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Panasonic G9 versus Sony A7R III

The Panasonic Lumix DC-G9 and the Sony Alpha A7R III are two enthusiast cameras that were revealed to the public, respectively, in November 2017 and October 2017. Both the G9 and the A7R III are mirrorless interchangeable lens cameras that are based on a Four Thirds (G9) and a full frame sensor. The Panasonic has a resolution of 20.2 megapixel, whereas the Sony provides 42.2 MP.

Body comparison

The side-by-side display below illustrates the physical size and weight of the Panasonic G9 and the Sony A7R III. Three successive views from the front, the top, and the rear are shown. All size dimensions 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 – the G9 – represents 100 percent across all the size and weight measures).

Panasonic G9 vs Sony A7R III front
G9 versus A7R III top view
G9 and A7R III rear side
Body view (G9 on the left)

If the front view area (width x height) of the cameras is taken as an aggregate measure of their size, the Sony A7R III is somewhat smaller (8 percent) than the Panasonic G9. Moreover, the A7R III is slightly lighter (1 percent) than the G9. 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. A larger imaging sensor will tend to go along with bigger and heavier lenses, although exceptions exist. You can find an overview of optics for the two cameras in the Micro Four Thirds Lens Catalog (G9) and the Sony FE Lens Catalog (A7R III). 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
Camera Camera
Width
Camera
Height
Camera
Depth
Camera
Weight
Battery
Life
(CIPA)
Weather
Sealing
(y/n)
Camera
Launch
(year)
Launch
Price
(USD)
Street
Price
(amazon)
Used
Price
(ebay)
Panasonic G9 (⇒ rgt) 137 mm 97 mm 92 mm 658 g 400 YES 2017 1,699 latest check
Sony A7R III (⇒ lft) 127 mm 96 mm 74 mm 650 g 650 YES 2017 3,199 latest check
Fujifilm X-Pro2 (⇒ lft | rgt) 141 mm 83 mm 46 mm 495 g 350 YES 2016 1,699 latest check
Fujifilm X-T2 (⇒ lft | rgt) 133 mm 92 mm 49 mm 507 g 340 YES 2016 1,599 latest check
Nikon D850 (⇒ lft | rgt) 146 mm 124 mm 79 mm 1005 g 1840 YES 2017 3,299 latest check
Nikon D500 (⇒ lft | rgt) 147 mm 115 mm 81 mm 860 g 1240 YES 2016 1,999 latest check
Olympus E-M1 II (⇒ lft | rgt) 134 mm 91 mm 67 mm 574 g 440 YES 2016 1,999 latest check
Olympus PEN-F (⇒ lft | rgt) 125 mm 72 mm 37 mm 427 g 330 no 2016 1,199 latest check
Panasonic GH5 (⇒ lft | rgt) 139 mm 98 mm 87 mm 725 g 410 YES 2017 1,999 latest check
Panasonic G80 (⇒ lft | rgt) 128 mm 89 mm 74 mm 505 g 330 YES 2016 899 latest check
Panasonic GX8 (⇒ lft | rgt) 133 mm 78 mm 63 mm 487 g 330 YES 2015 1,199 latest check
Sony A9 (⇒ lft | rgt) 127 mm 96 mm 63 mm 673 g 650 YES 2017 4,499 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 3,199discont. check
Sony A7S II (⇒ lft | rgt) 127 mm 96 mm 60 mm 627 g 370 YES 2015 2,999 latest check

The listed prices provide an indication of the market segment that the manufacturer of the cameras have been targeting. The G9 was launched at a markedly lower price (by 47 percent) than the A7R III, 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 imaging sensor is at the core of digital cameras and its size is one of the main determining factors 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 associated with larger, more expensive camera bodies and lenses.

Of the two cameras under consideration, the Panasonic G9 features a Four Thirds sensor and the Sony A7R III a full frame sensor. The sensor area in the A7R III is 283 percent bigger. As a result of these sensor size differences, the cameras have a format factor of, respectively, 2.0 and 1.0. The sensor in the G9 has a native 4:3 aspect ratio, while the one in the A7R III offers a 3:2 aspect.

Panasonic G9 and Sony A7R III sensor measures
Sensor size

With 42.2MP, the A7R III offers a higher resolution than the G9 (20.2MP), but the A7R III nevertheless has larger individual pixels (pixel pitch of 4.52μm versus 3.34μm for the G9) due to its larger sensor. It is noteworthy in this context that the two cameras were released in close succession, so that their sensors are from the same technological generation. Coming back to sensor resolution, it should be mentioned that neither of the two cameras has an anti-alias filter installed, so they are able to capture all the detail the sensor resolves.

