Sony A9 vs A7 III
The Sony Alpha A9 and the Sony Alpha A7 III are two digital cameras that were revealed to the public, respectively, in April 2017 and February 2018. Both the A9 and the A7 III are mirrorless interchangeable lens cameras that are equipped with a full frame sensor. Both cameras offer a resolution of 24 megapixels.
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 A9 and the Sony Alpha A7 III? 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.
Body comparison
The side-by-side display below illustrates the physical size and weight of the Sony A9 and the Sony A7 III. 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 A9 and the Sony A7 III have exactly the same width and height, and, thus, have identically-sized bodies. However, the A7 III is slightly lighter (3 percent) than the A9. 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. If you would like to visualize and compare a different camera combination, you can navigate to the CAM-parator app and make your selection from a broad list of cameras there.
# | Camera Model |
Camera Width |
Camera Height |
Camera Depth |
Camera Weight |
Battery Life |
Weather Sealing |
Camera Launch |
Launch Price (USD) |
Street Price |
|
---|---|---|---|---|---|---|---|---|---|---|---|
1. | Sony A9 | 127 mm | 96 mm | 63 mm | 673 g | 650 | Y | Apr 2017 | 4,499 | ebay.com | |
2. | Sony A7 III | 127 mm | 96 mm | 74 mm | 650 g | 610 | Y | Feb 2018 | 1,999 | amazon.com | |
3. | Nikon Z6 | 134 mm | 101 mm | 67 mm | 675 g | 310 | Y | Aug 2018 | 1,999 | ebay.com | |
4. | Sony A7R V | 131 mm | 97 mm | 82 mm | 723 g | 530 | Y | Oct 2022 | 3,899 | amazon.com | |
5. | Sony A7R IIIA | 127 mm | 96 mm | 74 mm | 650 g | 650 | Y | Apr 2021 | 3,199 | amazon.com | |
6. | Sony A9 II | 129 mm | 96 mm | 76 mm | 678 g | 690 | Y | Oct 2019 | 4,499 | amazon.com | |
7. | Sony A7R IV | 129 mm | 96 mm | 78 mm | 665 g | 670 | Y | Jul 2019 | 3,499 | ebay.com | |
8. | Sony A7R III | 127 mm | 96 mm | 74 mm | 650 g | 650 | Y | Oct 2017 | 3,199 | ebay.com | |
9. | Sony A7R II | 127 mm | 96 mm | 60 mm | 625 g | 290 | Y | Jun 2015 | 3,199 | ebay.com | |
10. | Sony A7S II | 127 mm | 96 mm | 60 mm | 627 g | 370 | Y | Sep 2015 | 2,999 | ebay.com | |
11. | Sony A7 II | 127 mm | 96 mm | 60 mm | 599 g | 350 | Y | Nov 2014 | 1,999 | ebay.com | |
12. | Sony A99 | 147 mm | 111 mm | 78 mm | 812 g | 500 | Y | Sep 2012 | 2,799 | ebay.com | |
Note: Measurements and pricing do not include easily detachable parts, such as add-on or interchangeable lenses or optional viewfinders. | |||||||||||
Any camera decision will naturally be influenced heavily by the price. 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 A7 III 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. 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. 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 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.
The two cameras under review do not only share the same sensor size, but also offer an identical resolution of 24 megapixels. This similarity in sensor specs implies that both the A9 and the A7 III have the same pixel density, as well as the same pixel size. It should, however, be noted that the A7 III is a somewhat more recent model (by 10 months) than the A9, and its sensor might have benefitted from technological advances during this time.
The Sony Alpha A9 has a native sensitivity range from ISO 100 to ISO 51200, which can be extended to ISO 50-204800. The Sony Alpha A7 III offers exactly the same ISO settings.
In terms of underlying technology, the A9 is build around a Stacked BSI-CMOS sensor, while the A7 III uses a BSI-CMOS imager. Both cameras use a Bayer filter for capturing RGB colors on a square grid of photosensors. This arrangement is found in most digital cameras.
Consistent information on actual sensor performance is available from DXO Mark for many 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 A7 III has a markedly higher DXO score than the A9 (overall score 4 points higher), which will translate into better image quality. The advantage is based on 0.1 bits higher color depth, 1.4 EV in additional dynamic range, and 0.1 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.
