Sony A77 vs A7 III

The Sony Alpha SLT-A77 and the Sony Alpha A7 III are two enthusiast cameras that were revealed to the public, respectively, in August 2011 and February 2018. The A77 is a DSLR, while the A7 III is a mirrorless interchangeable lens camera. The cameras are based on an APS-C (A77) and a full frame (A7 III) 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.

Headline Specifications

Sony A77		Sony A7 III
Digital single lens reflex		Mirrorless system camera
Sony A mount lenses		Sony E mount lenses
24 MP – APS-C sensor		24 MP – Full Frame sensor
1080/60p Video		4K/30p Video
ISO 100-16,000 (50 - 25,600)		ISO 100-51,200 (50 - 204,800)
Electronic viewfinder (2359k dots)		Electronic viewfinder (2359k dots)
3.0" LCD – 921k dots		3.0" LCD – 922k dots
Fully flexible screen (no touchscreen)		Tilting touchscreen
12 shutter flaps per second		10 shutter flaps per second
In-body stabilization		In-body stabilization
Weathersealed body		Weathersealed body
470 shots per battery charge		610 shots per battery charge
143 x 104 x 81 mm, 732 g		127 x 96 x 74 mm, 650 g

Check A77 offers at
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Check A7 III price at
amazon.com

Going beyond this snapshot of core features and characteristics, what are the differences between the Sony Alpha SLT-A77 and the Sony Alpha A7 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.

Body comparison

The side-by-side display below illustrates the physical size and weight of the Sony A77 and the Sony A7 III. The two cameras are presented according to their relative size. Three successive views from the front, the top, and the rear are shown. 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 A7 III is notably smaller (18 percent) than the Sony A77. Moreover, the A7 III is markedly lighter (11 percent) than the A77. 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 A77 gets 470 shots out of its Sony NP-FM500H battery, while the A7 III can take 610 images on a single charge of its Sony NP-FZ100 power pack. The power pack in the A7 III can be charged via the USB port, 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. In case you want to display and compare another camera duo, you can use the CAM-parator app to select your camera combination among a large number of options.

Body Specifications

		Camera Model	Camera Width	Camera Height	Camera Depth	Camera Weight	Battery Life	Weather Sealing	Camera Launch	Launch Price (USD)	Street Price
1.		Sony A77	143 mm	104 mm	81 mm	732 g	470	Y	Aug 2011	1,399	ebay.com
2.		Sony A7 III	127 mm	96 mm	74 mm	650 g	610	Y	Feb 2018	1,999	amazon.com
3.		Canon 6D	145 mm	111 mm	71 mm	770 g	1090	Y	Sep 2012	2,099	ebay.com
4.		Nikon Z6	134 mm	101 mm	67 mm	675 g	310	Y	Aug 2018	1,999	ebay.com
5.		Panasonic GH5	139 mm	98 mm	87 mm	725 g	410	Y	Jan 2017	1,999	ebay.com
6.		Pentax K-3	131 mm	100 mm	77 mm	800 g	560	Y	Oct 2013	1,299	ebay.com
7.		Sony A7 II	127 mm	96 mm	60 mm	599 g	350	Y	Nov 2014	1,999	ebay.com
8.		Sony A7R III	127 mm	96 mm	74 mm	650 g	650	Y	Oct 2017	3,199	ebay.com
9.		Sony A7R IV	129 mm	96 mm	78 mm	665 g	670	Y	Jul 2019	3,499	ebay.com
10.		Sony A9	127 mm	96 mm	63 mm	673 g	650	Y	Apr 2017	4,499	ebay.com
11.		Sony A68	143 mm	104 mm	81 mm	610 g	540	n	Nov 2015	699	ebay.com
12.		Sony A77 II	143 mm	104 mm	81 mm	647 g	480	Y	May 2014	1,199	ebay.com
13.		Sony A99	147 mm	111 mm	78 mm	812 g	500	Y	Sep 2012	2,799	ebay.com
14.		Sony A6500	120 mm	67 mm	53 mm	453 g	350	Y	Oct 2016	1,399	ebay.com
15.		Sony A6600	120 mm	67 mm	69 mm	503 g	810	Y	Aug 2019	1,399	amazon.com
Note: Measurements and pricing do not include easily detachable parts, such as add-on or interchangeable lenses or optional viewfinders.
Convert to Imperial

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.

