PW

Sony A9 versus Olympus E-M1 II

The Sony Alpha A9 and the Olympus OM-D E-M1 Mark II are two digital cameras that were revealed to the public, respectively, in April 2017 and September 2016. Both the A9 and the E-M1 II are mirrorless interchangeable lens cameras that are based on a full frame (A9) and a Four Thirds sensor. The Sony has a resolution of 24 megapixel, whereas the Olympus provides 20.2 MP.

Body comparison

The side-by-side display below illustrates the physical size and weight of the Sony A9 and the Olympus E-M1 II. Three consecutive perspectives from the front, the top, and the back are presented. All width, height and depth measures are rounded to the nearest millimeter. You can also toggle the display to switch to a percentage comparison if you prefer that the measures are being expressed in relative terms (in this case, the camera on the left side – the A9 – represents the basis for the calculations across all the size and weight measures).

Sony A9 vs Olympus E-M1 II front
A9 versus E-M1 II top view
A9 and E-M1 II rear side
Body view (A9 on the left)

If the front view area (width x height) of the cameras is taken as an aggregate measure of their size, the Sony A9 and the Olympus E-M1 IIare of equal size. However, the E-M1 II is markedly lighter (15 percent) than the A9. Cameras intended for semi-professional or professional use tend to be a bit bulkier in order to give them the necessary ruggedness. 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 find an overview of optics for the two cameras in the Sony FE Lens Catalog (A9) and the Micro Four Thirds Lens Catalog (E-M1 II). 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.

The table below summarizes the key physical specs of the two cameras alongside a broader set of comparators. 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 comparisons there.

Camera Body Specifications
Camera Camera
Width
Camera
Height
Camera
Depth
Camera
Weight
Battery
Life
(CIPA)
Weather
Sealing
(y/n)
Camera
Launch
(year)
Launch
Price
(USD)
Street
Price
(amazon)
Used
Price
(ebay)
Sony A9 (⇒ rgt) 5.0 in 3.8 in 2.5 in 23.7 oz 650 YES 2017 4,499 latest check
Olympus E-M1 II (⇒ lft) 5.3 in 3.6 in 2.6 in 20.2 oz 440 YES 2016 1,999 latest check
Olympus PEN-F (⇒ lft | rgt) 4.9 in 2.8 in 1.5 in 15.1 oz 330 no 2016 1,199 latest check
Olympus E-M5 II (⇒ lft | rgt) 4.9 in 3.3 in 1.8 in 16.5 oz 310 YES 2015 1,099 latest check
Panasonic G9 (⇒ lft | rgt) 5.4 in 3.8 in 3.6 in 23.2 oz 400 YES 2017 1,699 latest check
Panasonic GH5 (⇒ lft | rgt) 5.5 in 3.9 in 3.4 in 25.6 oz 410 YES 2017 1,999 latest check
Panasonic GX8 (⇒ lft | rgt) 5.2 in 3.1 in 2.5 in 17.2 oz 330 YES 2015 1,199 latest check
Sony A99 II (⇒ lft | rgt) 5.6 in 4.1 in 3.0 in 29.9 oz 490 YES 2016 3,199 latest check
Sony A6300 (⇒ lft | rgt) 4.7 in 2.6 in 1.9 in 14.3 oz 400 YES 2016 999discont. check
Sony A6500 (⇒ lft | rgt) 4.7 in 2.6 in 2.1 in 16.0 oz 350 YES 2016 1,399 latest check
Sony A7R II (⇒ lft | rgt) 5.0 in 3.8 in 2.4 in 22.0 oz 290 YES 2015 3,199discont. check
Sony A7S II (⇒ lft | rgt) 5.0 in 3.8 in 2.4 in 22.1 oz 370 YES 2015 2,999 latest check
Sony A7 II (⇒ lft | rgt) 5.0 in 3.8 in 2.4 in 21.1 oz 350 YES 2014 1,999 latest check
Sony A7 (⇒ lft | rgt) 5.0 in 3.7 in 1.9 in 16.7 oz 340 YES 2013 1,699discont. check
Sony A99 (⇒ lft | rgt) 5.8 in 4.4 in 3.1 in 28.6 oz 500 YES 2012 2,799discont. check

The listed prices provide an indication of the market segment that the manufacturer of the cameras have been targeting. 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. Then, after the new model is out, very good deals can frequently be found on the pre-owned market.

