Olympus E-M10 IV vs Sony A77
The Olympus OM-D E-M10 Mark IV and the Sony Alpha SLT-A77 are two digital cameras that were announced, respectively, in August 2020 and August 2011. The E-M10 IV is a mirrorless interchangeable lens camera, while the A77 is a DSLR. The cameras are based on a Four Thirds (E-M10 IV) and an APS-C (A77) sensor. The Olympus has a resolution of 20.2 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 IV and the Sony Alpha SLT-A77? 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 IV and the Sony A77 is provided 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 width, height and depth dimensions are rounded to the nearest millimeter.
The E-M10 IV can be obtained in two different colors (black, silver), while the A77 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 A77 is considerably larger (45 percent) than the Olympus E-M10 IV. Moreover, the A77 is substantially heavier (91 percent) than the E-M10 IV. It is noteworthy in this context that the A77 is splash and dust-proof, while the E-M10 IV 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.
Concerning battery life, the E-M10 IV gets 360 shots out of its BLS-50 battery, while the A77 can take 470 images on a single charge of its NP-FM500H power pack. The power pack in the E-M10 IV can be charged via the USB port, so that it is not always necessary to take the battery charger along when travelling.
The following table provides a synthesis of the main physical specifications of the two cameras and other similar ones. 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 IV||122 mm||84 mm||49 mm||383 g||360||n||Aug 2020||699|
|2.||Sony A77||143 mm||104 mm||81 mm||732 g||470||Y||Aug 2011||1,399|
|3.||Olympus E-M5 III||125 mm||85 mm||50 mm||414 g||310||Y||Oct 2019||1,199|
|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-M10 III||122 mm||84 mm||50 mm||410 g||330||n||Aug 2017||649|
|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.||Panasonic G110||116 mm||83 mm||54 mm||352 g||270||n||Jun 2020||649|
|13.||Panasonic GH5||139 mm||98 mm||87 mm||725 g||410||Y||Jan 2017||1,999|
|14.||Sony A9||127 mm||96 mm||63 mm||673 g||650||Y||Apr 2017||4,499|
|15.||Sony A7 II||127 mm||96 mm||60 mm||599 g||350||Y||Nov 2014||1,999|
|16.||Sony A77 II||143 mm||104 mm||81 mm||647 g||480||Y||May 2014||1,199|
|17.||Sony A99||147 mm||111 mm||78 mm||812 g||500||Y||Sep 2012||2,799|
|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 IV was launched at a markedly lower price (by 50 percent) than the A77, 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 tend to have larger individual pixels that provide better low-light sensitivity, wider dynamic range, and richer color-depth than smaller pixel-units 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 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 IV features a Four Thirds sensor and the Sony A77 an APS-C sensor. The sensor area in the A77 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 IV has a native 4:3 aspect ratio, while the one in the A77 offers a 3:2 aspect.
With 24MP, the A77 offers a higher resolution than the E-M10 IV (20.2MP), but the A77 nevertheless has larger individual pixels (pixel pitch of 3.91μm versus 3.34μm for the E-M10 IV) due to its larger sensor. However, the E-M10 IV is a much more recent model (by 8 years and 11 months) than the A77, 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 the E-M10 IV has no anti-alias filter installed, so that it can capture all the detail its sensor resolves.
The resolution advantage of the Sony A77 implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the A77 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 IV are 25.9 x 19.4 inches or 65.8 x 49.4 cm for good quality, 20.7 x 15.6 inches or 52.7 x 39.5 cm for very good quality, and 17.3 x 13 inches or 43.9 x 32.9 cm for excellent quality prints.
The Olympus OM-D E-M10 Mark IV 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 SLT-A77 are ISO 100 to ISO 16000, with the possibility to increase the ISO range to 50-25600.
For many cameras, data on sensor performance has been reported by DXO Mark. 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 following table provides an overview of the physical sensor characteristics, as well as the sensor quality measurements for a selection of comparators.
| DXO |
|1.||Olympus E-M10 IV||Four Thirds||20.2||5184||3888||4K/30p||..||..||..||..|
|3.||Olympus E-M5 III||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-M10 III||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.||Panasonic G110||Four Thirds||20.2||5184||3888||4K/30p||..||..||..||..|
|13.||Panasonic GH5||Four Thirds||20.2||5184||3888||4K/60p||23.9||13.0||807||77|
|14.||Sony A9||Full Frame||24.0||6000||4000||4K/30p||24.9||13.3||3517||92|
|15.||Sony A7 II||Full Frame||24.0||6000||4000||1080/60p||24.9||13.6||2449||90|
|16.||Sony A77 II||APS-C||24.0||6000||4000||1080/60p||..||..||..||..|
|17.||Sony A99||Full Frame||24.0||6000||4000||1080/60p||25.0||14.0||1555||89|
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 IV provides a higher video resolution than the A77. 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 consideration are similar with respect to both having an electronic viewfinder. However, the one in the E-M10 IV offers a slightly higher resolution than the one in the A77 (2360k vs 2359k dots). The following table reports on some other key feature differences and similarities of the Olympus E-M10 IV, the Sony A77, and comparable cameras.
