Sony A5100 vs A7S III
The Sony Alpha A5100 and the Sony Alpha 7S III are two digital cameras that were officially introduced, respectively, in August 2014 and July 2020. Both the A5100 and the A7S III are mirrorless interchangeable lens cameras that are based on an APS-C (A5100) and a full frame (A7S III) sensor. The A5100 has a resolution of 24 megapixels, whereas the A7S III provides 12 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 7S 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 side-by-side display below illustrates the physical size and weight of the Sony A5100 and the Sony A7S III. The two cameras are presented according to their relative size. 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.
The A5100 can be obtained in two different colors (black, white), while the A7S 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 A7S III is considerably larger (78 percent) than the Sony A5100. Moreover, the A7S III is substantially heavier (147 percent) than the A5100. It is noteworthy in this context that the A7S 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 (A7S 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 A7S III can take 600 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 following table provides a synthesis of the main physical specifications of the two cameras and other similar ones. If you want to switch the focus of the display and review another camera pair, you can move across to the CAM-parator tool and choose from the broad selection of possible camera comparisons there.
|1.||Sony A5100||110 mm||63 mm||36 mm||283 g||400||n||Aug 2014||549|
|2.||Sony A7S III||127 mm||97 mm||81 mm||699 g||600||Y||Jul 2020||3,499|
|3.||Sony A7R IV||129 mm||96 mm||78 mm||665 g||670||Y||Jul 2019||3,499|
|4.||Sony A7R III||127 mm||96 mm||74 mm||650 g||650||Y||Oct 2017||3,199|
|5.||Sony A9||127 mm||96 mm||63 mm||673 g||650||Y||Apr 2017||4,499|
|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 listed launch prices provide an indication of the market segment that the manufacturer of the cameras have been targeting. The A5100 was launched at a markedly lower price (by 84 percent) than the A7S 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. 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 tend to be more expensive and lead to bigger and heavier cameras and lenses.
Of the two cameras under consideration, the Sony A5100 features an APS-C sensor and the Sony A7S III a full frame sensor. The sensor area in the A7S III is 131 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.
Despite having a smaller sensor, the Sony A5100 offers a higher resolution of 24 megapixels, compared with 12 MP of the Sony A7S III. This megapixels advantage comes at the cost of a higher pixel density and a smaller size of the individual pixel (with a pixel pitch of 3.91μm versus 8.40μm for the A7S III). Moreover, it should be noted that the A7S III is much more recent (by 5 years and 11 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.
The resolution advantage of the Sony A5100 implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the A5100 for good quality output (200 dots per inch) amounts to 30 x 20 inches or 76.2 x 50.8 cm, for very good quality (250 dpi) 24 x 16 inches or 61 x 40.6 cm, and for excellent quality (300 dpi) 20 x 13.3 inches or 50.8 x 33.9 cm. The corresponding values for the Sony A7S III are 21.2 x 14.2 inches or 53.8 x 36 cm for good quality, 17 x 11.3 inches or 43.1 x 28.8 cm for very good quality, and 14.1 x 9.4 inches or 35.9 x 24 cm for excellent quality prints.
The A5100 has on-sensor phase detect pixels, which results in fast and reliable autofocus acquisition even during live view operation.
The Sony Alpha A5100 has a native sensitivity range from ISO 100 to ISO 25600. The corresponding ISO settings for the Sony Alpha 7S III are ISO 80 to ISO 102400, with the possibility to increase the ISO range to 40-409600.
