Sony A7 III vs A77
The Sony Alpha A7 III and the Sony Alpha SLT-A77 are two enthusiast cameras that were announced, respectively, in February 2018 and August 2011. The A7 III is a mirrorless interchangeable lens camera, while the A77 is a DSLR. The cameras are based on a full frame (A7 III) and an APS-C (A77) sensor. Both cameras offer a resolution of 24 megapixels.
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 A7 III and the Sony Alpha SLT-A77? 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 A7 III and the Sony A77 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 size 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 A77 is notably larger (22 percent) than the Sony A7 III. Moreover, the A77 is markedly heavier (13 percent) than the A7 III. 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. Hence, you might want to study and compare the specifications of available lenses in order to get the full picture of the size and weight of the two camera systems.
Concerning battery life, the A7 III gets 610 shots out of its NP-FZ100 battery, while the A77 can take 470 images on a single charge of its NP-FM500H power pack. The power pack in the A7 III can be charged via the USB port, so that it is not always necessary to take the battery charger along when travelling.
The adjacent table lists the principal physical characteristics of the two cameras alongside a wider set of alternatives. 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 A7 III||127 mm||96 mm||74 mm||650 g||610||Y||Feb 2018||1,999|
|2.||Sony A77||143 mm||104 mm||81 mm||732 g||470||Y||Aug 2011||1,399|
|3.||Canon 6D Mark II||144 mm||111 mm||75 mm||765 g||1200||Y||Jun 2017||1,999|
|4.||Nikon Z6||134 mm||101 mm||67 mm||675 g||310||Y||Aug 2018||1,999|
|5.||Pentax K-3||131 mm||100 mm||77 mm||800 g||560||Y||Oct 2013||1,299|
|6.||Sony A7C||124 mm||71 mm||60 mm||509 g||740||Y||Sep 2020||1,799|
|7.||Sony A9 II||129 mm||96 mm||76 mm||678 g||690||Y||Oct 2019||4,499|
|8.||Sony A7R IV||129 mm||96 mm||78 mm||665 g||670||Y||Jul 2019||3,499|
|9.||Sony A7R III||127 mm||96 mm||74 mm||650 g||650||Y||Oct 2017||3,199|
|10.||Sony A9||127 mm||96 mm||63 mm||673 g||650||Y||Apr 2017||4,499|
|11.||Sony A6500||120 mm||67 mm||53 mm||453 g||350||Y||Oct 2016||1,399|
|12.||Sony A7R II||127 mm||96 mm||60 mm||625 g||290||Y||Jun 2015||3,199|
|13.||Sony A7 II||127 mm||96 mm||60 mm||599 g||350||Y||Nov 2014||1,999|
|14.||Sony A77 II||143 mm||104 mm||81 mm||647 g||480||Y||May 2014||1,199|
|15.||Sony A7||127 mm||94 mm||48 mm||474 g||340||Y||Oct 2013||1,699|
|16.||Sony A99||147 mm||111 mm||78 mm||812 g||500||Y||Sep 2012||2,799|
|Notes: Measurements and pricing do not include easily detachable parts, such as add-on or interchangeable lenses or optional viewfinders.|
The price is, of course, an important factor in any camera decision. The manufacturer’s suggested retail prices give an idea on the placement of the camera in the maker’s lineup and the broader market. The A77 was launched at a markedly lower price (by 30 percent) than the A7 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 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. 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 tend to be associated with larger, more expensive camera bodies and lenses.
Of the two cameras under consideration, the Sony A7 III features a full frame sensor and the Sony A77 an APS-C sensor. The sensor area in the A77 is 57 percent smaller. As a result of these sensor size differences, the cameras have a format factor of, respectively, 1.0 and 1.5. Both cameras have a native aspect ratio (sensor width to sensor height) of 3:2.
Even though the A7 III has a larger sensor, both cameras offer the same resolution of 24 megapixels. This implies that the A7 III has a lower pixel density and larger individual pixels (with a pixel pitch of 5.94μm versus 3.91μm for the A77), which gives it a potential advantage in terms of light gathering capacity. In addition, the A7 III is much more recent (by 6 years and 6 months) than the A77, and its sensor will have benefitted from technological advances during this time.
The A7 III has on-sensor phase detect pixels, which results in fast and reliable autofocus acquisition even during live view operation.
The Sony Alpha A7 III has a native sensitivity range from ISO 100 to ISO 51200, which can be extended to ISO 50-204800. The corresponding ISO settings for the Sony Alpha SLT-A77 are ISO 100 to ISO 16000, with the possibility to increase the ISO range to 50-25600.
