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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.

Headline Specifications
Sony A9
versus
Sony A7 III
Sony A9   Sony A7 III
Mirrorless system camera Mirrorless system camera
Sony E mount lenses Sony E mount lenses
24 MP – Full Frame sensor 24 MP – Full Frame sensor
4K/30p Video 4K/30p Video
ISO 100-51,200 (50 - 204,800) ISO 100-51,200 (50 - 204,800)
Electronic viewfinder (3686k dots) Electronic viewfinder (2359k dots)
3.0" LCD – 1440k dots 3.0" LCD – 922k dots
Tilting touchscreen Tilting touchscreen
20 shutter flaps per second 10 shutter flaps per second
In-body stabilizationIn-body stabilization
Weathersealed bodyWeathersealed body
650 shots per battery charge610 shots per battery charge
127 x 96 x 63 mm, 673 g 127 x 96 x 74 mm, 650 g
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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.

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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.

Size Sony A9 vs Sony A7 III
Compare A9 versus A7 III top
Comparison A9 or A7 III rear

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.

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Body Specifications
# image 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 4,499ebay.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 1,999ebay.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 3,499ebay.com
8.
 
Sony A7R III 127 mm 96 mm 74 mm 650 g 650 Y Oct 2017 3,199ebay.com
9.
 
Sony A7R II 127 mm 96 mm 60 mm 625 g 290 Y Jun 2015 3,199ebay.com
10.
 
Sony A7S II 127 mm 96 mm 60 mm 627 g 370 Y Sep 2015 2,999ebay.com
11.
 
Sony A7 II 127 mm 96 mm 60 mm 599 g 350 Y Nov 2014 1,999ebay.com
12.
 
Sony A99 147 mm 111 mm 78 mm 812 g 500 Y Sep 2012 2,799ebay.com
Note: Measurements and pricing do not include easily detachable parts, such as add-on or interchangeable lenses or optional viewfinders.
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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.

Sony A9 and Sony A7 III sensor measures

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.

A9 versus A7 III MP

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.

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Sensor Characteristics
# image 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 40004K/30p24.913.3351792
2.
 
Sony A7 III Full Frame 24.0 6000 40004K/30p25.014.7373096
3.
 
Nikon Z6 Full Frame 24.3 6048 40244K/30p25.314.3329995
4.
 
Sony A7R V Full Frame 60.2 9504 63368k/24p26.514.83187100
5.
 
Sony A7R IIIA Full Frame 42.2 7952 53044K/30p26.014.73523100
6.
 
Sony A9 II Full Frame 24.0 6000 40004K/30p25.014.0343493
7.
 
Sony A7R IV Full Frame 60.2 9504 63364K/30p26.014.8334499
8.
 
Sony A7R III Full Frame 42.2 7952 53044K/30p26.014.73523100
9.
 
Sony A7R II Full Frame 42.2 7952 53044K/30p26.013.9343498
10.
 
Sony A7S II Full Frame 12.0 4240 28324K/30p23.613.3299385
11.
 
Sony A7 II Full Frame 24.0 6000 40001080/60p24.913.6244990
12.
 
Sony A99 Full Frame 24.0 6000 40001080/60p25.014.0155589
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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).

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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.

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Core Features
# image 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 A93686 n3.0 / 1440 tilting Y 1/8000s 20.0/s n Y
2.
 
Sony A7 III2359 n3.0 / 922 tilting Y 1/8000s 10.0/s n Y
3.
 
Nikon Z63690 Y3.2 / 2100 tilting Y 1/8000s 12.0/s n Y
4.
 
Sony A7R V9440 n3.2 / 2100 full-flex Y 1/8000s 10.0/s n Y
5.
 
Sony A7R IIIA3686 n3.0 / 2340 tilting Y 1/8000s 10.0/s n Y
6.
 
Sony A9 II3686 n3.0 / 1440 tilting Y 1/8000s 20.0/s n Y
7.
 
Sony A7R IV5760 n3.0 / 1440 tilting Y 1/8000s 10.0/s n Y
8.
 
