Sony A7 III vs A7S

The Sony Alpha A7 III and the Sony Alpha A7S are two digital cameras that were revealed to the public, respectively, in February 2018 and April 2014. Both the A7 III and the A7S 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 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
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		1080/60p 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 – 921k dots
Tilting touchscreen		Tilting screen (no touchscreen)
10 shutter flaps per second		5 shutter flaps per second
In-body stabilization		Lens stabilization only
Weathersealed body		Weathersealed body
610 shots per battery charge		380 shots per battery charge
127 x 96 x 74 mm, 650 g		127 x 94 x 48 mm, 489 g

Check A7 III price at
amazon.com
Check A7S 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 A7S? 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 is provided in the side-by-side display below. The two cameras are presented according to their relative size. Three successive views from the front, the top, and the rear are shown. 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 is somewhat smaller (2 percent) than the Sony A7 III. Moreover, the A7S is markedly lighter (25 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 Sony NP-FZ100 battery, while the A7S can take 380 images on a single charge of its Sony NP-FW50 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.

Body Specifications

		Camera Model	Camera Width	Camera Height	Camera Depth	Camera Weight	Battery Life	Weather Sealing	Camera Launch	Launch Price	Street Price
1.		Sony A7 III	127 mm	96 mm	74 mm	650 g	610	Y	Feb 2018	US$ 1 999	amazon.com
2.		Sony A7S	127 mm	94 mm	48 mm	489 g	380	Y	Apr 2014	US$ 2 499	ebay.com
3.		Nikon Z6	134 mm	101 mm	67 mm	675 g	310	Y	Aug 2018	US$ 1 999	ebay.com
4.		Panasonic GH5	139 mm	98 mm	87 mm	725 g	410	Y	Jan 2017	US$ 1 999	ebay.com
5.		Sony A7	127 mm	94 mm	48 mm	474 g	340	Y	Oct 2013	US$ 1 699	ebay.com
6.		Sony A7 II	127 mm	96 mm	60 mm	599 g	350	Y	Nov 2014	US$ 1 999	ebay.com
7.		Sony A7 IV	131 mm	96 mm	80 mm	659 g	580	Y	Oct 2021	US$ 2 499	amazon.com
8.		Sony A7C	124 mm	71 mm	60 mm	509 g	740	Y	Sep 2020	US$ 1 799	amazon.com
9.		Sony A7R	127 mm	94 mm	48 mm	465 g	340	Y	Oct 2013	US$ 2 299	ebay.com
10.		Sony A7R III	127 mm	96 mm	74 mm	650 g	650	Y	Oct 2017	US$ 3 199	ebay.com
11.		Sony A7R IIIA	127 mm	96 mm	74 mm	650 g	650	Y	Apr 2021	US$ 3 199	amazon.com
12.		Sony A7R IV	129 mm	96 mm	78 mm	665 g	670	Y	Jul 2019	US$ 3 499	ebay.com
13.		Sony A7S II	127 mm	96 mm	60 mm	627 g	370	Y	Sep 2015	US$ 2 999	ebay.com
14.		Sony A9	127 mm	96 mm	63 mm	673 g	650	Y	Apr 2017	US$ 4 499	ebay.com
15.		Sony A9 II	129 mm	96 mm	76 mm	678 g	690	Y	Oct 2019	US$ 4 499	amazon.com
16.		Sony RX1R	113 mm	65 mm	70 mm	482 g	270	n	Jun 2013	US$ 2 799	ebay.com
17.		Sony ZV-E1	121 mm	72 mm	54 mm	483 g	570	Y	Mar 2023	US$ 2 199	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 listed launch prices provide an indication of the market segment that the manufacturer of the cameras have been targeting. The A7 III was launched at a somewhat lower price (by 20 percent) than the A7S, which makes it more attractive for photographers on a tight budget. Normally, street prices remain initially close to the MSRP, but after a couple of months, the first discounts appear. 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 size of the sensor inside a digital camera is one of the key determinants 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 tend to be associated with larger, more expensive camera bodies and lenses.

Both cameras under consideration feature a full frame sensor, but their sensors differ slightly in size. The sensor area in the A7S is 1 percent bigger. They nevertheless have the same format factor of 1.0. Both cameras have a native aspect ratio (sensor width to sensor height) of 3:2.

Despite having a slightly smaller sensor, the Sony A7 III offers a higher resolution of 24 megapixels, compared with 12 MP of the Sony A7S. 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 5.94μm versus 8.45μm for the A7S). However, it should be noted that the A7 III is much more recent (by 3 years and 10 months) than the A7S, and its sensor will have benefitted from technological advances during this time that make it possible to gather light more efficiently.

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 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 A7S 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 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.

