Olympus E-M1 II vs Sony A9
The Olympus OM-D E-M1 Mark II and the Sony Alpha A9 are two digital cameras that were revealed to the public, respectively, in September 2016 and April 2017. Both the E-M1 II and the A9 are mirrorless interchangeable lens cameras that are based on a Four Thirds (E-M1 II) and a full frame (A9) 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.
|Olympus E-M1 II||Sony A9|
|Mirrorless system camera||Mirrorless system camera|
|Micro Four Thirds lenses||Sony E mount lenses|
|20.2 MP, Four Thirds Sensor||24 MP, Full Frame Sensor|
|4K/30p Video||4K/30p Video|
|ISO 200-25,600||ISO 100-51,200 (50 - 204,800)|
|Electronic viewfinder (2360k dots)||Electronic viewfinder (3686k dots)|
|3.0 LCD, 1037k dots||3.0 LCD, 1440k dots|
|Swivel touchscreen||Tilting touchscreen|
|18 shutter flaps per second||20 shutter flaps per second|
|In-body stabilization||In-body stabilization|
|Weathersealed body||Weathersealed body|
|440 shots per battery charge||650 shots per battery charge|
|134 x 91 x 67 mm, 574 g||127 x 96 x 63 mm, 673 g|
Going beyond this snapshot of core features and characteristics, what are the differences between the Olympus OM-D E-M1 Mark II and the Sony Alpha A9? 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-M1 II and the Sony A9 is provided 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.
If the front view area (width x height) of the cameras is taken as an aggregate measure of their size, the Olympus E-M1 II and the Sony A9 are of equal size. However, the A9 is markedly heavier (17 percent) than the E-M1 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. 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-M1 II) and the Sony FE Lens Catalog (A9). 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-M1 II gets 440 shots out of its BLH-1 battery, while the A9 can take 650 images on a single charge of its NP-FZ100 power pack. The power pack in the A9 can be charged via the USB port, which can be very convenient when travelling.
The table below summarizes the key physical specs of the two cameras alongside a broader set of comparators. In case you want to display and compare another camera duo, just click on the right or left arrow next to the camera that you would like to inspect. Alternatively, you can also use the CAM-parator to select your camera combination among a larger number of options.
|Olympus E-M1 II||5.3 in||3.6 in||2.6 in||20.2 oz||440||Y||Sep 2016||1,999|
|Sony A9||5.0 in||3.8 in||2.5 in||23.7 oz||650||Y||Apr 2017||4,499|
|Nikon Z6||5.3 in||4.0 in||2.6 in||23.8 oz||310||Y||Aug 2018||1,999|
|Olympus E-M1 III||5.3 in||3.6 in||2.7 in||20.5 oz||420||Y||Feb 2020||1,799|
|Olympus PEN-F||4.9 in||2.8 in||1.5 in||15.1 oz||330||n||Jan 2016||1,199|
|Olympus E-M5 II||4.9 in||3.3 in||1.8 in||16.5 oz||310||Y||Feb 2015||1,099|
|Olympus E-M1||5.1 in||3.7 in||2.5 in||17.5 oz||350||Y||Sep 2013||1,399|
|Panasonic G9||5.4 in||3.8 in||3.6 in||23.2 oz||400||Y||Nov 2017||1,699|
|Panasonic GH5||5.5 in||3.9 in||3.4 in||25.6 oz||410||Y||Jan 2017||1,999|
|Panasonic G85||5.0 in||3.5 in||2.9 in||17.8 oz||330||Y||Sep 2016||899|
|Panasonic GX8||5.2 in||3.1 in||2.5 in||17.2 oz||330||Y||Jul 2015||1,199|
|Sony A9 II||5.1 in||3.8 in||3.0 in||23.9 oz||690||Y||Oct 2019||4,499|
|Sony A7 III||5.0 in||3.8 in||2.9 in||22.9 oz||610||Y||Feb 2018||1,999|
|Sony A7R III||5.0 in||3.8 in||2.9 in||22.9 oz||650||Y||Oct 2017||3,199|
|Sony A7 II||5.0 in||3.8 in||2.4 in||21.1 oz||350||Y||Nov 2014||1,999|
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-M1 II was launched at a markedly lower price (by 56 percent) than the A9, 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 size of the sensor inside a digital camera is one of the key determinants 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 tend to be more expensive and lead to bigger and heavier cameras and lenses.
Of the two cameras under consideration, the Olympus E-M1 II features a Four Thirds sensor and the Sony A9 a full frame sensor. The sensor area in the A9 is 276 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-M1 II has a native 4:3 aspect ratio, while the one in the A9 offers a 3:2 aspect.
