PW

Sony A7S II versus Sony A9

The Sony Alpha 7S II and the Sony Alpha A9 are two professional cameras that were officially introduced, respectively, in September 2015 and April 2017. Both the A7S II and the A9 are mirrorless interchangeable lens cameras that are equipped with a full frame sensor. The A7S II has a resolution of 12 megapixel, whereas the A9 provides 24 MP. Read on to find out how these two cameras compare with respect to their size, their sensors, their features, and their reception by expert reviewers.

Body comparison: Sony A7S II vs Sony A9

The side-by-side display below illustrates the physical size and weight of the Sony A7S II and the Sony A9. Three successive views from the front, the top, and the rear are shown. All size dimensions 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 A7S II – represents the basis for the calculations across all the size and weight measures).

Compare Sony A7S II vs Sony A9
A7S II versus A9 top view
A7S II and A9 rear side

In this particular case, the Sony A7S II and the Sony A9 have exactly the same width and height, and, thus, have identically-sized bodies. However, the A9 is markedly heavier (7 percent) than the A7S 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. In this particular case, both cameras feature the same lens mount, so that they can use the same lenses. You can find an overview of suitable optics in the Sony FE Lens Catalog. 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 A7S II gets 370 shots out of its NP-FW50 battery, while the A9 can take 650 images on a single charge of its NP-FZ100 power pack.

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 camera 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 A7S II (⇒ rgt) 5.0 in 3.8 in 2.4 in 22.1 oz 370 YES 2015 2,999 latest check
Sony A9 (⇒ lft) 5.0 in 3.8 in 2.5 in 23.7 oz 650 YES 2017 4,499 latest check
Olympus E-M1 II (⇒ lft | rgt) 5.3 in 3.6 in 2.6 in 20.2 oz 440 YES 2016 1,999 latest check
Sony A7 III (⇒ lft | rgt) 5.0 in 3.8 in 2.9 in 22.9 oz 610 YES 2018 1,999 latest check
Sony A7R III (⇒ lft | rgt) 5.0 in 3.8 in 2.9 in 22.9 oz 650 YES 2017 3,199 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 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 A7 II (⇒ lft | rgt) 5.0 in 3.8 in 2.4 in 21.1 oz 350 YES 2014 1,999discont. check
Sony A7S (⇒ lft | rgt) 5.0 in 3.7 in 1.9 in 17.2 oz 380 YES 2014 2,499discont. check
Sony A99 (⇒ lft | rgt) 5.8 in 4.4 in 3.1 in 28.6 oz 500 YES 2012 2,799discont. check

The price is, of course, an important factor in any camera decision. The listed launch prices provide an indication of the market segment that the manufacturer of the cameras have been targeting. The A7S II was launched at a markedly lower price (by 33 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: Sony A7S II vs Sony A9

The size of the sensor inside a digital camera is one of the key determinants 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. 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.

Both cameras under consideration feature a full frame sensor and have a format factor (sometimes also referred to as "crop factor") of 1.0. Within the spectrum of camera sensors, this places the review cameras among the large-sensor cameras that aim for top notch image quality. Both cameras have a native aspect ratio (sensor width to sensor height) of 3:2.

Sony A7S II and Sony A9 sensor measures

While the two cameras under review share the same sensor size, the A9 offers a higher resolution of 24 megapixel, compared with 12 MP of the A7S II. This megapixel advantage translates into a 42 percent gain in linear resolution. On the other hand, these sensor specs imply that the A9 has a higher pixel density and a smaller size of the individual pixel (with a pixel pitch of 5.94μm versus 8.40μm for the A7S II). However, it should be noted that the A9 is a somewhat more recent model (by 1 year and 7 months) than the A7S II, and its sensor might have benefitted from technological advances during this time that at least partly compensate for the smaller pixel size.

A7S II versus A9 MP

Consistent information on actual sensor performance is available from DXO Mark for most cameras. 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. Of the two cameras under consideration, the A9 has a markedly higher DXO score than the A7S II (overall score 7 points higher), which will translate into better image quality. The advantage is based on 1.3 bits higher color depth, and 0.2 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 A7S II (⇒ rgt) Full Frame 12.0 4240 2832 4K/30p 23.6 13.3 2993 85
Sony A9 (⇒ lft) Full Frame 24.0 6000 4000 4K/30p 24.9 13.3 3517 92
Olympus E-M1 II (⇒ lft | rgt) Four Thirds 20.2 5184 3888 4K/30p 23.7 12.8 1312 80
Sony A7 III (⇒ lft | rgt) Full Frame 24.0 6000 4000 4K/30p 25.0 14.7 3730 96
Sony A7R III (⇒ lft | rgt) Full Frame 42.2 7952 5304 4K/30p 26.0 14.7 3523 100
Sony A99 II (⇒ lft | rgt) Full Frame 42.2 7952 5304 4K/30p 25.4 13.4 2317 92
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 A7 II (⇒ lft | rgt) Full Frame 24.0 6000 4000 1080/60p 24.9 13.6 2449 90
Sony A7S (⇒ lft | rgt) Full Frame 12.0 4240 2832 1080/60p 23.9 13.2 3702 87
Sony A99 (⇒ lft | rgt) 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. 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).