Since 2007, DXO Mark has published sensor performance measurements that have been derived using a consistent methodology. 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 review, the A7 III provides substantially higher image quality than the A77, with an overall score that is 18 points higher. This advantage is based on 1 bits higher color depth, 1.5 EV in additional dynamic range, and 2.2 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 |
|1.||Sony A7 III||Full Frame||24.0||6000||4000||4K/30p||25.0||14.7||3730||96|
|3.||Canon 6D Mark II||Full Frame||26.0||6240||4160||1080/60p||24.4||11.9||2862||85|
|4.||Nikon Z6||Full Frame||24.3||6048||4024||4K/30p||25.3||14.3||3299||95|
|6.||Sony A7C||Full Frame||24.0||6000||4000||4K/30p||25.0||14.7||3407||95|
|7.||Sony A9 II||Full Frame||24.0||6000||4000||4K/30p||25.0||14.0||3434||93|
|8.||Sony A7R IV||Full Frame||60.2||9504||6336||4K/30p||26.0||14.8||3344||99|
|9.||Sony A7R III||Full Frame||42.2||7952||5304||4K/30p||26.0||14.7||3523||100|
|10.||Sony A9||Full Frame||24.0||6000||4000||4K/30p||24.9||13.3||3517||92|
|12.||Sony A7R II||Full Frame||42.2||7952||5304||4K/30p||26.0||13.9||3434||98|
|13.||Sony A7 II||Full Frame||24.0||6000||4000||1080/60p||24.9||13.6||2449||90|
|14.||Sony A77 II||APS-C||24.0||6000||4000||1080/60p||..||..||..||..|
|15.||Sony A7||Full Frame||24.0||6000||4000||1080/60p||24.8||14.2||2248||90|
|16.||Sony A99||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. The two cameras under consideration both have sensors whose read-out speed is fast enough to capture moving pictures, but the A7 III provides a higher video resolution than the A77. It can shoot video footage at 4K/30p, while the A77 is limited to 1080/60p.
Beyond body and sensor, cameras can and do differ across a range of features. The A7 III and the A77 are similar in the sense that both feature an electronic viewfinder, which is helpful when framing images in bright sunlight. Moreover, their viewfinders offer an identical resolution of 2359k dots. The table below summarizes some of the other core capabilities of the Sony A7 III and Sony A77 in connection with corresponding information for a sample of similar cameras.
|1.||Sony A7 III||2359||n||3.0||922||tilting||Y||1/8000s||10.0||n||Y|
|3.||Canon 6D Mark II||optical||Y||3.0||1040||swivel||Y||1/4000s||6.5||n||n|
|7.||Sony A9 II||3686||n||3.0||1440||tilting||Y||1/8000s||10.0||n||Y|
|8.||Sony A7R IV||5760||n||3.0||1440||tilting||Y||1/8000s||10.0||n||Y|
|9.||Sony A7R III||3686||n||3.0||1440||tilting||Y||1/8000s||10.0||n||Y|
|12.||Sony A7R II||2400||n||3.0||1229||tilting||n||1/8000s||5.0||n||Y|
|13.||Sony A7 II||2400||n||3.0||1230||tilting||n||1/8000s||5.0||n||Y|
|14.||Sony A77 II||2359||Y||3.0||1229||full-flex||n||1/8000s||12.0||Y||Y|
One differentiating feature between the two cameras concerns the touch sensitivity of the rear screen. The A7 III has a touchscreen, while the A77 has a conventional panel. Touch control can be particularly helpful, for example, for setting the focus point.The A77 has an articulated screen that can be turned to be front-facing. This characteristic will be appreciated by vloggers and photographers who are interested in taking selfies. In contrast, the A7 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 A7 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 A7 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 A7 III and the A77 write their files to SDXC or Memory Stick PRO Duo cards. The A7 III features dual card slots, which can be very useful in case a memory card fails. In contrast, the A77 only has one slot. The A7 III supports UHS-II cards (on its first slot), while the A77 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 A7 III and Sony Alpha SLT-A77 and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.
| WiFi |
| NFC |
|1.||Sony A7 III||Y||stereo||mono||Y||Y||micro||3.1||Y||Y||Y|
|3.||Canon 6D Mark II||Y||stereo||mono||Y||-||mini||2.0||Y||Y||Y|
|7.||Sony A9 II||Y||stereo||mono||Y||Y||micro||3.1||Y||Y||Y|
|8.||Sony A7R IV||Y||stereo||mono||Y||Y||micro||3.1||Y||Y||Y|
|9.||Sony A7R III||Y||stereo||mono||Y||Y||micro||3.1||Y||Y||Y|
|12.||Sony A7R II||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||-|
|13.||Sony A7 II||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||-|
|14.||Sony A77 II||Y||stereo||mono||Y||-||mini||2.0||Y||Y||-|
It is notable that the A7 III has a headphone jack, which is not present on the A77 This port makes it possible to attach external headphones and monitor the quality of sound during the recording process.