Consistent information on actual sensor performance is available from DXO Mark for many 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 A7S III has a markedly higher DXO score than the A5100 (overall score 6 points higher), which will translate into better image quality. The advantage is based on 0.1 bits lower color depth, 1.2 EV in additional dynamic range, and 0.9 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 A7S III||Full Frame||12.0||4240||2832||4K/120p||23.7||13.9||2520||86|
|3.||Sony A7R IV||Full Frame||60.2||9504||6336||4K/30p||26.0||14.8||3344||99|
|4.||Sony A7R III||Full Frame||42.2||7952||5304||4K/30p||26.0||14.7||3523||100|
|5.||Sony A9||Full Frame||24.0||6000||4000||4K/30p||24.9||13.3||3517||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. Both cameras under consideration are equipped with sensors that have a sufficiently high read-out speed for moving images, but the A7S III provides a better video resolution than the A5100. It can shoot movie footage at 4K/120p, while the A5100 is limited to 1080/60p.
Apart from body and sensor, cameras can and do differ across a variety of features. For example, the A7S III has an electronic viewfinder (9440k 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 A7S III, and comparable cameras.
|2.||Sony A7S III||9440||n||3.0||1440||swivel||Y||1/8000s||10.0||n||Y|
|3.||Sony A7R IV||5760||n||3.0||1440||tilting||Y||1/8000s||10.0||n||Y|
|4.||Sony A7R III||3686||n||3.0||1440||tilting||Y||1/8000s||10.0||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 A7S 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.Both cameras have an articulated rear screen that can be turned to be front-facing. This feature will be particularly appreciated by vloggers and photographers who are interested in taking selfies.
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 A7S 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 A5100 writes its imaging data to SDXC or Memory Stick PRO Duo cards, while the A7S III uses CFexpress or SDXC cards. The A7S 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 A7S III supports UHS-II cards (on both slots), 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 7S III and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.
| WiFi |
| NFC |
|2.||Sony A7S III||Y||stereo||mono||Y||Y||full||3.2||Y||-||Y|
|3.||Sony A7R IV||Y||stereo||mono||Y||Y||micro||3.1||Y||Y||Y|
|4.||Sony A7R III||Y||stereo||mono||Y||Y||micro||3.1||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 A7S 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.
Both the A5100 and the A7S III are recent models that are part of the current product line-up. The A5100 replaced the earlier Sony A5000, while the A7S III followed on from the Sony A7S II. 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 A7S III – has the upper hand? Is one clearly better than the other? The listing below highlights the relative strengths of the two models.
Reasons to prefer the Sony Alpha A5100:
- More detail: Offers more megapixels (24 vs 12MP) with a 41% higher linear resolution.
- Better live-view autofocus: Features on-sensor phase-detection for more confident autofocus.
- More compact: Is smaller (110x63mm vs 127x97mm) and thus needs less room in the bag.
- Less heavy: Is lighter (by 416g or 60 percent) and hence easier to carry around.
- Easier fill-in: Is equipped with a small onboard flash to brighten deep shadow areas.
- Easier device pairing: Supports NFC for fast wireless image transfer over short distances.
- More affordable: Was introduced into a lower priced category (84 percent cheaper at launch).
- More heavily discounted: Has been available for much longer (launched in August 2014).
Arguments in favor of the Sony Alpha 7S III:
- Better image quality: Scores markedly higher (6 points) in the DXO overall evaluation.
- More dynamic range: Captures a broader range of light and dark details (1.2 EV of extra DR).
- Better low-light sensitivity: Can shoot in dim conditions (0.9 stops ISO advantage).
- Better video: Provides higher definition movie capture (4K/120p 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).
- More flexible LCD: Has a swivel screen for odd-angle shots in portrait or landscape orientation.
- 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.
- Longer lasting: Gets more shots (600 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 (3.2 vs 2.0).
- More solid recording: Has a full-sized HDMI port for a sturdy connection to an external recorder.
- Easier wireless transfer: Supports Bluetooth for image sharing without cables.
- 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 5 years and 11 months of technical progress since the A5100 launch.
