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Nikon D7100 versus Sony A7R III

The Nikon D7100 and the Sony Alpha A7R III are two enthusiast cameras that were revealed to the public, respectively, in February 2013 and October 2017. The D7100 is a DSLR, while the A7R III is a mirrorless interchangeable lens camera. The cameras are based on an APS-C (D7100) and a full frame sensor. The Nikon has a resolution of 24 megapixel, whereas the Sony provides 42.2 MP.

Body comparison

The side-by-side display below illustrates the physical size and weight of the Nikon D7100 and the Sony A7R III. 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. 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 D7100 – represents the basis for the calculations across all the size and weight measures).

Nikon D7100 vs Sony A7R III front
D7100 versus A7R III top view
D7100 and A7R III rear side
Body view (D7100 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 (16 percent) than the Nikon D7100. Moreover, the A7R III is markedly lighter (15 percent) than the D7100. 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 Nikon Lens Catalog (D7100) 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)
Nikon D7100 (⇒ rgt) 136 mm 107 mm 76 mm 765 g 950 YES 2013 1,199discont. check
Sony A7R III (⇒ lft) 127 mm 96 mm 74 mm 650 g 650 YES 2017 3,199 latest check
Canon 70D (⇒ lft | rgt) 139 mm 104 mm 79 mm 755 g 920 YES 2013 1,199discont. check
Nikon D7500 (⇒ lft | rgt) 136 mm 104 mm 73 mm 720 g 950 YES 2017 1,299 latest check
Nikon D500 (⇒ lft | rgt) 147 mm 115 mm 81 mm 860 g 1240 YES 2016 1,999 latest check
Nikon D7200 (⇒ lft | rgt) 136 mm 107 mm 76 mm 765 g 1110 YES 2015 1,199discont. check
Nikon D3300 (⇒ lft | rgt) 124 mm 98 mm 76 mm 430 g 700 no 2014 499discont. check
Nikon D750 (⇒ lft | rgt) 141 mm 113 mm 78 mm 750 g 1230 YES 2014 2,299 latest check
Nikon D610 (⇒ lft | rgt) 141 mm 113 mm 82 mm 850 g 900 YES 2013 1,999 latest check
Nikon D600 (⇒ lft | rgt) 141 mm 113 mm 82 mm 850 g 900 YES 2012 2,099discont. check
Nikon D7000 (⇒ lft | rgt) 132 mm 105 mm 77 mm 780 g 1050 YES 2010 1,499discont. check
Sony A99 II (⇒ lft | rgt) 143 mm 104 mm 76 mm 849 g 490 YES 2016 3,199 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 RX10 (⇒ lft | rgt) 129 mm 88 mm 102 mm 813 g 420 YES 2013 1,299discont. check

The listed prices provide an indication of the market segment that the manufacturer of the cameras have been targeting. The D7100 was launched at a markedly lower price (by 63 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 size of the imaging sensor is a crucial determinant 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. 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 more expensive and lead to bigger and heavier cameras and lenses.

Of the two cameras under consideration, the Nikon D7100 features an APS-C sensor and the Sony A7R III a full frame sensor. The sensor area in the A7R III is 135 percent bigger. As a result of these sensor size differences, the cameras have a format factor of, respectively, 1.5 and 1.0. Both cameras have a native aspect ratio (sensor width to sensor height) of 3:2.

Nikon D7100 and Sony A7R III sensor measures
Sensor size

With 42.2MP, the A7R III offers a higher resolution than the D7100 (24MP), but the A7R III nevertheless has larger individual pixels (pixel pitch of 4.52μm versus 3.91μm for the D7100) due to its larger sensor. Moreover, the A7R III is a much more recent model (by 4 years and 8 months) than the D7100, and its sensor will have benefitted from technological advances during this time that further enhance the light gathering capacity of its pixel-units. 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.

Unlike the D7100, 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).

