Sony A7R III versus Sony A9
The Sony Alpha A7R III and the Sony Alpha A9 are two digital cameras that were announced, respectively, in October 2017 and April 2017. Both the A7R III and the A9 are mirrorless interchangeable lens cameras that are equipped with a full frame sensor. The A7R III has a resolution of 42.2 megapixel, whereas the A9 provides 24 MP.
The physical size and weight of the Sony A7R III and the Sony A9 are illustrated in the side-by-side display below. Three consecutive views from the front, the top, and the rear side are shown. 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 A7R III – represents the basis for the calculations across all the size and weight measures).
In this particular case, the Sony A7R III and the Sony A9 have exactly the same width and height, and, thus, have identically-sized bodies. However, the A9 is slightly heavier (4 percent) than the A7R III. 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 A7R III (⇒ rgt)||127 mm||96 mm||74 mm||650 g||650||YES||2017||3,199||latest||check|
|Sony A9 (⇒ lft)||127 mm||96 mm||63 mm||673 g||650||YES||2017||4,499||latest||check|
|Nikon D850 (⇒ lft | rgt)||146 mm||124 mm||79 mm||1005 g||1840||YES||2017||3,299||latest||check|
|Olympus E-M1 II (⇒ lft | rgt)||134 mm||91 mm||67 mm||574 g||440||YES||2016||1,999||latest||check|
|Panasonic GH5 (⇒ lft | rgt)||139 mm||98 mm||87 mm||725 g||410||YES||2017||1,999||latest||check|
|Pentax K-1 (⇒ lft | rgt)||137 mm||110 mm||86 mm||1010 g||760||YES||2016||1,799||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 A7S II (⇒ lft | rgt)||127 mm||96 mm||60 mm||627 g||370||YES||2015||2,999||latest||check|
|Sony A7 II (⇒ lft | rgt)||127 mm||96 mm||60 mm||599 g||350||YES||2014||1,999||latest||check|
|Sony A7 (⇒ lft | rgt)||127 mm||94 mm||48 mm||474 g||340||YES||2013||1,699||discont.||check|
|Sony A7R (⇒ lft | rgt)||127 mm||94 mm||48 mm||465 g||340||YES||2013||2,299||discont.||check|
|Sony A99 (⇒ lft | rgt)||147 mm||111 mm||78 mm||812 g||500||YES||2012||2,799||discont.||check|
The listed prices provide an indication of the market segment that the manufacturer of the cameras have been targeting. The A7R III was launched at a markedly lower price (by 29 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 tend to be more expensive and lead to bigger and heavier cameras and lenses.
Both cameras under consideration feature a full frame sensor, but their sensors differ slightly in size. The sensor area in the A9 is 2 percent smaller. They nevertheless have the same format factor of 1.0. Both cameras have a native aspect ratio (sensor width to sensor height) of 3:2.
With 42.2MP, the A7R III offers a higher resolution than the A9 (24MP), but the A7R III has smaller individual pixels (pixel pitch of 4.52μm versus 5.94μm for the A9). However, the A7R III is a somewhat more recent model (by 6 months) than the A9, and its sensor might have benefitted from technological advances during this time that enhance the light gathering capacity of its pixels. Coming back to sensor resolution, it should be mentioned that the A7R III has no anti-alias filter installed, so that it can capture all the detail its sensor resolves.
Unlike the A9, the A7R III has the capacity to capture high quality composite images 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).
Consistent information on actual sensor performance is available from DXO Mark for most cameras. 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"). The table below summarizes the physical sensor characteristics and sensor quality findings and compares them across a set of similar cameras.