Feature comparison: Sony A7S II vs Sony A9

Apart from body and sensor, cameras can and do differ across a variety 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 A7S II (3686k vs 2400k dots). The adjacent table lists some of the other core features of the Sony A7S II and Sony A9 along with similar information for a selection of comparators. 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 A7S II (⇒ rgt) 2400 no 3.0 1229 tilting no 8000 5.0 no YES
Sony A9 (⇒ lft) 3686 no 3.0 1440 tilting YES 8000 20.0 no YES
Olympus E-M1 II (⇒ lft | rgt) 2360 no 3.0 1037 swivel YES 8000 18.0 no YES
Sony A7 III (⇒ lft | rgt) 2359 no 3.0 922 tilting YES 8000 10 no YES
Sony A7R III (⇒ lft | rgt) 3686 no 3.0 1440 tilting YES 8000 10.0 no YES
Sony A99 II (⇒ lft | rgt) 2400 YES 3.0 1229 full-flex no 8000 12.0 no YES
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 A7 II (⇒ lft | rgt) 2400 no 3.0 1230 tilting no 8000 5.0 no YES
Sony A7S (⇒ lft | rgt) 2400 no 3.0 921 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 A7S II and the A9 are current models that good online retailers will have in stock. You can check the latest prices, for example, at amazon. The A7S II replaced the earlier Sony A7S, while the A9 does not have a direct predecessor.

Review summary: Sony A7S II vs Sony A9

So what conclusions can be drawn? Is there a clear favorite between the Sony A7S II and the Sony A9? Below is a summary of the relative strengths of each of the two contestants.


Advantages of the Sony Alpha 7S II:

  • More affordable: Was introduced into a lower priced category (33 percent cheaper at launch).
  • More heavily discounted: Has been on the market for longer (launched in September 2015).

Arguments in favor of the Sony Alpha A9:

  • More detail: Has more megapixels (24 vs 12MP), which boosts linear resolution by 41%.
  • Better image quality: Scores markedly higher (7 points) in the DXO overall evaluation.
  • Richer colors: Generates noticeably more natural colors (1.3 bits more color depth).
  • More detailed viewfinder: Has higher resolution electronic viewfinder (3686k vs 2400k dots).
  • More detailed LCD: Has a higher resolution rear screen (1440k vs 1229k dots).
  • Fewer buttons to press: Has a touchscreen to facilitate handling and shooting adjustments.
  • Faster burst: Shoots at higher frequency (20 vs 5 flaps/sec) to capture the decisive moment.
  • Longer lasting: Gets more shots (650 versus 370) out of a single battery charge.
  • More modern: Was introduced somewhat (1 year and 7 months) more recently.

If the number of relative strengths (bullet points above) is taken as a guide, the A9 is the clear winner of the contest (9 : 2 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.

A7S II 02:09 A9

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 handling experience and imaging performance when actually working with the A7S II or the A9. 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 where reviews by experts come in. The adjacent table relays the overall verdicts of several of the most popular camera review sites (cameralabs, dpreview, ephotozine, imaging-resource, photographyblog). You can find the full text of the reviews by clicking on the site logo in the table header.

Review scores
Camera cameralabs dpreview ephotozine imaging-resource photographyblog Camera
Launch
(year)
Launch
Price
(USD)
Street
Price
(amazon)
Used
Price
(ebay)
Sony A7S II (⇒ rgt) Rec - 4.5/5 5/5 5/5 2015 2,999 latest check
Sony A9 (⇒ lft) HiRec 89/100 Gold 5/5 5/5 5/5 2017 4,499 latest check
Olympus E-M1 II (⇒ lft | rgt) HiRec 85/100 Gold 4.5/5 5/5 4.5/5 2016 1,999 latest check
Sony A7 III (⇒ lft | rgt) HiRec 89/100 Gold 5/5 .. 5/5 2018 1,999 latest check
Sony A7R III (⇒ lft | rgt) HiRec 90/100 Gold 4.5/5 5/5 5/5 2017 3,199 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 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 A7 II (⇒ lft | rgt) Rec 82/100 Silver 4.5/5 5/5 5/5 2014 1,999discont. check
Sony A7S (⇒ lft | rgt) - 86/100 Gold 4.5/5 4.5/5 5/5 2014 2,499discont. check
Sony A99 (⇒ lft | rgt) - 84/100 Gold 4.5/5 reviewed 4.5/5 2012 2,799discont. check

The above review scores should be interpreted 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 rating-comparisons among cameras that span long time periods or concern very differently equipped models make little sense. 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 are interested in seeing how other cameras pair up, just make your choice using the following search menu. 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 update the database with the necessary infos.

vs

    You are here  »   »