Sony A5100 vs A7R III
The Sony Alpha A5100 and the Sony Alpha A7R III are two digital cameras that were revealed to the public, respectively, in August 2014 and October 2017. Both the A5100 and the A7R III are mirrorless interchangeable lens cameras that are based on an APS-C (A5100) and a full frame (A7R III) sensor. The A5100 has a resolution of 24 megapixels, whereas the A7R III provides 42.2 MP.
Below is an overview of the main specs of the two cameras as a starting point for the comparison.
Going beyond this snapshot of core features and characteristics, what are the differences between the Sony Alpha A5100 and the Sony Alpha A7R III? Which one should you buy? Read on to find out how these two cameras compare with respect to their body size, their imaging sensors, their shooting features, their input-output connections, and their reception by expert reviewers.
The physical size and weight of the Sony A5100 and the Sony A7R III are illustrated in the side-by-side display below. The two cameras are presented according to their relative size. Three consecutive perspectives from the front, the top, and the back are available. All width, height and depth measures are rounded to the nearest millimeter.
The A5100 can be obtained in two different colors (black, white), while the A7R III is only available in black.
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 considerably larger (76 percent) than the Sony A5100. Moreover, the A7R III is substantially heavier (130 percent) than the A5100. It is noteworthy in this context that the A7R III is splash and dust-proof, while the A5100 does not feature any corresponding weather-sealing.
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 compare the optics available for the two cameras in the Sony E-Mount Lens Catalog (A5100) and the Sony FE Lens Catalog (A7R III). Mirrorless cameras, such as the two under consideration, have the additional advantage of having a short flange to focal plane distance, which makes it possible to mount many lenses from other systems onto the camera via adapters.
Concerning battery life, the A5100 gets 400 shots out of its NP-FW50 battery, while the A7R III can take 650 images on a single charge of its NP-FZ100 power pack. The battery packs of both cameras can be charged via USB, which can be very convenient when travelling.
The table below summarizes the key physical specs of the two cameras alongside a broader set of comparators. If you would like to visualize and compare a different camera combination, you can navigate to the CAM-parator app and make your selection from a broad list of cameras there.
|1.||Sony A5100||110 mm||63 mm||36 mm||283 g||400||n||Aug 2014||549|
|2.||Sony A7R III||127 mm||96 mm||74 mm||650 g||650||Y||Oct 2017||3,199|
|3.||Sony A7 III||127 mm||96 mm||74 mm||650 g||610||Y||Feb 2018||1,999|
|4.||Sony A9||127 mm||96 mm||63 mm||673 g||650||Y||Apr 2017||4,499|
|5.||Sony A99 II||143 mm||104 mm||76 mm||849 g||490||Y||Sep 2016||3,199|
|6.||Sony A7R II||127 mm||96 mm||60 mm||625 g||290||Y||Jun 2015||3,199|
|7.||Sony A7S II||127 mm||96 mm||60 mm||627 g||370||Y||Sep 2015||2,999|
|8.||Sony RX100 IV||102 mm||58 mm||41 mm||298 g||280||n||Jun 2015||999|
|9.||Sony A5000||110 mm||63 mm||36 mm||269 g||420||n||Jan 2014||449|
|10.||Sony A6000||120 mm||67 mm||45 mm||344 g||360||n||Feb 2014||599|
|11.||Sony RX100 III||102 mm||58 mm||41 mm||290 g||320||n||May 2014||799|
|12.||Sony A3000||128 mm||91 mm||85 mm||411 g||470||n||Aug 2013||329|
|13.||Sony NEX-3N||110 mm||62 mm||35 mm||269 g||480||n||Feb 2013||499|
|14.||Sony RX100 II||102 mm||58 mm||38 mm||281 g||350||n||Jun 2013||749|
|15.||Sony NEX-F3||117 mm||67 mm||42 mm||314 g||470||n||May 2012||599|
|16.||Sony RX100||102 mm||58 mm||36 mm||240 g||330||n||Jun 2012||649|
|17.||Sony NEX-3||117 mm||62 mm||33 mm||297 g||330||n||May 2010||599|
|Notes: Measurements and pricing do not include easily detachable parts, such as add-on or interchangeable lenses or optional viewfinders.|
Any camera decision will obviously take relative prices into account. The retail prices at the time of the camera’s release place the model in the market relative to other models in the producer’s line-up and the competition. The A5100 was launched at a markedly lower price (by 83 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.