Consistent information on actual sensor performance is available from DXO Mark for many cameras. This service assesses and scores the color depth ("DXO Portrait"), dynamic range ("DXO Landscape"), and low-light sensitivity ("DXO Sports") of camera sensors, and also publishes an overall camera score. Of the two cameras under review, the A7 III has a notably higher overall DXO score than the A7S (overall score 9 points higher), which gives it an advantage in terms of imaging quality. This advantage is based on 1.1 bits higher color depth, 1.5 EV in additional dynamic range, and 0 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.

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	Full Frame	12.0	4240	2832	1080/60p	23.9	13.2	3702	87
3.		Nikon Z6	Full Frame	24.3	6048	4024	4K/30p	25.3	14.3	3299	95
4.		Panasonic GH5	Four Thirds	20.2	5184	3888	4K/60p	23.9	13.0	807	77
5.		Sony A7	Full Frame	24.0	6000	4000	1080/60p	24.8	14.2	2248	90
6.		Sony A7 II	Full Frame	24.0	6000	4000	1080/60p	24.9	13.6	2449	90
7.		Sony A7 IV	Full Frame	32.7	7008	4672	4K/60p	25.4	14.7	3379	97
8.		Sony A7C	Full Frame	24.0	6000	4000	4K/30p	25.0	14.7	3407	95
9.		Sony A7R	Full Frame	36.2	7360	4912	1080/60p	25.6	14.1	2746	95
10.		Sony A7R III	Full Frame	42.2	7952	5304	4K/30p	26.0	14.7	3523	100
11.		Sony A7R IIIA	Full Frame	42.2	7952	5304	4K/30p	26.0	14.7	3523	100
12.		Sony A7R IV	Full Frame	60.2	9504	6336	4K/30p	26.0	14.8	3344	99
13.		Sony A7S II	Full Frame	12.0	4240	2832	4K/30p	23.6	13.3	2993	85
14.		Sony A9	Full Frame	24.0	6000	4000	4K/30p	24.9	13.3	3517	92
15.		Sony A9 II	Full Frame	24.0	6000	4000	4K/30p	25.0	14.0	3434	93
16.		Sony RX1R	Full Frame	24.0	6000	4000	1080/60p	25.0	13.6	2537	91
17.		Sony ZV-E1	Full Frame	12.0	4240	2832	4K/60p	25.4	14.6	3181	96
Note: DXO values in italics represent estimates based on sensor size and age.

Many modern cameras cannot only take still pictures, but also record videos. 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 higher video resolution than the A7S. It can shoot video footage at 4K/30p, while the A7S is limited to 1080/60p.

Feature comparison

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 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, 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	2400	n	3.0 / 921	tilting	n	1/8000s	5.0/s	n	n
3.		Nikon Z6	3690	Y	3.2 / 2100	tilting	Y	1/8000s	12.0/s	n	Y
4.		Panasonic GH5	3680	n	3.2 / 1620	swivel	Y	1/8000s	12.0/s	n	Y
5.		Sony A7	2400	n	3.0 / 1230	tilting	n	1/8000s	5.0/s	n	n
6.		Sony A7 II	2400	n	3.0 / 1230	tilting	n	1/8000s	5.0/s	n	Y
7.		Sony A7 IV	3686	n	3.0 / 1037	swivel	Y	1/8000s	10.0/s	n	Y
8.		Sony A7C	2360	n	3.0 / 922	swivel	Y	1/4000s	10.0/s	n	Y
9.		Sony A7R	2400	n	3.0 / 1230	tilting	n	1/8000s	4.0/s	n	n
10.		Sony A7R III	3686	n	3.0 / 1440	tilting	Y	1/8000s	10.0/s	n	Y
11.		Sony A7R IIIA	3686	n	3.0 / 2340	tilting	Y	1/8000s	10.0/s	n	Y
12.		Sony A7R IV	5760	n	3.0 / 1440	tilting	Y	1/8000s	10.0/s	n	Y
13.		Sony A7S II	2400	n	3.0 / 1229	tilting	n	1/8000s	5.0/s	n	Y
14.		Sony A9	3686	n	3.0 / 1440	tilting	Y	1/8000s	20.0/s	n	Y
15.		Sony A9 II	3686	n	3.0 / 1440	tilting	Y	1/8000s	20.0/s	n	Y
16.		Sony RX1R	optional	n	3.0 / 1229	fixed	n	1/4000s	5.0/s	Y	n
17.		Sony ZV-E1	none	n	3.0 / 1037	swivel	Y	1/8000s	10.0/s	n	Y
Note: *) Information refers to the mechanical shutter, unless the camera only has an electronic one.

One feature that differentiates the A7 III and the A7S is in-body image stabilization (IBIS). The A7 III reduces the risk of handshake-induced blur with all attached lenses, while the A7S offers no blur reduction with lenses that themselves do not provide optical image stabilization.