# | Camera Model |
Sensor Class |
Resolution (MP) |
Horiz. Pixels |
Vert. Pixels |
Video Format |
DXO Portrait |
DXO Landscape |
DXO Sports |
DXO Overall |
|
---|---|---|---|---|---|---|---|---|---|---|---|
1. | Sony A9 | Full Frame | 24.0 | 6000 | 4000 | 4K/30p | 24.9 | 13.3 | 3517 | 92 | |
2. | Sony A7 III | Full Frame | 24.0 | 6000 | 4000 | 4K/30p | 25.0 | 14.7 | 3730 | 96 | |
3. | Nikon Z6 | Full Frame | 24.3 | 6048 | 4024 | 4K/30p | 25.3 | 14.3 | 3299 | 95 | |
4. | Sony A7R V | Full Frame | 60.2 | 9504 | 6336 | 8k/24p | 26.5 | 14.8 | 3187 | 100 | |
5. | Sony A7R IIIA | Full Frame | 42.2 | 7952 | 5304 | 4K/30p | 26.0 | 14.7 | 3523 | 100 | |
6. | Sony A9 II | Full Frame | 24.0 | 6000 | 4000 | 4K/30p | 25.0 | 14.0 | 3434 | 93 | |
7. | Sony A7R IV | Full Frame | 60.2 | 9504 | 6336 | 4K/30p | 26.0 | 14.8 | 3344 | 99 | |
8. | Sony A7R III | Full Frame | 42.2 | 7952 | 5304 | 4K/30p | 26.0 | 14.7 | 3523 | 100 | |
9. | Sony A7R II | Full Frame | 42.2 | 7952 | 5304 | 4K/30p | 26.0 | 13.9 | 3434 | 98 | |
10. | Sony A7S II | Full Frame | 12.0 | 4240 | 2832 | 4K/30p | 23.6 | 13.3 | 2993 | 85 | |
11. | Sony A7 II | Full Frame | 24.0 | 6000 | 4000 | 1080/60p | 24.9 | 13.6 | 2449 | 90 | |
12. | Sony A99 | 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
Apart from 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 A7 III (3686k vs 2359k dots). The following table reports on some other key feature differences and similarities of the Sony A9, the Sony A7 III, and comparable cameras.
# | Camera Model |
Viewfinder (Type or 000 dots) |
Control Panel (yes/no) |
LCD Specifications (inch/000 dots) |
LCD Attach- ment |
Touch Screen (yes/no) |
Max Shutter Speed * |
Max Shutter Flaps * |
Built-in Flash (yes/no) |
Built-in Image Stab |
|
---|---|---|---|---|---|---|---|---|---|---|---|
1. | Sony A9 | 3686 | n | 3.0 / 1440 | tilting | Y | 1/8000s | 20.0/s | n | Y | |
2. | Sony A7 III | 2359 | n | 3.0 / 922 | tilting | Y | 1/8000s | 10.0/s | n | Y | |
3. | Nikon Z6 | 3690 | Y | 3.2 / 2100 | tilting | Y | 1/8000s | 12.0/s | n | Y | |
4. | Sony A7R V | 9440 | n | 3.2 / 2100 | full-flex | Y | 1/8000s | 10.0/s | n | Y | |
5. | Sony A7R IIIA | 3686 | n | 3.0 / 2340 | tilting | Y | 1/8000s | 10.0/s | n | Y | |
6. | Sony A9 II | 3686 | n | 3.0 / 1440 | tilting | Y | 1/8000s | 20.0/s | n | Y | |
7. | Sony A7R IV | 5760 | n | 3.0 / 1440 | tilting | Y | 1/8000s | 10.0/s | n | Y | |
8. | Sony A7R III | 3686 | n | 3.0 / 1440 | tilting | Y | 1/8000s | 10.0/s | n | Y | |
9. | Sony A7R II | 2400 | n | 3.0 / 1229 | tilting | n | 1/8000s | 5.0/s | n | Y | |
10. | Sony A7S II | 2400 | n | 3.0 / 1229 | tilting | n | 1/8000s | 5.0/s | n | Y | |
11. | Sony A7 II | 2400 | n | 3.0 / 1230 | tilting | n | 1/8000s | 5.0/s | n | Y | |
12. | Sony A99 | 2359 | Y | 3.0 / 1229 | full-flex | n | 1/8000s | 6.0/s | n | Y | |
Note: *) Information refers to the mechanical shutter, unless the camera only has an electronic one. |
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 A7 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 A9 and the A7 III 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 A9 and the A7 III 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.
Connectivity comparison
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 A9 and Sony Alpha A7 III and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.