|Sony A7R III (⇒ rgt)||Full Frame||42.2||7952||5304||4K/30p||..||..||..||..|
|Sony A9 (⇒ lft)||Full Frame||24.0||6000||4000||4K/30p||24.9||13.3||3517||92|
|Nikon D850 (⇒ lft | rgt)||Full Frame||45.4||8256||5504||4K/30p||26.4||14.8||2660||100|
|Olympus E-M1 II (⇒ lft | rgt)||Four Thirds||20.2||5184||3888||4K/30p||23.7||12.8||1312||80|
|Panasonic GH5 (⇒ lft | rgt)||Four Thirds||20.2||5184||3888||4K/60p||23.9||13.0||807||77|
|Pentax K-1 (⇒ lft | rgt)||Full Frame||36.2||7360||4912||1080/60i||25.4||14.6||3280||96|
|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 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 A7R (⇒ lft | rgt)||Full Frame||36.2||7360||4912||1080/60p||25.6||14.1||2746||95|
|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 are equipped with sensors that have a sufficiently high read-out speed for moving images, 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 A7R III and the A9 are similar in the sense that both feature an electronic viewfinder, which is helpful when framing images in bright sunlight. Moreover, their viewfinders offer an identical resolution of 3686k dots. The adjacent table lists some of the other core features of the Sony A7R III 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 A7R III (⇒ rgt)||3686||no||3.0||1440||tilting||YES||8000||10.0||no||YES|
|Sony A9 (⇒ lft)||3686||no||3.0||1440||tilting||YES||8000||20.0||no||YES|
|Nikon D850 (⇒ lft | rgt)||optical||YES||3.2||2359||tilting||YES||8000||9.0||no||no|
|Olympus E-M1 II (⇒ lft | rgt)||2360||no||3.0||1037||swivel||YES||8000||18.0||no||YES|
|Panasonic GH5 (⇒ lft | rgt)||3680||no||3.2||1620||swivel||YES||8000||12.0||no||YES|
|Pentax K-1 (⇒ lft | rgt)||optical||YES||3.2||1037||full-flex||no||8000||4.4||no||YES|
|Sony A99 II (⇒ lft | rgt)||2400||YES||3.0||1229||tilting||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 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 A7R (⇒ lft | rgt)||2400||no||3.0||1230||tilting||no||8000||4.0||no||no|
|Sony A99 (⇒ lft | rgt)||2359||YES||3.0||1229||full-flex||no||8000||6.0||no||YES|
Both the A7R III 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 A7R III replaced the earlier Sony A7R II, while the A9 does not have a direct predecessor.
So what conclusions can be drawn? Which of the two cameras – the Sony A7R III or the Sony A9 – has the upper hand? Below is a summary of the relative strengths of each of the two contestants.
Advantages of the Sony Alpha A7R III:
- More detail: Offers more megapixels (42.2 vs 24MP) with a 33% higher linear resolution.
- 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 affordable: Was introduced into a lower priced category (29 percent cheaper at launch).
- More modern: Is somewhat more recent (announced 6 months after the A9).
Arguments in favor of the Sony Alpha A9:
- Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
- Faster burst: Shoots at higher frequency (20 vs 10 flaps/sec) to capture the decisive moment.
- More heavily discounted: Has been on the market for longer (launched in October 2017).
If the count of individual advantages (bullet points above) is taken as a guide, the A7R III emerges as the winner of the contest (5 : 3 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.
In any case, while the comparison of technical specifications can provide a useful overview of the capabilities of different cameras, it remains incomplete and does no justice, for example, to the way the A7R III or the A9 handle or perform in practice. 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 table below summarizes the assessments of some of the best known camera review sites. The full reviews are available, respectively, at cameralabs.com, dpreview.com, ephotozine.com, imaging-resource.com, and photographyblog.com.
|Sony A7R III (⇒ rgt)||..||..||..||..||..||2017||3,199||latest||check|
|Sony A9 (⇒ lft)||..||89/100 Gold||5/5||5/5||5/5||2017||4,499||latest||check|
|Nikon D850 (⇒ lft | rgt)||..||89/100 Gold||4.5/5||..||5/5||2017||3,299||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|
|Panasonic GH5 (⇒ lft | rgt)||HiRec||85/100 Gold||4.5/5||5/5||5/5||2017||1,999||latest||check|
|Pentax K-1 (⇒ lft | rgt)||-||84/100 Silver||5/5||4.5/5||5/5||2016||1,799||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 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||1,699||discont.||check|
|Sony A7R (⇒ lft | rgt)||HiRec||82/100 Gold||4.5/5||5/5||5/5||2013||2,299||discont.||check|
|Sony A99 (⇒ lft | rgt)||-||84/100 Gold||4.5/5||reviewed||4.5/5||2012||2,799||discont.||check|
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. A score, therefore, has to be seen in close connection to the price and market introduction time of the camera, and rating-comparisons among cameras that span long time periods or concern very differently equipped models make little sense. Also, kindly note that some of the listed sites have over time developped their review approaches and their reporting style.
If you would like to see a different side-by-side camera review, just make your choice using the following search menu. There is also a set of direct links to comparison reviews that other users of the CAM-parator app explored. If the camera you are interested in is not available, please contact me, and I will try to add information on that model to the database.
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