Olympus E-M5 II vs Sony A77
The Olympus OM-D E-M5 Mark II and the Sony Alpha SLT-A77 are two enthusiast cameras that were revealed to the public, respectively, in February 2015 and August 2011. The E-M5 II is a mirrorless interchangeable lens camera, while the A77 is a DSLR. The cameras are based on a Four Thirds (E-M5 II) and an APS-C (A77) 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.
|Olympus E-M5 II||Sony A77|
|Mirrorless system camera||Digital single lens reflex|
|Micro Four Thirds lenses||Sony A mount lenses|
|15.9 MP, Four Thirds Sensor||24 MP, APS-C Sensor|
|1080/60p Video||1080/60p Video|
|ISO 200-25,600||ISO 100-16,000 (50 - 25,600)|
|Electronic viewfinder (2360k dots)||Electronic viewfinder (2359k dots)|
|3.0 LCD, 1037k dots||3.0 LCD, 921k dots|
|Swivel touchscreen||Fully flexible screen (no touchscreen)|
|10 shutter flaps per second||12 shutter flaps per second|
|In-body stabilization||In-body stabilization|
|Weathersealed body||Weathersealed body|
|310 shots per battery charge||470 shots per battery charge|
|124 x 85 x 45 mm, 469 g||143 x 104 x 81 mm, 732 g|
Going beyond this snapshot of core features and characteristics, what are the differences between the Olympus OM-D E-M5 Mark II 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.
The physical size and weight of the Olympus E-M5 II and the Sony A77 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 width, height and depth dimensions are rounded to the nearest millimeter.
The E-M5 II 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 notably larger (41 percent) than the Olympus E-M5 II. Moreover, the A77 is substantially heavier (56 percent) than the E-M5 II. In this context, it is worth noting that both cameras are splash and dust-proof and can, hence, be used in inclement weather conditions or harsh environments.
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 following table provides a synthesis of the main physical specifications of the two cameras and other similar ones. If you want to switch the focus of the display and review another camera pair, just select a new right or left comparator from among the camera models in the table. Alternatively, you can also move across to the CAM-parator tool and choose from the broad selection of possible camera comparisons there.
|Olympus E-M5 II||124 mm||85 mm||45 mm||469 g||310||Y||Feb 2015||1,099|
|Sony A77||143 mm||104 mm||81 mm||732 g||470||Y||Aug 2011||1,399|
|Olympus E-M5 III||125 mm||85 mm||50 mm||414 g||310||Y||Oct 2019||1,199|
|Olympus E-M1 II||134 mm||91 mm||67 mm||574 g||440||Y||Sep 2016||1,999|
|Olympus PEN-F||125 mm||72 mm||37 mm||427 g||330||n||Jan 2016||1,199|
|Olympus E-M10 II||120 mm||83 mm||47 mm||390 g||320||n||Aug 2015||649|
|Olympus E-M10||119 mm||82 mm||46 mm||396 g||320||n||Jan 2014||699|
|Olympus E-M1||130 mm||94 mm||63 mm||497 g||350||Y||Sep 2013||1,399|
|Olympus E-P5||122 mm||69 mm||37 mm||420 g||330||n||May 2013||999|
|Olympus E-M5||122 mm||89 mm||43 mm||425 g||360||Y||Feb 2012||1,299|
|Panasonic GH5||139 mm||98 mm||87 mm||725 g||410||Y||Jan 2017||1,999|
|Panasonic G80||128 mm||89 mm||74 mm||505 g||330||Y||Sep 2016||899|
|Panasonic GX8||133 mm||78 mm||63 mm||487 g||330||Y||Jul 2015||1,199|
|Sony A9||127 mm||96 mm||63 mm||673 g||650||Y||Apr 2017||4,499|
|Sony A7 II||127 mm||96 mm||60 mm||599 g||350||Y||Nov 2014||1,999|
|Sony A77 II||143 mm||104 mm||81 mm||647 g||480||Y||May 2014||1,199|
|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.
(1) Number of images that can be taken on a full battery charge according to the CIPA-standard; (2) Official announcement.
