Olympus E-M10 IV vs Sony A99
The Olympus OM-D E-M10 Mark IV and the Sony Alpha SLT-A99 are two digital cameras that were announced, respectively, in August 2020 and September 2012. The E-M10 IV is a mirrorless interchangeable lens camera, while the A99 is a DSLR. The cameras are based on a Four Thirds (E-M10 IV) and a full frame (A99) 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-A99? 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 IV and the Sony A99 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 size dimensions are rounded to the nearest millimeter.
The E-M10 IV can be obtained in two different colors (black, silver), while the A99 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 A99 is considerably larger (59 percent) than the Olympus E-M10 IV. Moreover, the A99 is substantially heavier (112 percent) than the E-M10 IV. It is noteworthy in this context that the A99 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 A99 can take 500 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 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 IV||122 mm||84 mm||49 mm||383 g||360||n||Aug 2020||699|
|2.||Sony A99||147 mm||111 mm||78 mm||812 g||500||Y||Sep 2012||2,799|
|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 G100||116 mm||83 mm||54 mm||352 g||270||n||Jun 2020||649|
|13.||Sony A9 II||129 mm||96 mm||76 mm||678 g||690||Y||Oct 2019||4,499|
|14.||Sony A99 II||143 mm||104 mm||76 mm||849 g||490||Y||Sep 2016||3,199|
|15.||Sony A77||143 mm||104 mm||81 mm||732 g||470||Y||Aug 2011||1,399|
|16.||Sony A850||156 mm||117 mm||82 mm||895 g||880||Y||Aug 2009||1,999|
|17.||Sony A900||156 mm||117 mm||82 mm||895 g||880||Y||Sep 2008||2,999|
|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 listed launch prices provide an indication of the market segment that the manufacturer of the cameras have been targeting. The E-M10 IV was launched at a markedly lower price (by 75 percent) than the A99, which puts it into a different market segment. 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 imaging sensor is at the core of digital cameras and its size is one of the main determining factors 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. 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 A99 a full frame sensor. The sensor area in the A99 is 279 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 IV has a native 4:3 aspect ratio, while the one in the A99 offers a 3:2 aspect.
With 24MP, the A99 offers a higher resolution than the E-M10 IV (20.2MP), but the A99 nevertheless has larger individual pixels (pixel pitch of 5.96μm 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 7 years and 10 months) than the A99, 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 A99 implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the A99 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-A99 are ISO 100 to ISO 25600, with the possibility to increase the ISO range to 50-25600.
Since 2007, DXO Mark has published sensor performance measurements that have been derived using a consistent methodology. 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||..||..||..||..|
|2.||Sony A99||Full Frame||24.0||6000||4000||1080/60p||25.0||14.0||1555||89|
|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 G100||Four Thirds||20.2||5184||3888||4K/30p||..||..||..||..|
|13.||Sony A9 II||Full Frame||24.0||6000||4000||4K/30p||25.0||14.0||3434||93|
|14.||Sony A99 II||Full Frame||42.2||7952||5304||4K/30p||25.4||13.4||2317||92|
|16.||Sony A850||Full Frame||24.4||6048||4032||none||23.8||12.2||1415||79|
|17.||Sony A900||Full Frame||24.4||6048||4032||none||23.7||12.3||1431||79|
Many modern cameras are not only capable of taking still images, but can also record movies. Both cameras under consideration are equipped with sensors that have a sufficiently high read-out speed for moving images, but the E-M10 IV provides a higher video resolution than the A99. It can shoot video footage at 4K/30p, while the Sony is limited to 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-M10 IV offers a slightly higher resolution than the one in the A99 (2360k vs 2359k dots). The adjacent table lists some of the other core features of the Olympus E-M10 IV and Sony A99 along with similar information for a selection of comparators.
|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|
|13.||Sony A9 II||3686||n||3.0||1440||tilting||Y||1/8000s||10.0||n||Y|
|14.||Sony A99 II||2400||Y||3.0||1229||full-flex||n||1/8000s||12.0||n||Y|
One difference between the cameras concerns the presence of an on-board flash. The E-M10 IV has one, while the A99 does not. While the built-in flash of the E-M10 IV is not very powerful, it can at times be useful as a fill-in light.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 A99 uses SDXC or Memory Stick PRO Duo cards. The A99 features dual card slots, which can be very useful in case a memory card fails. In contrast, the E-M10 IV only has one slot. The E-M10 IV supports UHS-II cards (Ultra High Speed data transfer of up to 312 MB/s), while the A99 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-A99 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||-||-|
|13.||Sony A9 II||Y||stereo||mono||Y||Y||micro||3.1||Y||Y||Y|
|14.||Sony A99 II||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||Y|
It is notable that the E-M10 IV offers wifi support, while the A99 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 A99 (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 A99 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 A99 has been discontinued (but can be found pre-owned on eBay). As a replacement in the same line of cameras, the A99 was succeeded by the Sony A99 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 is the bottom line? Is the Olympus E-M10 IV better than the Sony A99 or vice versa? The listing below highlights the relative strengths of the two models.