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 tend to be associated with larger, more expensive camera bodies and lenses.
Of the two cameras under consideration, the Sony A5100 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.
With 42.2MP, the A7R III offers a higher resolution than the A5100 (24MP), but the A7R III nevertheless has larger individual pixels (pixel pitch of 4.52μm versus 3.91μm for the A5100) due to its larger sensor. Moreover, the A7R III is a much more recent model (by 3 years and 2 months) than the A5100, 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 the A7R III has no anti-alias filter installed, so that it can capture all the detail its sensor resolves.
The resolution advantage of the Sony A7R III implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the A7R III for good quality output (200 dots per inch) amounts to 39.8 x 26.5 inches or 101 x 67.4 cm, for very good quality (250 dpi) 31.8 x 21.2 inches or 80.8 x 53.9 cm, and for excellent quality (300 dpi) 26.5 x 17.7 inches or 67.3 x 44.9 cm. The corresponding values for the Sony A5100 are 30 x 20 inches or 76.2 x 50.8 cm for good quality, 24 x 16 inches or 61 x 40.6 cm for very good quality, and 20 x 13.3 inches or 50.8 x 33.9 cm for excellent quality prints.
Unlike the A5100, 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).
The Sony Alpha A5100 has a native sensitivity range from ISO 100 to ISO 25600. The corresponding ISO settings for the Sony Alpha A7R III are ISO 100 to ISO 32000, with the possibility to increase the ISO range to 50-102400.
Consistent information on actual sensor performance is available from DXO Mark for many cameras. 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 consideration, the A7R III offers substantially better image quality than the A5100 (overall score 20 points higher). The advantage is based on 2.2 bits higher color depth, 2 EV in additional dynamic range, and 1.4 stops in additional low light sensitivity. The following table provides an overview of the physical sensor characteristics, as well as the sensor quality measurements for a selection of comparators.
| DXO |
|2.||Sony A7R III||Full Frame||42.2||7952||5304||4K/30p||26.0||14.7||3523||100|
|3.||Sony A7 III||Full Frame||24.0||6000||4000||4K/30p||25.0||14.7||3730||96|
|4.||Sony A9||Full Frame||24.0||6000||4000||4K/30p||24.9||13.3||3517||92|
|5.||Sony A99 II||Full Frame||42.2||7952||5304||4K/30p||25.4||13.4||2317||92|
|6.||Sony A7R II||Full Frame||42.2||7952||5304||4K/30p||26.0||13.9||3434||98|
|7.||Sony A7S II||Full Frame||12.0||4240||2832||4K/30p||23.6||13.3||2993||85|
|8.||Sony RX100 IV||1-inch||20.0||5472||3648||4K/30p||22.8||12.6||591||70|
|11.||Sony RX100 III||1-inch||20.0||5472||3648||1080/60p||22.4||12.3||495||67|
|14.||Sony RX100 II||1-inch||20.0||5472||3648||1080/60p||22.5||12.4||483||67|
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 A5100. It can shoot movie footage at 4K/30p, while the A5100 is limited to 1080/60p.
Beyond body and sensor, cameras can and do differ across a range 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 A5100 relies on live view and the rear LCD for framing. The following table reports on some other key feature differences and similarities of the Sony A5100, the Sony A7R III, and comparable cameras.
|2.||Sony A7R III||3686||n||3.0||1440||tilting||Y||1/8000s||10.0||n||Y|
|3.||Sony A7 III||2359||n||3.0||922||tilting||Y||1/8000s||10.0||n||Y|
|5.||Sony A99 II||2400||Y||3.0||1229||full-flex||n||1/8000s||12.0||n||Y|
|6.||Sony A7R II||2400||n||3.0||1229||tilting||n||1/8000s||5.0||n||Y|
|7.||Sony A7S II||2400||n||3.0||1229||tilting||n||1/8000s||5.0||n||Y|
|8.||Sony RX100 IV||2359||n||3.0||1228||tilting||n||1/2000s||16.0||Y||Y|
|11.||Sony RX100 III||1440||n||3.0||1229||tilting||n||1/2000s||10.0||Y||Y|
|14.||Sony RX100 II||optional||n||3.0||1229||tilting||n||1/2000s||10.0||Y||Y|
One difference between the cameras concerns the presence of an on-board flash. The A5100 has one, while the A7R III does not. While the built-in flash of the A5100 is not very powerful, it can at times be useful as a fill-in light.The A5100 has an articulated LCD that can be turned to be front-facing. This characteristic will be appreciated by vloggers and photographers who are interested in snapping selfies. In contrast, the A7R III does not have a selfie-screen.
