Olympus E-M10 III vs Sony A7S II
The Olympus OM-D E-M10 Mark III and the Sony Alpha 7S II are two digital cameras that were announced, respectively, in August 2017 and September 2015. Both the E-M10 III and the A7S II are mirrorless interchangeable lens cameras that are based on a Four Thirds (E-M10 III) and a full frame (A7S II) sensor. The Olympus has a resolution of 15.9 megapixels, whereas the Sony provides 12 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 7S 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.
An illustration of the physical size and weight of the Olympus E-M10 III and the Sony A7S II is provided 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 A7S 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 A7S II is notably larger (19 percent) than the Olympus E-M10 III. Moreover, the A7S II is substantially heavier (53 percent) than the E-M10 III. It is noteworthy in this context that the A7S 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 (A7S 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 A7S II can take 370 images on a single charge of its NP-FW50 power pack. The power pack in the A7S II can be charged via the USB port, which can be very convenient when travelling.
The following table provides a synthesis of the main physical specifications of the two cameras and other similar ones. 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.
|Olympus E-M10 III||4.8 in||3.3 in||2.0 in||14.5 oz||330||n||Aug 2017||649|
|Sony A7S II||5.0 in||3.8 in||2.4 in||22.1 oz||370||Y||Sep 2015||2,999|
|Olympus E-M10 IV||4.8 in||3.3 in||1.9 in||13.5 oz||360||n||Aug 2020||699|
|Olympus E-PL10||4.6 in||2.7 in||1.5 in||13.4 oz||350||n||Oct 2019||599|
|Olympus E-PL9||4.6 in||2.7 in||1.5 in||13.4 oz||350||n||Feb 2018||599|
|Olympus E-PL8||4.5 in||2.6 in||1.5 in||12.6 oz||350||n||Sep 2016||549|
|Olympus PEN-F||4.9 in||2.8 in||1.5 in||15.1 oz||330||n||Jan 2016||1,199|
|Olympus E-M10 II||4.7 in||3.3 in||1.9 in||13.8 oz||320||n||Aug 2015||649|
|Olympus E-M10||4.7 in||3.2 in||1.8 in||14.0 oz||320||n||Jan 2014||699|
|Olympus E-PL7||4.5 in||2.6 in||1.5 in||12.6 oz||350||n||Aug 2014||599|
|Olympus E-PL6||4.4 in||2.5 in||1.5 in||11.5 oz||360||n||May 2013||599|
|Panasonic GX85||4.8 in||2.8 in||1.7 in||15.0 oz||290||n||Apr 2016||799|
|Sony A7S III||5.0 in||3.8 in||3.2 in||24.7 oz||600||Y||Jul 2020||3,499|
|Sony A99 II||5.6 in||4.1 in||3.0 in||29.9 oz||490||Y||Sep 2016||3,199|
|Sony A7R II||5.0 in||3.8 in||2.4 in||22.0 oz||290||Y||Jun 2015||3,199|
|Sony A7 II||5.0 in||3.8 in||2.4 in||21.1 oz||350||Y||Nov 2014||1,999|
|Sony A7S||5.0 in||3.7 in||1.9 in||17.2 oz||380||Y||Apr 2014||2,499|
|Notes: Measurements and pricing do not include easily detachable parts, such as add-on or interchangeable lenses or optional viewfinders.|
Any camera decision will obviously take relative prices into account. The manufacturer’s suggested retail prices give an idea on the placement of the camera in the maker’s lineup and the broader market. The E-M10 III was launched at a markedly lower price (by 78 percent) than the A7S 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.
The size of the sensor inside a digital camera is one of the key determinants 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. Furthermore, a large sensor camera will give the photographer more possibilities to use shallow depth-of-field in order to isolate a subject from the 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 A7S II a full frame sensor. The sensor area in the A7S 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 A7S II offers a 3:2 aspect.