Sensor comparison

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. Further, a large sensor camera will give the photographer additional creative options when using shallow depth-of-field to isolate a subject from its background. On the downside, larger sensors tend to be associated with larger, more expensive camera bodies and lenses.

Of the two cameras under consideration, the Sony A9 features a full frame sensor and the Olympus E-M1 II a Four Thirds sensor. The sensor area in the E-M1 II is 73 percent smaller. As a result of these sensor size differences, the cameras have a format factor of, respectively, 1.0 and 2.0. The sensor in the A9 has a native 3:2 aspect ratio, while the one in the E-M1 II offers a 4:3 aspect.

Sony A9 and Olympus E-M1 II sensor measures
Sensor size

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 5.93μm 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 pixels. Coming back 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.

A9 versus E-M1 II MP
Sensor resolution

Consistent information on actual sensor performance is available from DXO Mark for most cameras. 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 review, the A9 provides substantially higher image quality than the E-M1 II, with an overall score that is 12 points higher. This 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.

Sensor Characteristics
Camera Sensor
Class
Resolution
(Megapixel)
Horiz.
Pixels
Vert.
Pixels
Video
Format
DXO
Portrait
DXO
Landscape
DXO
Sports
DXO
Overall
Sony A9 (⇒ rgt) Full Frame 24.0 6000 4000 4K/30p 24.9 13.3 3517 92
Olympus E-M1 II (⇒ lft) Four Thirds 20.2 5184 3888 4K/30p 23.7 12.8 1312 80
Olympus PEN-F (⇒ lft | rgt) Four Thirds 20.2 5184 3888 1080/60p 23.1 12.4 894 74
Olympus E-M5 II (⇒ lft | rgt) Four Thirds 15.9 4608 3456 1080/60p 23.0 12.5 842 73
Panasonic G9 (⇒ lft | rgt) Four Thirds 20.2 5184 3888 4K/60p - - - -
Panasonic GH5 (⇒ lft | rgt) Four Thirds 20.2 5184 3888 4K/60p 23.9 13.0 807 77
Panasonic GX8 (⇒ lft | rgt) Four Thirds 20.2 5184 3888 4K/30p 23.5 12.6 806 75
Sony A99 II (⇒ lft | rgt) Full Frame 42.2 7952 5304 4K/30p 25.4 13.4 2317 92
Sony A6300 (⇒ lft | rgt) APS-C 24.0 6000 4000 4K/30p 24.4 13.7 1437 85
Sony A6500 (⇒ lft | rgt) APS-C 24.0 6000 4000 4K/30p 24.5 13.7 1405 85
Sony A7R II (⇒ lft | rgt) Full Frame 42.2 7952 5304 4K/30p 26.0 13.9 3434 98
Sony A7S II (⇒ lft | rgt) Full Frame 12.0 4240 2832 4K/30p 23.6 13.3 2993 85
Sony A7 II (⇒ lft | rgt) Full Frame 24.0 6000 4000 1080/60p 24.9 13.6 2449 90
Sony A7 (⇒ lft | rgt) Full Frame 24.0 6000 4000 1080/60p 24.8 14.2 2248 90
Sony A99 (⇒ lft | rgt) 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. Both cameras under consideration are equipped with sensors that have a sufficiently high read-out speed for moving images, and both provide the same movie specifications (4K/30p).