D7100 versus A7R III MP
Sensor resolution

Consistent information on actual sensor performance is available from DXO Mark for most cameras. This service is based on lab testing and assigns an overall score to each camera sensor, as well as ratings for dynamic range ("DXO Landscape"), color depth ("DXO Portrait"), and low-light sensitivity ("DXO Sports"). Of the two cameras under consideration, the A7R III offers substantially better image quality than the D7100 (overall score 17 points higher). The advantage is based on 1.8 bits higher color depth, 1 EV in additional dynamic range, and 1.5 stops in additional low light sensitivity. The adjacent table reports on the physical sensor characteristics and the outcomes of the DXO sensor quality tests for a sample of comparator-cameras.

Sensor Characteristics
Camera Sensor
Class
Resolution
(Megapixel)
Horiz.
Pixels
Vert.
Pixels
Video
Format
DXO
Portrait
DXO
Landscape
DXO
Sports
DXO
Overall
Nikon D7100 (⇒ rgt) APS-C 24.0 6000 4000 1080/60p 24.2 13.7 1256 83
Sony A7R III (⇒ lft) Full Frame 42.2 7952 5304 4K/30p 26.0 14.7 3523 100
Canon 70D (⇒ lft | rgt) APS-C 20.0 5472 3648 1080/30p 22.5 11.6 926 68
Nikon D7500 (⇒ lft | rgt) APS-C 20.7 5568 3712 4K/30p 24.8 13.9 1192 86
Nikon D500 (⇒ lft | rgt) APS-C 20.7 5568 3712 4K/30p 24.0 14.0 1324 83
Nikon D7200 (⇒ lft | rgt) APS-C 24.0 6000 4000 1080/60p 24.5 14.6 1333 87
Nikon D3300 (⇒ lft | rgt) APS-C 24.0 6000 4000 1080/60p 24.3 12.8 1385 82
Nikon D750 (⇒ lft | rgt) Full Frame 24.2 6016 4016 1080/60p 24.8 14.5 2956 93
Nikon D610 (⇒ lft | rgt) Full Frame 24.2 6016 4016 1080/30p 25.1 14.4 2925 94
Nikon D600 (⇒ lft | rgt) Full Frame 24.2 6016 4016 1080/30p 25.1 14.2 2980 94
Nikon D7000 (⇒ lft | rgt) APS-C 16.1 4928 3264 10800/24p 23.5 13.9 1167 80
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
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 RX10 (⇒ lft | rgt) 1-inch 20.0 5472 3648 1080/60p 22.9 12.6 474 69

Many modern cameras are not only capable of taking still images, but can also record movies. The two cameras under consideration both have sensors whose read-out speed is fast enough to capture moving pictures, but the A7R III provides a better video resolution than the D7100. It can shoot movie footage at 4K/30p, while the Nikon is limited to 1080/60p.

Feature comparison

Apart from body and sensor, cameras can and do differ across a range of features. For example, the A7R III has an electronic viewfinder (3686k dots), while the D7100 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 Nikon D7100 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
Nikon D7100 (⇒ rgt) optical YES 3.2 1229 fixed no 8000 6.0 12 no
Sony A7R III (⇒ lft) 3686 no 3.0 1440 tilting YES 8000 10.0 no YES
Canon 70D (⇒ lft | rgt) optical YES 3.0 1040 swivel YES 8000 7.0 12 no
Nikon D7500 (⇒ lft | rgt) optical YES 3.2 922 tilting YES 8000 8.0 12 no
Nikon D500 (⇒ lft | rgt) optical YES 3.2 2359 tilting YES 8000 10.0 no no
Nikon D7200 (⇒ lft | rgt) optical YES 3.2 1229 fixed no 8000 6.0 12 no
Nikon D3300 (⇒ lft | rgt) optical no 3.0 921 fixed no 4000 5.0 12 no
Nikon D750 (⇒ lft | rgt) optical YES 3.2 1229 tilting no 4000 6.0 12 no
Nikon D610 (⇒ lft | rgt) optical YES 3.2 921 fixed no 4000 6.0 12 no
Nikon D600 (⇒ lft | rgt) optical YES 3.0 921 fixed no 4000 5.5 12 no
Nikon D7000 (⇒ lft | rgt) optical YES 3.0 921 fixed no 8000 6.0 12 no
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
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 RX10 (⇒ lft | rgt) 1440 YES 3.0 1229 tilting no 3200 10.0 10.2 YES

The A7R III is a current model that online retailers, such as amazon, will have in stock. In contrast, the D7100 has been discontinued (but it can be found pre-owned on ebay). As a replacement in the same line of cameras, the D7100 was succeeded by the Nikon D7200.