Despite having a smaller sensor, the Olympus E-M10 III offers a higher resolution of 15.9 megapixels, compared with 12 MP of the Sony A7S II. This megapixels advantage comes at the cost of a higher pixel density and a smaller size of the individual pixel (with a pixel pitch of 3.76μm versus 8.40μm for the A7S II). However, it should be noted that the E-M10 III is a somewhat more recent model (by 1 year and 11 months) than the A7S II, and its sensor might have benefitted from technological advances during this time that partly offset its pixel-size disadvantage. 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 Olympus E-M10 III implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the E-M10 III for good quality output (200 dots per inch) amounts to 23 x 17.3 inches or 58.5 x 43.9 cm, for very good quality (250 dpi) 18.4 x 13.8 inches or 46.8 x 35.1 cm, and for excellent quality (300 dpi) 15.4 x 11.5 inches or 39 x 29.3 cm. The corresponding values for the Sony A7S II are 21.2 x 14.2 inches or 53.8 x 36 cm for good quality, 17 x 11.3 inches or 43.1 x 28.8 cm for very good quality, and 14.1 x 9.4 inches or 35.9 x 24 cm for excellent quality prints.
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 7S II are ISO 100 to ISO 102400, with the possibility to increase the ISO range to 50-409600.
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 |
|Olympus E-M10 III||Four Thirds||15.9||4608||3456||4K/30p||..||..||..||..|
|Sony A7S II||Full Frame||12.0||4240||2832||4K/30p||23.6||13.3||2993||85|
|Olympus E-M10 IV||Four Thirds||20.2||5184||3888||4K/30p||..||..||..||..|
|Olympus E-PL10||Four Thirds||15.9||4608||3456||4K/30p||..||..||..||..|
|Olympus E-PL9||Four Thirds||15.9||4608||3456||4K/30p||..||..||..||..|
|Olympus E-PL8||Four Thirds||15.9||4608||3456||1080/30p||..||..||..||..|
|Olympus PEN-F||Four Thirds||20.2||5184||3888||1080/60p||23.1||12.4||894||74|
|Olympus E-M10 II||Four Thirds||15.9||4608||3456||1080/60p||23.1||12.5||842||73|
|Olympus E-M10||Four Thirds||15.9||4608||3456||1080/30p||22.8||12.3||884||72|
|Olympus E-PL7||Four Thirds||15.9||4608||3456||1080/30p||22.7||12.4||873||72|
|Olympus E-PL6||Four Thirds||15.9||4608||3456||1080/30p||..||..||..||..|
|Panasonic GX85||Four Thirds||15.8||4592||3448||4K/30p||22.9||12.6||662||71|
|Sony A7S III||Full Frame||12.0||4240||2832||4K/120p||..||..||..||..|
|Sony A99 II||Full Frame||42.2||7952||5304||4K/30p||25.4||13.4||2317||92|
|Sony A7R II||Full Frame||42.2||7952||5304||4K/30p||26.0||13.9||3434||98|
|Sony A7 II||Full Frame||24.0||6000||4000||1080/60p||24.9||13.6||2449||90|
|Sony A7S||Full Frame||12.0||4240||2832||1080/60p||23.9||13.2||3702||87|
Many modern cameras are not only capable of taking still images, but can also record movies. 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 range of features. The two cameras under review are similar with respect to both having an electronic viewfinder. However, the one in the A7S II offers a slightly higher resolution than the one in the E-M10 III (2400k vs 2360k dots). The table below summarizes some of the other core capabilities of the Olympus E-M10 III and Sony A7S II in connection with corresponding information for a sample of similar cameras.
|Olympus E-M10 III||2360||n||3.0||1040||tilting||Y||1/4000s||8.6||Y||Y|
|Sony A7S II||2400||n||3.0||1229||tilting||n||1/8000s||5.0||n||Y|
|Olympus E-M10 IV||2360||n||3.0||1040||tilting||Y||1/4000s||15.0||Y||Y|
|Olympus E-M10 II||2360||n||3.0||1040||tilting||Y||1/4000s||8.0||Y||Y|
|Sony A7S III||9440||n||3.0||1440||swivel||Y||1/8000s||10.0||n||Y|
|Sony A99 II||2400||Y||3.0||1229||full-flex||n||1/8000s||12.0||n||Y|
|Sony A7R II||2400||n||3.0||1229||tilting||n||1/8000s||5.0||n||Y|
|Sony A7 II||2400||n||3.0||1230||tilting||n||1/8000s||5.0||n||Y|
One difference between the cameras concerns the presence of an on-board flash. The E-M10 III has one, while the A7S 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 has 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.
