PW

Sony A7R III versus Canon G7 X Mark II

The Sony Alpha A7R III and the Canon PowerShot G7 X Mark II are two digital cameras that were revealed to the public, respectively, in October 2017 and February 2016. The A7R III is a mirrorless interchangeable lens camera, while the G7X Mark II is a fixed lens compact. The cameras are based on a full frame (A7R III) and an one-inch sensor. The Sony has a resolution of 42.2 megapixel, whereas the Canon provides 20 MP.

Body comparison

The side-by-side display below illustrates the physical size and weight of the Sony A7R III and the Canon G7 X Mark II. Three consecutive perspectives from the front, the top, and the back are presented. All width, height and depth measures 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 side – the A7R III – represents the basis for the calculations across all the size and weight measures).

Sony A7R III vs Canon G7 X Mark II front
A7R III versus G7X Mark II top view
A7R III and G7X Mark II rear side
Body view (A7R III on the left)

If the front view area (width x height) of the cameras is taken as an aggregate measure of their size, the Canon G7 X Mark II is considerably smaller (47 percent) than the Sony A7R III. It is worth mentioning in this context that the A7R III is splash and dust resistant, while the G7X Mark II does not feature any corresponding weather-sealing.

The above size and weight comparisons are to some extent incomplete and possibly misleading, as the G7X Mark II has a lens build in, whereas the A7R III is an interchangeable lens camera that requires a separate lens. Attaching the latter will add extra weight and bulk to the setup. You can find an overview of optics for the A7R III and their specifications in the Sony FE Lens Catalog.

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)
Sony A7R III (⇒ rgt) 127 mm 96 mm 74 mm 650 g 650 YES 2017 3,199 latest check
Canon G7 X Mark II (⇒ lft) 106 mm 61 mm 42 mm 319 g 265 no 2016 699 latest check
Canon SX730 (⇒ lft | rgt) 110 mm 64 mm 40 mm 300 g 250 no 2017 399 latest check
Canon M6 (⇒ lft | rgt) 112 mm 68 mm 45 mm 390 g 295 no 2017 779 latest check
Canon M3 (⇒ lft | rgt) 111 mm 68 mm 44 mm 366 g 250 no 2015 679discont. check
Canon G5 X (⇒ lft | rgt) 112 mm 76 mm 44 mm 353 g 210 no 2015 799 latest check
Canon G7 X (⇒ lft | rgt) 103 mm 60 mm 40 mm 304 g 210 no 2014 699discont. check
Hasselblad X1D (⇒ lft | rgt) 150 mm 98 mm 71 mm 725 g .. YES 2016 8,995 latest check
Pentax K-1 (⇒ lft | rgt) 137 mm 110 mm 86 mm 1010 g 760 YES 2016 1,799 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
Sony A7 II (⇒ lft | rgt) 127 mm 96 mm 60 mm 599 g 350 YES 2014 1,999 latest check
Sony A7R (⇒ lft | rgt) 127 mm 94 mm 48 mm 465 g 340 YES 2013 2,299discont. check
Sony A99 (⇒ lft | rgt) 147 mm 111 mm 78 mm 812 g 500 YES 2012 2,799discont. check

The listed prices provide an indication of the market segment that the manufacturer of the cameras have been targeting. The G7X Mark II was launched at a lower price than the A7R III, despite having a lens build in. 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 imaging sensor is a crucial determinant 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. Moreover, a large sensor camera will give the photographer more control over depth-of-field in the image and, thus, the ability to better isolate a subject from the background. On the downside, larger sensors tend to be more expensive and lead to bigger and heavier cameras and lenses.

Of the two cameras under consideration, the Sony A7R III features a full frame sensor and the Canon G7 X Mark II an one-inch sensor. The sensor area in the G7X Mark II is 87 percent smaller. As a result of these sensor size differences, the cameras have a format factor of, respectively, 1.0 and 2.7. Both cameras have a native aspect ratio (sensor width to sensor height) of 3:2.

Sony A7R III and Canon G7 X Mark II sensor measures
Sensor size

With 42.2MP, the A7R III offers a higher resolution than the G7X Mark II (20MP), but the A7R III nevertheless has larger individual pixels (pixel pitch of 4.52μm versus 2.41μm for the G7X Mark II) due to its larger sensor. Moreover, the A7R III is a somewhat more recent model (by 1 year and 8 months) than the G7X Mark II, and its sensor might have benefitted from technological advances during this time that further 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.