If the count of individual advantages (bullet points above) is taken as a guide, the A7S III is the clear winner of the contest (22 : 8 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 before making a camera decision. 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 A7S 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 comparison of technical specifications can provide a useful overview of the capabilities of different cameras, it says little about, for example, the shooting experience and imaging performance of the A5100 and the A7S 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 where reviews by experts come in. 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 A7S III||..||+ +||91/100||4.5/5||5/5||Jul 2020||3,499|
|3.||Sony A7R IV||5/5||+||91/100||4.5/5||5/5||Jul 2019||3,499|
|4.||Sony A7R III||..||+ +||90/100||4.5/5||5/5||Oct 2017||3,199|
|5.||Sony A9||5/5||+ +||89/100||5/5||5/5||Apr 2017||4,499|
|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.|
The review scores listed above should be treated 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 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 camera comparisons
Did this review help to inform your camera decision process? If you would like to see a different side-by-side camera review, just make a corresponding selection in the search boxes below. As an alternative, you can also directly jump to any one of the listed comparisons that were previously generated by the CAM-parator tool.
Specifications: Sony A5100 vs Sony A7S 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 A7S III|
|Camera Type||Mirrorless system camera||Mirrorless system camera|
|Camera Lens||Sony E mount lenses||Sony E mount lenses|
|Launch Date||August 2014||July 2020|
|Launch Price||USD 549||USD 3,499|
|Sensor Specs||Sony A5100||Sony A7S III|
|Sensor Format||APS-C Sensor||Full Frame Sensor|
|Sensor Size||23.5 x 15.6 mm||35.6 x 23.8 mm|
|Sensor Area||366.6 mm2||847.28 mm2|
|Sensor Diagonal||28.2 mm||42.8 mm|
|Sensor Resolution||24 Megapixels||12 Megapixels|
|Image Resolution||6000 x 4000 pixels||4240 x 2832 pixels|
|Pixel Pitch||3.91 μm||8.40 μm|
|Pixel Density||6.55 MP/cm2||1.42 MP/cm2|
|Moiré control||Anti-Alias filter||Anti-Alias filter|
|Movie Capability||1080/60p Video||4K/120p Video|
|ISO Setting||100 - 25,600 ISO||80 - 102,400 ISO|
|ISO Boost||no Enhancement||40 - 409,600 ISO|
|Image Processor||BIONZ X||BIONZ XR|
|DXO Sensor Quality (score)||80||86|
|DXO Color Depth (bits)||23.8||23.7|
|DXO Dynamic Range (EV)||12.7||13.9|
|DXO Low Light (ISO)||1347||2520|
|Screen Specs||Sony A5100||Sony A7S III|
|Viewfinder Type||no viewfinder||Electronic viewfinder|
|Viewfinder Field of View||100%|
|Viewfinder Resolution||9440k dots|
|LCD Framing||Live View||Live View|
|Rear LCD Size||3.0inch||3.0inch|
|LCD Resolution||922k dots||1440k dots|
|LCD Attachment||Tilting screen||Swivel screen|
|Shooting Specs||Sony A5100||Sony A7S III|
|Focus System||On-Sensor Phase-detect||Contrast-detect AF|
|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|
|Image Stabilization||Lens stabilization only||In-body stabilization|
|Fill Flash||Build-in Flash||no On-Board Flash|
|Storage Medium||MS or SDXC cards||CFexpress or SDXC cards|
|Second Storage Option||Single card slot||Dual card slots|
|UHS card support||UHS-I||Dual UHS-II|
|Connectivity Specs||Sony A5100||Sony A7S III|
|External Flash||no Hotshoe||Hotshoe|
|USB Connector||USB 2.0||USB 3.2|
|HDMI Port||micro HDMI||full 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||no NFC|
|Bluetooth Support||no Bluetooth||Bluetooth built-in|
|Body Specs||Sony A5100||Sony A7S III|
|Environmental Sealing||not weather sealed||Weathersealed body|
|Battery Life (CIPA)||400 shots per charge||600 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 97 x 81 mm
(5.0 x 3.8 x 3.2 in)
|Camera Weight||283 g (10.0 oz)||699 g (24.7 oz)|
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