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Sony A7 III vs A9

The Sony Alpha A7 III and the Sony Alpha A9 are two digital cameras that were revealed to the public, respectively, in February 2018 and April 2017. Both the A7 III and the A9 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 A7 III   Sony A9
Sony A7 III Sony A9
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 100-51200 (50-204800) ISO 100-51200 (50-204800)
Electronic viewfinder (2359k dots) Electronic viewfinder (3686k dots)
3.0" LCD, 922k dots 3.0" LCD, 1440k dots
Tilting touchscreen Tilting touchscreen
10 shutter flaps per second 20 shutter flaps per second
In-body stabilizationIn-body stabilization
Weathersealed bodyWeathersealed body
610 shots per battery charge650 shots per battery charge
127 x 96 x 74 mm, 650 g 127 x 96 x 63 mm, 673 g

Going beyond this snapshot of core features and characteristics, what are the differences between the Sony Alpha A7 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.

Body comparison: Sony A7 III vs A9

The physical size and weight of the Sony A7 III and the Sony A9 are illustrated 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.

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

In this particular case, the Sony A7 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 A7 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, just click on the right or left arrow next to the camera that you would like to inspect. Alternatively, you can also use the CAM-parator to select your camera combination among a larger number of options.

Camera Body Specifications
  Camera
Model
Camera
Width
Camera
Height
Camera
Depth
Camera
Weight
Battery
Life
(CIPA)
Weather
Sealing
(yes/no)
Camera
Launch
(announced)
Launch
Price
(USD)
Street
Price
(USD)
Used
Price
(USD)
Camera
Model
 
Sony A7 III» 127 mm 96 mm 74 mm 650 g 610 Y Feb 2018 1,999 i i Sony A7 III
 
Sony A9« 127 mm 96 mm 63 mm 673 g 650 Y Apr 2017 4,499 i i Sony A9
 
Canon 6D Mark II« » 144 mm 111 mm 75 mm 765 g 1200 Y Jun 2017 1,999 i i Canon 6D Mark II
 
Nikon Z6« » 134 mm 101 mm 67 mm 675 g 310 Y Aug 2018 1,999 i i Nikon Z6
 
Olympus E-M1 II« » 134 mm 91 mm 67 mm 574 g 440 Y Sep 2016 1,999 i i Olympus E-M1 II
 
Panasonic G9« » 137 mm 97 mm 92 mm 658 g 400 Y Nov 2017 1,699 i i Panasonic G9
 
Panasonic GH5« » 139 mm 98 mm 87 mm 725 g 410 Y Jan 2017 1,999 i i Panasonic GH5
 
Sony A7R III« » 127 mm 96 mm 74 mm 650 g 650 Y Oct 2017 3,199 i i Sony A7R III
 
Sony A7R II« » 127 mm 96 mm 60 mm 625 g 290 Y Jun 2015 3,199- i Sony A7R II
 
Sony A7S II« » 127 mm 96 mm 60 mm 627 g 370 Y Sep 2015 2,999 i i Sony A7S II
 
Sony A7 II« » 127 mm 96 mm 60 mm 599 g 350 Y Nov 2014 1,999- i Sony A7 II
Note: Measurements and pricing do not include easily detachable parts, such as interchangeable lenses or optional viewfinders.

The price is, of course, an important factor in any camera decision. The manufacturer’s suggested retail prices give an idea on the placement of the camera in the maker’s lineup and the broader market. 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: Sony A7 III vs A9

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. Furthermore, a large sensor camera will give the photographer more possibilities to use shallow depth-of-field in order to isolate a subject from the background. On the downside, larger sensors tend to be associated with larger, more expensive camera bodies 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 A7 III and Sony A9 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 A7 III and the A9 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. Coming back to sensor resolution, it should be mentioned that the A7 III has no anti-alias filter installed, so that it can capture all the detail its sensor resolves.

