Olympus E-M10 III vs Sony A7S
The Olympus OM-D E-M10 Mark III and the Sony Alpha A7S are two digital cameras that were officially introduced, respectively, in August 2017 and April 2014. Both the E-M10 III and the A7S are mirrorless interchangeable lens cameras that are based on a Four Thirds (E-M10 III) and a full frame (A7S) 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 A7S? 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 A7S are illustrated in the side-by-side display below. The two cameras are presented according to their relative size. Three consecutive perspectives from the front, the top, and the back are available. All width, height and depth measures are rounded to the nearest millimeter.
The E-M10 III can be obtained in two different colors (black, silver), while the A7S 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 is notably larger (16 percent) than the Olympus E-M10 III. Moreover, the A7S is markedly heavier (19 percent) than the E-M10 III. It is noteworthy in this context that the A7S 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). 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 can take 380 images on a single charge of its NP-FW50 power pack. The power pack in the A7S 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 want to switch the focus of the display and review another camera pair, you can move across to the CAM-parator tool and choose from the broad selection of possible camera comparisons there.
|1.||Olympus E-M10 III||122 mm||84 mm||50 mm||410 g||330||n||Aug 2017||649|
|2.||Sony A7S||127 mm||94 mm||48 mm||489 g||380||Y||Apr 2014||2,499|
|3.||Nikon Df||144 mm||110 mm||67 mm||760 g||1400||Y||Nov 2013||2,749|
|4.||Olympus E-M10 IV||122 mm||84 mm||49 mm||383 g||360||n||Aug 2020||699|
|5.||Olympus E-PL10||117 mm||68 mm||39 mm||380 g||350||n||Oct 2019||599|
|6.||Olympus E-PL9||117 mm||68 mm||39 mm||380 g||350||n||Feb 2018||599|
|7.||Olympus E-PL8||115 mm||67 mm||38 mm||357 g||350||n||Sep 2016||549|
|8.||Olympus PEN-F||125 mm||72 mm||37 mm||427 g||330||n||Jan 2016||1,199|
|9.||Olympus E-M10 II||120 mm||83 mm||47 mm||390 g||320||n||Aug 2015||649|
|10.||Olympus E-M10||119 mm||82 mm||46 mm||396 g||320||n||Jan 2014||699|
|11.||Olympus E-PL7||115 mm||67 mm||38 mm||357 g||350||n||Aug 2014||599|
|12.||Olympus E-PL6||111 mm||64 mm||38 mm||325 g||360||n||May 2013||599|
|13.||Panasonic GX85||122 mm||71 mm||44 mm||426 g||290||n||Apr 2016||799|
|14.||Sony A7S II||127 mm||96 mm||60 mm||627 g||370||Y||Sep 2015||2,999|
|15.||Sony A7 II||127 mm||96 mm||60 mm||599 g||350||Y||Nov 2014||1,999|
|16.||Sony A7||127 mm||94 mm||48 mm||474 g||340||Y||Oct 2013||1,699|
|17.||Sony A7R||127 mm||94 mm||48 mm||465 g||340||Y||Oct 2013||2,299|
|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 74 percent) than the A7S, 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. 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. 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 a full frame sensor. The sensor area in the A7S is 280 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 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. 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 8.45μm for the A7S). However, it should be noted that the E-M10 III is much more recent (by 3 years and 4 months) than the A7S, and its sensor will have benefitted from technological advances during this time that make it possible to gather light more efficiently. 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 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 A7S 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 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 A7S||Full Frame||12.0||4240||2832||1080/60p||23.9||13.2||3702||87|
|3.||Nikon Df||Full Frame||16.2||4928||3280||none||24.6||13.1||3279||89|
|4.||Olympus E-M10 IV||Four Thirds||20.2||5184||3888||4K/30p||..||..||..||..|
|5.||Olympus E-PL10||Four Thirds||15.9||4608||3456||4K/30p||..||..||..||..|
|6.||Olympus E-PL9||Four Thirds||15.9||4608||3456||4K/30p||..||..||..||..|
|7.||Olympus E-PL8||Four Thirds||15.9||4608||3456||1080/30p||..||..||..||..|
|8.||Olympus PEN-F||Four Thirds||20.2||5184||3888||1080/60p||23.1||12.4||894||74|
|9.||Olympus E-M10 II||Four Thirds||15.9||4608||3456||1080/60p||23.1||12.5||842||73|