Feature comparison

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 A9 offers a substantially higher resolution than the one in the E-M1 II (3686k vs 2360k dots). The table below summarizes some of the other core capabilities of the Sony A9 and Olympus E-M1 II in connection with corresponding information for a sample of similar cameras. If needed, the dpreview camera hub, for example, contains further detail on the cameras' specs.

Core Features
Camera Viewfinder
(Type or
'000 dots)
Control
Panel
(Y/n)
LCD
Size
(inch)
LCD
Resolution
('000 dots)
LCD
Attach-
ment
Touch
Screen
(Y/n)
Shutter
speed
(1/sec)
Shutter
flaps
(1/sec))
Build-in
Flash
(GN)
Build-in
Image
Stab
Sony A9 (⇒ rgt) 3686 no 3.0 1440 tilting YES 8000 20.0 no YES
Olympus E-M1 II (⇒ lft) 2360 no 3.0 1037 swivel YES 8000 18.0 no YES
Olympus PEN-F (⇒ lft | rgt) 2360 no 3.0 1037 swivel YES 8000 10.0 no YES
Olympus E-M5 II (⇒ lft | rgt) 2360 no 3.0 1037 swivel YES 8000 10.0 no YES
Panasonic G9 (⇒ lft | rgt) 3680 YES 3.0 1040 swivel YES 8000 20.0 no YES
Panasonic GH5 (⇒ lft | rgt) 3680 no 3.2 1620 swivel YES 8000 12.0 no YES
Panasonic GX8 (⇒ lft | rgt) 2360 no 3.0 1040 swivel YES 8000 10.0 no YES
Sony A99 II (⇒ lft | rgt) 2400 YES 3.0 1229 tilting no 8000 12.0 no YES
Sony A6300 (⇒ lft | rgt) 2300 no 3.0 922 tilting no 4000 11.0 6 no
Sony A6500 (⇒ lft | rgt) 2300 no 3.0 922 tilting YES 4000 11.0 6 YES
Sony A7R II (⇒ lft | rgt) 2400 no 3.0 1229 tilting no 8000 5.0 no YES
Sony A7S II (⇒ lft | rgt) 2400 no 3.0 1229 tilting no 8000 5.0 no YES
Sony A7 II (⇒ lft | rgt) 2400 no 3.0 1230 tilting no 8000 5.0 no YES
Sony A7 (⇒ lft | rgt) 2400 no 3.0 1230 tilting no 8000 5.0 no no
Sony A99 (⇒ lft | rgt) 2359 YES 3.0 1229 full-flex no 8000 6.0 no YES

Both the A9 and the E-M1 II are current models that good online retailers will have in stock. You can check the latest prices, for example, at amazon. The E-M1 II replaced the earlier Olympus E-M1, while the A9 does not have a direct predecessor.

Summary

So what conclusions can be drawn? Is there a clear favorite between the Sony A9 and the Sony A9? A synthesis of the relative strong points of each of the models is listed below.


logo checkmark

Advantages of the Sony Alpha A9:

  • More detail: Offers more megapixels (24 vs 20.2MP) with a 11% higher linear resolution.
  • 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 assessment.
  • Richer colors: Generates images with noticeably better colors (1.2 bits more color depth).
  • Better low-light sensitivity: Requires less light for good images (1.4 stops ISO advantage).
  • More detailed viewfinder: Has a higher resolution electronic viewfinder (3686k vs 2360k dots).
  • More detailed LCD: Has a higher resolution rear screen (1440k vs 1037k dots).
  • Faster burst: Shoots at higher frequency (20 vs 16 flaps/sec) to capture the decisive moment.
  • Longer lasting: Can take more shots (650 versus 440) on a single battery charge.
  • More modern: Is somewhat more recent (announced 6 months after the E-M1 II).

logo checkmark

Arguments in favor of the Olympus OM-D E-M1 Mark II:

  • Maximized detail: Lacks an anti-alias filter to exploit the sensor's full resolution potential.
  • More flexible LCD: Has a swivel screen for odd-angle shots in portrait or landscape orientation.
  • Less heavy: Has a lower weight (by 99g or 15 percent) and is thus easier to take along.
  • 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 April 2017).