The Sony Alpha A7 III has a native sensitivity range from ISO 100 to ISO 51200, which can be extended to ISO 50-204800. The Sony Alpha A9 offers exactly the same ISO settings.

A7 III versus A9 MP

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 A7 III has a notably higher overall DXO score than the A9 (overall score 4 points higher), which gives it an advantage in terms of imaging quality. This 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 table below summarizes the physical sensor characteristics and sensor quality findings and compares them across a set of similar cameras.

Sensor Characteristics
  Camera
Model
Sensor
Class
Resolution
(MP)
Horiz.
Pixels
Vert.
Pixels
Video
Format
DXO
Portrait
DXO
Landscape
DXO
Sports
DXO
Overall
Camera
Model
 
Sony A7 III» Full Frame 24.0 6000 40004K/30p25.014.7373096Sony A7 III
 
Sony A9« Full Frame 24.0 6000 40004K/30p24.913.3351792Sony A9
 
Canon 6D Mark II« » Full Frame 26.0 6240 41601080/60p24.411.9286285Canon 6D Mark II
 
Nikon Z6« » Full Frame 24.3 6048 40244K/30p25.314.3329995Nikon Z6
 
Olympus E-M1 II« » Four Thirds 20.2 5184 38884K/30p23.712.8131280Olympus E-M1 II
 
Panasonic G9« » Four Thirds 20.2 5184 38884K/60p----Panasonic G9
 
Panasonic GH5« » Four Thirds 20.2 5184 38884K/60p23.913.080777Panasonic GH5
 
Sony A7R III« » Full Frame 42.2 7952 53044K/30p26.014.73523100Sony A7R III
 
Sony A7R II« » Full Frame 42.2 7952 53044K/30p26.013.9343498Sony A7R II
 
Sony A7S II« » Full Frame 12.0 4240 28324K/30p23.613.3299385Sony A7S II
 
Sony A7 II« » Full Frame 24.0 6000 40001080/60p24.913.6244990Sony A7 II

Many modern cameras are not only capable of taking still images, but also of capturing video footage. 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).

 

Feature comparison: Sony A7 III vs A9

Beyond body and sensor, cameras can and do differ across a range 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 A7 III (3686k vs 2359k dots). The following table reports on some other key feature differences and similarities of the Sony A7 III, the Sony A9, and comparable cameras.

Core Features
  Camera
Model
Viewfinder
(Type or
'000 dots)
Control
Panel
(yes/no)
LCD
Size
(inch)
LCD
Resolution
('000 dots)
LCD
Attach-
ment
Touch
Screen
(yes/no)
Mech
Shutter
Speed
Shutter
Flaps
(1/sec)
Built-in
Flash
(yes/no)
Built-in
Image
Stab
Camera
Model
 
Sony A7 III»2359 n 3.0 922 tilting Y 1/8000s 10.0 n Y Sony A7 III
 
Sony A9«3686 n 3.0 1440 tilting Y 1/8000s 20.0 n Y Sony A9
 
Canon 6D Mark II« »optical Y 3.0 1040 swivel Y 1/4000s 6.5 n n Canon 6D Mark II
 
Nikon Z6« »3690 Y 3.2 2100 tilting Y 1/8000s 12.0 n Y Nikon Z6
 
Olympus E-M1 II« »2360 n 3.0 1037 swivel Y 1/8000s 18.0 n Y Olympus E-M1 II
 
Panasonic G9« »3680 Y 3.0 1040 swivel Y 1/8000s 20.0 n Y Panasonic G9
 
Panasonic GH5« »3680 n 3.2 1620 swivel Y 1/8000s 12.0 n Y Panasonic GH5
 
Sony A7R III« »3686 n 3.0 1440 tilting Y 1/8000s 10.0 n Y Sony A7R III
 
Sony A7R II« »2400 n 3.0 1229 tilting n 1/8000s 5.0 n Y Sony A7R II
 
Sony A7S II« »2400 n 3.0 1229 tilting n 1/8000s 5.0 n Y Sony A7S II
 
Sony A7 II« »2400 n 3.0 1230 tilting n 1/8000s 5.0 n Y Sony A7 II

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 A7 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 A7 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.