Unlike the G7X Mark II, 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).

A7R III versus G7X Mark II MP
Sensor resolution

Since 2007, DXO Mark has published sensor performance measurements that have been derived using a consistent methodology. 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
Sony A7R III (⇒ rgt) Full Frame 42.2 7952 5304 4K/30p 26.0 14.7 3523 100
Canon G7 X Mark II (⇒ lft) 1-inch 20.0 5472 3648 1080/60p - - - -
Canon SX730 (⇒ lft | rgt) 1/2.3 20.2 5184 3888 1080/60p - - - -
Canon M6 (⇒ lft | rgt) APS-C 24.0 6000 4000 1080/60p .. .. .. ..
Canon M3 (⇒ lft | rgt) APS-C 24.0 6000 4000 1080/30p 22.8 11.8 1169 72
Canon G5 X (⇒ lft | rgt) 1-inch 20.0 5472 3648 1080/60p - - - -
Canon G7 X (⇒ lft | rgt) 1-inch 20.0 5472 3648 1080/60p 23.0 12.7 556 71
Hasselblad X1D (⇒ lft | rgt) Medium Format 51.3 8272 6200 1080/25p 26.2 14.8 4489 102
Pentax K-1 (⇒ lft | rgt) Full Frame 36.2 7360 4912 1080/60i 25.4 14.6 3280 96
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
Sony A7 II (⇒ lft | rgt) Full Frame 24.0 6000 4000 1080/60p 24.9 13.6 2449 90
Sony A7R (⇒ lft | rgt) Full Frame 36.2 7360 4912 1080/60p 25.6 14.1 2746 95
Sony A99 (⇒ lft | rgt) 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 also of capturing video footage. Both cameras under consideration have a sensor with sufficiently fast read-out times for moving pictures, but the A7R III provides a higher video resolution than the G7X Mark II. It can shoot video footage at 4K/30p, while the Canon is limited to 1080/60p.

Feature comparison

Apart from body and sensor, cameras can and do differ across a variety of features. For example, the A7R III has an electronic viewfinder (3686k dots), which can be very helpful when shooting in bright sunlight. In contrast, the G7X Mark II relies on live view and the rear LCD for framing. The table below summarizes some of the other core capabilities of the Sony A7R III and Canon G7 X Mark II in connection with corresponding information for a sample of similar cameras. The full specs-sheets can be found in the camera manual or, for example, in the dpreview camera hub.

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
Sony A7R III (⇒ rgt) 3686 no 3.0 1440 tilting YES 8000 10.0 no YES
Canon G7 X Mark II (⇒ lft) no no 3.0 1040 tilting YES 2000 8.0 7 YES
Canon SX730 (⇒ lft | rgt) no no 3.0 922 tilting no 3200 5.9 4 YES
Canon M6 (⇒ lft | rgt) no no 3.0 1040 tilting YES 4000 9.0 5 no
Canon M3 (⇒ lft | rgt) no no 3.0 1040 tilting YES 4000 4.2 5 no
Canon G5 X (⇒ lft | rgt) 2360 no 3.0 1040 swivel YES 2000 5.9 7 YES
Canon G7 X (⇒ lft | rgt) no no 3.0 1040 tilting YES 2000 6.5 7 YES
Hasselblad X1D (⇒ lft | rgt) 2360 no 3.0 920 fixed YES 2000 2.3 no no
Pentax K-1 (⇒ lft | rgt) optical YES 3.2 1037 full-flex no 8000 4.4 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
Sony A7 II (⇒ lft | rgt) 2400 no 3.0 1230 tilting no 8000 5.0 no YES
Sony A7R (⇒ lft | rgt) 2400 no 3.0 1230 tilting no 8000 4.0 no no
Sony A99 (⇒ lft | rgt) 2359 YES 3.0 1229 full-flex no 8000 6.0 no YES

Both the A7R III and the G7X Mark II are current models that good online retailers will have in stock. You can check the latest prices, for example, at amazon. The G7X Mark II replaced the earlier Canon G7 X, while the A7R III followed on from the Sony A7R II.

