larger individual pixel-units that offer better low-light sensitivity, wider dynamic range, and richer color-depth than smaller pixels in a sensor of the same technological generation. Further, a large sensor camera will give the photographer additional creative options when using shallow depth-of-field to isolate a subject from its background. On the downside, larger sensors are more costly to manufacture and tend to 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 Sony A9 II a full frame sensor. The sensor area in the A9 II is 276 percent bigger. As a result of these sensor size differences, the cameras have a format factor of, respectively, 2.0 and 1.0. The sensor in the E-M10 III has a native 4:3 aspect ratio, while the one in the A9 II offers a 3:2 aspect.
With 24MP, the A9 II offers a higher resolution than the E-M10 III (15.9MP), but the A9 II nevertheless has larger individual pixels (pixel pitch of 5.94μm versus 3.76μm for the E-M10 III) due to its larger sensor. Moreover, the A9 II is a much more recent model (by 2 years and 1 month) than the E-M10 III, and its sensor will have benefitted from technological advances during this time that further enhance the light gathering capacity of its pixel-units. Coming back to sensor resolution, it should be mentioned that the E-M10 III has no anti-alias filter installed, so that it can capture all the detail its sensor resolves.
The resolution advantage of the Sony A9 II implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the A9 II for good quality output (200 dots per inch) amounts to 30 x 20 inches or 76.2 x 50.8 cm, for very good quality (250 dpi) 24 x 16 inches or 61 x 40.6 cm, and for excellent quality (300 dpi) 20 x 13.3 inches or 50.8 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.
The A9 II has on-sensor phase detect pixels, which results in fast and reliable autofocus acquisition even during live view operation.
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 Sony Alpha A9 II are ISO 100 to ISO 51200, with the possibility to increase the ISO range to 50-204800.
For many cameras, data on sensor performance has been reported by DXO Mark. This service determines an overall sensor rating, as well as sub-scores for low-light sensitivity ("DXO Sports"), dynamic range ("DXO Landscape"), and color depth ("DXO Portrait"). The adjacent table reports on the physical sensor characteristics and the outcomes of the DXO sensor quality tests for a sample of comparator-cameras.
| DXO |
|1.||Olympus E-M10 III||Four Thirds||15.9||4608||3456||4K/30p||..||..||..||..|
|2.||Sony A9 II||Full Frame||24.0||6000||4000||4K/30p||25.0||14.0||3434||93|
|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.||Sony A7S III||Full Frame||12.0||4240||2832||4K/120p||23.7||13.9||2520||86|
|14.||Sony A7C||Full Frame||24.0||6000||4000||4K/30p||25.0||14.7||3407||95|
|15.||Sony A7R IV||Full Frame||60.2||9504||6336||4K/30p||26.0||14.8||3344||99|
|16.||Sony A7 III||Full Frame||24.0||6000||4000||4K/30p||25.0||14.7||3730||96|
|17.||Sony A9||Full Frame||24.0||6000||4000||4K/30p||24.9||13.3||3517||92|
Many modern cameras are not only capable of taking still images, but also of capturing video footage. The two cameras under consideration both have sensors whose read-out speed is fast enough to capture moving pictures, and both provide the same movie specifications (4K/30p).
Apart from body and sensor, cameras can and do differ across a variety of features. The two cameras under review are similar with respect to both having an electronic viewfinder. However, the one in the A9 II offers a substantially higher resolution than the one in the E-M10 III (3686k vs 2360k dots). The adjacent table lists some of the other core features of the Olympus E-M10 III and Sony A9 II along with similar information for a selection of comparators.
|1.||Olympus E-M10 III||2360||n||3.0||1040||tilting||Y||1/4000s||8.6||Y||Y|
|2.||Sony A9 II||3686||n||3.0||1440||tilting||Y||1/8000s||10.0||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.||Sony A7S III||9440||n||3.0||1440||swivel||Y||1/8000s||10.0||n||Y|
|15.||Sony A7R IV||5760||n||3.0||1440||tilting||Y||1/8000s||10.0||n||Y|
|16.||Sony A7 III||2359||n||3.0||922||tilting||Y||1/8000s||10.0||n||Y|
One difference between the cameras concerns the presence of an on-board flash. The E-M10 III has one, while the A9 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, both cameras under consideration feature an 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 Sony A9 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 A9 II write their files to SDXC cards. The A9 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. Moreover, both cameras support UHS-II cards (Ultra High Speed data transfer of up to 312 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 Sony Alpha A9 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.||Sony A9 II||Y||stereo||mono||Y||Y||micro||3.1||Y||Y||Y|
|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.||Sony A7S III||Y||stereo||mono||Y||Y||full||3.2||Y||-||Y|
|15.||Sony A7R IV||Y||stereo||mono||Y||Y||micro||3.1||Y||Y||Y|
|16.||Sony A7 III||Y||stereo||mono||Y||Y||micro||3.1||Y||Y||Y|
It is notable that the A9 II has a headphone jack, which makes it possible to attach external headphones and monitor the quality of sound during the recording process. The E-M10 III lacks such a headphone port.
