Sony A6400 vs A7S III
The Sony Alpha A6400 and the Sony Alpha 7S III are two digital cameras that were revealed to the public, respectively, in January 2019 and July 2020. Both the A6400 and the A7S III are mirrorless interchangeable lens cameras that are based on an APS-C (A6400) and a full frame (A7S III) sensor. The A6400 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 A6400 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.
An illustration of the physical size and weight of the Sony A6400 and the Sony A7S III is provided 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 dimensions are rounded to the nearest millimeter.
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 (53 percent) than the Sony A6400. Moreover, the A7S III is substantially heavier (73 percent) than the A6400. 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 compare the optics available for the two cameras in the Sony E-Mount Lens Catalog (A6400) 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 A6400 gets 410 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 adjacent table lists the principal physical characteristics of the two cameras alongside a wider set of alternatives. 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 A6400||120 mm||67 mm||50 mm||403 g||410||Y||Jan 2019||899|
|2.||Sony A7S III||127 mm||97 mm||81 mm||699 g||600||Y||Jul 2020||3,499|
|3.||Fujifilm X-T30||118 mm||83 mm||47 mm||383 g||380||n||Feb 2019||899|
|4.||Nikon D5300||125 mm||98 mm||76 mm||480 g||600||n||Oct 2013||799|
|5.||Sony A7R IV||129 mm||96 mm||78 mm||665 g||670||Y||Jul 2019||3,499|
|6.||Sony A6100||120 mm||67 mm||59 mm||396 g||420||n||Aug 2019||749|
|7.||Sony A7R III||127 mm||96 mm||74 mm||650 g||650||Y||Oct 2017||3,199|
|8.||Sony A9||127 mm||96 mm||63 mm||673 g||650||Y||Apr 2017||4,499|
|9.||Sony A6300||120 mm||67 mm||49 mm||404 g||400||Y||Feb 2016||999|
|10.||Sony A7R II||127 mm||96 mm||60 mm||625 g||290||Y||Jun 2015||3,199|
|11.||Sony A7S II||127 mm||96 mm||60 mm||627 g||370||Y||Sep 2015||2,999|
|12.||Sony A5100||110 mm||63 mm||36 mm||283 g||400||n||Aug 2014||549|
|13.||Sony A6000||120 mm||67 mm||45 mm||344 g||360||n||Feb 2014||599|
|14.||Sony A3000||128 mm||91 mm||85 mm||411 g||470||n||Aug 2013||329|
|15.||Sony NEX-5R||111 mm||59 mm||39 mm||276 g||330||n||Aug 2012||749|
|16.||Sony NEX-6||120 mm||67 mm||43 mm||345 g||360||n||Sep 2012||999|
|17.||Sony NEX-7||120 mm||67 mm||43 mm||400 g||430||n||Aug 2011||1,349|
|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 A6400 was launched at a markedly lower price (by 74 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 imaging sensor is at the core of digital cameras and its size is one of the main determining factors 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. Moreover, a large sensor camera will give the photographer more control over depth-of-field in the image and, thus, the ability to better isolate a subject from the background. On the downside, larger sensors are more costly to manufacture and tend to lead to bigger and heavier cameras and lenses.
Of the two cameras under consideration, the Sony A6400 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 A6400 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 a somewhat more recent model (by 1 year and 6 months) than the A6400, and its sensor might 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 A6400 implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the A6400 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 A6400 has on-sensor phase detect pixels, which results in fast and reliable autofocus acquisition even during live view operation.
The Sony Alpha A6400 has a native sensitivity range from ISO 100 to ISO 32000, which can be extended to ISO 100-102400. 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 determines an overall sensor rating, as well as sub-scores for low-light sensitivity ("DXO Sports"), dynamic range ("DXO Landscape"), and color depth ("DXO Portrait"). The Overall DXO ratings for the two cameras under consideration are close, suggesting that they provide similar imaging performance. The table below summarizes the physical sensor characteristics and sensor quality findings and compares them across a set of similar cameras.