Summary

So what conclusions can be drawn? Is the Sony A7R III better than the Canon G7 X Mark II or vice versa? A synthesis of the relative strong points of each of the models is listed below.


logo checkmark

Reasons to prefer the Sony Alpha A7R III:

  • More detail: Offers more megapixels (42.2 vs 20MP) with a 45% 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: Features a larger and more technologically advanced imaging sensor.
  • Better video: Provides higher definition movie capture (4K/30p vs 1080/60p).
  • Easier framing: Has an electronic viewfinder for image framing and settings control.
  • More detailed LCD: Has a higher resolution rear screen (1440k vs 1040k dots).
  • Faster shutter: Has higher mechanical shutter speed (8000/sec vs 2000/sec) to freeze action.
  • Faster burst: Shoots at higher frequency (10 vs 8 flaps/sec) to capture the decisive moment.
  • More flexible: Accepts interchangeable lenses, so that lens characteristics can be altered.
  • Longer lasting: Can take more shots (650 versus 265) on a single battery charge.
  • Better sealing: Is weather sealed to enable shooting in dusty or wet environments.
  • Sharper images: Has hand-shake reducing image stabilization build-in.
  • More modern: Is somewhat more recent (announced 1 year and 8 months after the G7X Mark II).

logo checkmark

Advantages of the Canon PowerShot G7 X Mark II:

  • Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
  • Ready to shoot: Has an integrated lens, whereas the A7R III necessitates an extra lens.
  • More compact: Is smaller (106x61mm vs 127x96mm) and will fit more readily into a bag.
  • Less heavy: Has a lower weight even though it has a lens build in (unlike the A7R III).
  • Easier fill-in: Has a small integrated flash to brighten shadows of backlit subjects.
  • More affordable: Was introduced at a lower price, despite coming with a build-in lens.
  • More heavily discounted: Has been on the market for longer (launched in February 2016).

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 (14 : 7 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.

A7R III 14:07 G7X Mark II

In any case, while the specs-based evaluation of cameras is instructive in revealing their potential as photographic tools, it says nothing about, for example, the handling, responsiveness, and overall imaging quality of the A7R III and the G7X Mark II 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 why hands-on reviews by experts are important. The following table reports the overall rankings of the cameras as published by some of the major camera review sites. You can find the full text of the reviews, respectively, at 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)
Sony A7R III (⇒ rgt) HiRec 90/100 Gold .. .. .. 2017 3,199 latest check
Canon G7 X Mark II (⇒ lft) HiRec 81/100 Silver 4.5/5 4/5 4.5/5 2016 699 latest check
Canon SX730 (⇒ lft | rgt) Rec - 4/5 - 4/5 2017 399 latest check
Canon M6 (⇒ lft | rgt) - 80/100 Silver 4/5 4.5/5 4/5 2017 779 latest check
Canon M3 (⇒ lft | rgt) reviewed 75/100 4.5/5 4.5/5 4/5 2015 679discont. check
Canon G5 X (⇒ lft | rgt) HiRec 78/100 Silver 4.5/5 4/5 4.5/5 2015 799 latest check
Canon G7 X (⇒ lft | rgt) HiRec 77/100 Silver 4.5/5 3.5/5 4.5/5 2014 699discont. check
Hasselblad X1D (⇒ lft | rgt) - - - - 4/5 2016 8,995 latest check
Pentax K-1 (⇒ lft | rgt) - 84/100 Silver 5/5 4.5/5 5/5 2016 1,799 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
Sony A7 II (⇒ lft | rgt) Rec 82/100 Silver 4.5/5 5/5 5/5 2014 1,999 latest check
Sony A7R (⇒ lft | rgt) HiRec 82/100 Gold 4.5/5 5/5 5/5 2013 2,299discont. check
Sony A99 (⇒ lft | rgt) - 84/100 Gold 4.5/5 reviewed 4.5/5 2012 2,799discont. check

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. A score, therefore, has to be seen in close connection to the price and market introduction time of the camera, and rating-comparisons among cameras that span long time periods or concern very differently equipped models make little sense. Also, kindly note that some of the listed sites have over time developped their review approaches and their reporting style.

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 cannot find the camera you are interested in, please contact me, and I will try to update the database with the necessary infos.

vs