The E-M10 III writes its imaging data to SDXC cards, while the A7S II uses SDXC or Memory Stick PRO Duo cards. The E-M10 III supports UHS-II cards (Ultra High Speed data transfer of up to 312 MB/s), while the A7S 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 Sony Alpha 7S II and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.
| WiFi |
| NFC |
|Olympus E-M10 III||Y||stereo||mono||-||-||micro||2.0||Y||-||-|
|Sony A7S II||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||-|
|Olympus E-M10 IV||Y||stereo||mono||-||-||micro||2.0||Y||-||Y|
|Olympus E-M10 II||Y||stereo||mono||-||-||micro||2.0||Y||-||-|
|Sony A7S III||Y||stereo||mono||Y||Y||full||3.2||Y||-||Y|
|Sony A99 II||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||Y|
|Sony A7R II||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||-|
|Sony A7 II||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||-|
It is notable that the A7S 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.
Both the E-M10 III and the A7S II have been discontinued, but can regularly be found used on eBay. The A7S II was replaced by the Sony A7S 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 Sony websites.
So how do things add up? Is the Olympus E-M10 III better than the Sony A7S II or vice versa? A synthesis of the relative strong points of each of the models is listed below.
Reasons to prefer the Olympus OM-D E-M10 Mark III:
- More detail: Offers more megapixels (15.9 vs 12MP) with a 13% higher linear resolution.
- Maximized detail: Lacks an anti-alias filter to exploit the sensor's full resolution potential.
- Fewer buttons to press: Is equipped with a touch-sensitive rear screen to facilitate handling.
- Faster burst: Shoots at higher frequency (8.6 vs 5 flaps/sec) to capture the decisive moment.
- Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
- More compact: Is smaller (122x84mm vs 127x96mm) and thus needs less room in the bag.
- Less heavy: Is lighter (by 217g or 35 percent) and hence easier to carry around.
- Easier fill-in: Is equipped with a small onboard flash to brighten deep shadow areas.
- 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 (78 percent cheaper at launch).
- More modern: Is somewhat more recent (announced 1 year and 11 months after the A7S II).
Advantages of the Sony Alpha 7S II:
- Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
- 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.
- Larger viewfinder image: Features a viewfinder with a higher magnification (0.78x vs 0.62x).
- More detailed LCD: Has a higher resolution rear screen (1229k vs 1040k dots).
- Faster shutter: Has higher mechanical shutter speed (1/8000s vs 1/4000s) to freeze action.
- Longer lasting: Gets more shots (370 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.
- Easier device pairing: Supports NFC for fast wireless image transfer over short distances.
- More heavily discounted: Has been on the market for longer (launched in September 2015).
If the number of relative strengths (bullet points above) is taken as a guide, the A7S II is the clear winner of the contest (15 : 11 points). However, the pertinence of the various camera strengths will differ across photographers, so that you might want to weigh individual camera traits according to their importance for your own imaging needs before making a camera decision. 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 Sony A7S 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 specs-based evaluation of cameras can be instructive in revealing their potential as photographic tools, it says little about, for example, the shooting experience and imaging performance of the E-M10 III and the A7S 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 hands-on reviews by experts are important. The adjacent summary-table relays the overall verdicts of several of the most popular camera review sites (cameralabs, dpreview, ephotozine, imaging-resource, and photographyblog). 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.