| DXO |
|2.||Sony A7S III||Full Frame||12.0||4240||2832||4K/120p||23.7||13.9||2520||86|
|5.||Sony A7R IV||Full Frame||60.2||9504||6336||4K/30p||26.0||14.8||3344||99|
|7.||Sony A7R III||Full Frame||42.2||7952||5304||4K/30p||26.0||14.7||3523||100|
|8.||Sony A9||Full Frame||24.0||6000||4000||4K/30p||24.9||13.3||3517||92|
|10.||Sony A7R II||Full Frame||42.2||7952||5304||4K/30p||26.0||13.9||3434||98|
|11.||Sony A7S II||Full Frame||12.0||4240||2832||4K/30p||23.6||13.3||2993||85|
Many modern cameras are not only capable of taking still images, but can also record movies. Both cameras under consideration have a sensor with sufficiently fast read-out times for moving pictures, but the A7S III provides a faster frame rate than the A6400. It can shoot movie footage at 4K/120p, while the A6400 is limited to 4K/30p.
Apart from body and sensor, cameras can and do differ across a range of features. The two cameras under review are similar with respect to both having an electronic viewfinder. However, the one in the A7S III offers a substantially higher resolution than the one in the A6400 (9440k vs 2359k dots). The adjacent table lists some of the other core features of the Sony A6400 and Sony A7S III along with similar information for a selection of comparators.
|2.||Sony A7S III||9440||n||3.0||1440||swivel||Y||1/8000s||10.0||n||Y|
|5.||Sony A7R IV||5760||n||3.0||1440||tilting||Y||1/8000s||10.0||n||Y|
|7.||Sony A7R III||3686||n||3.0||1440||tilting||Y||1/8000s||10.0||n||Y|
|10.||Sony A7R II||2400||n||3.0||1229||tilting||n||1/8000s||5.0||n||Y|
|11.||Sony A7S II||2400||n||3.0||1229||tilting||n||1/8000s||5.0||n||Y|
One difference between the cameras concerns the presence of an on-board flash. The A6400 has one, while the A7S III does not. While the built-in flash of the A6400 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, both cameras under consideration feature an 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 A6400 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 A6400 only has one slot. The A7S III supports UHS-II cards (on both slots), while the A6400 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 A6400 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|
|5.||Sony A7R IV||Y||stereo||mono||Y||Y||micro||3.1||Y||Y||Y|
|7.||Sony A7R III||Y||stereo||mono||Y||Y||micro||3.1||Y||Y||Y|
|10.||Sony A7R II||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||-|
|11.||Sony A7S II||Y||stereo||mono||Y||Y||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 A6400 lacks such a headphone port.
Both the A6400 and the A7S III are recent models that are part of the current product line-up. The A6400 replaced the earlier Sony A6300, 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 how do things add up? Is there a clear favorite between the Sony A6400 and the Sony A7S III? Which camera is better? Below is a summary of the relative strengths of each of the two contestants.
Arguments in favor of the Sony Alpha A6400:
- 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 (120x67mm vs 127x97mm) and thus needs less room in the bag.
- Less heavy: Is lighter (by 296g or 42 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 (74 percent cheaper at launch).
- More heavily discounted: Has been on the market for longer (launched in January 2019).
Advantages of the Sony Alpha 7S III:
- Better low-light sensitivity: Can shoot in dim conditions (0.8 stops ISO advantage).
- Better video: Provides higher movie framerates (4K/120p versus 4K/30p).
- Better sound control: Has a headphone port that enables audio monitoring while recording.
- More detailed viewfinder: Has higher resolution electronic viewfinder (9440k vs 2359k dots).
- Larger viewfinder image: Features a viewfinder with a higher magnification (0.91x vs 0.70x).
- 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.
- Longer lasting: Gets more shots (600 versus 410) out of a single battery charge.
- Sharper images: Has stabilization technology built-in to reduce the impact of hand-shake.
- 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.
- 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: Was introduced somewhat (1 year and 6 months) more recently.