Studio photographers will appreciate that the Sony A77 (unlike the A7 III) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.
Travel and landscape photographers will find it useful that the A77 has an internal geolocalization sensor and can record GPS coordinates in its EXIF data.
The A7 III is a recent model that features in the current product line-up of Sony. In contrast, the A77 has been discontinued (but can be found pre-owned on eBay). As a replacement in the same line of cameras, the A77 was succeeded by the Sony A77 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? Is the Sony A7 III better than the Sony A77 or vice versa? The listing below highlights the relative strengths of the two models.
Reasons to prefer the Sony Alpha A7 III:
- Better image quality: Scores substantially higher (18 points) in the DXO overall assessment.
- More dynamic range: Captures a larger spectrum of light and dark details (1.5 EV of extra DR).
- Better low-light sensitivity: Requires less light for good images (2.2 stops ISO advantage).
- Better video: Provides higher definition movie capture (4K/30p vs 1080/60p).
- Better live-view autofocus: Features on-sensor phase-detection for more confident autofocus.
- Better sound control: Has a headphone port that enables audio monitoring while recording.
- Larger viewfinder image: Features a viewfinder with a higher magnification (0.78x vs 0.73x).
- Fewer buttons to press: Is equipped with a touch-sensitive rear screen to facilitate handling.
- Less disturbing: Has an electronic shutter option for completely silent shooting.
- Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
- More compact: Is smaller (127x96mm vs 143x104mm) and thus needs less room in the bag.
- Less heavy: Is lighter (by 82g or 11 percent) and hence easier to carry around.
- Longer lasting: Can take more shots (610 versus 470) on a single battery charge.
- Easier travel charging: Can be conveniently charged via its USB port.
- More legacy lens friendly: Can take a broad range of non-native lenses via adapters.
- Faster data transfer: Supports a more advanced USB protocol (3.1 vs 2.0).
- Easier file upload: Has wifi built in for automatic backup or image transfer to the web.
- Easier device pairing: Supports NFC for fast wireless image transfer over short distances.
- 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 6 years and 6 months of technical progress since the A77 launch.
Advantages of the Sony Alpha SLT-A77:
- Easier setting verification: Features a control panel on top to check shooting parameters.
- More flexible LCD: Has a full-flex screen for odd-angle shots in portrait or landscape orientation.
- More selfie-friendly: Has an articulated screen that can be turned to be front-facing.
- Faster burst: Shoots at higher frequency (12 vs 10 flaps/sec) to capture the decisive moment.
- Easier fill-in: Has a small integrated flash to brighten shadows of backlit subjects.
- Easier geotagging: Features an internal GPS sensor to log localization data.
- Better studio light control: Has a PC Sync socket to connect to professional strobe lights.
- More affordable: Was introduced into a lower priced category (30 percent cheaper at launch).
- More heavily discounted: Has been around for much longer (launched in August 2011).
If the count of individual advantages (bullet points above) is taken as a guide, the A7 III is the clear winner of the match-up (22 : 9 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 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 A7 III and the Sony A77 place the cameras among the top in their class? Find out in the latest Best Mirrorless Interchangeable Lens Camera and Best DSLR Camera listings whether the two cameras rank among the cream of the crop.
In any case, while the comparison of the spec-sheets of cameras can offer a general idea of their imaging potential, it remains partial and cannot reveal, for example, the shooting experience and imaging performance when actually working with the A7 III or the A77. 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 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 A7 III||..||+ +||89/100||5/5||5/5||Feb 2018||1,999|
|2.||Sony A77||5/5||91/100||81/100||..||5/5||Aug 2011||1,399|
|3.||Canon 6D Mark II||4/5||+||80/100||4.5/5||4/5||Jun 2017||1,999|
|4.||Nikon Z6||5/5||..||89/100||4.5/5||5/5||Aug 2018||1,999|