The reported shutter speed information refers to the use of the mechanical shutter. Yet, some cameras only have an electronic shutter, while others have an electronic shutter in addition to a mechanical one. In fact, the A7R III is one of those camera that have an additional electronic shutter, which makes completely silent shooting possible. However, this mode is less suitable for photographing moving objects (risk of rolling shutter) or shooting under artificial light sources (risk of flickering).
The Sony A7R III has an intervalometer built-in. This enables the photographer to capture time lapse sequences, such as flower blooming, a sunset or moon rise, without purchasing an external camera trigger and related software.
Concerning the storage of imaging data, both the A5100 and the A7R III write their files to SDXC or Memory Stick PRO Duo cards. The A7R III features dual card slots, which can be very useful in case a memory card fails. In contrast, the A5100 only has one slot. The A7R III supports UHS-II cards (on its first slot), while the A5100 can use UHS-I cards.
For some imaging applications, the extent to which a camera can communicate with its environment can be an important aspect in the camera decision process. The table below provides an overview of the connectivity of the Sony Alpha A5100 and Sony Alpha A7R III and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.
| WiFi |
| NFC |
|2.||Sony A7R III||Y||stereo||mono||Y||Y||micro||3.1||Y||Y||Y|
|3.||Sony A7 III||Y||stereo||mono||Y||Y||micro||3.1||Y||Y||Y|
|5.||Sony A99 II||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||Y|
|6.||Sony A7R II||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||-|
|7.||Sony A7S II||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||-|
|8.||Sony RX100 IV||-||stereo||mono||-||-||micro||2.0||Y||Y||-|
|11.||Sony RX100 III||-||stereo||mono||-||-||micro||2.0||Y||Y||-|
|14.||Sony RX100 II||Y||stereo||mono||-||-||micro||2.0||Y||Y||-|
It is notable that the A7R III has a headphone jack, which makes it possible to attach external headphones and monitor the quality of sound during the recording process. The A5100 lacks such a headphone port.
Studio photographers will appreciate that the Sony A7R III (unlike the A5100) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.
The A5100 is a recent model that features in the current product line-up of Sony. In contrast, the A7R III has been discontinued (but can be found pre-owned on eBay). As a replacement in the same line of cameras, the A7R III was succeeded by the Sony A7R IV. Further information on the two cameras (e.g. user guides, manuals), as well as related accessories, can be found on the official Sony website.
So what conclusions can be drawn? Which of the two cameras – the Sony A5100 or the Sony A7R III – has the upper hand? Is one clearly better than the other? Below is a summary of the relative strengths of each of the two contestants.
Reasons to prefer the Sony Alpha A5100:
- Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
- More selfie-friendly: Has an articulated screen that can be turned to be front-facing.
- More compact: Is smaller (110x63mm vs 127x96mm) and thus needs less room in the bag.
- Less heavy: Is lighter (by 367g or 56 percent) and hence easier to carry around.
- Easier fill-in: Is equipped with a small onboard flash to brighten deep shadow areas.
- More affordable: Was introduced into a lower priced category (83 percent cheaper at launch).
- More heavily discounted: Has been available for much longer (launched in August 2014).
Arguments in favor of the Sony Alpha A7R III:
- More detail: Has more megapixels (42.2 vs 24MP), which boosts linear resolution by 33%.
- 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 (20 points) in the DXO overall evaluation.
- Richer colors: Generates noticeably more natural colors (2.2 bits more color depth).
- More dynamic range: Captures a broader range of light and dark details (2 EV of extra DR).
- Better low-light sensitivity: Can shoot in dim conditions (1.4 stops ISO advantage).
- Better video: Provides higher definition movie capture (4K/30p vs 1080/60p).
- Better sound: Can connect to an external microphone for higher quality sound recording.
- Better sound control: Has a headphone port that enables audio monitoring while recording.
