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Canon 5D Mark III versus Sony A7R III

The Canon EOS 5D Mark III and the Sony Alpha A7R III are two digital cameras that were officially introduced, respectively, in March 2012 and October 2017. The 5D Mark III is a DSLR, while the A7R III is a mirrorless interchangeable lens camera. Both cameras are equipped with a full frame sensor. The Canon has a resolution of 22.1 megapixel, whereas the Sony provides 42.2 MP.

Body comparison

The side-by-side display below illustrates the physical size and weight of the Canon 5D Mark III 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. If you prefer, you can also use the toggle button to switch to a comparison in percentage terms (in this case, the camera on the left side – the 5D Mark III – represents the basis for the calculations across all the size and weight measures).

Canon 5D Mark III vs Sony A7R III front
5D Mark III versus A7R III top view
5D Mark III and A7R III rear side
Body view (5D Mark 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 Sony A7R III is notably smaller (31 percent) than the Canon 5D Mark III. Moreover, the A7R III is markedly lighter (32 percent) than the 5D Mark 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. Both cameras have similarly sized sensors, but DSLRs have a larger flange-to-focal plane distance than mirrorless cameras, which imposes contraints on the optical engineering process and generally leads to bigger and heavier lenses. You can find an overview of optics for the two cameras in the Canon EF Lens Catalog (5D Mark III) and the Sony FE Lens Catalog (A7R III). Mirrorless cameras, such as the A7R III, have moreover the advantage that they can use many lenses from other systems via adapters, as they have a relatively short flange to focal plane distance.

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)
Canon 5D Mark III (⇒ rgt) 6.0 in 4.6 in 3.0 in 33.5 oz 950 YES 2012 3,499discont. check
Sony A7R III (⇒ lft) 5.0 in 3.8 in 2.9 in 22.9 oz 650 YES 2017 3,199 latest check
Canon 6D Mark II (⇒ lft | rgt) 5.7 in 4.4 in 3.0 in 27.0 oz 1200 YES 2017 1,999 latest check
Canon 5D Mark IV (⇒ lft | rgt) 5.9 in 4.6 in 3.0 in 31.4 oz 900 YES 2016 3,499 latest check
Canon 1D X Mark II (⇒ lft | rgt) 6.2 in 6.6 in 3.3 in 54.0 oz 1210 YES 2016 5,999 latest check
Canon 5DS R (⇒ lft | rgt) 6.0 in 4.6 in 3.0 in 32.8 oz 700 YES 2015 3,699 latest check
Canon 5DS (⇒ lft | rgt) 6.0 in 4.6 in 3.0 in 32.8 oz 700 YES 2015 3,699 latest check
Canon 70D (⇒ lft | rgt) 5.5 in 4.1 in 3.1 in 26.6 oz 920 YES 2013 1,199discont. check
Canon 6D (⇒ lft | rgt) 5.7 in 4.4 in 2.8 in 27.2 oz 1090 YES 2012 2,099discont. check
Canon 1D X (⇒ lft | rgt) 6.2 in 6.6 in 3.3 in 54.7 oz 1120 YES 2011 6,799discont. check
Canon 5D Mark II (⇒ lft | rgt) 6.0 in 4.5 in 3.0 in 30.0 oz 850 YES 2008 3,499discont. check
Canon 5D (⇒ lft | rgt) 6.0 in 4.4 in 3.0 in 31.6 oz 400 YES 2005 3,299discont. check
Nikon D850 (⇒ lft | rgt) 5.7 in 4.9 in 3.1 in 35.5 oz 1840 YES 2017 3,299 latest check
Sony A9 (⇒ lft | rgt) 5.0 in 3.8 in 2.5 in 23.7 oz 650 YES 2017 4,499 latest check
Sony A99 II (⇒ lft | rgt) 5.6 in 4.1 in 3.0 in 29.9 oz 490 YES 2016 3,199 latest check
Sony A7R II (⇒ lft | rgt) 5.0 in 3.8 in 2.4 in 22.0 oz 290 YES 2015 3,199discont. check
Sony A7S II (⇒ lft | rgt) 5.0 in 3.8 in 2.4 in 22.1 oz 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 A7R III was somewhat cheaper (by 9 percent) than the 5D Mark III at launch, but both cameras fall into the same price category. 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. All other things equal, a large sensor will have larger individual pixel-units that offer better low-light sensitivity, wider dynamic range, and 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 are more costly to manufacture and tent to lead to bigger and heavier cameras and lenses.

Both cameras under consideration feature a full frame sensor, but their sensors differ slightly in size. They nevertheless have the same format factor of 1.0. Both cameras have a native aspect ratio (sensor width to sensor height) of 3:2.