# | Camera Model |
Hotshoe Port |
Internal Mic / Speaker |
Microphone Port |
Headphone Port |
HDMI Port |
USB Port |
WiFi Support |
NFC Support |
Bluetooth Support |
|
---|---|---|---|---|---|---|---|---|---|---|---|
1. | Sony A9 | Y | stereo / mono | Y | Y | micro | 2.0 | Y | Y | Y | |
2. | Sony A7 III | Y | stereo / mono | Y | Y | micro | 3.1 | Y | Y | Y | |
3. | Nikon Z6 | Y | stereo / mono | Y | Y | micro | 3.1 | Y | - | Y | |
4. | Sony A7R V | Y | stereo / mono | Y | Y | full | 3.2 | Y | - | Y | |
5. | Sony A7R IIIA | Y | stereo / mono | Y | Y | micro | 3.2 | Y | Y | Y | |
6. | Sony A9 II | Y | stereo / mono | Y | Y | micro | 3.1 | Y | Y | Y | |
7. | Sony A7R IV | Y | stereo / mono | Y | Y | micro | 3.1 | Y | Y | Y | |
8. | Sony A7R III | Y | stereo / mono | Y | Y | micro | 3.1 | Y | Y | Y | |
9. | Sony A7R II | Y | stereo / mono | Y | Y | micro | 2.0 | Y | Y | - | |
10. | Sony A7S II | Y | stereo / mono | Y | Y | micro | 2.0 | Y | Y | - | |
11. | Sony A7 II | Y | stereo / mono | Y | Y | micro | 2.0 | Y | Y | - | |
12. | Sony A99 | Y | stereo / mono | Y | Y | mini | 2.0 | - | - | - |
Studio photographers will appreciate that the Sony A9 (unlike the A7 III) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.
The A7 III is a recent model that features in the current product line-up of Sony. In contrast, the A9 has been discontinued (but can be found pre-owned on ebay). As a replacement in the same line of cameras, the A9 was succeeded by the Sony A9 II. Further information on the features and operation of the A9 and A7 III can be found, respectively, in the Sony A9 Manual (free pdf) or the online Sony A7 III Manual.
Review summary
So what conclusions can be drawn? Which of the two cameras – the Sony A9 or the Sony A7 III – has the upper hand? Is one clearly better than the other? Below is a summary of the relative strengths of each of the two contestants.
Reasons to prefer the Sony Alpha A9:
- More detailed viewfinder: Has higher resolution electronic viewfinder (3686k vs 2359k dots).
- More detailed LCD: Has a higher resolution rear screen (1440k vs 922k dots).
- Faster burst: Shoots at higher frequency (20 vs 10 flaps/sec) to capture the decisive moment.
- Better studio light control: Has a PC Sync socket to connect to professional strobe lights.
- More heavily discounted: Has been on the market for longer (launched in April 2017).
Arguments in favor of the Sony Alpha A7 III:
- Better image quality: Scores markedly higher (4 points) in the DXO overall evaluation.
- More dynamic range: Captures a broader range 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 (56 percent cheaper at launch).
- More modern: Was introduced somewhat (10 months) more recently.
If the number of relative strengths (bullet points above) is taken as a guide, the A7 III comes out slightly ahead of the A9 (6 : 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 before making a decision on a new camera. A professional wildlife photographer will view the differences between cameras in a way that diverges from the perspective of a family photog, and a person interested in architecture has distinct needs from a sports 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 A9 and the Sony A7 III 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 specs-based evaluation of cameras can be instructive in revealing their potential as photographic tools, it remains partial and cannot reveal, for example, the shooting experience and imaging performance when actually working with the A9 or the A7 III. 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.
Expert reviews
This is why expert reviews are important. The table below provides a synthesis of the camera assessments of some of the best known photo-gear review sites (amateurphotographer [AP], cameralabs [CL], digitalcameraworld [DCW], dpreview [DPR], ephotozine [EPZ], photographyblog [PB]). 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.
# | Camera Model |
AP score |
CL score |
DCW score |
DPR score |
EPZ score |
PB score |
Camera Launch |
Launch Price (USD) |
Street Price |
|
---|---|---|---|---|---|---|---|---|---|---|---|
1. | Sony A9 | 5/5 | + + | 4.8/5 | 89/100 | 5/5 | 5/5 | Apr 2017 | 4,499 | ebay.com | |
2. | Sony A7 III | .. | + + | 4.5/5 | 89/100 | 5/5 | 5/5 | Feb 2018 | 1,999 | amazon.com | |
3. | Nikon Z6 | 5/5 | .. | 5/5 | 89/100 | 4.5/5 | 5/5 | Aug 2018 | 1,999 | ebay.com | |
4. | Sony A7R V | 5/5 | + + | 4.5/5 | 92/100 | .. | .. | Oct 2022 | 3,899 | amazon.com | |
5. | Sony A7R IIIA | .. | + + | 4/5 | 90/100 | 4.5/5 | 5/5 | Apr 2021 | 3,199 | amazon.com | |
6. | Sony A9 II | .. | .. | 5/5 | 90/100 | 5/5 | 5/5 | Oct 2019 | 4,499 | amazon.com | |
7. | Sony A7R IV | 5/5 | + | 4.5/5 | 91/100 | 4.5/5 | 5/5 | Jul 2019 | 3,499 | ebay.com | |
8. | Sony A7R III | .. | + + | 4/5 | 90/100 | 4.5/5 | 5/5 | Oct 2017 | 3,199 | ebay.com | |
9. | Sony A7R II | 5/5 | + + | 5/5 | 90/100 | 5/5 | 5/5 | Jun 2015 | 3,199 | ebay.com | |
10. | Sony A7S II | 5/5 | + | .. | .. | 4.5/5 | 5/5 | Sep 2015 | 2,999 | ebay.com | |
11. | Sony A7 II | 5/5 | + | 4/5 | 82/100 | 4.5/5 | 5/5 | Nov 2014 | 1,999 | ebay.com | |
12. | Sony A99 | 5/5 | .. | .. | 84/100 | 4.5/5 | 4.5/5 | Sep 2012 | 2,799 | ebay.com | |
Note: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available. |
Care should be taken when interpreting the review scores above, 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 comparisons of ratings among very different cameras or across long time periods have little meaning. It should also be noted that some of the review sites have over time altered the way they render their verdicts.