|10.||Olympus E-M10||Four Thirds||15.9||4608||3456||1080/30p||22.8||12.3||884||72|
|11.||Olympus E-PL7||Four Thirds||15.9||4608||3456||1080/30p||22.7||12.4||873||72|
|12.||Olympus E-PL6||Four Thirds||15.9||4608||3456||1080/30p||..||..||..||..|
|13.||Panasonic GX85||Four Thirds||15.8||4592||3448||4K/30p||22.9||12.6||662||71|
|14.||Sony A7S II||Full Frame||12.0||4240||2832||4K/30p||23.6||13.3||2993||85|
|15.||Sony A7 II||Full Frame||24.0||6000||4000||1080/60p||24.9||13.6||2449||90|
|16.||Sony A7||Full Frame||24.0||6000||4000||1080/60p||24.8||14.2||2248||90|
|17.||Sony A7R||Full Frame||36.2||7360||4912||1080/60p||25.6||14.1||2746||95|
Many modern cameras cannot only take still pictures, but also record videos. The two cameras under consideration both have sensors whose read-out speed is fast enough to capture moving pictures, but the E-M10 III provides a higher video resolution than the A7S. It can shoot video footage at 4K/30p, while the Sony is limited to 1080/60p.
Beyond 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 offers a slightly higher resolution than the one in the E-M10 III (2400k vs 2360k dots). The following table reports on some other key feature differences and similarities of the Olympus E-M10 III, the Sony A7S, and comparable cameras.
|1.||Olympus E-M10 III||2360||n||3.0||1040||tilting||Y||1/4000s||8.6||Y||Y|
|4.||Olympus E-M10 IV||2360||n||3.0||1040||tilting||Y||1/4000s||15.0||Y||Y|
|9.||Olympus E-M10 II||2360||n||3.0||1040||tilting||Y||1/4000s||8.0||Y||Y|
|14.||Sony A7S II||2400||n||3.0||1229||tilting||n||1/8000s||5.0||n||Y|
|15.||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 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 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 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 A7S 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||-||-|
|4.||Olympus E-M10 IV||Y||stereo||mono||-||-||micro||2.0||Y||-||Y|
|9.||Olympus E-M10 II||Y||stereo||mono||-||-||micro||2.0||Y||-||-|
|14.||Sony A7S II||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||-|
|15.||Sony A7 II||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||-|
It is notable that the A7S 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 have been discontinued, but can regularly be found used on eBay. The A7S was replaced by the Sony A7S II, 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 or vice versa? The listing below highlights the relative strengths of the two models.
Arguments in favor of 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.
- Better video: Provides higher definition movie capture (4K/30p vs 1080/60p).
- More detailed LCD: Has a higher resolution rear screen (1040k vs 921k dots).
- 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 127x94mm) and thus needs less room in the bag.
- Less heavy: Is lighter (by 79g or 16 percent) and hence easier to carry around.
- Sharper images: Has hand-shake reducing image stabilization built-in.
- 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 (74 percent cheaper at launch).
- More modern: Reflects 3 years and 4 months of technical progress since the A7S launch.
Reasons to prefer the Sony Alpha A7S:
- Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
- 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 (0.71x vs 0.62x).
- Faster shutter: Has higher mechanical shutter speed (1/8000s vs 1/4000s) to freeze action.
- Longer lasting: Gets more shots (380 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 around for much longer (launched in April 2014).
If the count of individual advantages (bullet points above) is taken as a guide, the E-M10 III is the clear winner of the match-up (14 : 10 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 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 A7S 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 the spec-sheets of cameras can offer a general idea of their imaging potential, it says little about, for example, the shooting experience and imaging performance of the E-M10 III and the A7S in practical situations. User reviews that are available, for instance, at amazon can sometimes shed light on these issues, but such feedback is all too often partial, inconsistent, and inaccurate.