Studio photographers will appreciate that the Sony A9 II (unlike the E-M10 III) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.
The A9 II is a recent model that features in the current product line-up of Sony. In contrast, the E-M10 III has been discontinued (but can be found pre-owned on eBay). As a replacement in the same line of cameras, the E-M10 III was succeeded 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 Sony websites.
So how do things add up? Which of the two cameras – the Olympus E-M10 III or the Sony A9 II – has the upper hand? Is one clearly better than the other? The listing below highlights the relative strengths of the two models.
Advantages of the Olympus OM-D E-M10 Mark III:
- Maximized detail: Lacks an anti-alias filter to exploit the sensor's full resolution potential.
- More compact: Is smaller (122x84mm vs 129x96mm) and thus needs less room in the bag.
- Less heavy: Is lighter (by 268g or 40 percent) and hence easier to carry around.
- Easier fill-in: Is equipped with a small onboard flash to brighten deep shadow areas.
- More affordable: Was introduced into a lower priced category (86 percent cheaper at launch).
- More heavily discounted: Has been available for much longer (launched in August 2017).
Arguments in favor of the Sony Alpha A9 II:
- More detail: Has more megapixels (24 vs 15.9MP), which boosts linear resolution by 25%.
- Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
- Better image quality: Is equipped with a larger and more technologically advanced sensor.
- Richer colors: The sensor size advantage translates into images with better, more accurate colors.
- More dynamic range: Larger sensor captures a wider spectrum of light and dark details.
- Better low-light sensitivity: Larger sensor produces good images even in poorly lit environments.
- Better live-view autofocus: Features on-sensor phase-detection for more confident autofocus.
- 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.
- More detailed viewfinder: Has higher resolution electronic viewfinder (3686k vs 2360k dots).
- Larger viewfinder image: Features a viewfinder with a higher magnification (0.78x vs 0.62x).
- More detailed LCD: Has a higher resolution rear screen (1440k vs 1040k dots).
- Faster shutter: Has higher mechanical shutter speed (1/8000s vs 1/4000s) to freeze action.
- Faster burst: Shoots at higher frequency (10 vs 8.6 flaps/sec) to capture the decisive moment.
- Longer lasting: Gets more shots (690 versus 330) out of a single battery charge.
- Easier travel charging: Can be conveniently charged via its USB port.
- Better sealing: Is splash and dust sealed for shooting in inclement weather conditions.
- Faster data transfer: Supports a more advanced USB protocol (3.1 vs 2.0).
- Easier device pairing: Supports NFC for fast wireless image transfer over short distances.
- Easier wireless transfer: Supports Bluetooth for image sharing without cables.
- 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 modern: Reflects 2 years and 1 month of technical progress since the E-M10 III launch.
If the count of relative strengths (bullet points above) is taken as a measure, the A9 II is the clear winner of the contest (23 : 6 points). However, the relevance of individual strengths will vary across photographers, so that you might want to apply your own weighing scheme to the summary points when reflecting and deciding on a new camera. A professional wildlife photographer will view the differences between cameras in a way that diverges from the perspective of a family photog, and a person interested in architecture has distinct needs from a sports 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 Sony A9 II place the cameras among the top in their class? Find out in the latest Best Mirrorless Interchangeable Lens Camera listing 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 says little about, for example, the shooting experience and imaging performance of the E-M10 III and the A9 II in practical situations. At times, user reviews, such as those published at amazon, address these issues in a useful manner, but such feedback is on many occasions incomplete, inconsistent, and unreliable.