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 a corresponding selection in the search boxes below. Alternatively, you can follow any of the listed hyperlinks for comparisons that others found interesting.
Specifications: Sony A9 vs Sony A7 III
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 A9 | Sony A7 III |
---|---|---|
Camera Type | Mirrorless system camera | Mirrorless system camera |
Camera Lens | Sony E mount lenses | Sony E mount lenses |
Launch Date | April 2017 | February 2018 |
Launch Price | USD 4,499 | USD 1,999 |
Sensor Specs | Sony A9 | Sony A7 III |
Sensor Technology | Stacked BSI-CMOS | BSI-CMOS |
Sensor Format | Full Frame Sensor | Full Frame Sensor |
Sensor Size | 35.6 x 23.8 mm | 35.6 x 23.8 mm |
Sensor Area | 847.28 mm2 | 847.28 mm2 |
Sensor Diagonal | 42.8 mm | 42.8 mm |
Crop Factor | 1.0x | 1.0x |
Sensor Resolution | 24 Megapixels | 24 Megapixels |
Image Resolution | 6000 x 4000 pixels | 6000 x 4000 pixels |
Pixel Pitch | 5.94 μm | 5.94 μm |
Pixel Density | 2.83 MP/cm2 | 2.83 MP/cm2 |
Moiré control | Anti-Alias filter | Anti-Alias filter |
Movie Capability | 4K/30p Video | 4K/30p Video |
ISO Setting | 100 - 51,200 ISO | 100 - 51,200 ISO |
ISO Boost | 50 - 204,800 ISO | 50 - 204,800 ISO |
Image Processor | BIONZ X | BIONZ X |
DXO Sensor Quality (score) | 92 | 96 |
DXO Color Depth (bits) | 24.9 | 25.0 |
DXO Dynamic Range (EV) | 13.3 | 14.7 |
DXO Low Light (ISO) | 3517 | 3730 |
Screen Specs | Sony A9 | Sony A7 III |
Viewfinder Type | Electronic viewfinder | Electronic viewfinder |
Viewfinder Field of View | 100% | 100% |
Viewfinder Magnification | 0.78x | 0.78x |
Viewfinder Resolution | 3686k dots | 2359k dots |
LCD Framing | Live View | Live View |
Rear LCD Size | 3.0inch | 3.0inch |
LCD Resolution | 1440k dots | 922k dots |
LCD Attachment | Tilting screen | Tilting screen |
Touch Input | Touchscreen | Touchscreen |
Shooting Specs | Sony A9 | Sony A7 III |
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 | 20 shutter flaps/s | 10 shutter flaps/s |
Shutter Life Expectancy | 500 000 actuations | 200 000 actuations |
Electronic Shutter | up to 1/32000s | YES |
Time-Lapse Photography | no Intervalometer | Intervalometer built-in |
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 |
Single or Dual Card Slots | Dual card slots | Dual card slots |
UHS card support | Single UHS-II | Single UHS-II |
Connectivity Specs | Sony A9 | Sony A7 III |
External Flash | Hotshoe | Hotshoe |
Studio Flash | PC Sync socket | no PC Sync |
USB Connector | USB 2.0 | USB 3.1 |
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 A9 | Sony A7 III |
Environmental Sealing | Weathersealed body | Weathersealed body |
Battery Type | Sony NP-FZ100 | Sony NP-FZ100 |
Battery Life (CIPA) | 650 shots per charge | 610 shots per charge |
In-Camera Charging | USB charging | USB charging |
Body Dimensions |
127 x 96 x 63 mm (5.0 x 3.8 x 2.5 in) |
127 x 96 x 74 mm (5.0 x 3.8 x 2.9 in) |
Camera Weight | 673 g (23.7 oz) | 650 g (22.9 oz) |
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