- Easier framing: Has an electronic viewfinder for image composition and settings control.
- More detailed LCD: Has a higher resolution rear screen (1440k vs 922k dots).
- Faster shutter: Has higher mechanical shutter speed (1/8000s vs 1/4000s) to freeze action.
- Faster burst: Shoots at higher frequency (10 vs 6 flaps/sec) to capture the decisive moment.
- Less disturbing: Has an electronic shutter option for completely silent shooting.
- Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
- Longer lasting: Gets more shots (650 versus 400) out of a single battery charge.
- Better sealing: Is splash and dust sealed for shooting in inclement weather conditions.
- Sharper images: Has stabilization technology built-in to reduce the impact of hand-shake.
- Better lighting: Features a hotshoe and can thus hold and trigger an external flash gun.
- Faster data transfer: Supports a more advanced USB protocol (3.1 vs 2.0).
- Easier wireless transfer: Supports Bluetooth for image sharing without cables.
- Better studio light control: Has a PC Sync socket to connect to professional strobe lights.
- Greater peace of mind: Features a second card slot as a backup in case of memory card failure.
- Faster buffer clearing: Supports a more advanced SD data transfer standard (UHS-II vs UHS-I).
- More modern: Reflects 3 years and 2 months of technical progress since the A5100 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 (26 : 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 before making a decision on a new camera. A professional wildlife photographer will view the differences between cameras in a way that diverges from the perspective of a family photog, and a person interested in architecture has distinct needs from a sports shooter. Hence, the decision which camera is best and worth buying is often a very personal one.
How about other alternatives? Do the specifications of the Sony A5100 and the Sony A7R III place the cameras among the top in their class? Find out in the latest Best Mirrorless Interchangeable Lens Camera listing whether the two cameras rank among the cream of the crop.
In any case, while the specs-based evaluation of cameras can be instructive in revealing their potential as photographic tools, it remains partial and cannot reveal, for example, the shooting experience and imaging performance when actually working with the A5100 or the A7R III. User reviews that are available, for instance, at amazon can sometimes shed light on these issues, but such feedback is all too often partial, inconsistent, and inaccurate.
This is why expert reviews are important. The following table reports the overall ratings of the cameras as published by some of the major camera review sites (amateurphotographer [AP], cameralabs [CL], dpreview [DPR], ephotozine [EPZ], photographyblog [PB]). As can be seen, the professional reviewers agree in many cases on the quality of different cameras, but sometimes their assessments diverge, reinforcing the earlier point that a camera decision is often a very personal choice.
|1.||Sony A5100||4.5/5||+||..||4.5/5||5/5||Aug 2014||549|
|2.||Sony A7R III||..||+ +||90/100||4.5/5||5/5||Oct 2017||3,199|
|3.||Sony A7 III||..||+ +||89/100||5/5||5/5||Feb 2018||1,999|
|4.||Sony A9||5/5||+ +||89/100||5/5||5/5||Apr 2017||4,499|
|5.||Sony A99 II||..||..||85/100||4.5/5||4.5/5||Sep 2016||3,199|
|6.||Sony A7R II||5/5||+ +||90/100||5/5||5/5||Jun 2015||3,199|
|7.||Sony A7S II||5/5||+||..||4.5/5||5/5||Sep 2015||2,999|
|8.||Sony RX100 IV||4.5/5||+ +||85/100||4/5||4.5/5||Jun 2015||999|
|9.||Sony A5000||3/5||+||..||4.5/5||4.5/5||Jan 2014||449|
|10.||Sony A6000||5/5||+||80/100||4.5/5||5/5||Feb 2014||599|
|11.||Sony RX100 III||5/5||+ +||82/100||4.5/5||5/5||May 2014||799|
|12.||Sony A3000||3/5||+||..||4/5||4/5||Aug 2013||329|
|13.||Sony NEX-3N||3/5||..||..||4.5/5||4.5/5||Feb 2013||499|
|14.||Sony RX100 II||5/5||+ +||79/100||4.5/5||4.5/5||Jun 2013||749|
|15.||Sony NEX-F3||4/5||..||74/100||4.5/5||4.5/5||May 2012||599|
|16.||Sony RX100||5/5||+ +||78/100||4/5||5/5||Jun 2012||649|
|17.||Sony NEX-3||..||..||70/100||4.5/5||4/5||May 2010||599|
|Notes: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.|
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 camera comparisons
Did this review help to inform your camera decision process? In case you are interested in seeing how other cameras pair up, just make a corresponding selection in the search boxes below. Alternatively, you can follow any of the listed hyperlinks for comparisons that others found interesting.
