Sony A7R III vs A9
The Sony Alpha A7R III and the Sony Alpha A9 are two digital cameras that were officially introduced, 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 megapixels, whereas the A9 provides 24 MP.
Below is an overview of the main specs of the two cameras as a starting point for the comparison.
Going beyond this snapshot of core features and characteristics, what are the differences between the Sony Alpha A7R III 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 Sony A7R III and the Sony A9 is provided in the side-by-side display below. The two cameras are presented according to their relative size. Three consecutive perspectives from the front, the top, and the back are available. All width, height and depth dimensions are rounded to the nearest millimeter.
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 compare the optics available 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 battery packs of both cameras can be charged via USB, which can be very convenient when travelling.
The following table provides a synthesis of the main physical specifications of the two cameras and other similar ones. In case you want to display and compare another camera duo, you can use the CAM-parator app to select your camera combination among a large number of options.
|Sony A7R III||5.0 in||3.8 in||2.9 in||22.9 oz||650||Y||Oct 2017||3,199|
|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|
|Nikon Z7||5.3 in||4.0 in||2.6 in||23.8 oz||330||Y||Aug 2018||3,399|
|Sony A7S III||5.0 in||3.8 in||3.2 in||24.7 oz||600||Y||Jul 2020||3,499|
|Sony A9 II||5.1 in||3.8 in||3.0 in||23.9 oz||690||Y||Oct 2019||4,499|
|Sony A7R IV||5.1 in||3.8 in||3.1 in||23.5 oz||670||Y||Jul 2019||3,499|
|Sony A7 III||5.0 in||3.8 in||2.9 in||22.9 oz||610||Y||Feb 2018||1,999|
|Sony A99 II||5.6 in||4.1 in||3.0 in||29.9 oz||490||Y||Sep 2016||3,199|
|Sony A7R II||5.0 in||3.8 in||2.4 in||22.0 oz||290||Y||Jun 2015||3,199|
|Sony A7S II||5.0 in||3.8 in||2.4 in||22.1 oz||370||Y||Sep 2015||2,999|
|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.|
Any camera decision will obviously take relative prices into account. 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 A7R III was launched at a markedly lower price (by 29 percent) than the A9, which puts it into a different market segment. Normally, street prices remain initially close to the MSRP, but after a couple of months, the first discounts appear. 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 imaging sensor is a crucial determinant of image quality. A large sensor will generally have larger individual pixels that offer better low-light sensitivity, provide wider dynamic range, and have 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 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.
The resolution advantage of the Sony A7R III implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the A7R III for good quality output (200 dots per inch) amounts to 39.8 x 26.5 inches or 101 x 67.4 cm, for very good quality (250 dpi) 31.8 x 21.2 inches or 80.8 x 53.9 cm, and for excellent quality (300 dpi) 26.5 x 17.7 inches or 67.3 x 44.9 cm. The corresponding values for the Sony A9 are 30 x 20 inches or 76.2 x 50.8 cm for good quality, 24 x 16 inches or 61 x 40.6 cm for very good quality, and 20 x 13.3 inches or 50.8 x 33.9 cm for excellent quality prints.
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).
The Sony Alpha A7R III has a native sensitivity range from ISO 100 to ISO 32000, which can be extended to ISO 50-102400. 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.
Since 2007, DXO Mark has published sensor performance measurements that have been derived using a consistent methodology. 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 review, the A7R III has a notably higher overall DXO score than the A9 (overall score 8 points higher), which gives it an advantage in terms of imaging quality. This advantage is based on 1.1 bits higher color depth, 1.4 EV in additional dynamic range, and 0 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.
| DXO |
|Sony A7R III||Full Frame||42.2||7952||5304||4K/30p||26.0||14.7||3523||100|
|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|
|Nikon Z7||Full Frame||45.4||8256||5504||4K/30p||26.3||14.6||2668||99|
|Sony A7S III||Full Frame||12.0||4240||2832||4K/120p||..||..||..||..|
|Sony A9 II||Full Frame||24.0||6000||4000||4K/30p||25.0||14.0||3434||93|
|Sony A7R IV||Full Frame||60.2||9504||6336||4K/30p||26.0||14.8||3344||99|
|Sony A7 III||Full Frame||24.0||6000||4000||4K/30p||25.0||14.7||3730||96|
|Sony A99 II||Full Frame||42.2||7952||5304||4K/30p||25.4||13.4||2317||92|
|Sony A7R II||Full Frame||42.2||7952||5304||4K/30p||26.0||13.9||3434||98|
|Sony A7S II||Full Frame||12.0||4240||2832||4K/30p||23.6||13.3||2993||85|
|Sony A7 II||Full Frame||24.0||6000||4000||1080/60p||24.9||13.6||2449||90|
Many modern cameras cannot only take still pictures, but also record videos. 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 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.
|Sony A7R III||3686||n||3.0||1440||tilting||Y||1/8000s||10.0||n||Y|
|Sony A7S III||9440||n||3.0||1440||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 A7R IV||5760||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 A99 II||2400||Y||3.0||1229||full-flex||n||1/8000s||12.0||n||Y|
|Sony A7R II||2400||n||3.0||1229||tilting||n||1/8000s||5.0||n||Y|
|Sony A7S II||2400||n||3.0||1229||tilting||n||1/8000s||5.0||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 Sony A7R III 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.