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-M5 II was launched at a somewhat lower price (by 21 percent) than the A77, which makes it more attractive for photographers on a tight budget. Normally, street prices remain initially close to the MSRP, but after a couple of months, the first discounts appear. 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 imaging sensor is a crucial determinant 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. 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 tend to be more expensive and lead to bigger and heavier cameras and lenses.
Of the two cameras under consideration, the Olympus E-M5 II 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-M5 II has a native 4:3 aspect ratio, while the one in the A77 offers a 3:2 aspect.
In terms of underlying technology, both cameras are build around CMOS sensors.
With 24MP, the A77 offers a higher resolution than the E-M5 II (15.9MP), but the A77 nevertheless has larger individual pixels (pixel pitch of 3.91μm versus 3.76μm for the E-M5 II) due to its larger sensor. However, the E-M5 II is a much more recent model (by 3 years and 5 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.
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-M5 II 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 A77, the E-M5 II has the capacity to capture high quality composite images (40MP) 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-M5 Mark II 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.
Consistent information on actual sensor performance is available from DXO Mark for many cameras. This service is based on lab testing and assigns an overall score to each camera sensor, as well as ratings for dynamic range ("DXO Landscape"), color depth ("DXO Portrait"), and low-light sensitivity ("DXO Sports"). Of the two cameras under consideration, the A77 has a markedly higher DXO score than the E-M5 II (overall score 5 points higher), which will translate into better image quality. The advantage is based on 1 bits higher color depth, 0.7 EV in additional dynamic range, and 0.1 stops of reduced low light sensitivity. The adjacent table reports on the physical sensor characteristics and the outcomes of the DXO sensor quality tests for a sample of comparator-cameras.
|Olympus E-M5 II||Four Thirds||15.9||4608||3456||1080/60p||23.0||12.5||842||73|
|Olympus E-M5 III||Four Thirds||20.2||5184||3888||4k/24p||..||..||..||..|
|Olympus E-M1 II||Four Thirds||20.2||5184||3888||4K/30p||23.7||12.8||1312||80|
|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-M1||Four Thirds||15.9||4608||3456||1080/30p||23.0||12.7||757||73|
|Olympus E-P5||Four Thirds||15.9||4608||3456||1080/30p||22.8||12.4||895||72|
|Olympus E-M5||Four Thirds||15.9||4608||3456||1080/60i||22.8||12.3||826||71|
|Panasonic GH5||Four Thirds||20.2||5184||3888||4K/60p||23.9||13.0||807||77|
|Panasonic G80||Four Thirds||15.8||4592||3448||4K/30p||22.8||12.5||656||71|
|Panasonic GX8||Four Thirds||20.2||5184||3888||4K/30p||23.5||12.6||806||75|
|Sony A9||Full Frame||24.0||6000||4000||4K/30p||24.9||13.3||3517||92|
|Sony A7 II||Full Frame||24.0||6000||4000||1080/60p||24.9||13.6||2449||90|
|Sony A77 II||APS-C||24.0||6000||4000||1080/60p||..||..||..||..|
|Sony A99||Full Frame||24.0||6000||4000||1080/60p||25.0||14.0||1555||89|
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 (1080/60p).
Apart from body and sensor, cameras can and do differ across a variety of features. The two cameras under consideration are similar with respect to both having an electronic viewfinder. However, the one in the E-M5 II 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-M5 II, the Sony A77, and comparable cameras.
|Olympus E-M5 II||2360||n||3.0||1037||swivel||Y||1/8000s||10.0||n||Y|
|Olympus E-M5 III||2360||n||3.0||1040||swivel||Y||1/8000s||10.0||n||Y|
|Olympus E-M1 II||2360||n||3.0||1037||swivel||Y||1/8000s||18.0||n||Y|
|Olympus E-M10 II||2360||n||3.0||1040||tilting||Y||1/4000s||8.0||Y||Y|
|Sony A7 II||2400||n||3.0||1230||tilting||n||1/8000s||5.0||n||Y|
|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-M5 II 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-M5 II 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-M5 II 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-M5 II writes its imaging data to SDXC cards, while the A77 uses SDXC or Memory Stick PRO Duo cards. The E-M5 II 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-M5 Mark II and Sony Alpha SLT-A77 and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.