With 24MP, the A9 offers a higher resolution than the E-M1 II (20.2MP), but the A9 nevertheless has larger individual pixels (pixel pitch of 5.94μm versus 3.34μm for the E-M1 II) due to its larger sensor. Moreover, the A9 is a somewhat more recent model (by 6 months) than the E-M1 II, and its sensor might have benefitted from technological advances during this time that further enhance the light gathering capacity of its pixel-units. Coming back to sensor resolution, it should be mentioned that the E-M1 II has no anti-alias filter installed, so that it can capture all the detail its sensor resolves.
The resolution advantage of the Sony A9 implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the A9 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-M1 II 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.
Unlike the A9, the E-M1 II has the capacity to capture high quality composite images (50MP) 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-M1 Mark II has a native sensitivity range from ISO 200 to ISO 25600, which can be extended to ISO 64-25600. The corresponding ISO settings for the Sony Alpha A9 are ISO 100 to ISO 51200, with the possibility to increase the ISO range to 50-204800.
For many cameras, data on sensor performance has been reported by DXO Mark. 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 A9 offers substantially better image quality than the E-M1 II (overall score 12 points higher). The advantage is based on 1.2 bits higher color depth, 0.5 EV in additional dynamic range, and 1.4 stops in additional low light sensitivity. The following table provides an overview of the physical sensor characteristics, as well as the sensor quality measurements for a selection of comparators.
|Olympus E-M1 II||Four Thirds||20.2||5184||3888||4K/30p||23.7||12.8||1312||80|
|Sony A9||Full Frame||24.0||6000||4000||4K/30p||24.9||13.3||3517||92|
|Nikon Z6||Full Frame||24.3||6048||4024||4K/30p||25.3||14.3||3299||95|
|Olympus E-M1 III||Four Thirds||20.2||5184||3888||4K/30p||..||..||..||..|
|Olympus PEN-F||Four Thirds||20.2||5184||3888||1080/60p||23.1||12.4||894||74|
|Olympus E-M5 II||Four Thirds||15.9||4608||3456||1080/60p||23.0||12.5||842||73|
|Olympus E-M1||Four Thirds||15.9||4608||3456||1080/30p||23.0||12.7||757||73|
|Panasonic G9||Four Thirds||20.2||5184||3888||4K/60p||..||..||..||..|
|Panasonic GH5||Four Thirds||20.2||5184||3888||4K/60p||23.9||13.0||807||77|
|Panasonic G85||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 II||Full Frame||24.0||6000||4000||4K/30p||25.0||14.0||3434||93|
|Sony A7 III||Full Frame||24.0||6000||4000||4K/30p||25.0||14.7||3730||96|
|Sony A7R III||Full Frame||42.2||7952||5304||4K/30p||26.0||14.7||3523||100|
|Sony A7 II||Full Frame||24.0||6000||4000||1080/60p||24.9||13.6||2449||90|
Many modern cameras are not only capable of taking still images, but also of capturing video footage. Both cameras under consideration have a sensor with sufficiently fast read-out times for moving pictures, and both provide the same movie specifications (4K/30p).
Apart from 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 A9 offers a substantially higher resolution than the one in the E-M1 II (3686k vs 2360k dots). The following table reports on some other key feature differences and similarities of the Olympus E-M1 II, the Sony A9, and comparable cameras.
|Olympus E-M1 II||2360||n||3.0||1037||swivel||Y||1/8000s||18.0||n||Y|
|Olympus E-M1 III||2360||n||3.0||1037||swivel||Y||1/8000s||18.0||n||Y|
|Olympus E-M5 II||2360||n||3.0||1037||swivel||Y||1/8000s||10.0||n||Y|
|Sony A9 II||3686||n||3.0||1440||tilting||Y||1/8000s||10.0||n||Y|
|Sony A7 III||2359||n||3.0||922||tilting||Y||1/8000s||10.0||n||Y|
|Sony A7R III||3686||n||3.0||1440||tilting||Y||1/8000s||10.0||n||Y|
|Sony A7 II||2400||n||3.0||1230||tilting||n||1/8000s||5.0||n||Y|
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-M1 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-M1 II writes its imaging data to SDXC cards, while the A9 uses SDXC or Memory Stick PRO Duo cards. Both cameras feature dual card slots, which can be very useful in case a memory card fails. Both the E-M1 II and the A9 support UHS-II cards (Ultra High Speed data transfer of up to 312 MB/s) on the first slot and UHS-I cards (104 MB/s) on the second one.
