Sony A7 III vs A7S II

The Sony Alpha A7 III and the Sony Alpha 7S II are two digital cameras that were revealed to the public, respectively, in February 2018 and September 2015. Both the A7 III and the A7S II are mirrorless interchangeable lens cameras that are equipped with a full frame sensor. The A7 III has a resolution of 24 megapixels, whereas the A7S II provides 12 MP.

Below is an overview of the main specs of the two cameras as a starting point for the comparison.

Headline Specifications

Sony A7 III		Sony A7S II
Mirrorless system camera		Mirrorless system camera
Sony E mount lenses		Sony E mount lenses
24 MP – Full Frame sensor		12 MP – Full Frame sensor
4K/30p Video		4K/30p Video
ISO 100-51,200 (50 - 204,800)		ISO 100-102,400 (50 - 409,600)
Electronic viewfinder (2359k dots)		Electronic viewfinder (2400k dots)
3.0" LCD – 922k dots		3.0" LCD – 1229k dots
Tilting touchscreen		Tilting screen (no touchscreen)
10 shutter flaps per second		5 shutter flaps per second
In-body stabilization		In-body stabilization
Weathersealed body		Weathersealed body
610 shots per battery charge		370 shots per battery charge
127 x 96 x 74 mm, 650 g		127 x 96 x 60 mm, 627 g

Check A7 III price at
amazon.com
Check A7S II offers at
ebay.com

Going beyond this snapshot of core features and characteristics, what are the differences between the Sony Alpha A7 III and the Sony Alpha 7S II? 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

An illustration of the physical size and weight of the Sony A7 III and the Sony A7S II is provided in the side-by-side display below. 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.

In this particular case, the Sony A7 III and the Sony A7S II have exactly the same width and height, and, thus, have identically-sized bodies. However, the A7S II is slightly lighter (4 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. In this particular case, both cameras feature the same lens mount, so that they can use the same lenses. You can compare the optics available in the Sony FE Lens Catalog. 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 A7 III gets 610 shots out of its NP-FZ100 battery, while the A7S II can take 370 images on a single charge of its NP-FW50 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.

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 A7 III	127 mm	96 mm	74 mm	650 g	610	Y	Feb 2018	1,999	amazon.com
2.		Sony A7S II	127 mm	96 mm	60 mm	627 g	370	Y	Sep 2015	2,999	ebay.com
3.		Canon 6D Mark II	144 mm	111 mm	75 mm	765 g	1200	Y	Jun 2017	1,999	amazon.com
4.		Nikon Z6	134 mm	101 mm	67 mm	675 g	310	Y	Aug 2018	1,999	ebay.com
5.		Sony A7 IV	131 mm	96 mm	80 mm	659 g	580	Y	Oct 2021	2,499	amazon.com
6.		Sony A7S III	127 mm	97 mm	81 mm	699 g	600	Y	Jul 2020	3,499	amazon.com
7.		Sony A7C	124 mm	71 mm	60 mm	509 g	740	Y	Sep 2020	1,799	amazon.com
8.		Sony A9 II	129 mm	96 mm	76 mm	678 g	690	Y	Oct 2019	4,499	amazon.com
9.		Sony A7R IV	129 mm	96 mm	78 mm	665 g	670	Y	Jul 2019	3,499	amazon.com
10.		Sony A7R III	127 mm	96 mm	74 mm	650 g	650	Y	Oct 2017	3,199	ebay.com
11.		Sony A9	127 mm	96 mm	63 mm	673 g	650	Y	Apr 2017	4,499	ebay.com
12.		Sony A7R II	127 mm	96 mm	60 mm	625 g	290	Y	Jun 2015	3,199	ebay.com
13.		Sony A7 II	127 mm	96 mm	60 mm	599 g	350	Y	Nov 2014	1,999	ebay.com
14.		Sony A7S	127 mm	94 mm	48 mm	489 g	380	Y	Apr 2014	2,499	ebay.com
15.		Sony A7	127 mm	94 mm	48 mm	474 g	340	Y	Oct 2013	1,699	ebay.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 A7 III was launched at a markedly lower price (by 33 percent) than the A7S II, 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.

Sensor comparison

The size of the imaging sensor is a crucial determinant 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. 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 more expensive and lead to bigger and heavier cameras and lenses.

Both cameras under consideration feature a full frame sensor and have a format factor (sometimes also referred to as "crop factor") of 1.0. Within the spectrum of camera sensors, this places the review cameras among the large-sensor cameras that aim for top notch image quality. Both cameras have a native aspect ratio (sensor width to sensor height) of 3:2.