If the count of individual advantages (bullet points above) is taken as a guide, the A7S III is the clear winner of the contest (15 : 8 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 when reflecting and deciding on a new camera. A professional wedding photographer will view the differences between cameras in a way that diverges from the perspective of a travel photog, and a person interested in cityscapes has distinct needs from a macro 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 A6400 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 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 A6400 or the A7S III. 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 hands-on reviews by experts 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 A6400||4/5||+||85/100||4.5/5||4/5||Jan 2019||899|
|2.||Sony A7S III||..||+ +||91/100||4.5/5||5/5||Jul 2020||3,499|
|3.||Fujifilm X-T30||5/5||+ +||84/100||4.5/5||4.5/5||Feb 2019||899|
|4.||Nikon D5300||4/5||+ +||79/100||4.5/5||4.5/5||Oct 2013||799|
|5.||Sony A7R IV||5/5||+||91/100||4.5/5||5/5||Jul 2019||3,499|
|6.||Sony A6100||..||..||82/100||4/5||5/5||Aug 2019||749|
|7.||Sony A7R III||..||+ +||90/100||4.5/5||5/5||Oct 2017||3,199|
|8.||Sony A9||5/5||+ +||89/100||5/5||5/5||Apr 2017||4,499|
|9.||Sony A6300||4.5/5||+||85/100||5/5||5/5||Feb 2016||999|
|10.||Sony A7R II||5/5||+ +||90/100||5/5||5/5||Jun 2015||3,199|
|11.||Sony A7S II||5/5||+||..||4.5/5||5/5||Sep 2015||2,999|
|12.||Sony A5100||4.5/5||+||..||4.5/5||5/5||Aug 2014||549|
|13.||Sony A6000||5/5||+||80/100||4.5/5||5/5||Feb 2014||599|
|14.||Sony A3000||3/5||+||..||4/5||4/5||Aug 2013||329|
|15.||Sony NEX-5R||..||..||..||4.5/5||4.5/5||Aug 2012||749|
|16.||Sony NEX-6||5/5||+ +||78/100||4.5/5||4.5/5||Sep 2012||999|
|17.||Sony NEX-7||5/5||+ +||81/100||4.5/5||5/5||Aug 2011||1,349|
|Notes: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.|
Care should be taken when interpreting the review scores above, though. The ratings were established in reference to similarly priced cameras that were available in the market at the time of the review. Thus, a score needs to be put into the context of the launch date and the launch price of the camera, and comparisons of ratings among very different cameras or across long time periods have little meaning. It should also be noted that some of the review sites have over time altered the way they render their verdicts.
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 use the search menu below. There is also a set of direct links to comparison reviews that other users of the CAM-parator app explored.
Specifications: Sony A6400 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 A6400||Sony A7S III|
|Camera Type||Mirrorless system camera||Mirrorless system camera|
|Camera Lens||Sony E mount lenses||Sony E mount lenses|
|Launch Date||January 2019||July 2020|
|Launch Price||USD 899||USD 3,499|
|Sensor Specs||Sony A6400||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||4K/30p Video||4K/120p Video|
|ISO Setting||100 - 32,000 ISO||80 - 102,400 ISO|
|ISO Boost||100 - 102,400 ISO||40 - 409,600 ISO|
|Image Processor||BIONZ X||BIONZ XR|
|DXO Sensor Quality (score)||83||86|
|DXO Color Depth (bits)||24||23.7|
|DXO Dynamic Range (EV)||13.6||13.9|
|DXO Low Light (ISO)||1431||2520|
|Screen Specs||Sony A6400||Sony A7S III|
|Viewfinder Type||Electronic viewfinder||Electronic viewfinder|
|Viewfinder Field of View||100%||100%|
|Viewfinder Resolution||2359k dots||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 A6400||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||11 shutter flaps/s||10 shutter flaps/s|
|Shutter Life Expectancy||200 000 actuations||200 000 actuations|
|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 A6400||Sony A7S III|
|USB Connector||USB 2.0||USB 3.2|
|HDMI Port||micro HDMI||full HDMI|
|Microphone Port||External MIC port||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||Bluetooth built-in||Bluetooth built-in|
|Body Specs||Sony A6400||Sony A7S III|
|Environmental Sealing||Weathersealed body||Weathersealed body|
|Battery Life (CIPA)||410 shots per charge||600 shots per charge|
|In-Camera Charging||USB charging||USB charging|
120 x 67 x 50 mm
(4.7 x 2.6 x 2.0 in)
127 x 97 x 81 mm
(5.0 x 3.8 x 3.2 in)
|Camera Weight||403 g (14.2 oz)||699 g (24.7 oz)|
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