Both cameras have the capacity to capture high quality composite images by combining multiple shots after shifting the sensor by miniscule distances. This multi-shot, pixel-shift mode is most suitable for photography of stationary objects (landscapes, studio scenes).

G9 versus A7R III MP
Sensor resolution

For most cameras, data on sensor performance has been reported by DXO Mark. This service determines an overall sensor rating, as well as sub-scores for low-light sensitivity ("DXO Sports"), dynamic range ("DXO Landscape"), and color depth ("DXO Portrait"). The following table provides an overview of the physical sensor characteristics, as well as the sensor quality measurements for a selection of comparators.

Sensor Characteristics
Camera Sensor
Class
Resolution
(Megapixel)
Horiz.
Pixels
Vert.
Pixels
Video
Format
DXO
Portrait
DXO
Landscape
DXO
Sports
DXO
Overall
Panasonic G9 (⇒ rgt) Four Thirds 20.2 5184 3888 4K/60p - - - -
Sony A7R III (⇒ lft) Full Frame 42.2 7952 5304 4K/30p .. .. .. ..
Fujifilm X-Pro2 (⇒ lft | rgt) APS-C 24.0 6000 4000 1080/60p - - - -
Fujifilm X-T2 (⇒ lft | rgt) APS-C 24.0 6000 4000 4K/30p - - - -
Nikon D850 (⇒ lft | rgt) Full Frame 45.4 8256 5504 4K/30p 26.4 14.8 2660 100
Nikon D500 (⇒ lft | rgt) APS-C 20.7 5568 3712 4K/30p 24.0 14.0 1324 83
Olympus E-M1 II (⇒ lft | rgt) Four Thirds 20.2 5184 3888 4K/30p 23.7 12.8 1312 80
Olympus PEN-F (⇒ lft | rgt) Four Thirds 20.2 5184 3888 1080/60p 23.1 12.4 894 74
Panasonic GH5 (⇒ lft | rgt) Four Thirds 20.2 5184 3888 4K/60p 23.9 13.0 807 77
Panasonic G80 (⇒ lft | rgt) Four Thirds 15.8 4592 3448 4K/30p 22.8 12.5 656 71
Panasonic GX8 (⇒ lft | rgt) Four Thirds 20.2 5184 3888 4K/30p 23.5 12.6 806 75
Sony A9 (⇒ lft | rgt) Full Frame 24.0 6000 4000 4K/30p 24.9 13.3 3517 92
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

Many modern cameras are not only capable of taking still images, but also of capturing video footage. Both cameras under consideration have a sensor with sufficiently fast read-out times for moving pictures, but the G9 provides a higher frame rate than the A7R III. It can shoot video footage at 4K/60p, while the Sony is limited to 4K/30p.

Feature comparison

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 A7R III offers a slightly higher resolution than the one in the G9 (3686k vs 3680k dots). The table below summarizes some of the other core capabilities of the Panasonic G9 and Sony A7R III in connection with corresponding information for a sample of similar cameras. If needed, the dpreview camera hub, for example, contains further detail on the cameras' specs.

Core Features
Camera Viewfinder
(Type or
'000 dots)
Control
Panel
(Y/n)
LCD
Size
(inch)
LCD
Resolution
('000 dots)
LCD
Attach-
ment
Touch
Screen
(Y/n)
Shutter
speed
(1/sec)
Shutter
flaps
(1/sec))
Build-in
Flash
(GN)
Build-in
Image
Stab
Panasonic G9 (⇒ rgt) 3680 YES 3.0 1040 swivel YES 8000 20.0 no YES
Sony A7R III (⇒ lft) 3686 no 3.0 1440 tilting YES 8000 10.0 no YES
Fujifilm X-Pro2 (⇒ lft | rgt) 2360 no 3.0 1620 fixed no 8000 8.0 no no
Fujifilm X-T2 (⇒ lft | rgt) 2360 no 3.0 1040 tilting no 8000 14.0 no no
Nikon D850 (⇒ lft | rgt) optical YES 3.2 2359 tilting YES 8000 9.0 no no
Nikon D500 (⇒ lft | rgt) optical YES 3.2 2359 tilting YES 8000 10.0 no no
Olympus E-M1 II (⇒ lft | rgt) 2360 no 3.0 1037 swivel YES 8000 18.0 no YES
Olympus PEN-F (⇒ lft | rgt) 2360 no 3.0 1037 swivel YES 8000 10.0 no YES
Panasonic GH5 (⇒ lft | rgt) 3680 no 3.2 1620 swivel YES 8000 12.0 no YES
Panasonic G80 (⇒ lft | rgt) 2360 no 3.0 1040 swivel YES 4000 9.0 6.2 YES
Panasonic GX8 (⇒ lft | rgt) 2360 no 3.0 1040 swivel YES 8000 10.0 no YES
Sony A9 (⇒ lft | rgt) 3686 no 3.0 1440 tilting YES 8000 20.0 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

Both the G9 and the A7R III 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 G9 followed on from the Panasonic G85.