While the two cameras under review share the same sensor size, the A7 III offers a higher resolution of 24 megapixels, compared with 12 MP of the A7S II. This megapixels advantage translates into a 42 percent gain in linear resolution. On the other hand, these sensor specs imply that the A7 III has a higher pixel density and a smaller size of the individual pixel (with a pixel pitch of 5.94μm versus 8.40μm for the A7S II). In this context, it should be noted, however, that the A7 III is much more recent (by 2 years and 5 months) than the A7S II, and its sensor will have benefitted from technological advances during this time that compensate for the smaller pixel size.

The resolution advantage of the Sony A7 III implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the A7 III 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 II 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 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 7S II are ISO 100 to ISO 102400, with the possibility to increase the ISO range to 50-409600.

In terms of underlying technology, the A7 III is build around a BSI-CMOS sensor, while the A7S II uses a 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.

For many cameras, data on sensor performance has been reported by DXO Mark. 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 review, the A7 III provides substantially higher image quality than the A7S II, with an overall score that is 11 points higher. This advantage is based on 1.4 bits higher color depth, 1.4 EV in additional dynamic range, and 0.3 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 A7 III	Full Frame	24.0	6000	4000	4K/30p	25.0	14.7	3730	96
2.		Sony A7S II	Full Frame	12.0	4240	2832	4K/30p	23.6	13.3	2993	85
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
5.		Sony A7 IV	Full Frame	32.7	7008	4672	4K/60p	25.4	14.7	3379	97
6.		Sony A7S III	Full Frame	12.0	4240	2832	4K/120p	23.7	13.9	2520	86
7.		Sony A7C	Full Frame	24.0	6000	4000	4K/30p	25.0	14.7	3407	95
8.		Sony A9 II	Full Frame	24.0	6000	4000	4K/30p	25.0	14.0	3434	93
9.		Sony A7R IV	Full Frame	60.2	9504	6336	4K/30p	26.0	14.8	3344	99
10.		Sony A7R III	Full Frame	42.2	7952	5304	4K/30p	26.0	14.7	3523	100
11.		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 A7S	Full Frame	12.0	4240	2832	1080/60p	23.9	13.2	3702	87
15.		Sony A7	Full Frame	24.0	6000	4000	1080/60p	24.8	14.2	2248	90

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, and both provide the same movie specifications (4K/30p).

Feature comparison

Beyond 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 II offers a slightly higher resolution than the one in the A7 III (2400k vs 2359k dots). The following table reports on some other key feature differences and similarities of the Sony A7 III, the Sony A7S II, and comparable cameras.

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 A7 III	2359	n	3.0 / 922	tilting	Y	1/8000s	10.0/s	n	Y
2.		Sony A7S II	2400	n	3.0 / 1229	tilting	n	1/8000s	5.0/s	n	Y
3.		Canon 6D Mark II	optical	Y	3.0 / 1040	swivel	Y	1/4000s	6.5/s	n	n
4.		Nikon Z6	3690	Y	3.2 / 2100	tilting	Y	1/8000s	12.0/s	n	Y
5.		Sony A7 IV	3686	n	3.0 / 1037	swivel	Y	1/8000s	10.0/s	n	Y
6.		Sony A7S III	9440	n	3.0 / 1440	swivel	Y	1/8000s	10.0/s	n	Y
7.		Sony A7C	2360	n	3.0 / 922	swivel	Y	1/4000s	10.0/s	n	Y
8.		Sony A9 II	3686	n	3.0 / 1440	tilting	Y	1/8000s	20.0/s	n	Y
9.		Sony A7R IV	5760	n	3.0 / 1440	tilting	Y	1/8000s	10.0/s	n	Y
10.		Sony A7R III	3686	n	3.0 / 1440	tilting	Y	1/8000s	10.0/s	n	Y
11.		Sony A9	3686	n	3.0 / 1440	tilting	Y	1/8000s	20.0/s	n	Y
12.		Sony A7R II	2400	n	3.0 / 1229	tilting	n	1/8000s	5.0/s	n	Y
13.		Sony A7 II	2400	n	3.0 / 1230	tilting	n	1/8000s	5.0/s	n	Y
14.		Sony A7S	2400	n	3.0 / 921	tilting	n	1/8000s	5.0/s	n	n
15.		Sony A7	2400	n	3.0 / 1230	tilting	n	1/8000s	5.0/s	n	n
Notes: *) Information refers to the mechanical shutter, unless the camera only has an electronic one.

One differentiating feature between the two cameras concerns the touch sensitivity of the rear screen. The A7 III has a touchscreen, while the A7S II has a conventional panel. Touch control can be particularly helpful, for example, for setting the focus point.