| WiFi |
|Olympus E-M5 II||Y||stereo||mono||Y||-||micro||2.0||Y||-||-|
|Olympus E-M5 III||Y||stereo||mono||Y||-||micro||2.0||Y||-||Y|
|Olympus E-M1 II||Y||stereo||mono||Y||Y||micro||3.0||Y||-||-|
|Olympus E-M10 II||Y||stereo||mono||-||-||micro||2.0||Y||-||-|
|Sony A7 II||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||-|
|Sony A77 II||Y||stereo||mono||Y||-||mini||2.0||Y||Y||-|
It is notable that the E-M5 II offers wifi support, while the A77 does not. Wifi can be a very convenient means to transfer image data to an off-camera location.
Both cameras feature a PC Sync terminal to control professional strobe lights, which will be appreciated by studio photographers.
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.
Both the E-M5 II and the A77 have been discontinued, but can regularly be found used on eBay. The A77 was replaced by the Sony A77 II, while the E-M5 II was followed by the Olympus E-M5 III. 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? Is there a clear favorite between the Olympus E-M5 II and the Sony A77? Which camera is better? The listing below highlights the relative strengths of the two models.
Reasons to prefer the Olympus OM-D E-M5 Mark II:
- High quality composites: Can combine several shots after pixel-shifting its sensor.
- Larger viewfinder image: Features a viewfinder with a higher magnification (0.74x vs 0.73x).
- More detailed LCD: Has a higher resolution rear screen (1037k vs 921k dots).
- 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.
- Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
- More compact: Is smaller (124x85mm vs 143x104mm) and thus needs less room in the bag.
- Less heavy: Is lighter (by 263g or 36 percent) and hence easier to carry around.
- 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.
- Faster buffer clearing: Supports a more advanced SD data transfer standard (UHS-II vs UHS-I).
- More affordable: Was introduced into a lower priced segment (21 percent cheaper at launch).
- More modern: Reflects 3 years and 5 months of technical progress since the A77 launch.
Arguments in favor of the Sony Alpha SLT-A77:
- More detail: Has more megapixels (24 vs 15.9MP), which boosts linear resolution by 25%.
- Better image quality: Scores markedly higher (5 points) in the DXO overall evaluation.
- More dynamic range: Captures a broader range of light and dark details (0.7 EV of extra DR).
- Easier setting verification: Features a control panel on top to check shooting parameters.
- Faster burst: Shoots at higher frequency (12 vs 10 flaps/sec) to capture the decisive moment.
- Longer lasting: Gets more shots (470 versus 310) out of a single battery charge.
- Easier fill-in: Has a small integrated flash to brighten shadows of backlit subjects.
- Easier geotagging: Features an internal GPS sensor to log localization data.
- More heavily discounted: Has been around for much longer (launched in August 2011).