Specifications: Sony A5100 vs Sony A7R III
Below is a side-by-side comparison of the specs of the two cameras to facilitate a quick review of their differences and common features.
|Camera Model||Sony A5100||Sony A7R III|
|Camera Type||Mirrorless system camera||Mirrorless system camera|
|Camera Lens||Sony E mount lenses||Sony E mount lenses|
|Launch Date||August 2014||October 2017|
|Launch Price||USD 549||USD 3,199|
|Sensor Specs||Sony A5100||Sony A7R III|
|Sensor Format||APS-C Sensor||Full Frame Sensor|
|Sensor Size||23.5 x 15.6 mm||35.9 x 24.0 mm|
|Sensor Area||366.6 mm2||861.6 mm2|
|Sensor Diagonal||28.2 mm||43.2 mm|
|Sensor Resolution||24 Megapixels||42.2 Megapixels|
|Image Resolution||6000 x 4000 pixels||7952 x 5304 pixels|
|Pixel Pitch||3.91 μm||4.52 μm|
|Pixel Density||6.55 MP/cm2||4.90 MP/cm2|
|Moiré control||Anti-Alias filter||no AA filter|
|Movie Capability||1080/60p Video||4K/30p Video|
|ISO Setting||100 - 25,600 ISO||100 - 32,000 ISO|
|ISO Boost||no Enhancement||50 - 102,400 ISO|
|Image Processor||BIONZ X||BIONZ X|
|DXO Sensor Quality (score)||80||100|
|DXO Color Depth (bits)||23.8||26.0|
|DXO Dynamic Range (EV)||12.7||14.7|
|DXO Low Light (ISO)||1347||3523|
|Screen Specs||Sony A5100||Sony A7R III|
|Viewfinder Type||no viewfinder||Electronic viewfinder|
|Viewfinder Field of View||100%|
|Viewfinder Resolution||3686k dots|
|LCD Framing||Live View||Live View|
|Rear LCD Size||3.0inch||3.0inch|
|LCD Resolution||922k dots||1440k dots|
|LCD Attachment||Tilting screen||Tilting screen|
|Shooting Specs||Sony A5100||Sony A7R III|
|Focus System||On-Sensor Phase-detect||On-Sensor Phase-detect|
|Manual Focusing Aid||Focus Peaking||Focus Peaking|
|Max Shutter Speed (mechanical)||1/4000s||1/8000s|
|Continuous Shooting||6 shutter flaps/s||10 shutter flaps/s|
|Electronic Shutter||no E-Shutter||YES|
|Time-Lapse Photography||no Intervalometer||Intervalometer built-in|
|Image Stabilization||Lens stabilization only||In-body stabilization|
|Fill Flash||Build-in Flash||no On-Board Flash|
|Storage Medium||MS or SDXC cards||MS or SDXC cards|
|Second Storage Option||Single card slot||Dual card slots|
|UHS card support||UHS-I||Single UHS-II|
|Connectivity Specs||Sony A5100||Sony A7R III|
|External Flash||no Hotshoe||Hotshoe|
|Studio Flash||no PC Sync||PC Sync socket|
|USB Connector||USB 2.0||USB 3.1|
|HDMI Port||micro HDMI||micro HDMI|
|Microphone Port||no MIC socket||External MIC port|
|Headphone Socket||no Headphone port||Headphone port|
|Wifi Support||Wifi built-in||Wifi built-in|
|Near-Field Communication||NFC built-in||NFC built-in|
|Bluetooth Support||no Bluetooth||Bluetooth built-in|
|Body Specs||Sony A5100||Sony A7R III|
|Environmental Sealing||not weather sealed||Weathersealed body|
|Battery Life (CIPA)||400 shots per charge||650 shots per charge|
|In-Camera Charging||USB charging||USB charging|
110 x 63 x 36 mm
(4.3 x 2.5 x 1.4 in)
127 x 96 x 74 mm
(5.0 x 3.8 x 2.9 in)
|Camera Weight||283 g (10.0 oz)||650 g (22.9 oz)|
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