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Sony A7R III versus Sony RX10 IV

The Sony Alpha A7R III and the Sony Cyber-shot DSC-RX10 IV are two enthusiast cameras that were announced, respectively, in October 2017 and September 2017. The A7R III is a mirrorless interchangeable lens camera, while the RX10 IV is a fixed lens compact. The cameras are based on a full frame (A7R III) and an one-inch sensor. The A7R III has a resolution of 42.2 megapixel, whereas the RX10 IV provides 20 MP.

Body comparison

An illustration of the physical size and weight of the Sony A7R III and the Sony RX10 IV is provided in the side-by-side display below. Three consecutive views from the front, the top, and the rear side are shown. All width, height and depth 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 A7R III – represents 100 percent across all the size and weight measures).

Sony A7R III vs Sony RX10 IV front
A7R III versus RX10 IV top view
A7R III and RX10 IV 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 Sony RX10 IV is somewhat larger (3 percent) than the Sony A7R 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 and possibly misleading, as the RX10 IV 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) 5.0 in 3.8 in 2.9 in 22.9 oz 650 YES 2017 3,199 latest check
Sony RX10 IV (⇒ lft) 5.2 in 3.7 in 5.7 in 38.6 oz 400 YES 2017 1,699 latest check
Fujifilm X-Pro2 (⇒ lft | rgt) 5.6 in 3.3 in 1.8 in 17.5 oz 350 YES 2016 1,699 latest check
Fujifilm X-T2 (⇒ lft | rgt) 5.2 in 3.6 in 1.9 in 17.9 oz 340 YES 2016 1,599 latest check
Nikon D850 (⇒ lft | rgt) 5.7 in 4.9 in 3.1 in 35.5 oz 1840 YES 2017 3,299 latest check
Nikon D500 (⇒ lft | rgt) 5.8 in 4.5 in 3.2 in 30.3 oz 1240 YES 2016 1,999 latest check
Pentax K-1 (⇒ lft | rgt) 5.4 in 4.3 in 3.4 in 35.6 oz 760 YES 2016 1,799 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 A6300 (⇒ lft | rgt) 4.7 in 2.6 in 1.9 in 14.3 oz 400 YES 2016 999discont. check
Sony A6500 (⇒ lft | rgt) 4.7 in 2.6 in 2.1 in 16.0 oz 350 YES 2016 1,399 latest check
Sony RX10 III (⇒ lft | rgt) 5.2 in 3.7 in 5.0 in 37.1 oz 420 YES 2016 1,499discont. 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
Sony A7 II (⇒ lft | rgt) 5.0 in 3.8 in 2.4 in 21.1 oz 350 YES 2014 1,999 latest check
Sony A7R (⇒ lft | rgt) 5.0 in 3.7 in 1.9 in 16.4 oz 340 YES 2013 2,299discont. check
Sony A99 (⇒ lft | rgt) 5.8 in 4.4 in 3.1 in 28.6 oz 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 RX10 IV 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 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. 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.

Of the two cameras under consideration, the Sony A7R III features a full frame sensor and the Sony RX10 IV an one-inch sensor. The sensor area in the RX10 IV 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 Sony RX10 IV sensor measures
Sensor size

With 42.2MP, the A7R III offers a higher resolution than the RX10 IV (20MP), but the A7R III nevertheless has larger individual pixels (pixel pitch of 4.52μm versus 2.41μm for the RX10 IV) 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 the A7R III has no anti-alias filter installed, so that it can capture all the detail its sensor resolves.

Unlike the RX10 IV, 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 RX10 IV MP
Sensor resolution

Since 2007, DXO Mark has published sensor performance measurements that have been derived using a consistent methodology. 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. 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 .. .. .. ..
Sony RX10 IV (⇒ lft) 1-inch 20.0 5472 3648 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
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 A6300 (⇒ lft | rgt) APS-C 24.0 6000 4000 4K/30p 24.4 13.7 1437 85
Sony A6500 (⇒ lft | rgt) APS-C 24.0 6000 4000 4K/30p 24.5 13.7 1405 85
Sony RX10 III (⇒ lft | rgt) 1-inch 20.0 5472 3648 4K/30p 23.1 12.6 472 70
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, and both provide the same movie specifications (4K/30p).

