Olympus E-PM2 vs Sony A77
The Olympus PEN E-PM2 and the Sony Alpha SLT-A77 are two digital cameras that were announced, respectively, in September 2012 and August 2011. The E-PM2 is a mirrorless interchangeable lens camera, while the A77 is a DSLR. The cameras are based on a Four Thirds (E-PM2) 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.
Going beyond this snapshot of core features and characteristics, what are the differences between the Olympus PEN E-PM2 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-PM2 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-PM2 can be obtained in four different colors (black, silver, red, white), 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 (111 percent) than the Olympus E-PM2. Moreover, the A77 is substantially heavier (172 percent) than the E-PM2. It is noteworthy in this context that the A77 is splash and dust-proof, while the E-PM2 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.
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, you can move across to the CAM-parator tool and choose from the broad selection of possible camera comparisons there.
|1.||Olympus E-PM2||110 mm||64 mm||34 mm||269 g||360||n||Sep 2012||499|
|2.||Sony A77||143 mm||104 mm||81 mm||732 g||470||Y||Aug 2011||1,399|
|3.||Olympus E-PL9||117 mm||68 mm||39 mm||380 g||350||n||Feb 2018||599|
|4.||Olympus E-PL8||115 mm||67 mm||38 mm||357 g||350||n||Sep 2016||549|
|5.||Olympus E-M10 II||120 mm||83 mm||47 mm||390 g||320||n||Aug 2015||649|
|6.||Olympus E-PL7||115 mm||67 mm||38 mm||357 g||350||n||Aug 2014||599|
|7.||Olympus E-P5||122 mm||69 mm||37 mm||420 g||330||n||May 2013||999|
|8.||Olympus E-PL6||111 mm||64 mm||38 mm||325 g||360||n||May 2013||599|
|9.||Olympus E-PL5||111 mm||64 mm||38 mm||325 g||360||n||Sep 2012||599|
|10.||Olympus E-PL3||110 mm||64 mm||37 mm||313 g||300||n||Jun 2011||599|
|11.||Olympus E-PM1||110 mm||64 mm||34 mm||265 g||330||n||Jun 2011||499|
|12.||Panasonic GX850||107 mm||65 mm||33 mm||269 g||210||n||Jan 2017||549|
|13.||Pentax K-3||131 mm||100 mm||77 mm||800 g||560||Y||Oct 2013||1,299|
|14.||Sony A6500||120 mm||67 mm||53 mm||453 g||350||Y||Oct 2016||1,399|
|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.|
Any camera decision will naturally be influenced heavily by the price. 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-PM2 was launched at a markedly lower price (by 64 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.
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. 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-PM2 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-PM2 has a native 4:3 aspect ratio, while the one in the A77 offers a 3:2 aspect.
Technology-wise, both cameras are equipped with CMOS (Complementary Metal–Oxide–Semiconductor) sensors.
With 24MP, the A77 offers a higher resolution than the E-PM2 (15.9MP), but the A77 nevertheless has larger individual pixels (pixel pitch of 3.91μm versus 3.76μm for the E-PM2) due to its larger sensor. However, the E-PM2 is a somewhat more recent model (by 1 year) than the A77, and its sensor might 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-PM2 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 Olympus PEN E-PM2 has a native sensitivity range from ISO 100 to ISO 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 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"). Of the two cameras under consideration, the A77 has a markedly higher DXO score than the E-PM2 (overall score 6 points higher), which will translate into better image quality. The advantage is based on 1.3 bits higher color depth, 1 EV in additional dynamic range, and 0.2 stops of reduced low light sensitivity. The table below summarizes the physical sensor characteristics and sensor quality findings and compares them across a set of similar cameras.