Summary

So what conclusions can be drawn? Is the Nikon D7100 better than the Sony A7R III or vice versa? A synthesis of the relative strong points of each of the models is listed below.


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Advantages of the Nikon D7100:

  • 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.
  • Easier fill-in: Is equipped with a small onboard flash to brighten deep shadow areas.
  • More affordable: Was introduced into a lower priced category (63 percent cheaper at launch).
  • More heavily discounted: Has been available for much longer (launched in February 2013).

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Arguments in favor of the Sony Alpha A7R III:

  • More detail: Has more megapixels (42.2 vs 24MP), which boosts linear resolution by 33%.
  • High quality composites: Can combine several shots after pixel-shifting its sensor.
  • Better image quality: Scores substantially higher (17 points) in the DXO overall evaluation.
  • Richer colors: Generates noticeably more natural colors (1.8 bits more color depth).
  • More dynamic range: Captures a broader range of light and dark details (1 EV of extra DR).
  • Better low-light sensitivity: Can shoot in dim conditions (1.5 stops ISO advantage).
  • Better video: Provides higher definition movie capture (4K/30p vs 1080/60p).
  • More framing info: Has an electronic viewfinder that displays shooting data.
  • More detailed LCD: Has a higher resolution rear screen (1440k vs 1229k 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 136x107mm) and will fit more readily into a bag.
  • Less heavy: Has a lower weight (by 115g or 15 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 4 years and 8 months of technical progress since the D7100 launch.

If the count of individual advantages (bullet points above) is taken as a guide, the A7R III is the clear winner of the contest (17 : 7 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.

D7100 07:17 A7R III

In any case, while the comparison of the spec-sheets of cameras can offer a general idea of their imaging potential, it remains incomplete and does no justice, for example, to the way the D7100 or the A7R III handle or perform in practice. 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 following table reports the overall rankings of the cameras as published by some of the major 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)
Nikon D7100 (⇒ rgt) HiRec 85/100 Gold 4.5/5 5/5 4.5/5 2013 1,199discont. check
Sony A7R III (⇒ lft) HiRec 90/100 Gold .. .. .. 2017 3,199 latest check
Canon 70D (⇒ lft | rgt) HiRec 83/100 Gold 4.5/5 4.5/5 5/5 2013 1,199discont. check
Nikon D7500 (⇒ lft | rgt) HiRec 86/100 Silver 5/5 4.5/5 4.5/5 2017 1,299 latest check
Nikon D500 (⇒ lft | rgt) HiRec 91/100 Gold 4.5/5 5/5 5/5 2016 1,999 latest check
Nikon D7200 (⇒ lft | rgt) HiRec 84/100 Silver 4.5/5 4/5 4.5/5 2015 1,199discont. check
Nikon D3300 (⇒ lft | rgt) Rec 77/100 Silver 4.5/5 4.5/5 4.5/5 2014 499discont. check
Nikon D750 (⇒ lft | rgt) HiRec 90/100 Gold 4.5/5 5/5 4.5/5 2014 2,299 latest check
Nikon D610 (⇒ lft | rgt) HiRec 87/100 Gold 4.5/5 4.5/5 4.5/5 2013 1,999 latest check
Nikon D600 (⇒ lft | rgt) HiRec 87/100 Gold 5/5 4.5/5 4.5/5 2012 2,099discont. check
Nikon D7000 (⇒ lft | rgt) - 80/100 Silver 4.5/5 5/5 4.5/5 2010 1,499discont. 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
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 RX10 (⇒ lft | rgt) Rec 80/100 Gold 4.5/5 4.5/5 4.5/5 2013 1,299discont. 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 rating-comparisons among cameras that span long time periods or concern very differently equipped models make little sense. 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. Alternatively, you can follow any of the listed hyperlinks for comparisons that others found interesting. If you cannot find the camera you are interested in, please send me an email, and I will try to locate and add the respective data to the application.

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