This is why expert reviews are important. The adjacent summary-table relays the overall verdicts of several of the most popular 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.||Sony A9 II||..||..||90/100||5/5||5/5||Oct 2019||4,499|
|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.||Sony A7S III||..||+ +||91/100||4.5/5||5/5||Jul 2020||3,499|
|14.||Sony A7C||3.5/5||..||86/100||4/5||4/5||Sep 2020||1,799|
|15.||Sony A7R IV||5/5||+||91/100||4.5/5||5/5||Jul 2019||3,499|
|16.||Sony A7 III||..||+ +||89/100||5/5||5/5||Feb 2018||1,999|
|17.||Sony A9||5/5||+ +||89/100||5/5||5/5||Apr 2017||4,499|
|Notes: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.|
The above review scores should be interpreted with care, though. The assessments were made in relation to similar cameras of the same technological generation. Thus, a score needs to be put into the context of the launch date and the launch price of the camera, and rating-comparisons among cameras that span long time periods or concern very differently equipped models make little sense. It should also be noted that some of the review sites have over time altered the way they render their verdicts.
Other camera comparisons
Did this review help to inform your camera decision process? If you would like to see a different side-by-side camera review, just make a corresponding selection in the search boxes below. As an alternative, you can also directly jump to any one of the listed comparisons that were previously generated by the CAM-parator tool.
Specifications: Olympus E-M10 III vs Sony A9 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||Sony A9 II|
|Camera Type||Mirrorless system camera||Mirrorless system camera|
|Camera Lens||Micro Four Thirds lenses||Sony E mount lenses|
|Launch Date||August 2017||October 2019|
|Launch Price||USD 649||USD 4,499|
|Sensor Specs||Olympus E-M10 III||Sony A9 II|
|Sensor Format||Four Thirds Sensor||Full Frame Sensor|
|Sensor Size||17.3 x 13.0 mm||35.6 x 23.8 mm|
|Sensor Area||224.9 mm2||847.28 mm2|
|Sensor Diagonal||21.6 mm||42.8 mm|
|Sensor Resolution||15.9 Megapixels||24 Megapixels|
|Image Resolution||4608 x 3456 pixels||6000 x 4000 pixels|
|Pixel Pitch||3.76 μm||5.94 μm|
|Pixel Density||7.08 MP/cm2||2.83 MP/cm2|
|Moiré control||no AA filter||Anti-Alias filter|
|Movie Capability||4K/30p Video||4K/30p Video|
|ISO Setting||200 - 25,600 ISO||100 - 51,200 ISO|
|ISO Boost||100 - 25,600 ISO||50 - 204,800 ISO|
|Image Processor||TruePic VIII||BIONZ X|
|DXO Sensor Quality (score)||..||93|
|DXO Color Depth (bits)||..||25.0|
|DXO Dynamic Range (EV)||..||14.0|
|DXO Low Light (ISO)||..||3434|
|Screen Specs||Olympus E-M10 III||Sony A9 II|
|Viewfinder Type||Electronic viewfinder||Electronic viewfinder|
|Viewfinder Field of View||100%||100%|
|Viewfinder Resolution||2360k dots||3686k dots|
|LCD Framing||Live View||Live View|
|Rear LCD Size||3.0inch||3.0inch|
|LCD Resolution||1040k dots||1440k dots|
|LCD Attachment||Tilting screen||Tilting screen|
|Shooting Specs||Olympus E-M10 III||Sony A9 II|
|Focus System||Contrast-detect AF||On-Sensor Phase-detect|
|Manual Focusing Aid||Focus Peaking||Focus Peaking|
|Max Shutter Speed (mechanical)||1/4000s||1/8000s|
|Continuous Shooting||8.6 shutter flaps/s||10 shutter flaps/s|
|Electronic Shutter||up to 1/16000s||up to 1/32000s|
|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||Dual UHS-II|
|Connectivity Specs||Olympus E-M10 III||Sony A9 II|
|Studio Flash||no PC Sync||PC Sync socket|
|USB Connector||USB 2.0||USB 3.1|
|HDMI Port||micro HDMI||micro HDMI|
|Microphone Port||no MIC socket||External MIC port|
|Headphone Socket||no Headphone port||Headphone port|
|Wifi Support||Wifi built-in||Wifi built-in|
|Near-Field Communication||no NFC||NFC built-in|
|Bluetooth Support||no Bluetooth||Bluetooth built-in|
|Body Specs||Olympus E-M10 III||Sony A9 II|
|Environmental Sealing||not weather sealed||Weathersealed body|
|Battery Life (CIPA)||330 shots per charge||690 shots per charge|
|In-Camera Charging||no USB charging||USB charging|
122 x 84 x 50 mm
(4.8 x 3.3 x 2.0 in)
129 x 96 x 76 mm
(5.1 x 3.8 x 3.0 in)
|Camera Weight||410 g (14.5 oz)||678 g (23.9 oz)|
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