If the count of individual advantages (bullet points above) is taken as a guide, the A9 is the clear winner of the match-up (10 : 5 points). However, the relative importance of the various individual camera aspects will vary according to personal preferences and needs, so that you might like to apply corresponding weights to the particular features.

A9 10:05 E-M1 II

In any case, while the specs-based evaluation of cameras is instructive in revealing their potential as photographic tools, it remains incomplete and does no justice, for example, to the way the A9 or the E-M1 II handle or perform in practice. At times, user reviews, such as those published at amazon, address these issues in a useful manner, but such feedback is on many occasions incomplete, inconsistent, and unreliable. This is why expert reviews are important. The adjacent table relays the overall verdicts of several of the most popular camera review sites. You can find the full text of the reviews, respectively, at cameralabs.com, dpreview.com, ephotozine.com, imaging-resource.com, and photographyblog.com.

Review scores
Camera camera
labs
dp
review
ephoto
zine
imaging
resource
photography
blog
Camera
Launch
(year)
Launch
Price
(USD)
Street
Price
(amazon)
Used
Price
(ebay)
Sony A9 (⇒ rgt) .. 89/100 Gold 5/5 5/5 5/5 2017 4,499 latest check
Olympus E-M1 II (⇒ lft) HiRec 85/100 Gold 4.5/5 5/5 4.5/5 2016 1,999 latest check
Olympus PEN-F (⇒ lft | rgt) - 82/100 Silver 4.5/5 4.5/5 5/5 2016 1,199 latest check
Olympus E-M5 II (⇒ lft | rgt) HiRec 81/100 Silver 5/5 4.5/5 5/5 2015 1,099 latest check
Panasonic G9 (⇒ lft | rgt) .. .. .. .. .. 2017 1,699 latest check
Panasonic GH5 (⇒ lft | rgt) HiRec 85/100 Gold 4.5/5 5/5 5/5 2017 1,999 latest check
Panasonic GX8 (⇒ lft | rgt) Rec 82/100 Silver 4.5/5 5/5 4.5/5 2015 1,199 latest check
Sony A99 II (⇒ lft | rgt) - 85/100 Silver 4.5/5 4.5/5 4.5/5 2016 3,199 latest check
Sony A6300 (⇒ lft | rgt) Rec 85/100 Gold 5/5 5/5 5/5 2016 999discont. check
Sony A6500 (⇒ lft | rgt) HiRec 85/100 Silver 4.5/5 5/5 4.5/5 2016 1,399 latest check
Sony A7R II (⇒ lft | rgt) HiRec 90/100 Gold 5/5 4.5/5 5/5 2015 3,199discont. check
Sony A7S II (⇒ lft | rgt) Rec - 4.5/5 5/5 5/5 2015 2,999 latest check
Sony A7 II (⇒ lft | rgt) Rec 82/100 Silver 4.5/5 5/5 5/5 2014 1,999 latest check
Sony A7 (⇒ lft | rgt) HiRec 80/100 Silver 5/5 4.5/5 5/5 2013 1,699discont. check
Sony A99 (⇒ lft | rgt) - 84/100 Gold 4.5/5 reviewed 4.5/5 2012 2,799discont. check

The review scores listed above should be treated with care, though. The ratings are only valid when refering 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, kindly note that some of the listed sites have over time developped their review approaches and their reporting style.

Other comparisons

In case you are interested in seeing how other cameras pair up, just make a corresponding selection in the search boxes below. An an alternative, you can also directly jump to any one of the listed comparisons that were previously generated by the CAM-parator tool. If you cannot find the camera you are interested in, please send me an email, and I will try to add information on that model to the database.

vs