Sensor comparison

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. 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 are more costly to manufacture and tend to lead to bigger and heavier cameras and lenses.

Of the two cameras under consideration, the Sony A77 features an APS-C sensor and the Sony A7 III a full frame sensor. The sensor area in the A7 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.

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 SLT-A77 has a native sensitivity range from ISO 100 to ISO 16000, which can be extended to ISO 50-25600. The corresponding ISO settings for the Sony Alpha A7 III are ISO 100 to ISO 51200, with the possibility to increase the ISO range to 50-204800.

In terms of underlying technology, the A77 is build around a CMOS sensor, while the A7 III uses a BSI-CMOS imager. Both cameras use a Bayer filter for capturing RGB colors on a square grid of photosensors. This arrangement is found in most digital cameras.

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"). Of the two cameras under consideration, the A7 III offers substantially better image quality than the A77 (overall score 18 points higher). The 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 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 Model	Sensor Class	Resolution (MP)	Horiz. Pixels	Vert. Pixels	Video Format	DXO Portrait	DXO Landscape	DXO Sports	DXO Overall
1.		Sony A77	APS-C	24.0	6000	4000	1080/60p	24.0	13.2	801	78
2.		Sony A7 III	Full Frame	24.0	6000	4000	4K/30p	25.0	14.7	3730	96
3.		Canon 6D	Full Frame	20.0	5472	3648	1080/30p	23.8	12.1	2340	82
4.		Nikon Z6	Full Frame	24.3	6048	4024	4K/30p	25.3	14.3	3299	95
5.		Panasonic GH5	Four Thirds	20.2	5184	3888	4K/60p	23.9	13.0	807	77
6.		Pentax K-3	APS-C	24.1	6016	4000	1080/60i	23.7	13.4	1216	80
7.		Sony A7 II	Full Frame	24.0	6000	4000	1080/60p	24.9	13.6	2449	90
8.		Sony A7R III	Full Frame	42.2	7952	5304	4K/30p	26.0	14.7	3523	100
9.		Sony A7R IV	Full Frame	60.2	9504	6336	4K/30p	26.0	14.8	3344	99
10.		Sony A9	Full Frame	24.0	6000	4000	4K/30p	24.9	13.3	3517	92
11.		Sony A68	APS-C	24.0	6000	4000	1080/60i	24.1	13.5	701	79
12.		Sony A77 II	APS-C	24.0	6000	4000	1080/60p	24.4	13.4	1013	82
13.		Sony A99	Full Frame	24.0	6000	4000	1080/60p	25.0	14.0	1555	89
14.		Sony A6500	APS-C	24.0	6000	4000	4K/30p	24.5	13.7	1405	85
15.		Sony A6600	APS-C	24.0	6000	4000	4K/30p	23.8	13.4	1497	82

Many modern cameras are not only capable of taking still images, but also of capturing video footage. Both cameras under consideration are equipped with sensors that have a sufficiently high read-out speed for moving images, but the A7 III provides a better video resolution than the A77. It can shoot movie footage at 4K/30p, while the A77 is limited to 1080/60p.

Feature comparison

Apart from body and sensor, cameras can and do differ across a variety of features. The A77 and the A7 III 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 adjacent table lists some of the other core features of the Sony A77 and Sony A7 III along with similar information for a selection of comparators.