Concerning the storage of imaging data, both the A7R III and the A9 write their files to 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 A7R III 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 Sony Alpha A7R III and Sony Alpha A9 and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.
| WiFi |
| NFC |
|Sony A7R III||Y||stereo||mono||Y||Y||micro||3.1||Y||Y||Y|
|Sony A7S III||Y||stereo||mono||Y||Y||full||3.2||Y||-||Y|
|Sony A9 II||Y||stereo||mono||Y||Y||micro||3.1||Y||Y||Y|
|Sony A7R IV||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 A99 II||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||Y|
|Sony A7R II||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||-|
|Sony A7S II||Y||stereo||mono||Y||Y||micro||2.0||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.
Both the A7R III and the A9 have been discontinued, but can regularly be found used on eBay. The A9 was replaced by the Sony A9 II, while the A7R III was followed by the Sony A7R IV. Further information on the two cameras (e.g. user guides, manuals), as well as related accessories, can be found on the official Sony website.
So what is the bottom line? Which of the two cameras – the Sony A7R III or the Sony A9 – has the upper hand? Is one clearly better than the other? The listing below highlights the relative strengths of the two models.
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.
- Better image quality: Scores markedly higher (8 points) in the DXO overall assessment.
- Richer colors: Generates images with noticeably better colors (1.1 bits more color depth).
- More dynamic range: Captures a larger spectrum of light and dark details (1.4 EV of extra DR).
- Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
- Faster data transfer: Supports a more advanced USB protocol (3.1 vs 2.0).
- 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 April 2017).
If the count of relative strengths (bullet points above) is taken as a measure, the A7R III is the clear winner of the match-up (10 : 3 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. 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 Sony A7R III 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 the spec-sheets of cameras can offer a general idea of their imaging potential, it remains partial and cannot reveal, for example, the shooting experience and imaging performance when actually working with the A7R III 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 where reviews by experts come in. 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.
|Sony A7R III||+ +||90/100||4.5/5||5/5||5/5||Oct 2017||3,199|
|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|
|Nikon Z7||+||89/100||4.5/5||4.5/5||5/5||Aug 2018||3,399|
|Sony A7S III||+ +||..||4.5/5||..||5/5||Jul 2020||3,499|
|Sony A9 II||..||90/100||5/5||..||5/5||Oct 2019||4,499|
|Sony A7R IV||+||91/100||4.5/5||5/5||5/5||Jul 2019||3,499|
|Sony A7 III||+ +||89/100||5/5||5/5||5/5||Feb 2018||1,999|
|Sony A99 II||..||85/100||4.5/5||4.5/5||4.5/5||Sep 2016||3,199|
|Sony A7R II||+ +||90/100||5/5||4.5/5||5/5||Jun 2015||3,199|
|Sony A7S II||+||..||4.5/5||5/5||5/5||Sep 2015||2,999|
|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 above review scores should be interpreted with care, though. The assessments were made in relation to similar cameras of the same technological generation. Hence, a score should always be seen in the context of the camera's market launch date and its price, 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
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Specifications: Sony A7R III 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||Sony A7R III||Sony A9|
|Camera Type||Mirrorless system camera||Mirrorless system camera|
|Camera Lens||Sony E mount lenses||Sony E mount lenses|
|Launch Date||October 2017||April 2017|
|Launch Price||USD 3,199||USD 4,499|
|Sensor Specs||Sony A7R III||Sony A9|
|Sensor Format||Full Frame Sensor||Full Frame Sensor|
|Sensor Size||35.9 x 24.0 mm||35.6 x 23.8 mm|
|Sensor Area||861.6 mm2||847.28 mm2|
|Sensor Diagonal||43.2 mm||42.8 mm|
|Sensor Resolution||42.2 Megapixels||24 Megapixels|
|Image Resolution||7952 x 5304 pixels||6000 x 4000 pixels|
|Pixel Pitch||4.52 μm||5.94 μm|
|Pixel Density||4.90 MP/cm2||2.83 MP/cm2|
|Moiré control||no AA filter||Anti-Alias filter|
|Movie Capability||4K/30p Video||4K/30p Video|
|ISO Setting||100 - 32,000 ISO||100 - 51,200 ISO|
|ISO Boost||50 - 102,400 ISO||50 - 204,800 ISO|
|Image Processor||BIONZ X||BIONZ X|
|DXO Sensor Quality (score)||100||92|
|DXO Color Depth (bits)||26.0||24.9|
|DXO Dynamic Range (EV)||14.7||13.3|
|DXO Low Light (ISO)||3523||3517|
|Screen Specs||Sony A7R III||Sony A9|
|Viewfinder Type||Electronic viewfinder||Electronic viewfinder|
|Viewfinder Field of View||100%||100%|
|Viewfinder Resolution||3686k dots||3686k dots|
|LCD Framing||Live View||Live View|
|Rear LCD Size||3.0inch||3.0inch|
|LCD Resolution||1440k dots||1440k dots|
|LCD Attachment||Tilting screen||Tilting screen|
|Shooting Specs||Sony A7R III||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||10 shutter flaps/s||20 shutter flaps/s|
|Shutter Life Expectancy||500 000 actuations||500 000 actuations|
|Electronic Shutter||YES||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||MS or 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||Sony A7R III||Sony A9|
|Studio Flash||PC Sync socket||PC Sync socket|
|USB Connector||USB 3.1||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||NFC built-in||NFC built-in|
|Bluetooth Support||Bluetooth built-in||Bluetooth built-in|
|Body Specs||Sony A7R III||Sony A9|
|Environmental Sealing||Weathersealed body||Weathersealed body|
|Battery Life (CIPA)||650 shots per charge||650 shots per charge|
|In-Camera Charging||USB charging||USB charging|
127 x 96 x 74 mm
(5.0 x 3.8 x 2.9 in)
127 x 96 x 63 mm
(5.0 x 3.8 x 2.5 in)
|Camera Weight||650 g (22.9 oz)||673 g (23.7 oz)|
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