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 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 A7S II 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 A7S II only has one slot. The A7 III supports UHS-II cards (on its first slot), while the A7S II 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 A7 III and Sony Alpha 7S II 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 A7 III	Y	stereo / mono	Y	Y	micro	3.1	Y	Y	Y
2.		Sony A7S II	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
3.		Canon 6D Mark II	Y	stereo / mono	Y	-	mini	2.0	Y	Y	Y
4.		Nikon Z6	Y	stereo / mono	Y	Y	micro	3.1	Y	-	Y
5.		Sony A7 IV	Y	stereo / mono	Y	Y	full	3.2	Y	-	Y
6.		Sony A7S III	Y	stereo / mono	Y	Y	full	3.2	Y	-	Y
7.		Sony A7C	Y	stereo / mono	Y	Y	micro	3.2	Y	Y	Y
8.		Sony A9 II	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 A7R III	Y	stereo / mono	Y	Y	micro	3.1	Y	Y	Y
11.		Sony A9	Y	stereo / mono	Y	Y	micro	2.0	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 A7S	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
15.		Sony A7	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-

The A7 III is a recent model that features in the current product line-up of Sony. In contrast, the A7S II has been discontinued (but can be found pre-owned on ebay). As a replacement in the same line of cameras, the A7S II was succeeded by the Sony A7S III. Further information on the features and operation of the A7 III and A7S II can be found, respectively, in the Sony A7 III Manual (free pdf) or the online Sony A7S II Manual.

Review summary

So how do things add up? Is the Sony A7 III better than the Sony A7S II or vice versa? The listing below highlights the relative strengths of the two models.

Reasons to prefer the Sony Alpha A7 III:

• More detail: Offers more megapixels (24 vs 12MP) with a 41% higher linear resolution.
• Better image quality: Scores substantially higher (11 points) in the DXO overall assessment.
• Richer colors: Generates images with noticeably better colors (1.4 bits more color depth).
• More dynamic range: Captures a larger spectrum of light and dark details (1.4 EV of extra DR).
• Better live-view autofocus: Features on-sensor phase-detection for more confident autofocus.
• Fewer buttons to press: Is equipped with a touch-sensitive rear screen to facilitate handling.
• Faster burst: Shoots at higher frequency (10 vs 5 flaps/sec) to capture the decisive moment.
• Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
• Longer lasting: Can take more shots (610 versus 370) on a single battery charge.
• Faster data transfer: Supports a more advanced USB protocol (3.1 vs 2.0).
• 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 affordable: Was introduced into a lower priced category (33 percent cheaper at launch).
• More modern: Reflects 2 years and 5 months of technical progress since the A7S II launch.

Arguments in favor of the Sony Alpha 7S II:

• More detailed LCD: Has a higher resolution rear screen (1229k vs 922k dots).
• More heavily discounted: Has been around for much longer (launched in September 2015).

If the count of relative strengths (bullet points above) is taken as a measure, the A7 III is the clear winner of the match-up (15 : 2 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 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 A7 III and the Sony A7S II 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 incomplete and does no justice, for example, to the way the A7 III or the A7S II perform in practice. 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 hands-on reviews by experts 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 A7 III	..	+ +	4.5/5	89/100	5/5	5/5	Feb 2018	1,999	amazon.com
2.		Sony A7S II	5/5	+	..	..	4.5/5	5/5	Sep 2015	2,999	ebay.com
3.		Canon 6D Mark II	4/5	+	4/5	80/100	4.5/5	4/5	Jun 2017	1,999	amazon.com
4.		Nikon Z6	5/5	..	5/5	89/100	4.5/5	5/5	Aug 2018	1,999	ebay.com
5.		Sony A7 IV	5/5	+ +	4.5/5	89/100	4.5/5	4.5/5	Oct 2021	2,499	amazon.com
6.		Sony A7S III	4.5/5	+ +	5/5	91/100	4.5/5	5/5	Jul 2020	3,499	amazon.com
7.		Sony A7C	3.5/5	..	3.5/5	86/100	4/5	4/5	Sep 2020	1,799	amazon.com
8.		Sony A9 II	..	..	5/5	90/100	5/5	5/5	Oct 2019	4,499	amazon.com
9.		Sony A7R IV	5/5	+	4.5/5	91/100	4.5/5	5/5	Jul 2019	3,499	amazon.com
10.		Sony A7R III	..	+ +	4/5	90/100	4.5/5	5/5	Oct 2017	3,199	ebay.com
11.		Sony A9	5/5	+ +	4.8/5	89/100	5/5	5/5	Apr 2017	4,499	ebay.com
12.		Sony A7R II	5/5	+ +	5/5	90/100	5/5	5/5	Jun 2015	3,199	ebay.com
13.		Sony A7 II	5/5	+	4/5	82/100	4.5/5	5/5	Nov 2014	1,999	ebay.com
14.		Sony A7S	4/5	..	..	86/100	4.5/5	5/5	Apr 2014	2,499	ebay.com
15.		Sony A7	5/5	+ +	..	80/100	5/5	5/5	Oct 2013	1,699	ebay.com
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. 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.

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Other camera comparisons

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