If the count of individual advantages (bullet points above) is taken as a guide, the E-M5 II is the clear winner of the match-up (13 : 9 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-M5 II 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 the spec-sheets of cameras can offer a general idea of their imaging potential, it remains partial and cannot reveal, for example, the shooting experience and imaging performance when actually working with the E-M5 II or the A77. 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 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-M5 II||+ +||81/100||5/5||4.5/5||5/5||Feb 2015||1,099|
|Sony A77||91/100||81/100||..||4.5/5||5/5||Aug 2011||1,399|
|Olympus E-M5 III||+||82/100||4.5/5||5/5||4.5/5||Oct 2019||1,199|
|Olympus E-M1 II||+ +||85/100||4.5/5||5/5||4.5/5||Sep 2016||1,999|
|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-M1||+ +||84/100||4.5/5||4.5/5||4.5/5||Sep 2013||1,399|
|Olympus E-P5||+ +||78/100||4.5/5||4.5/5||5/5||May 2013||999|
|Olympus E-M5||+ +||80/100||4.5/5||5/5||5/5||Feb 2012||1,299|
|Panasonic GH5||+ +||85/100||4.5/5||5/5||5/5||Jan 2017||1,999|
|Panasonic G80||+ +||84/100||5/5||4.5/5||4.5/5||Sep 2016||899|
|Panasonic GX8||+||82/100||4.5/5||5/5||4.5/5||Jul 2015||1,199|
|Sony A9||+ +||89/100||5/5||5/5||5/5||Apr 2017||4,499|
|Sony A7 II||+||82/100||4.5/5||5/5||5/5||Nov 2014||1,999|
|Sony A77 II||..||80/100||4.5/5||4/5||5/5||May 2014||1,199|
|Sony A99||..||84/100||4.5/5||o||4.5/5||Sep 2012||2,799|
|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 comparisons of ratings among very different cameras or across long time periods have little meaning. 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 would like to check on the differences and similarities of other camera models, just make your choice using the following search menu. There is also a set of direct links to comparison reviews that other users of the CAM-parator app explored.
- Canon 1Ds Mark II vs Sony A77
- Canon 250D vs Sony A77
- Canon 350D vs Sony A77
- Canon M100 vs Sony A77
- Canon SX740 vs Sony A77 II
- Leica TL2 vs Sony A77 II
- Nikon D70s vs Olympus E-M5 II
- Olympus E-M1 III vs Olympus E-M5 II
- Panasonic G80 vs Sony A77 II
- Panasonic GH5 vs Sony A77
- Panasonic LX100 vs Sony A77 II
- Sony A77 vs YI M1
Specifications: Olympus E-M5 II 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-M5 II||Sony A77|
|Camera Type||Mirrorless system camera||Digital single lens reflex|
|Camera Lens||Micro Four Thirds lenses||Sony A mount lenses|
|Launch Date||February 2015||August 2011|
|Launch Price||USD 1,099||USD 1,399|
|Sensor Specs||Olympus E-M5 II||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||15.9 Megapixels||24 Megapixels|
|Image Resolution||4608 x 3456 pixels||6000 x 4000 pixels|
|Pixel Pitch||3.76 μm||3.91 μm|
|Pixel Density||7.08 MP/cm2||6.55 MP/cm2|
|Moiré control||Anti-Alias filter||Anti-Alias filter|
|Movie Capability||1080/60p 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 VII||BIONZ X|
|DXO Sensor Quality (score)||73||78|
|DXO Color Depth (bits)||23.0||24.0|
|DXO Dynamic Range (EV)||12.5||13.2|
|DXO Low Light (ISO)||842||801|
|Screen Specs||Olympus E-M5 II||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||1037k dots||921k dots|
|LCD Attachment||Swivel screen||Fully flexible screen|
|Touch Input||Touchscreen||no Touchscreen|
|Shooting Specs||Olympus E-M5 II||Sony A77|
|Focus System||Contrast-detect AF||Phase-detect AF|
|Manual Focusing Aid||Focus Peaking||Focus Peaking|
|Max Shutter Speed (mechanical)||1/8000s||1/8000s|
|Continuous Shooting||10 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||no On-Board 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-M5 II||Sony A77|
|Studio Flash||PC Sync socket||PC Sync socket|
|USB Connector||USB 2.0||USB 2.0|
|HDMI Port||micro HDMI||mini HDMI|
|Microphone Port||External MIC port||External MIC port|
|Wifi Support||Wifi built-in||no Wifi|
|Geotagging||no internal GPS||GPS built-in|
|Body Specs||Olympus E-M5 II||Sony A77|
|Environmental Sealing||Weathersealed body||Weathersealed body|
|Battery Life (CIPA)||310 shots per charge||470 shots per charge|
124 x 85 x 45 mm
(4.9 x 3.3 x 1.8 in)
143 x 104 x 81 mm
(5.6 x 4.1 x 3.2 in)
|Camera Weight||469 g (16.5 oz)||732 g (25.8 oz)|
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