Feature comparison

Apart from body and sensor, cameras can and do differ across a variety of features. The two cameras under consideration are similar with respect to both having an electronic viewfinder. However, the one in the A7R III offers a substantially higher resolution than the one in the RX10 IV (3686k vs 2359k dots). The table below summarizes some of the other core capabilities of the Sony A7R III and Sony RX10 IV 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
Sony A7R III (⇒ rgt) 3686 no 3.0 1440 tilting YES 8000 10.0 no YES
Sony RX10 IV (⇒ lft) 2359 YES 3.0 1440 tilting YES 2000 24.0 10.8 no
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
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 A6300 (⇒ lft | rgt) 2300 no 3.0 922 tilting no 4000 11.0 6 no
Sony A6500 (⇒ lft | rgt) 2300 no 3.0 922 tilting YES 4000 11.0 6 YES
Sony RX10 III (⇒ lft | rgt) 2359 YES 3.0 1229 tilting no 2000 14.0 10.8 no
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 RX10 IV are current models that good online retailers will have in stock. You can check the latest prices, for example, at amazon. The RX10 IV replaced the earlier Sony RX10 III, while the A7R III followed on from the Sony A7R II.

Summary

So what conclusions can be drawn? Is there a clear favorite between the Sony A7R III and the Sony A7R III? The listing below highlights the relative strengths of the two models.


Advantages of 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 low-light imaging: Features bigger pixels on a larger sensor for better high-ISO images.
  • More detailed viewfinder: Has a higher resolution electronic viewfinder (3686k vs 2359k dots).
  • Faster shutter: Has a higher mechanical shutter speed (8000/sec vs 2000/sec) to freeze action.
  • More flexible: Accepts interchangeable lenses, so that lens characteristics can be altered.
  • Longer lasting: Can take more shots (650 versus 400) on a single battery charge.
  • Sharper images: Has hand-shake reducing image stabilization build-in.

Arguments in favor of the Sony Cyber-shot DSC-RX10 IV:

  • Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
  • Easier setting verification: Has a control panel on top to check shooting parameters.
  • Faster burst: Shoots at higher frequency (24 vs 10 flaps/sec) to capture the decisive moment.
  • Ready to shoot: Has an integrated lens, whereas the A7R III necessitates an extra lens.
  • 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.

If the number of relative strengths (bullet points above) is taken as a guide, the A7R III emerges as the winner of the contest (9 : 6 points). However, the relevance of individual strengths will vary across photographers, so that you might want to apply your own weighing scheme to the summary points.

A7R III 09:06 RX10 IV

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 A7R III and the RX10 IV in practical situations. 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. This is where reviews by experts come in. The following table reports the overall rankings of the cameras as published by some of the major camera review sites. The full reviews are available, 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) .. .. .. .. .. 2017 3,199 latest check
Sony RX10 IV (⇒ lft) Rec 84/100 Gold 4.5/5 .. .. 2017 1,699 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
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 A6300 (⇒ lft | rgt) Rec 85/100 Gold 5/5 5/5 5/5 2016 999discont. check
Sony A6500 (⇒ lft | rgt) HiRec 85/100 Silver 4.5/5 5/5 4.5/5 2016 1,399 latest check
Sony RX10 III (⇒ lft | rgt) Rec 84/100 Silver 4.5/5 4.5/5 4.5/5 2016 1,499discont. 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. 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. Also, please note that some of the review sites have changed their methodology and reporting over time.

Other comparisons

If you would like to see a different side-by-side camera review, just make your choice using the following search menu. Alternatively, you can follow any of the listed hyperlinks for comparisons that others found interesting. If the camera you are interested in is not available, please contact me, and I will try to locate and add the respective data to the application.

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