|Olympus E-M10 III||+||80/100||4.5/5||4/5||4.5/5||Aug 2017||649|
|Sony A7S II||+||..||4.5/5||5/5||5/5||Sep 2015||2,999|
|Olympus E-M10 IV||..||..||4.5/5||..||4.5/5||Aug 2020||699|
|Olympus E-PL10||..||77/100||..||..||4/5||Oct 2019||599|
|Olympus E-PL9||+||..||4.5/5||4.5/5||4/5||Feb 2018||599|
|Olympus E-PL8||..||..||4.5/5||..||4/5||Sep 2016||549|
|Olympus PEN-F||..||82/100||4.5/5||4.5/5||5/5||Jan 2016||1,199|
|Olympus E-M10 II||+ +||80/100||5/5||5/5||5/5||Aug 2015||649|
|Olympus E-M10||..||80/100||5/5||4.5/5||5/5||Jan 2014||699|
|Olympus E-PL7||+||..||5/5||4.5/5||4/5||Aug 2014||599|
|Olympus E-PL6||..||..||..||..||..||May 2013||599|
|Panasonic GX85||+ +||82/100||5/5||4.5/5||5/5||Apr 2016||799|
|Sony A7S III||+ +||..||4.5/5||..||5/5||Jul 2020||3,499|
|Sony A99 II||..||85/100||4.5/5||4.5/5||4.5/5||Sep 2016||3,199|
|Sony A7R II||+ +||90/100||5/5||4.5/5||5/5||Jun 2015||3,199|
|Sony A7 II||+||82/100||4.5/5||5/5||5/5||Nov 2014||1,999|
|Sony A7S||..||86/100||4.5/5||4.5/5||5/5||Apr 2014||2,499|
|Notes: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.|
The review scores listed above should be treated with care, though. The ratings are only valid when referring to cameras in the same category and of the same age. Thus, a score needs to be put into the context of the launch date and the launch price of the camera, and comparing ratings of very distinct cameras or ones that are far apart in terms of their release date have little meaning. 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? 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 Sony A7S 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 A7S II|
|Camera Type||Mirrorless system camera||Mirrorless system camera|
|Camera Lens||Micro Four Thirds lenses||Sony E mount lenses|
|Launch Date||August 2017||September 2015|
|Launch Price||USD 649||USD 2,999|
|Sensor Specs||Olympus E-M10 III||Sony A7S 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||12 Megapixels|
|Image Resolution||4608 x 3456 pixels||4240 x 2832 pixels|
|Pixel Pitch||3.76 μm||8.40 μm|
|Pixel Density||7.08 MP/cm2||1.42 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 - 102,400 ISO|
|ISO Boost||100 - 25,600 ISO||50 - 409,600 ISO|
|Image Processor||TruePic VIII||BIONZ X|
|DXO Sensor Quality (score)||..||85|
|DXO Color Depth (bits)||..||23.6|
|DXO Dynamic Range (EV)||..||13.3|
|DXO Low Light (ISO)||..||2993|
|Screen Specs||Olympus E-M10 III||Sony A7S II|
|Viewfinder Type||Electronic viewfinder||Electronic viewfinder|
|Viewfinder Field of View||100%||100%|
|Viewfinder Resolution||2360k dots||2400k dots|
|LCD Framing||Live View||Live View|
|Rear LCD Size||3.0inch||3.0inch|
|LCD Resolution||1040k dots||1229k dots|
|LCD Attachment||Tilting screen||Tilting screen|
|Touch Input||Touchscreen||no Touchscreen|
|Shooting Specs||Olympus E-M10 III||Sony A7S II|
|Focus System||Contrast-detect AF||Contrast-detect AF|
|Manual Focusing Aid||Focus Peaking||Focus Peaking|
|Max Shutter Speed (mechanical)||1/4000s||1/8000s|
|Continuous Shooting||8.6 shutter flaps/s||5 shutter flaps/s|
|Electronic Shutter||up to 1/16000s||YES|
|Time-Lapse Photography||Intervalometer built-in||no Intervalometer|
|Image Stabilization||In-body stabilization||In-body stabilization|
|Fill Flash||Build-in Flash||no On-Board Flash|
|Storage Medium||SDXC cards||MS or SDXC cards|
|Second Storage Option||Single card slot||Single card slot|
|UHS card support||UHS-II||UHS-I|
|Connectivity Specs||Olympus E-M10 III||Sony A7S II|
|USB Connector||USB 2.0||USB 2.0|
|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|
|Body Specs||Olympus E-M10 III||Sony A7S II|
|Environmental Sealing||not weather sealed||Weathersealed body|
|Battery Life (CIPA)||330 shots per charge||370 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)
127 x 96 x 60 mm
(5.0 x 3.8 x 2.4 in)
|Camera Weight||410 g (14.5 oz)||627 g (22.1 oz)|
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