|5.||Pentax K-3||4/5||..||83/100||5/5||5/5||Oct 2013||1,299|
|6.||Sony A7C||3.5/5||..||86/100||4/5||4/5||Sep 2020||1,799|
|7.||Sony A9 II||..||..||90/100||5/5||5/5||Oct 2019||4,499|
|8.||Sony A7R IV||5/5||+||91/100||4.5/5||5/5||Jul 2019||3,499|
|9.||Sony A7R III||..||+ +||90/100||4.5/5||5/5||Oct 2017||3,199|
|10.||Sony A9||5/5||+ +||89/100||5/5||5/5||Apr 2017||4,499|
|11.||Sony A6500||5/5||+ +||85/100||4.5/5||4.5/5||Oct 2016||1,399|
|12.||Sony A7R II||5/5||+ +||90/100||5/5||5/5||Jun 2015||3,199|
|13.||Sony A7 II||5/5||+||82/100||4.5/5||5/5||Nov 2014||1,999|
|14.||Sony A77 II||4/5||..||80/100||4.5/5||5/5||May 2014||1,199|
|15.||Sony A7||5/5||+ +||80/100||5/5||5/5||Oct 2013||1,699|
|16.||Sony A99||5/5||..||84/100||4.5/5||4.5/5||Sep 2012||2,799|
|Notes: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.|
Care should be taken when interpreting the review scores above, though. The ratings are only valid when referring to cameras in the same category and of the same age. Hence, a score should always be seen in the context of the camera's market launch date and its price, and rating-comparisons among cameras that span long time periods or concern very differently equipped models make little sense. 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? 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 A7 III vs Sony A77
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 A7 III||Sony A77|
|Camera Type||Mirrorless system camera||Digital single lens reflex|
|Camera Lens||Sony E mount lenses||Sony A mount lenses|
|Launch Date||February 2018||August 2011|
|Launch Price||USD 1,999||USD 1,399|
|Sensor Specs||Sony A7 III||Sony A77|
|Sensor Format||Full Frame Sensor||APS-C Sensor|
|Sensor Size||35.6 x 23.8 mm||23.5 x 15.6 mm|
|Sensor Area||847.28 mm2||366.6 mm2|
|Sensor Diagonal||42.8 mm||28.2 mm|
|Sensor Resolution||24 Megapixels||24 Megapixels|
|Image Resolution||6000 x 4000 pixels||6000 x 4000 pixels|
|Pixel Pitch||5.94 μm||3.91 μm|
|Pixel Density||2.83 MP/cm2||6.55 MP/cm2|
|Moiré control||Anti-Alias filter||Anti-Alias filter|
|Movie Capability||4K/30p Video||1080/60p Video|
|ISO Setting||100 - 51,200 ISO||100 - 16,000 ISO|
|ISO Boost||50 - 204,800 ISO||50 - 25,600 ISO|
|Image Processor||BIONZ X||BIONZ X|
|DXO Sensor Quality (score)||96||78|
|DXO Color Depth (bits)||25.0||24.0|
|DXO Dynamic Range (EV)||14.7||13.2|
|DXO Low Light (ISO)||3730||801|
|Screen Specs||Sony A7 III||Sony A77|
|Viewfinder Type||Electronic viewfinder||Electronic viewfinder|
|Viewfinder Field of View||100%||100%|
|Viewfinder Resolution||2359k dots||2359k dots|
|Top-Level Screen||no Top Display||Control Panel|
|LCD Framing||Live View||Live View|
|Rear LCD Size||3.0inch||3.0inch|
|LCD Resolution||922k dots||921k dots|
|LCD Attachment||Tilting screen||Fully flexible screen|
|Touch Input||Touchscreen||no Touchscreen|
|Shooting Specs||Sony A7 III||Sony A77|
|Focus System||On-Sensor Phase-detect||Phase-detect AF|
|Manual Focusing Aid||Focus Peaking||Focus Peaking|
|Max Shutter Speed (mechanical)||1/8000s||1/8000s|
|Continuous Shooting||10 shutter flaps/s||12 shutter flaps/s|
|Shutter Life Expectancy||200 000 actuations||150 000 actuations|
|Electronic Shutter||YES||no E-Shutter|
|Time-Lapse Photography||Intervalometer built-in||no Intervalometer|
|Image Stabilization||In-body stabilization||In-body stabilization|
|Fill Flash||no On-Board Flash||Built-in Flash|
|Storage Medium||MS or SDXC cards||MS or SDXC cards|
|Second Storage Option||Dual card slots||Single card slot|
|UHS card support||Single UHS-II||UHS-I|
|Connectivity Specs||Sony A7 III||Sony A77|
|Studio Flash||no PC Sync||PC Sync socket|
|USB Connector||USB 3.1||USB 2.0|
|HDMI Port||micro HDMI||mini HDMI|
|Microphone Port||External MIC port||External MIC port|
|Headphone Socket||Headphone port||no Headphone port|
|Wifi Support||Wifi built-in||no Wifi|
|Near-Field Communication||NFC built-in||no NFC|
|Bluetooth Support||Bluetooth built-in||no Bluetooth|
|Geotagging||no internal GPS||GPS built-in|
|Body Specs||Sony A7 III||Sony A77|
|Environmental Sealing||Weathersealed body||Weathersealed body|
|Battery Life (CIPA)||610 shots per charge||470 shots per charge|
|In-Camera Charging||USB charging||no USB charging|
127 x 96 x 74 mm
(5.0 x 3.8 x 2.9 in)
143 x 104 x 81 mm
(5.6 x 4.1 x 3.2 in)
|Camera Weight||650 g (22.9 oz)||732 g (25.8 oz)|
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