Core Features

		Camera Model	Viewfinder (Type or 000 dots)	Control Panel (yes/no)	LCD Specifications (inch/000 dots)	LCD Attach- ment	Touch Screen (yes/no)	Max Shutter Speed *	Max Shutter Flaps *	Built-in Flash (yes/no)	Built-in Image Stab
1.		Sony A77	2359	Y	3.0 / 921	full-flex	n	1/8000s	12.0/s	Y	Y
2.		Sony A7 III	2359	n	3.0 / 922	tilting	Y	1/8000s	10.0/s	n	Y
3.		Canon 6D	optical	Y	3.0 / 1040	fixed	n	1/4000s	4.5/s	n	n
4.		Nikon Z6	3690	Y	3.2 / 2100	tilting	Y	1/8000s	12.0/s	n	Y
5.		Panasonic GH5	3680	n	3.2 / 1620	swivel	Y	1/8000s	12.0/s	n	Y
6.		Pentax K-3	optical	Y	3.2 / 1037	fixed	n	1/8000s	8.3/s	Y	Y
7.		Sony A7 II	2400	n	3.0 / 1230	tilting	n	1/8000s	5.0/s	n	Y
8.		Sony A7R III	3686	n	3.0 / 1440	tilting	Y	1/8000s	10.0/s	n	Y
9.		Sony A7R IV	5760	n	3.0 / 1440	tilting	Y	1/8000s	10.0/s	n	Y
10.		Sony A9	3686	n	3.0 / 1440	tilting	Y	1/8000s	20.0/s	n	Y
11.		Sony A68	1440	Y	2.7 / 460	tilting	n	1/4000s	8.0/s	Y	Y
12.		Sony A77 II	2359	Y	3.0 / 1229	full-flex	n	1/8000s	12.0/s	Y	Y
13.		Sony A99	2359	Y	3.0 / 1229	full-flex	n	1/8000s	6.0/s	n	Y
14.		Sony A6500	2359	n	3.0 / 922	tilting	Y	1/4000s	11.0/s	Y	Y
15.		Sony A6600	2359	n	3.0 / 922	tilting	Y	1/4000s	11.0/s	n	Y
Note: *) Information refers to the mechanical shutter, unless the camera only has an electronic one.

One difference between the cameras concerns the presence of an on-board flash. The A77 has one, while the A7 III does not. While the built-in flash of the A77 is not very powerful, it can at times be useful as a fill-in light.

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 A77 and the A7 III 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.

Connectivity comparison

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 SLT-A77 and Sony Alpha A7 III and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.

Input-Output Connections

		Camera Model	Hotshoe Port	Internal Mic / Speaker	Microphone Port	Headphone Port	HDMI Port	USB Port	WiFi Support	NFC Support	Bluetooth Support
1.		Sony A77	Y	stereo / mono	Y	-	mini	2.0	-	-	-
2.		Sony A7 III	Y	stereo / mono	Y	Y	micro	3.1	Y	Y	Y
3.		Canon 6D	Y	mono / mono	Y	-	mini	2.0	Y	-	-
4.		Nikon Z6	Y	stereo / mono	Y	Y	micro	3.1	Y	-	Y
5.		Panasonic GH5	Y	stereo / mono	Y	Y	full	3.1	Y	-	Y
6.		Pentax K-3	Y	mono / mono	Y	Y	mini	3.0	-	-	-
7.		Sony A7 II	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
8.		Sony A7R III	Y	stereo / mono	Y	Y	micro	3.1	Y	Y	Y
9.		Sony A7R IV	Y	stereo / mono	Y	Y	micro	3.1	Y	Y	Y
10.		Sony A9	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	Y
11.		Sony A68	Y	stereo / mono	Y	-	micro	2.0	-	-	-
12.		Sony A77 II	Y	stereo / mono	Y	-	mini	2.0	Y	Y	-
13.		Sony A99	Y	stereo / mono	Y	Y	mini	2.0	-	-	-
14.		Sony A6500	Y	stereo / mono	Y	-	micro	2.0	Y	Y	-
15.		Sony A6600	Y	stereo / mono	Y	Y	YES	2.0	Y	Y	Y

It is notable that the A7 III offers wifi support, which can be a very convenient means to transfer image data to an off-camera location. In contrast, the A77 does not provide wifi capability.

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 features and operation of the A77 and A7 III can be found, respectively, in the Sony A77 Manual (free pdf) or the online Sony A7 III Manual.