Summary

So what is the bottom line? Which of the two cameras – the Panasonic G9 or the Sony A7R III – has the upper hand? Below is a summary of the relative strengths of each of the two contestants.


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Reasons to prefer the Panasonic Lumix DC-G9:

  • Better video: Provides higher movie framerates (4K/60p vs 4K/30p).
  • Easier setting verification: Has an LCD display on top to control shooting parameters.
  • More flexible LCD: Has a swivel screen for odd-angle shots in portrait or landscape orientation.
  • Faster burst: Shoots at higher frequency (20 vs 10 flaps/sec) to capture the decisive moment.
  • More affordable: Was introduced into a lower priced category (47 percent cheaper at launch).

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Advantages of the Sony Alpha A7R III:

  • More detail: Has more megapixels (42.2 vs 20.2MP), which boosts linear resolution by 48%.
  • Better low-light imaging: Features bigger pixels on a larger sensor for better high-ISO images.
  • More detailed LCD: Has a higher resolution rear screen (1440k vs 1040k dots).
  • Longer lasting: Gets more shots (650 versus 400) out of a single battery charge.

If the count of relative strengths (bullet points above) is taken as a measure, the G9 comes out slightly ahead of the A7R III (5 : 4 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.

G9 05:04 A7R III

In any case, while the comparison of technical specifications can provide a useful overview of the capabilities of different cameras, it says nothing about, for example, the handling, responsiveness, and overall imaging quality of the G9 and the A7R III in practical situations. 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 table below summarizes the assessments of some of the best known camera review sites. The detailed reviews can be accessed, respectively, on the websites of cameralabs.com, dpreview.com, ephotozine.com, imaging-resource.com, and photographyblog.com.

Review scores
Camera camera
labs
dp
review
ephoto
zine
imaging
resource
photography
blog
Camera
Launch
(year)
Launch
Price
(USD)
Street
Price
(amazon)
Used
Price
(ebay)
Panasonic G9 (⇒ rgt) .. .. .. .. .. 2017 1,699 latest check
Sony A7R III (⇒ lft) .. .. .. .. .. 2017 3,199 latest check
Fujifilm X-Pro2 (⇒ lft | rgt) Rec 83/100 Silver 4.5/5 4.5/5 4.5/5 2016 1,699 latest check
Fujifilm X-T2 (⇒ lft | rgt) HiRec 86/100 Gold 4.5/5 5/5 5/5 2016 1,599 latest check
Nikon D850 (⇒ lft | rgt) .. 89/100 Gold 4.5/5 .. 5/5 2017 3,299 latest check
Nikon D500 (⇒ lft | rgt) HiRec 91/100 Gold 4.5/5 5/5 5/5 2016 1,999 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
Olympus PEN-F (⇒ lft | rgt) - 82/100 Silver 4.5/5 4.5/5 5/5 2016 1,199 latest check
Panasonic GH5 (⇒ lft | rgt) HiRec 85/100 Gold 4.5/5 5/5 5/5 2017 1,999 latest check
Panasonic G80 (⇒ lft | rgt) HiRec 84/100 Gold 5/5 4.5/5 4.5/5 2016 899 latest check
Panasonic GX8 (⇒ lft | rgt) Rec 82/100 Silver 4.5/5 5/5 4.5/5 2015 1,199 latest check
Sony A9 (⇒ lft | rgt) .. 89/100 Gold 5/5 5/5 5/5 2017 4,499 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 3,199discont. check
Sony A7S II (⇒ lft | rgt) Rec - 4.5/5 5/5 5/5 2015 2,999 latest check

The above review scores should be interpreted with care, though. The ratings were established in reference to similarly priced cameras that were available in the market at the time of the review. A score, therefore, has to be seen in close connection to the price and market introduction time of the camera, 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 comparisons

In case you are interested in seeing how other cameras pair up, just make a corresponding selection in the search boxes below. There is also a set of direct links to comparison reviews that other users of the CAM-parator app explored. If you do not see the camera that you are looking for, kindly get in touch, and I will try to locate and add the respective data to the application.

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