|1.||Olympus E-M10 IV||2360||n||3.0||1040||tilting||Y||1/4000s||15.0||Y||Y|
|3.||Olympus E-M5 III||2360||n||3.0||1040||swivel||Y||1/8000s||10.0||n||Y|
|6.||Olympus E-M10 III||2360||n||3.0||1040||tilting||Y||1/4000s||8.6||Y||Y|
|9.||Olympus E-M10 II||2360||n||3.0||1040||tilting||Y||1/4000s||8.0||Y||Y|
|15.||Sony A7 II||2400||n||3.0||1230||tilting||n||1/8000s||5.0||n||Y|
|16.||Sony A77 II||2359||Y||3.0||1229||full-flex||n||1/8000s||12.0||Y||Y|
One differentiating feature between the two cameras concerns the touch sensitivity of the rear screen. The E-M10 IV has a touchscreen, while the A77 has a conventional panel. Touch control can be particularly helpful, for example, for setting the focus point.Both cameras have an articulated rear screen that can be turned to be front-facing. This feature will be particularly appreciated by vloggers and photographers who are interested in taking selfies.
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 IV 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 IV 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 IV writes its imaging data to SDXC cards, while the A77 uses SDXC or Memory Stick PRO Duo cards. The E-M10 IV supports UHS-II cards (Ultra High Speed data transfer of up to 312 MB/s), while the A77 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 IV and Sony Alpha SLT-A77 and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.
| WiFi |
| NFC |
|1.||Olympus E-M10 IV||Y||stereo||mono||-||-||micro||2.0||Y||-||Y|
|3.||Olympus E-M5 III||Y||stereo||mono||Y||-||micro||2.0||Y||-||Y|
|6.||Olympus E-M10 III||Y||stereo||mono||-||-||micro||2.0||Y||-||-|
|9.||Olympus E-M10 II||Y||stereo||mono||-||-||micro||2.0||Y||-||-|
|15.||Sony A7 II||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||-|
|16.||Sony A77 II||Y||stereo||mono||Y||-||mini||2.0||Y||Y||-|
It is notable that the E-M10 IV offers wifi support, while the A77 does not. Wifi can be a very convenient means to transfer image data to an off-camera location.
Studio photographers will appreciate that the Sony A77 (unlike the E-M10 IV) 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 A77 has an internal geolocalization sensor and can record GPS coordinates in its EXIF data.
The E-M10 IV is a recent model that features in the current product line-up of Olympus. In contrast, the A77 has been discontinued (but can be found pre-owned on eBay). As a replacement in the same line of cameras, the A77 was succeeded by the Sony A77 II. 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 what conclusions can be drawn? Which of the two cameras – the Olympus E-M10 IV or the Sony A77 – has the upper hand? Is one clearly better than the other? A synthesis of the relative strong points of each of the models is listed below.
Arguments in favor of the Olympus OM-D E-M10 Mark IV:
- 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 (15 vs 12 flaps/sec) to capture the decisive moment.
- Less disturbing: Has an electronic shutter option for completely silent shooting.
- Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
- More compact: Is smaller (122x84mm vs 143x104mm) and thus needs less room in the bag.
- Less heavy: Is lighter (by 349g or 48 percent) and hence easier to carry around.
- Easier travel charging: Can be conveniently charged via its USB port.
- More legacy lens friendly: Can take a broad range of non-native lenses via adapters.
- Easier file upload: Has wifi built in for automatic backup or image transfer to the web.
- Easier wireless transfer: Supports Bluetooth for image sharing without cables.
- 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 (50 percent cheaper at launch).
- More modern: Reflects 8 years and 11 months of technical progress since the A77 launch.
Reasons to prefer the Sony Alpha SLT-A77:
- More detail: Has more megapixels (24 vs 20.2MP), which boosts linear resolution by 11%.
- 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.
- Larger viewfinder image: Features a viewfinder with a higher magnification (0.73x vs 0.62x).
- Easier setting verification: Features a control panel on top to check shooting parameters.
- More flexible LCD: Has a full-flex screen for odd-angle shots in portrait or landscape orientation.
- Faster shutter: Has higher mechanical shutter speed (1/8000s vs 1/4000s) to freeze action.
- Longer lasting: Gets more shots (470 versus 360) 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.
- Better studio light control: Has a PC Sync socket to connect to professional strobe lights.
- More heavily discounted: Has been around for much longer (launched in August 2011).