Review summary

So what conclusions can be drawn? Is the Sony A77 better than the Sony A7 III or vice versa? The listing below highlights the relative strengths of the two models.

Advantages of the Sony Alpha SLT-A77:

• Easier setting verification: Features an LCD display on top to control 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: Is equipped with a small onboard flash to brighten deep shadow areas.
• 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 available for much longer (launched in August 2011).

Arguments in favor of the Sony Alpha A7 III:

• Better image quality: Scores substantially higher (18 points) in the DXO overall evaluation.
• More dynamic range: Captures a broader range of light and dark details (1.5 EV of extra DR).
• Better low-light sensitivity: Can shoot in dim conditions (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: Has a touchscreen to facilitate handling and shooting adjustments.
• 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 will fit more readily into a bag.
• Less heavy: Has a lower weight (by 82g or 11 percent) and is thus easier to take along.
• Longer lasting: Gets more shots (610 versus 470) out of a single battery charge.
• Easier travel charging: Can be conveniently charged via its USB port.
• More legacy lens friendly: Can use many 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.

If the number of relative strengths (bullet points above) is taken as a guide, the A7 III is the clear winner of the contest (22 : 9 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 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 A77 and the Sony A7 III place the cameras among the top in their class? Find out in the latest Best DSLR Camera and Best Mirrorless Interchangeable Lens 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 says little about, for example, the shooting experience and imaging performance of the A77 and the A7 III in practical situations. At times, user reviews, such as those published at amazon, address these issues in a useful manner, but such feedback is on many occasions incomplete, inconsistent, and unreliable.

Expert reviews

This is why expert reviews are important. The table below provides a synthesis of the camera assessments of some of the best known photo-gear review sites (amateurphotographer [AP], cameralabs [CL], digitalcameraworld [DCW], 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.

Expert Camera Reviews

		Camera   Model	AP   score	CL   score	DCW   score	DPR   score	EPZ   score	PB   score	Camera Launch	Launch Price (USD)	Street Price
1.		Sony A77	5/5	91/100	..	81/100	..	5/5	Aug 2011	1,399	ebay.com
2.		Sony A7 III	..	+ +	4.5/5	89/100	5/5	5/5	Feb 2018	1,999	amazon.com
3.		Canon 6D	5/5	+ +	..	83/100	4.5/5	4.5/5	Sep 2012	2,099	ebay.com
4.		Nikon Z6	5/5	..	5/5	89/100	4.5/5	5/5	Aug 2018	1,999	ebay.com
5.		Panasonic GH5	4.5/5	+ +	..	85/100	4.5/5	5/5	Jan 2017	1,999	ebay.com
6.		Pentax K-3	4/5	..	..	83/100	5/5	5/5	Oct 2013	1,299	ebay.com
7.		Sony A7 II	5/5	+	4/5	82/100	4.5/5	5/5	Nov 2014	1,999	ebay.com
8.		Sony A7R III	..	+ +	4/5	90/100	4.5/5	5/5	Oct 2017	3,199	ebay.com
9.		Sony A7R IV	5/5	+	4.5/5	91/100	4.5/5	5/5	Jul 2019	3,499	ebay.com
10.		Sony A9	5/5	+ +	4.8/5	89/100	5/5	5/5	Apr 2017	4,499	ebay.com
11.		Sony A68	3/5	..	..	..	4/5	4/5	Nov 2015	699	ebay.com
12.		Sony A77 II	4/5	..	..	80/100	4.5/5	5/5	May 2014	1,199	ebay.com
13.		Sony A99	5/5	..	..	84/100	4.5/5	4.5/5	Sep 2012	2,799	ebay.com
14.		Sony A6500	5/5	+ +	3.5/5	85/100	4.5/5	4.5/5	Oct 2016	1,399	ebay.com
15.		Sony A6600	4/5	+	4/5	83/100	4.5/5	4/5	Aug 2019	1,399	amazon.com
Note: (+ +) 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 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.

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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.

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