| DXO |
|1.||Olympus E-PM2||Four Thirds||15.9||4608||3456||1080/30p||22.7||12.2||932||72|
|3.||Olympus E-PL9||Four Thirds||15.9||4608||3456||4K/30p||..||..||..||..|
|4.||Olympus E-PL8||Four Thirds||15.9||4608||3456||1080/30p||..||..||..||..|
|5.||Olympus E-M10 II||Four Thirds||15.9||4608||3456||1080/60p||23.1||12.5||842||73|
|6.||Olympus E-PL7||Four Thirds||15.9||4608||3456||1080/30p||22.7||12.4||873||72|
|7.||Olympus E-P5||Four Thirds||15.9||4608||3456||1080/30p||22.8||12.4||895||72|
|8.||Olympus E-PL6||Four Thirds||15.9||4608||3456||1080/30p||..||..||..||..|
|9.||Olympus E-PL5||Four Thirds||15.9||4608||3456||1080/30p||22.8||12.3||889||72|
|10.||Olympus E-PL3||Four Thirds||12.2||4032||3024||1080/60i||20.9||10.3||499||52|
|11.||Olympus E-PM1||Four Thirds||12.2||4032||3024||1080/60i||21.0||10.3||499||52|
|12.||Panasonic GX850||Four Thirds||15.8||4592||3448||4K/30p||23.2||13.3||586||73|
|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 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, but the A77 provides a faster frame rate than the E-PM2. It can shoot movie footage at 1080/60p, while the Olympus is limited to 1080/30p.
Beyond body and sensor, cameras can and do differ across a range of features. For example, the A77 has an electronic viewfinder (2359k dots), which can be very helpful when shooting in bright sunlight. In contrast, the E-PM2 relies on live view and the rear LCD for framing. That said, the E-PM2 can be equipped with an optional viewfinder – the VF-4. The adjacent table lists some of the other core features of the Olympus E-PM2 and Sony A77 along with similar information for a selection of comparators.
|5.||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-PM2 has a touchscreen, while the A77 has a conventional panel. Touch control can be particularly helpful, for example, for setting the focus point.The A77 has an articulated screen that can be turned to be front-facing. This characteristic will be appreciated by vloggers and photographers who are interested in taking selfies. In contrast, the E-PM2 does not have a selfie-screen.
The E-PM2 writes its imaging data to SDXC cards, while the A77 uses SDXC or Memory Stick PRO Duo cards. Both cameras can use UHS-I cards, which provide for Ultra High Speed data transfer of 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 PEN E-PM2 and Sony Alpha SLT-A77 and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.
| WiFi |
| NFC |
|5.||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 A77 has a microphone port, which can help to improve the quality of audio recordings by attaching an external microphone. The E-PM2 does not feature such a mic input.
Studio photographers will appreciate that the Sony A77 (unlike the E-PM2) 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.
Both the E-PM2 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-PM2 does not have a direct successor. 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 is the bottom line? Which of the two cameras – the Olympus E-PM2 or the Sony A77 – has the upper hand? Is one clearly better than the other? The listing below highlights the relative strengths of the two models.
Arguments in favor of the Olympus PEN E-PM2:
- Fewer buttons to press: Is equipped with a touch-sensitive rear screen to facilitate handling.
- More compact: Is smaller (110x64mm vs 143x104mm) and thus needs less room in the bag.
- Less heavy: Is lighter (by 463g or 63 percent) and hence easier to carry around.
- More legacy lens friendly: Can take a broad range of non-native lenses via adapters.
- More affordable: Was introduced into a lower priced category (64 percent cheaper at launch).
- More modern: Is somewhat more recent (announced 1 year after the A77).
Advantages 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 (6 points) in the DXO overall evaluation.
- Richer colors: Generates noticeably more natural colors (1.3 bits more color depth).
- More dynamic range: Captures a broader range of light and dark details (1 EV of extra DR).
- Better video: Provides higher movie framerates (1080/60p versus 1080/30p).
- Better sound: Can connect to an external microphone for higher quality sound recording.
- Easier framing: Has an electronic viewfinder for image composition and settings control.
- Easier setting verification: Features a control panel on top to check shooting parameters.
- More detailed LCD: Has a higher resolution rear screen (921k vs 460k dots).
- More flexible LCD: Has a full-flex screen for odd-angle shots in portrait or landscape orientation.
- More selfie-friendly: Has an articulated screen that can be turned to be front-facing.
- Faster shutter: Has higher mechanical shutter speed (1/8000s vs 1/4000s) to freeze action.
- Faster burst: Shoots at higher frequency (12 vs 8 flaps/sec) to capture the decisive moment.
- 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 fill-in: Has a small integrated flash to brighten shadows of backlit subjects.
- 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 on the market for longer (launched in August 2011).