This is why hands-on reviews by experts 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.||Sony A7S||4/5||..||86/100||4.5/5||5/5||Apr 2014||2,499|
|3.||Nikon Df||4/5||..||81/100||4/5||4/5||Nov 2013||2,749|
|4.||Olympus E-M10 IV||4.5/5||..||81/100||4.5/5||4.5/5||Aug 2020||699|
|5.||Olympus E-PL10||..||..||77/100||..||4/5||Oct 2019||599|
|6.||Olympus E-PL9||..||+||..||4.5/5||4/5||Feb 2018||599|
|7.||Olympus E-PL8||..||..||..||4.5/5||4/5||Sep 2016||549|
|8.||Olympus PEN-F||..||..||82/100||4.5/5||5/5||Jan 2016||1,199|
|9.||Olympus E-M10 II||4.5/5||+ +||80/100||5/5||5/5||Aug 2015||649|
|10.||Olympus E-M10||4/5||..||80/100||5/5||5/5||Jan 2014||699|
|11.||Olympus E-PL7||4/5||+||..||5/5||4/5||Aug 2014||599|
|12.||Olympus E-PL6||..||..||..||..||..||May 2013||599|
|13.||Panasonic GX85||4.5/5||+ +||82/100||5/5||5/5||Apr 2016||799|
|14.||Sony A7S II||5/5||+||..||4.5/5||5/5||Sep 2015||2,999|
|15.||Sony A7 II||5/5||+||82/100||4.5/5||5/5||Nov 2014||1,999|
|16.||Sony A7||5/5||+ +||80/100||5/5||5/5||Oct 2013||1,699|
|17.||Sony A7R||5/5||+ +||82/100||4.5/5||5/5||Oct 2013||2,299|
|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. 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. Also, kindly note that some of the listed sites have over time developped their review approaches and their reporting style.
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 your choice using the following search menu. Alternatively, you can follow any of the listed hyperlinks for comparisons that others found interesting.
Specifications: Olympus E-M10 III vs Sony A7S
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|
|Camera Type||Mirrorless system camera||Mirrorless system camera|
|Camera Lens||Micro Four Thirds lenses||Sony E mount lenses|
|Launch Date||August 2017||April 2014|
|Launch Price||USD 649||USD 2,499|
|Sensor Specs||Olympus E-M10 III||Sony A7S|
|Sensor Format||Four Thirds Sensor||Full Frame Sensor|
|Sensor Size||17.3 x 13.0 mm||35.8 x 23.9 mm|
|Sensor Area||224.9 mm2||855.62 mm2|
|Sensor Diagonal||21.6 mm||43 mm|
|Sensor Resolution||15.9 Megapixels||12 Megapixels|
|Image Resolution||4608 x 3456 pixels||4240 x 2832 pixels|
|Pixel Pitch||3.76 μm||8.45 μm|
|Pixel Density||7.08 MP/cm2||1.40 MP/cm2|
|Moiré control||no AA filter||Anti-Alias filter|
|Movie Capability||4K/30p Video||1080/60p 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)||..||87|
|DXO Color Depth (bits)||..||23.9|
|DXO Dynamic Range (EV)||..||13.2|
|DXO Low Light (ISO)||..||3702|
|Screen Specs||Olympus E-M10 III||Sony A7S|
|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||921k dots|
|LCD Attachment||Tilting screen||Tilting screen|
|Touch Input||Touchscreen||no Touchscreen|
|Shooting Specs||Olympus E-M10 III||Sony A7S|
|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||Lens stabilization only|
|Fill Flash||Built-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|
|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|
|Environmental Sealing||not weather sealed||Weathersealed body|
|Battery Life (CIPA)||330 shots per charge||380 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 94 x 48 mm
(5.0 x 3.7 x 1.9 in)
|Camera Weight||410 g (14.5 oz)||489 g (17.2 oz)|
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