Sony A7R III3686 n3.0 / 1440 tilting Y 1/8000s 10.0/s n Y
9.
 
Sony A7R II2400 n3.0 / 1229 tilting n 1/8000s 5.0/s n Y
10.
 
Sony A7S II2400 n3.0 / 1229 tilting n 1/8000s 5.0/s n Y
11.
 
Sony A7 II2400 n3.0 / 1230 tilting n 1/8000s 5.0/s n Y
12.
 
Sony A992359 Y3.0 / 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.
padding

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.

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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.

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Input-Output Connections
# image Camera
Model
Hotshoe
Port
Internal
Mic / Speaker
Microphone
Port
Headphone
Port
HDMI
Port
USB
Port
WiFi
Support
NFC
Support
Bluetooth
Support
1.
 
Sony A9Ystereo / monoYYmicro2.0YYY
2.
 
Sony A7 IIIYstereo / monoYYmicro3.1YYY
3.
 
Nikon Z6Ystereo / monoYYmicro3.1Y-Y
4.
 
Sony A7R VYstereo / monoYYfull3.2Y-Y
5.
 
Sony A7R IIIAYstereo / monoYYmicro3.2YYY
6.
 
Sony A9 IIYstereo / monoYYmicro3.1YYY
7.
 
Sony A7R IVYstereo / monoYYmicro3.1YYY
8.
 
Sony A7R IIIYstereo / monoYYmicro3.1YYY
9.
 
Sony A7R IIYstereo / monoYYmicro2.0YY-
10.
 
Sony A7S IIYstereo / monoYYmicro2.0YY-
11.
 
Sony A7 IIYstereo / monoYYmicro2.0YY-
12.
 
Sony A99Ystereo / monoYYmini2.0---
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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.

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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.

A9 05:06 A7 III

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.

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Expert Camera Reviews
# image  Camera 
 Model 
 AP 
 score 
 CL 
 score 
 DCW 
 score 
 DPR 
 score 
 EPZ 
 score 
 PB 
 score 
Camera
Launch
Launch
Price (USD)
Street
Price
1.
 
Sony A95/5+ +4.8/589/1005/55/5 Apr 2017 4,499ebay.com
2.
 
Sony A7 III..+ +4.5/589/1005/55/5 Feb 2018 1,999 amazon.com
3.
 
Nikon Z65/5..5/589/1004.5/55/5 Aug 2018 1,999ebay.com
4.
 
Sony A7R V5/5+ +4.5/592/100.... Oct 2022 3,899 amazon.com
5.
 
Sony A7R IIIA..+ +4/590/1004.5/55/5 Apr 2021 3,199 amazon.com
6.
 
Sony A9 II....5/590/1005/55/5 Oct 2019 4,499 amazon.com
7.
 
Sony A7R IV5/5+4.5/591/1004.5/55/5 Jul 2019 3,499ebay.com
8.
 
Sony A7R III..+ +4/590/1004.5/55/5 Oct 2017 3,199ebay.com
9.
 
Sony A7R II5/5+ +5/590/1005/55/5 Jun 2015 3,199ebay.com
10.
 
Sony A7S II5/5+....4.5/55/5 Sep 2015 2,999ebay.com
11.
 
Sony A7 II5/5+4/582/1004.5/55/5 Nov 2014 1,999ebay.com
12.
 
Sony A995/5....84/1004.5/54.5/5 Sep 2012 2,799ebay.com
Note: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.
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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.

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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.

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    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 Specifications
    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 AidFocus PeakingFocus Peaking
    Max Shutter Speed (mechanical) 1/8000s 1/8000s
    Continuous Shooting 20 shutter flaps/s 10 shutter flaps/s
    Shutter Life Expectancy500 000 actuations200 000 actuations
    Electronic Shutterup to 1/32000sYES
    Time-Lapse Photographyno IntervalometerIntervalometer built-in
    Image StabilizationIn-body stabilizationIn-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 SealingWeathersealed bodyWeathersealed body
    Battery Type Sony NP-FZ100 Sony NP-FZ100
    Battery Life (CIPA)650 shots per charge610 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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