Canon 5D Mark III and Sony A7R III sensor measures
Sensor size

Despite having a slightly smaller sensor, the A7R III offers a higher resolution of 42.2 megapixel, compared with 22.1 MP of the 5D Mark III. This megapixel advantage comes at the cost of a higher pixel density and a smaller size of the individual pixel (with a pixel pitch of 4.52μm versus 6.25μm for the 5D Mark III). However, it should be noted that the A7R III is much more recent (by 5 years and 7 months) than the 5D Mark III, and its sensor will have benefitted from technological advances during this time that make it possible to gather light more efficiently. 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 5D Mark III, 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).

5D Mark III versus A7R III MP
Sensor resolution

Consistent information on actual sensor performance is available from DXO Mark for most cameras. 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 table below summarizes the physical sensor characteristics and sensor quality findings and compares them across a set of similar cameras.

Sensor Characteristics
Camera Sensor
Class
Resolution
(Megapixel)
Horiz.
Pixels
Vert.
Pixels
Video
Format
DXO
Portrait
DXO
Landscape
DXO
Sports
DXO
Overall
Canon 5D Mark III (⇒ rgt) Full Frame 22.1 5760 3840 1080/30p 24 11.7 2293 81
Sony A7R III (⇒ lft) Full Frame 42.2 7952 5304 4K/30p .. .. .. ..
Canon 6D Mark II (⇒ lft | rgt) Full Frame 26.0 6240 4160 1080/60p 24.4 11.9 2862 85
Canon 5D Mark IV (⇒ lft | rgt) Full Frame 30.1 6720 4480 4K/30p 24.8 13.6 2995 91
Canon 1D X Mark II (⇒ lft | rgt) Full Frame 20.0 5472 3648 4K/60p 24.1 13.5 3207 88
Canon 5DS R (⇒ lft | rgt) Full Frame 50.3 8688 5792 1080/60p 24.6 12.4 2308 86
Canon 5DS (⇒ lft | rgt) Full Frame 50.3 8688 5792 1080/60p 24.7 12.4 2381 87
Canon 70D (⇒ lft | rgt) APS-C 20.0 5472 3648 1080/30p 22.5 11.6 926 68
Canon 6D (⇒ lft | rgt) Full Frame 20.0 5472 3648 1080/30p 23.8 12.1 2340 82
Canon 1D X (⇒ lft | rgt) Full Frame 17.9 5184 3456 1080/30p 23.8 11.8 2786 82
Canon 5D Mark II (⇒ lft | rgt) Full Frame 21.0 5616 3744 1080/30p 23.7 11.9 1815 79
Canon 5D (⇒ lft | rgt) Full Frame 12.7 4368 2912 no 22.9 11.1 1368 71
Nikon D850 (⇒ lft | rgt) Full Frame 45.4 8256 5504 4K/30p 26.4 14.8 2660 100
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 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 A7R III provides a better video resolution than the 5D Mark III. It can shoot movie footage at 4K/30p, while the Canon is limited to 1080/30p.

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), while the 5D Mark III has an optical one. Both systems have their advantages, with the electronic viewfinder making it possible to project supplementary shooting information into the framing view, whereas the optical viewfinder offers lag-free viewing and a very clear framing image. The adjacent table lists some of the other core features of the Canon 5D Mark III and Sony A7R III along with similar information for a selection of comparators. 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
Canon 5D Mark III (⇒ rgt) optical YES 3.2 1040 fixed no 8000 6.0 no no
Sony A7R III (⇒ lft) 3686 no 3.0 1440 tilting YES 8000 10.0 no YES
Canon 6D Mark II (⇒ lft | rgt) optical YES 3.0 1040 swivel YES 4000 6.5 no no
Canon 5D Mark IV (⇒ lft | rgt) optical YES 3.2 1620 fixed YES 8000 7.0 no no
Canon 1D X Mark II (⇒ lft | rgt) optical YES 3.2 1620 fixed YES 8000 16.0 no no
Canon 5DS R (⇒ lft | rgt) optical YES 3.2 1040 fixed no 8000 5.0 no no
Canon 5DS (⇒ lft | rgt) optical YES 3.2 1040 fixed no 8000 5.0 no no
Canon 70D (⇒ lft | rgt) optical YES 3.0 1040 swivel YES 8000 7.0 12 no
Canon 6D (⇒ lft | rgt) optical YES 3.0 1040 fixed no 4000 4.5 no no
Canon 1D X (⇒ lft | rgt) optical YES 3.2 1040 fixed no 8000 14.0 no no
Canon 5D Mark II (⇒ lft | rgt) optical YES 3.0 920 fixed no 8000 3.9 no no
Canon 5D (⇒ lft | rgt) optical YES 2.5 230 fixed no 8000 3.0 no no
Nikon D850 (⇒ lft | rgt) optical YES 3.2 2359 tilting YES 8000 9.0 no no
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 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

The A7R III is a current model that online retailers, such as amazon, will have in stock. In contrast, the 5D Mark III has been discontinued (but it can be found pre-owned on ebay). As a replacement in the same line of cameras, the 5D Mark III was succeeded by the Canon 5D Mark IV.