If the number of relative strengths (bullet points above) is taken as a guide, the A77 is the clear winner of the contest (19 : 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-PM2 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 specs-based evaluation of cameras can be instructive in revealing their potential as photographic tools, it remains incomplete and does no justice, for example, to the way the E-PM2 or the A77 perform in practice. 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 where reviews by experts come in. 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-PM2||3/5||..||77/100||5/5||4.5/5||Sep 2012||499|
|2.||Sony A77||5/5||91/100||81/100||..||5/5||Aug 2011||1,399|
|3.||Olympus E-PL9||..||+||..||4.5/5||4/5||Feb 2018||599|
|4.||Olympus E-PL8||..||..||..||4.5/5||4/5||Sep 2016||549|
|5.||Olympus E-M10 II||4.5/5||+ +||80/100||5/5||5/5||Aug 2015||649|
|6.||Olympus E-PL7||4/5||+||..||5/5||4/5||Aug 2014||599|
|7.||Olympus E-P5||5/5||+ +||78/100||4.5/5||5/5||May 2013||999|
|8.||Olympus E-PL6||..||..||..||..||..||May 2013||599|
|9.||Olympus E-PL5||3/5||+ +||..||4.5/5||4.5/5||Sep 2012||599|
|10.||Olympus E-PL3||3/5||+ +||72/100||4.5/5||4/5||Jun 2011||599|
|11.||Olympus E-PM1||..||86/100||71/100||4.5/5||4.5/5||Jun 2011||499|
|12.||Panasonic GX850||..||+||76/100||4.5/5||4.5/5||Jan 2017||549|
|13.||Pentax K-3||4/5||..||83/100||5/5||5/5||Oct 2013||1,299|
|14.||Sony A6500||5/5||+ +||85/100||4.5/5||4.5/5||Oct 2016||1,399|
|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.|
Care should be taken when interpreting the review scores above, though. The ratings are only valid when referring to cameras in the same category and of the same age. Hence, a score should always be seen in the context of the camera's market launch date and its price, 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.
Specifications: Olympus E-PM2 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-PM2||Sony A77|
|Camera Type||Mirrorless system camera||Digital single lens reflex|
|Camera Lens||Micro Four Thirds lenses||Sony A mount lenses|
|Launch Date||September 2012||August 2011|
|Launch Price||USD 499||USD 1,399|
|Sensor Specs||Olympus E-PM2||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||1080/30p Video||1080/60p Video|
|ISO Setting||100 - 25,600 ISO||100 - 16,000 ISO|
|ISO Boost||no Enhancement||50 - 25,600 ISO|
|Image Processor||TruePic VI||BIONZ X|
|DXO Sensor Quality (score)||72||78|
|DXO Color Depth (bits)||22.7||24.0|
|DXO Dynamic Range (EV)||12.2||13.2|
|DXO Low Light (ISO)||932||801|
|Screen Specs||Olympus E-PM2||Sony A77|
|Viewfinder Type||Viewfinder optional||Electronic viewfinder|
|Viewfinder Field of View||100%|
|Viewfinder Resolution||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||460k dots||921k dots|
|LCD Attachment||Fixed screen||Fully flexible screen|
|Touch Input||Touchscreen||no Touchscreen|
|Shooting Specs||Olympus E-PM2||Sony A77|
|Focus System||Contrast-detect AF||Phase-detect AF|
|Manual Focusing Aid||no Peaking Feature||Focus Peaking|
|Max Shutter Speed (mechanical)||1/4000s||1/8000s|
|Continuous Shooting||8 shutter flaps/s||12 shutter flaps/s|
|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-I||UHS-I|
|Connectivity Specs||Olympus E-PM2||Sony A77|
|Studio Flash||no PC Sync||PC Sync socket|
|USB Connector||USB 2.0||USB 2.0|
|HDMI Port||mini HDMI||mini HDMI|
|Microphone Port||no MIC socket||External MIC port|
|Wifi Support||no Wifi||no Wifi|
|Geotagging||no internal GPS||GPS built-in|
|Body Specs||Olympus E-PM2||Sony A77|
|Environmental Sealing||not weather sealed||Weathersealed body|
|Battery Life (CIPA)||360 shots per charge||470 shots per charge|
110 x 64 x 34 mm
(4.3 x 2.5 x 1.3 in)
143 x 104 x 81 mm
(5.6 x 4.1 x 3.2 in)
|Camera Weight||269 g (9.5 oz)||732 g (25.8 oz)|
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