Advantages 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).
- Fewer buttons to press: Is equipped with a touch-sensitive rear screen to facilitate handling.
- Faster burst: Shoots at higher frequency (15 vs 6 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 147x111mm) and thus needs less room in the bag.
- Less heavy: Is lighter (by 429g or 53 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 fill-in: Is equipped with a small onboard flash to brighten deep shadow areas.
- 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 (75 percent cheaper at launch).
- More modern: Reflects 7 years and 10 months of technical progress since the A99 launch.
Arguments in favor of the Sony Alpha SLT-A99:
- 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.
- 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).
- Easier setting verification: Features a control panel on top to check shooting parameters.
- More detailed LCD: Has a higher resolution rear screen (1229k vs 1040k dots).
- 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 (500 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.
- Greater peace of mind: Features a second card slot as a backup in case of memory card failure.
- More heavily discounted: Has been around for much longer (launched in September 2012).
If the count of relative strengths (bullet points above) is taken as a measure, the E-M10 IV comes out slightly ahead of the A99 (16 : 15 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 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 A99 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 partial and cannot reveal, for example, the shooting experience and imaging performance when actually working with the E-M10 IV or the A99. 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 IV||4.5/5||..||81/100||4.5/5||4.5/5||Aug 2020||699|
|2.||Sony A99||5/5||..||84/100||4.5/5||4.5/5||Sep 2012||2,799|
|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 G100||..||..||78/100||4/5||4/5||Jun 2020||649|
|13.||Sony A9 II||..||..||90/100||5/5||5/5||Oct 2019||4,499|
|14.||Sony A99 II||..||..||85/100||4.5/5||4.5/5||Sep 2016||3,199|
|15.||Sony A77||5/5||91/100||81/100||..||5/5||Aug 2011||1,399|
|16.||Sony A850||3/5||..||75/100||..||4.5/5||Aug 2009||1,999|
|17.||Sony A900||..||+ +||+ +||4.5/5||5/5||Sep 2008||2,999|
|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. 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. 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? If you would like to see a different side-by-side camera review, just use the search menu below. Alternatively, you can follow any of the listed hyperlinks for comparisons that others found interesting.
Specifications: Olympus E-M10 IV vs Sony A99
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 A99|
|Camera Type||Mirrorless system camera||Digital single lens reflex|
|Camera Lens||Micro Four Thirds lenses||Sony A mount lenses|
|Launch Date||August 2020||September 2012|
|Launch Price||USD 699||USD 2,799|
|Sensor Specs||Olympus E-M10 IV||Sony A99|
|Sensor Format||Four Thirds Sensor||Full Frame Sensor|
|Sensor Size||17.3 x 13.0 mm||35.8 x 23.8 mm|
|Sensor Area||224.9 mm2||852.04 mm2|
|Sensor Diagonal||21.6 mm||43 mm|
|Sensor Resolution||20.2 Megapixels||24 Megapixels|
|Image Resolution||5184 x 3888 pixels||6000 x 4000 pixels|
|Pixel Pitch||3.34 μm||5.96 μm|
|Pixel Density||8.96 MP/cm2||2.82 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 - 25,600 ISO|
|ISO Boost||100 - 25,600 ISO||50 - 25,600 ISO|
|Image Processor||TruePic VIII||BIONZ X|
|DXO Sensor Quality (score)||..||89|
|DXO Color Depth (bits)||..||25.0|
|DXO Dynamic Range (EV)||..||14.0|
|DXO Low Light (ISO)||..||1555|
|Screen Specs||Olympus E-M10 IV||Sony A99|
|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||1229k dots|
|LCD Attachment||Tilting screen||Fully flexible screen|
|Touch Input||Touchscreen||no Touchscreen|
|Shooting Specs||Olympus E-M10 IV||Sony A99|
|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||6 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||no On-Board Flash|
|Storage Medium||SDXC cards||MS or SDXC cards|
|Second Storage Option||Single card slot||Dual card slots|
|UHS card support||UHS-II||UHS-I|
|Connectivity Specs||Olympus E-M10 IV||Sony A99|
|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|
|Headphone Socket||no Headphone port||Headphone 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 A99|
|Environmental Sealing||not weather sealed||Weathersealed body|
|Battery Life (CIPA)||360 shots per charge||500 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)
147 x 111 x 78 mm
(5.8 x 4.4 x 3.1 in)
|Camera Weight||383 g (13.5 oz)||812 g (28.6 oz)|
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