Summary

So what is the bottom line? Is the Canon 5D Mark III better than the Sony A7R III or vice versa? The listing below highlights the relative strengths of the two models.


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Arguments in favor of the Canon EOS 5D Mark III:

  • Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
  • Brighter framing: Features an optical viewfinder for clear, lag-free composition.
  • Easier setting verification: Has an LCD display on top to control shooting parameters.
  • Larger screen: Has a bigger rear LCD (3.2" vs 3.0") for image review and settings control.
  • Longer lasting: Can take more shots (950 versus 650) on a single battery charge.
  • More heavily discounted: Has been available for much longer (launched in March 2012).

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Reasons to prefer the Sony Alpha A7R III:

  • More detail: Has more megapixels (42.2 vs 22.1MP), which boosts linear resolution by 38%.
  • 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 video: Provides higher definition movie capture (4K/30p vs 1080/30p).
  • More framing info: Has an electronic viewfinder that displays shooting data.
  • More detailed LCD: Has a higher resolution rear screen (1440k vs 1040k dots).
  • More flexible LCD: Has a tilting screen for odd-angle shots in landscape orientation.
  • Fewer buttons to press: Has a touchscreen to facilitate handling and shooting adjustments.
  • Faster burst: Shoots at higher frequency (10 vs 6 flaps/sec) to capture the decisive moment.
  • More compact: Is smaller (127x96mm vs 152x116mm) and will fit more readily into a bag.
  • Less heavy: Has a lower weight (by 300g or 32 percent) and is thus easier to take along.
  • More legacy lens friendly: Can use many non-native lenses via adapters.
  • Sharper images: Has stabilization technology build-in to reduce the impact of hand-shake.
  • More modern: Reflects 5 years and 7 months of technical progress since the 5D Mark III launch.

If the number of relative strengths (bullet points above) is taken as a guide, the A7R III is the clear winner of the contest (14 : 6 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.

5D Mark III 06:14 A7R III

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 5D Mark III 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 why expert reviews are important. The table below summarizes the assessments of some of the best known 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)
Canon 5D Mark III (⇒ rgt) HiRec 82/100 Gold 4.5/5 5/5 4.5/5 2012 3,499discont. check
Sony A7R III (⇒ lft) .. .. .. .. .. 2017 3,199 latest check
Canon 6D Mark II (⇒ lft | rgt) Rec 80/100 4.5/5 4/5 4/5 2017 1,999 latest check
Canon 5D Mark IV (⇒ lft | rgt) HiRec 87/100 Gold 4.5/5 5/5 4.5/5 2016 3,499 latest check
Canon 1D X Mark II (⇒ lft | rgt) - 89/100 Gold 4.5/5 5/5 4.5/5 2016 5,999 latest check
Canon 5DS R (⇒ lft | rgt) Rec 83/100 Silver 5/5 5/5 4.5/5 2015 3,699 latest check
Canon 5DS (⇒ lft | rgt) Rec 83/100 Silver 4.5/5 5/5 4.5/5 2015 3,699 latest check
Canon 70D (⇒ lft | rgt) HiRec 83/100 Gold 4.5/5 4.5/5 5/5 2013 1,199discont. check
Canon 6D (⇒ lft | rgt) HiRec 83/100 Silver 4.5/5 4.5/5 4.5/5 2012 2,099discont. check
Canon 1D X (⇒ lft | rgt) - - 4.5/5 4.5/5 4.5/5 2011 6,799discont. check
Canon 5D Mark II (⇒ lft | rgt) 91/100 79/100 HiRec 4/5 5/5 - 2008 3,499discont. check
Canon 5D (⇒ lft | rgt) 88/100 HiRec reviewed reviewed - 2005 3,299discont. check
Nikon D850 (⇒ lft | rgt) .. 89/100 Gold 4.5/5 .. 5/5 2017 3,299 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 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

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. 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 comparisons

In case you would like to check on the differences and similarities of other camera models, just make your choice using the following search menu. There is also a set of direct links to comparison reviews that other users of the CAM-parator app explored. If the camera you are interested in is not available, please contact me, and I will try to add information on that model to the database.

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