If the number of relative strengths (bullet points above) is taken as a guide, the E-M10 IV is the clear winner of the match-up (16 : 12 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 wedding photographer will view the differences between cameras in a way that diverges from the perspective of a travel photog, and a person interested in cityscapes has distinct needs from a macro 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 IV and the Sony A77 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 says little about, for example, the shooting experience and imaging performance of the E-M10 IV and the A77 in practical situations. 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 table below provides a synthesis of the camera assessments of some of the best known photo-gear 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 IV||4.5/5||..||..||4.5/5||4.5/5||Aug 2020||699|
|2.||Sony A77||5/5||91/100||81/100||..||5/5||Aug 2011||1,399|
|3.||Olympus E-M5 III||5/5||+||82/100||4.5/5||4.5/5||Oct 2019||1,199|
|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-M10 III||..||+||80/100||4.5/5||4.5/5||Aug 2017||649|
|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.||Panasonic G110||..||..||..||4/5||4/5||Jun 2020||649|
|13.||Panasonic GH5||4.5/5||+ +||85/100||4.5/5||5/5||Jan 2017||1,999|
|14.||Sony A9||5/5||+ +||89/100||5/5||5/5||Apr 2017||4,499|
|15.||Sony A7 II||5/5||+||82/100||4.5/5||5/5||Nov 2014||1,999|
|16.||Sony A77 II||4/5||..||80/100||4.5/5||5/5||May 2014||1,199|
|17.||Sony A99||5/5||..||84/100||4.5/5||4.5/5||Sep 2012||2,799|
|Notes: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.|
The review scores listed above should be treated with care, though. The assessments were made in relation to similar cameras of the same technological generation. Hence, a score should always be seen in the context of the camera's market launch date and its price, and rating-comparisons among cameras that span long time periods or concern very differently equipped models make little sense. 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? If you would like to see a different side-by-side camera review, just use the search menu 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 IV vs Sony A77
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 IV||Sony A77|
|Camera Type||Mirrorless system camera||Digital single lens reflex|
|Camera Lens||Micro Four Thirds lenses||Sony A mount lenses|
|Launch Date||August 2020||August 2011|
|Launch Price||USD 699||USD 1,399|
|Sensor Specs||Olympus E-M10 IV||Sony A77|
|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||20.2 Megapixels||24 Megapixels|
|Image Resolution||5184 x 3888 pixels||6000 x 4000 pixels|
|Pixel Pitch||3.34 μm||3.91 μm|
|Pixel Density||8.96 MP/cm2||6.55 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 - 16,000 ISO|
|ISO Boost||100 - 25,600 ISO||50 - 25,600 ISO|
|Image Processor||TruePic VIII||BIONZ X|
|DXO Sensor Quality (score)||..||78|
|DXO Color Depth (bits)||..||24.0|
|DXO Dynamic Range (EV)||..||13.2|
|DXO Low Light (ISO)||..||801|
|Screen Specs||Olympus E-M10 IV||Sony A77|
|Viewfinder Type||Electronic viewfinder||Electronic viewfinder|
|Viewfinder Field of View||100%||100%|
|Viewfinder Resolution||2360k dots||2359k dots|
|Top-Level Screen||no Top Display||Control Panel|
|LCD Framing||Live View||Live View|
|Rear LCD Size||3.0inch||3.0inch|
|LCD Resolution||1040k dots||921k dots|
|LCD Attachment||Tilting screen||Fully flexible screen|
|Touch Input||Touchscreen||no Touchscreen|
|Shooting Specs||Olympus E-M10 IV||Sony A77|
|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||15 shutter flaps/s||12 shutter flaps/s|
|Electronic Shutter||up to 1/16000s||no E-Shutter|
|Time-Lapse Photography||Intervalometer built-in||no Intervalometer|
|Image Stabilization||In-body stabilization||In-body stabilization|
|Fill Flash||Build-in Flash||Build-in 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 IV||Sony A77|
|Studio Flash||no PC Sync||PC Sync socket|
|USB Connector||USB 2.0||USB 2.0|
|HDMI Port||micro HDMI||mini HDMI|
|Microphone Port||no MIC socket||External MIC port|
|Wifi Support||Wifi built-in||no Wifi|
|Bluetooth Support||Bluetooth built-in||no Bluetooth|
|Geotagging||no internal GPS||GPS built-in|
|Body Specs||Olympus E-M10 IV||Sony A77|
|Environmental Sealing||not weather sealed||Weathersealed body|
|Battery Life (CIPA)||360 shots per charge||470 shots per charge|
|In-Camera Charging||USB charging||no USB charging|
122 x 84 x 49 mm
(4.8 x 3.3 x 1.9 in)
143 x 104 x 81 mm
(5.6 x 4.1 x 3.2 in)
|Camera Weight||383 g (13.5 oz)||732 g (25.8 oz)|
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