 

Connectivity comparison: Sony A7 III vs A9

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 A7 III and Sony Alpha A9 and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.

Input-Output Connections
  Camera
Model
Hotshoe
Port
Internal
Microphone
Internal
Speaker
Microphone
Port
Headphone
Port
HDMI
Port
USB
Type
WiFi
Support
NFC
Support
Bluetooth
Support
Camera
Model
 
Sony A7 III»YstereomonoYYmicro3.1YYYSony A7 III
 
Sony A9«YstereomonoYYmicro2.0YYYSony A9
 
Canon 6D Mark II« »YstereomonoY-mini2.0YYYCanon 6D Mark II
 
Nikon Z6« »YstereomonoYYmicro3.1Y-YNikon Z6
 
Olympus E-M1 II« »YstereomonoYYmicro3.0Y--Olympus E-M1 II
 
Panasonic G9« »YstereomonoYYfull3.0Y-YPanasonic G9
 
Panasonic GH5« »YstereomonoYYfull3.1Y-YPanasonic GH5
 
Sony A7R III« »YstereomonoYYmicro3.1YYYSony A7R III
 
Sony A7R II« »YstereomonoYYmicro2.0YY-Sony A7R II
 
Sony A7S II« »YstereomonoYYmicro2.0YY-Sony A7S II
 
Sony A7 II« »YstereomonoYYmicro2.0YY-Sony A7 II

Both the A7 III and the A9 are recent models that are part of the current product line-up. The A7 III replaced the earlier Sony A7 II, while the A9 does not have a direct predecessor. Further information on the two cameras (e.g. user guides, manuals), as well as related accessories, can be found on the official Sony website.


Review summary: Sony A7 III vs A9

So how do things add up? Which of the two cameras – the Sony A7 III or the Sony A9 – has the upper hand? Is one clearly better than the other? A synthesis of the relative strong points of each of the models is listed below.


Arguments in favor of the Sony Alpha A7 III:

  • Maximized detail: Lacks an anti-alias filter to exploit the sensor's full resolution potential.
  • Better image quality: Scores markedly higher (4 points) in the DXO overall assessment.
  • 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 (56 percent cheaper at launch).
  • More modern: Is somewhat more recent (announced 10 months after the A9).


Reasons to prefer the Sony Alpha A9:

  • Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
  • 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.
  • More heavily discounted: Has been on the market for longer (launched in April 2017).

If the count of individual advantages (bullet points above) is taken as a guide, the A7 III emerges as the winner of the contest (7 : 5 points). However, the pertinence of the various camera strengths will differ across photographers, so that you might want to weigh individual camera traits according to their importance for your own imaging needs before making a camera decision. 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.

A7 III 07:05 A9

How about other alternatives? Do the specifications of the Sony A7 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 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 A7 III or the A9. 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: Sony A7 III vs A9

This is where reviews by experts come in. The adjacent summary-table relays the overall verdicts of several of the most popular 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.

Review Scores
  Camera
Model
cameralabs dpreview ephotozine imaging-resource photographyblog Camera
Launch
(announced)
Launch
Price
(USD)
Street
Price
(USD)
Used
Price
(USD)
Camera
Model
 
