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.
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).
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.
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
|Sony A7S II (⇒ rgt)||127 mm||96 mm||60 mm||627 g||370||YES||2015||2,999||latest||check|
|Sony A9 (⇒ lft)||127 mm||96 mm||63 mm||673 g||650||YES||2017||4,499||latest||check|
|Olympus E-M1 II (⇒ lft | rgt)||134 mm||91 mm||67 mm||574 g||440||YES||2016||1,999||latest||check|
|Sony A7 III (⇒ lft | rgt)||127 mm||96 mm||74 mm||650 g||610||YES||2018||1,999||latest||check|
|Sony A7R III (⇒ lft | rgt)||127 mm||96 mm||74 mm||650 g||650||YES||2017||3,199||latest||check|
|Sony A99 II (⇒ lft | rgt)||143 mm||104 mm||76 mm||849 g||490||YES||2016||3,199||latest||check|
|Sony A6500 (⇒ lft | rgt)||120 mm||67 mm||53 mm||453 g||350||YES||2016||1,399||latest||check|
|Sony A7R II (⇒ lft | rgt)||127 mm||96 mm||60 mm||625 g||290||YES||2015||3,199||discont.||check|
|Sony A7 II (⇒ lft | rgt)||127 mm||96 mm||60 mm||599 g||350||YES||2014||1,999||discont.||check|
|Sony A7S (⇒ lft | rgt)||127 mm||94 mm||48 mm||489 g||380||YES||2014||2,499||discont.||check|
|Sony A99 (⇒ lft | rgt)||147 mm||111 mm||78 mm||812 g||500||YES||2012||2,799||discont.||check|
|Sony A900 (⇒ lft | rgt)||156 mm||117 mm||82 mm||895 g||880||YES||2008||2,999||discont.||check|
The listed 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.
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 tent 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.
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.
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.
|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||..||..||..||..|
|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|
|Sony A900 (⇒ lft | rgt)||Full Frame||24.4||6048||4032||no||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 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 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.
|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|
|Sony A900 (⇒ lft | rgt)||optical||YES||3.0||922||fixed||no||8000||5.0||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.
So what conclusions can be drawn? Is there a clear favorite between the Sony A7S II and the Sony A7S II? 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.
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. You can find the full text of the reviews, respectively, at cameralabs.com, dpreview.com, ephotozine.com, imaging-resource.com, and photographyblog.com.
|Sony A7S II (⇒ rgt)||Rec||-||4.5/5||5/5||5/5||2015||2,999||latest||check|
|Sony A9 (⇒ lft)||..||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||..||..||..||..||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||3,199||discont.||check|
|Sony A7 II (⇒ lft | rgt)||Rec||82/100 Silver||4.5/5||5/5||5/5||2014||1,999||discont.||check|
|Sony A7S (⇒ lft | rgt)||-||86/100 Gold||4.5/5||4.5/5||5/5||2014||2,499||discont.||check|
|Sony A99 (⇒ lft | rgt)||-||84/100 Gold||4.5/5||reviewed||4.5/5||2012||2,799||discont.||check|
|Sony A900 (⇒ lft | rgt)||90/100 HiRec||HiRec||4.5/5||4/5||5/5||2008||2,999||discont.||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.
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.
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