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-M1 Mark II and Sony Alpha A9 and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.
| WiFi |
|Olympus E-M1 II||Y||stereo||mono||Y||Y||micro||3.0||Y||-||-|
|Olympus E-M1 III||Y||stereo||mono||Y||Y||micro||3.1||Y||-||Y|
|Olympus E-M5 II||Y||stereo||mono||Y||-||micro||2.0||Y||-||-|
|Sony A9 II||Y||stereo||mono||Y||Y||micro||3.1||Y||Y||Y|
|Sony A7 III||Y||stereo||mono||Y||Y||micro||3.1||Y||Y||Y|
|Sony A7R III||Y||stereo||mono||Y||Y||micro||3.1||Y||Y||Y|
|Sony A7 II||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||-|
Both cameras feature a PC Sync terminal to control professional strobe lights, which will be appreciated by studio photographers.
The E-M1 II is a recent model that features in the current product line-up of Olympus. In contrast, the A9 has been discontinued (but can be found pre-owned on eBay). As a replacement in the same line of cameras, the A9 was succeeded by the Sony A9 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 how do things add up? Is the Olympus E-M1 II better than the Sony A9 or vice versa? A synthesis of the relative strong points of each of the models is listed below.
Reasons to prefer the Olympus OM-D E-M1 Mark II:
- Maximized detail: Lacks an anti-alias filter to exploit the sensor's full resolution potential.
- High quality composites: Can combine several shots after pixel-shifting its sensor.
- More flexible LCD: Has a swivel 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.
- Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
- Less heavy: Is lighter (by 99g or 15 percent) and hence easier to carry around.
- Faster data transfer: Supports a more advanced USB protocol (3.0 vs 2.0).
- More affordable: Was introduced into a lower priced category (56 percent cheaper at launch).
- More heavily discounted: Has been on the market for longer (launched in September 2016).
Arguments in favor of the Sony Alpha A9:
- 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 image quality: Scores substantially higher (12 points) in the DXO overall evaluation.
- Richer colors: Generates noticeably more natural colors (1.2 bits more color depth).
- Better low-light sensitivity: Can shoot in dim conditions (1.4 stops ISO advantage).
- More detailed viewfinder: Has higher resolution electronic viewfinder (3686k vs 2360k dots).
- Larger viewfinder image: Features a viewfinder with a higher magnification (0.78x vs 0.74x).
- More detailed LCD: Has a higher resolution rear screen (1440k vs 1037k dots).
- Longer lasting: Gets more shots (650 versus 440) out of a single battery charge.
- Easier travel charging: Can be conveniently charged via its USB port.
- Easier device pairing: Supports NFC for fast wireless image transfer over short distances.
- Easier wireless transfer: Supports Bluetooth for image sharing without cables.
- More modern: Was introduced somewhat (6 months) more recently.
If the number of relative strengths (bullet points above) is taken as a guide, the A9 emerges as the winner of the match-up (12 : 9 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-M1 II and the Sony A9 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 technical specifications can provide a useful overview of the capabilities of different cameras, it remains partial and cannot reveal, for example, the shooting experience and imaging performance when actually working with the E-M1 II or the A9. 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 following table reports the overall ratings of the cameras as published by some of the major 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-M1 II||+ +||85/100||4.5/5||5/5||4.5/5||Sep 2016||1,999|
|Sony A9||+ +||89/100||5/5||5/5||5/5||Apr 2017||4,499|
|Nikon Z6||..||..||4.5/5||4.5/5||5/5||Aug 2018||1,999|
|Olympus E-M1 III||..||83/100||4.5/5||..||4/5||Feb 2020||1,799|
|Olympus PEN-F||..||82/100||4.5/5||4.5/5||5/5||Jan 2016||1,199|
|Olympus E-M5 II||+ +||81/100||5/5||4.5/5||5/5||Feb 2015||1,099|
|Olympus E-M1||+ +||84/100||4.5/5||4.5/5||4.5/5||Sep 2013||1,399|
|Panasonic G9||+ +||85/100||5/5||5/5||5/5||Nov 2017||1,699|
|Panasonic GH5||+ +||85/100||4.5/5||5/5||5/5||Jan 2017||1,999|
|Panasonic G85||+ +||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 II||..||..||5/5||..||5/5||Oct 2019||4,499|
|Sony A7 III||+ +||89/100||5/5||5/5||5/5||Feb 2018||1,999|
|Sony A7R III||+ +||90/100||4.5/5||5/5||5/5||Oct 2017||3,199|
|Sony A7 II||+||82/100||4.5/5||5/5||5/5||Nov 2014||1,999|
|Notes: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.|
The review scores listed above should be treated with care, though. The ratings are only valid when referring to cameras in the same category and of the same age. Thus, a score needs to be put into the context of the launch date and the launch price of the camera, and comparing ratings of very distinct cameras or ones that are far apart in terms of their release date have little meaning. 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? In case you would like to check on the differences and similarities of other camera models, just use the search menu below. As an alternative, you can also directly jump to any one of the listed comparisons that were previously generated by the CAM-parator tool.
