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Sony A7R III versus Sony RX100 III

The Sony Alpha A7R III and the Sony Cyber-shot DSC-RX100 III are two digital cameras that were announced, respectively, in October 2017 and May 2014. The A7R III is a mirrorless interchangeable lens camera, while the RX100 III 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 RX100 III provides 20 MP.

Body comparison

The side-by-side display below illustrates the physical size and weight of the Sony A7R III and the Sony RX100 III. 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 – the A7R III – represents the basis or 100 percent across all the size and weight measures).

Sony A7R III vs Sony RX100 III front
A7R III versus RX100 III top view
A7R III and RX100 III 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 RX100 III is notably smaller (31 percent) than the Sony A7R III. It is worth mentioning in this context that the A7R III is splash and dust resistant, while the RX100 III does not feature any corresponding weather-sealing.

The above size and weight comparisons are to some extent incomplete and possibly misleading, as the RX100 III 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
Sony RX100 III (⇒ lft) 102 mm 58 mm 41 mm 290 g 320 no 2014 799discont. 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
Panasonic FZ1000 (⇒ lft | rgt) 137 mm 99 mm 131 mm 831 g 360 no 2014 899discont. 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 RX100 IV (⇒ lft | rgt) 102 mm 58 mm 41 mm 298 g 280 no 2015 999discont. 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 RX100 II (⇒ lft | rgt) 102 mm 58 mm 38 mm 281 g 350 no 2013 749discont. 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 RX100 III 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 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. 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 are more costly to manufacture and tent to 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 Sony RX100 III an one-inch sensor. The sensor area in the RX100 III 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 RX100 III sensor measures
Sensor size

With 42.2MP, the A7R III offers a higher resolution than the RX100 III (20MP), but the A7R III nevertheless has larger individual pixels (pixel pitch of 4.52μm versus 2.41μm for the RX100 III) due to its larger sensor. Moreover, the A7R III is a somewhat more recent model (by 3 years and 5 months) than the RX100 III, 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 RX100 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).

A7R III versus RX100 III MP
Sensor resolution

For most cameras, data on sensor performance has been reported by DXO Mark. 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. Of the two cameras under review, the A7R III provides substantially higher image quality than the RX100 III, with an overall score that is 33 points higher. This advantage is based on 3.6 bits higher color depth, 2.4 EV in additional dynamic range, and 2.8 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 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
Sony RX100 III (⇒ lft) 1-inch 20.0 5472 3648 1080/60p 22.4 12.3 495 67
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
Panasonic FZ1000 (⇒ lft | rgt) 1-inch 20.0 5472 3648 4K/30p 22.1 11.7 517 64
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 RX100 IV (⇒ lft | rgt) 1-inch 20.0 5472 3648 4K/30p 22.8 12.6 591 70
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 RX100 II (⇒ lft | rgt) 1-inch 20.0 5472 3648 1080/60p 22.5 12.4 483 67
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 RX100 III. It can shoot video footage at 4K/30p, while the RX100 III is limited to 1080/60p.

Feature comparison

Apart from body and sensor, cameras can and do differ across a range 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 RX100 III (3686k vs 1440k dots). The following table reports on some other key feature differences and similarities of the Sony A7R III, the Sony RX100 III, and comparable 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 RX100 III (⇒ lft) 1440 no 3.0 1229 tilting no 2000 10.0 YES YES
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
Panasonic FZ1000 (⇒ lft | rgt) 2359 no 3.0 921 swivel no 4000 12.0 13.5 YES
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 RX100 IV (⇒ lft | rgt) 2359 no 3.0 1228 tilting no 2000 16.0 10.2 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 RX100 II (⇒ lft | rgt) no no 3.0 1229 tilting no 2000 10.0 15 YES
Sony A99 (⇒ lft | rgt) 2359 YES 3.0 1229 full-flex no 8000 6.0 no YES

The A7R III is a current model that online retailers, such as amazon, will have in stock. In contrast, the RX100 III has been discontinued (but it can be found pre-owned on ebay). As a replacement in the same line of cameras, the RX100 III was succeeded by the Sony RX100 IV.

Summary

So what is the bottom line? 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.


Arguments in favor 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 image quality: Scores substantially higher (33 points) in the DXO overall assessment.
  • Richer colors: Generates images with noticeably better colors (3.6 bits more color depth).
  • More dynamic range: Captures a larger spectrum of light and dark details (2.4 EV of extra DR).
  • Better low-light sensitivity: Requires less light for good images (2.8 stops ISO advantage).
  • Better video: Provides higher definition movie capture (4K/30p vs 1080/60p).
  • More detailed viewfinder: Has higher resolution electronic viewfinder (3686k vs 1440k dots).
  • More detailed LCD: Has a higher resolution rear screen (1440k vs 1229k dots).
  • Fewer buttons to press: Is equipped with a touch-sensitive rear screen to facilitate handling.
  • Faster shutter: Has 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 320) 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: Reflects 3 years and 5 months of technical progress since the RX100 III launch.

Reasons to prefer the Sony Cyber-shot DSC-RX100 III:

  • 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 (102x58mm 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 around for much longer (launched in May 2014).

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 (17 : 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 17:07 RX100 III

In any case, while the comparison of technical specifications can provide a useful overview of the capabilities of different cameras, it remains partial and cannot reveal, for example, the handling experience and imaging performance when actually working with the A7R III or the RX100 III. 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 table below summarizes the assessments of some of the best known 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) HiRec 90/100 Gold 4.5/5 5/5 5/5 2017 3,199 latest check
Sony RX100 III (⇒ lft) HiRec 82/100 Gold 4.5/5 4.5/5 5/5 2014 799discont. 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
Panasonic FZ1000 (⇒ lft | rgt) HiRec 82/100 Gold 4.5/5 4.5/5 4.5/5 2014 899discont. 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 RX100 IV (⇒ lft | rgt) HiRec 85/100 Gold 4/5 4.5/5 4.5/5 2015 999discont. 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 RX100 II (⇒ lft | rgt) HiRec 79/100 Silver 4.5/5 5/5 4.5/5 2013 749discont. check
Sony A99 (⇒ lft | rgt) - 84/100 Gold 4.5/5 reviewed 4.5/5 2012 2,799discont. check

The review scores listed above should be treated with care, though. The ratings are only valid when refering to cameras in the same category and of the same age. Thus, a score needs to be put into the context of the launch date and the launch price of the camera, and comparing ratings of very distinct cameras or ones that are far apart in terms of their release date have little meaning. 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 do not see the camera that you are looking for, please contact me, and I will try to update the database with the necessary infos.

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