Sony A7 III»+ +89/1005/55/55/5 Feb 2018 1,999 i i Sony A7 III
 
Sony A9«+ +89/1005/55/55/5 Apr 2017 4,499 i i Sony A9
 
Canon 6D Mark II« »+80/1004.5/54/54/5 Jun 2017 1,999 i i Canon 6D Mark II
 
Nikon Z6« »--4.5/5-5/5 Aug 2018 1,999 i i Nikon Z6
 
Olympus E-M1 II« »+ +85/1004.5/55/54.5/5 Sep 2016 1,999 i i Olympus E-M1 II
 
Panasonic G9« »+ +85/1005/55/55/5 Nov 2017 1,699 i i Panasonic G9
 
Panasonic GH5« »+ +85/1004.5/55/55/5 Jan 2017 1,999 i i Panasonic GH5
 
Sony A7R III« »+ +90/1004.5/55/55/5 Oct 2017 3,199 i i Sony A7R III
 
Sony A7R II« »+ +90/1005/54.5/55/5 Jun 2015 3,199- i Sony A7R II
 
Sony A7S II« »+-4.5/55/55/5 Sep 2015 2,999 i i Sony A7S II
 
Sony A7 II« »+82/1004.5/55/55/5 Nov 2014 1,999- i Sony A7 II
Notes: (+ +) highly recommended; (+) recommended; (o) reviewed; (-) not available.

Care should be taken when interpreting the review scores above, though. The ratings were established in reference to similarly priced cameras that were available in the market at the time of the review. 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.

Sony A7 III:
Check Amazon price
Sony A9:
Check Amazon price

Other camera comparisons

Did this review help to inform your camera decision process? If you would like to see a different side-by-side camera review, just make your choice using the following search menu. As an alternative, you can also directly jump to any one of the listed comparisons that were previously generated by the CAM-parator tool.

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    Specifications: Sony A7 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 Specifications
    Camera Model Sony A7 III Sony A9
    Camera Type Mirrorless system camera Mirrorless system camera
    Camera Lens Sony E mount lenses Sony E mount lenses
    Launch Date February 2018 April 2017
    Launch Price USD 1999 USD 4499
    Sensor Specs Sony A7 III Sony A9
    Sensor Technology 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 no AA filter Anti-Alias filter
    Movie Capability 4K/30p Video 4K/30p Video
    ISO Setting 100-51200 ISO 100-51200 ISO
    ISO Boost 50-204800 ISO 50-204800 ISO
    Image Processor BIONZ X BIONZ X
    DXO Sensor Quality (score) 96 92
    DXO Color Depth (bits) 25.0 24.9
    DXO Dynamic Range (EV) 14.7 13.3
    DXO Low Light (ISO) 3730 3517
    Screen Specs Sony A7 III Sony A9
    Viewfinder Type Electronic viewfinder Electronic viewfinder
    Viewfinder Field of View 100% 100%
    Viewfinder Magnification 0.78x 0.78x
    Viewfinder Resolution 2359k dots 3686k dots
    LCD Framing Live View Live View
    Rear LCD Size 3.0 inch 3.0 inch
    LCD Resolution 922k dots 1440k dots
    LCD Attachment Tilting screen Tilting screen
    Touch Input Touchscreen Touchscreen
    Shooting Specs Sony A7 III Sony A9
    Autofocus System On-Sensor Phase-detect On-Sensor Phase-detect
    Manual Focusing AidFocus PeakingFocus Peaking
    Max Shutter Speed (mechanical) 1/8000/s 1/8000/s
    Continuous Shooting 10 shutter flaps/s 20 shutter flaps/s
    Shutter Life Expectancy200 000 actuations500 000 actuations
    Electronic ShutterYESup to 1/32000s
    Time-Lapse PhotographyIntervalometer built-inno Intervalometer
    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
    Second Storage Option Dual card slots Dual card slots
    UHS card support Single UHS-II Single UHS-II
    Connectivity Specs Sony A7 III Sony A9
    External Flash Hotshoe Hotshoe
    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 A7 III Sony A9
    Environmental SealingWeathersealed bodyWeathersealed body
    Battery Type NP-FZ100 power pack NP-FZ100 power pack
    Battery Life (CIPA)610 shots per charge650 shots per charge
    In-Camera Charging USB charging USB charging
    Body Dimensions 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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