- Canon 1D Mark II vs Sony A9
- Canon 550D vs Sony A9
- Canon 77D vs Sony A9
- Fujifilm X-E3 vs Sony A9 II
- Fujifilm X20 vs Sony A9
- Nikon W300 vs Olympus E-M1 II
- Olympus E-M1 II vs Panasonic GH3
- Olympus E-M1 II vs Sony HX80
- Olympus E-PM2 vs Sony A9
- Olympus XZ-1 vs Sony A9
- Panasonic G80 vs Sony A9
- Sony A3000 vs Sony A9 II
Specifications: Olympus E-M1 II vs Sony A9
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-M1 II||Sony A9|
|Camera Type||Mirrorless system camera||Mirrorless system camera|
|Camera Lens||Micro Four Thirds lenses||Sony E mount lenses|
|Launch Date||September 2016||April 2017|
|Launch Price||USD 1,999||USD 4,499|
|Sensor Specs||Olympus E-M1 II||Sony A9|
|Sensor Format||Four Thirds Sensor||Full Frame Sensor|
|Sensor Size||17.3 x 13.0 mm||35.6 x 23.8 mm|
|Sensor Area||224.9 mm2||847.28 mm2|
|Sensor Diagonal||21.6 mm||42.8 mm|
|Sensor Resolution||20.2 Megapixels||24 Megapixels|
|Image Resolution||5184 x 3888 pixels||6000 x 4000 pixels|
|Pixel Pitch||3.34 μm||5.94 μm|
|Pixel Density||8.96 MP/cm2||2.83 MP/cm2|
|Moiré control||no AA filter||Anti-Alias filter|
|Movie Capability||4K/30p Video||4K/30p Video|
|ISO Setting||200 - 25,600 ISO||100 - 51,200 ISO|
|ISO Boost||64 - 25,600 ISO||50 - 204,800 ISO|
|Image Processor||TruePic VIII||BIONZ X|
|DXO Sensor Quality (score)||80||92|
|DXO Color Depth (bits)||23.7||24.9|
|DXO Dynamic Range (EV)||12.8||13.3|
|DXO Low Light (ISO)||1312||3517|
|Screen Specs||Olympus E-M1 II||Sony A9|
|Viewfinder Type||Electronic viewfinder||Electronic viewfinder|
|Viewfinder Field of View||100%||100%|
|Viewfinder Resolution||2360k dots||3686k dots|
|LCD Framing||Live View||Live View|
|Rear LCD Size||3.0inch||3.0inch|
|LCD Resolution||1037k dots||1440k dots|
|LCD Attachment||Swivel screen||Tilting screen|
|Shooting Specs||Olympus E-M1 II||Sony A9|
|Focus System||On-Sensor Phase-detect||On-Sensor Phase-detect|
|Manual Focusing Aid||Focus Peaking||Focus Peaking|
|Max Shutter Speed (mechanical)||1/8000s||1/8000s|
|Continuous Shooting||18 shutter flaps/s||20 shutter flaps/s|
|Shutter Life Expectancy||200 000 actuations||500 000 actuations|
|Electronic Shutter||up to 1/32000s||up to 1/32000s|
|Time-Lapse Photography||Intervalometer built-in||no Intervalometer|
|Image Stabilization||In-body stabilization||In-body stabilization|
|Fill Flash||no On-Board Flash||no On-Board Flash|
|Storage Medium||SDXC cards||MS or SDXC cards|
|Second Storage Option||Dual card slots||Dual card slots|
|UHS card support||Single UHS-II||Single UHS-II|
|Connectivity Specs||Olympus E-M1 II||Sony A9|
|Studio Flash||PC Sync socket||PC Sync socket|
|USB Connector||USB 3.0||USB 2.0|
|HDMI Port||micro HDMI||micro HDMI|
|Microphone Port||External MIC port||External MIC port|
|Headphone Socket||Headphone port||Headphone port|
|Wifi Support||Wifi built-in||Wifi built-in|
|Near-Field Communication||no NFC||NFC built-in|
|Bluetooth Support||no Bluetooth||Bluetooth built-in|
|Body Specs||Olympus E-M1 II||Sony A9|
|Environmental Sealing||Weathersealed body||Weathersealed body|
|Battery Life (CIPA)||440 shots per charge||650 shots per charge|
|In-Camera Charging||no USB charging||USB charging|
134 x 91 x 67 mm
(5.3 x 3.6 x 2.6 in)
127 x 96 x 63 mm
(5.0 x 3.8 x 2.5 in)
|Camera Weight||574 g (20.2 oz)||673 g (23.7 oz)|
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