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 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 only has one slot. The A7 III supports UHS-II cards (on its first slot), while the A7S 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 A7S 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	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
3.		Nikon Z6	Y	stereo / mono	Y	Y	micro	3.1	Y	-	Y
4.		Panasonic GH5	Y	stereo / mono	Y	Y	full	3.1	Y	-	Y
5.		Sony A7	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
6.		Sony A7 II	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
7.		Sony A7 IV	Y	stereo / mono	Y	Y	full	3.2	Y	-	Y
8.		Sony A7C	Y	stereo / mono	Y	Y	micro	3.2	Y	Y	Y
9.		Sony A7R	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
10.		Sony A7R III	Y	stereo / mono	Y	Y	micro	3.1	Y	Y	Y
11.		Sony A7R IIIA	Y	stereo / mono	Y	Y	micro	3.2	Y	Y	Y
12.		Sony A7R IV	Y	stereo / mono	Y	Y	micro	3.1	Y	Y	Y
13.		Sony A7S II	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
14.		Sony A9	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	Y
15.		Sony A9 II	Y	stereo / mono	Y	Y	micro	3.1	Y	Y	Y
16.		Sony RX1R	Y	stereo / mono	Y	-	mini	2.0	-	-	-
17.		Sony ZV-E1	Y	stereo / mono	Y	Y	micro	3.2	Y	-	Y

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

Review summary

So what is the bottom line? Is there a clear favorite between the Sony A7 III and the Sony A7S? Which camera is better? The listing below highlights the relative strengths of the two models.

Arguments in favor of the Sony Alpha A7 III:

• More detail: Offers more megapixels (24 vs 12MP) with a 41% higher linear resolution.
• Better image quality: Scores markedly higher (9 points) in the DXO overall assessment.
• Richer colors: Generates images with noticeably better colors (1.1 bits more color depth).
• More dynamic range: Captures a larger spectrum of light and dark details (1.5 EV of extra DR).
• 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.
• Larger viewfinder image: Features a viewfinder with a higher magnification (0.78x vs 0.71x).
• 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 380) on a single battery charge.
• Sharper images: Has hand-shake reducing image stabilization built-in.
• 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 segment (20 percent cheaper at launch).
• More modern: Reflects 3 years and 10 months of technical progress since the A7S launch.

Reasons to prefer the Sony Alpha A7S:

• Less heavy: Has a lower weight (by 161g or 25 percent) and is thus easier to take along.
• More heavily discounted: Has been around for much longer (launched in April 2014).

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 (18 : 2 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 A7S 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 remains incomplete and does no justice, for example, to the way the A7 III or the A7S perform in practice. User reviews, such as those found at amazon, can sometimes inform about these issues, but such feedback is often incomplete, inconsistent, and biased.

Expert reviews

This is where reviews by experts come in. 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	Street Price
1.		Sony A7 III	..	+ +	4.5/5	89/100	5/5	5/5	Feb 2018	US$ 1 999	amazon.com
2.		Sony A7S	4/5	..	..	86/100	4.5/5	5/5	Apr 2014	US$ 2 499	ebay.com
3.		Nikon Z6	5/5	..	5/5	89/100	4.5/5	5/5	Aug 2018	US$ 1 999	ebay.com
4.		Panasonic GH5	4.5/5	+ +	..	85/100	4.5/5	5/5	Jan 2017	US$ 1 999	ebay.com
5.		Sony A7	5/5	+ +	..	80/100	5/5	5/5	Oct 2013	US$ 1 699	ebay.com
6.		Sony A7 II	5/5	+	4/5	82/100	4.5/5	5/5	Nov 2014	US$ 1 999	ebay.com
7.		Sony A7 IV	5/5	+ +	4.5/5	89/100	4.5/5	4.5/5	Oct 2021	US$ 2 499	amazon.com
8.		Sony A7C	3.5/5	..	3.5/5	86/100	4/5	4/5	Sep 2020	US$ 1 799	amazon.com
9.		Sony A7R	5/5	+ +	..	82/100	4.5/5	5/5	Oct 2013	US$ 2 299	ebay.com
10.		Sony A7R III	..	+ +	4/5	90/100	4.5/5	5/5	Oct 2017	US$ 3 199	ebay.com
11.		Sony A7R IIIA	..	+ +	4/5	90/100	4.5/5	5/5	Apr 2021	US$ 3 199	amazon.com
12.		Sony A7R IV	5/5	+	4.5/5	91/100	4.5/5	5/5	Jul 2019	US$ 3 499	ebay.com
13.		Sony A7S II	5/5	+	..	..	4.5/5	5/5	Sep 2015	US$ 2 999	ebay.com
14.		Sony A9	5/5	+ +	4.8/5	89/100	5/5	5/5	Apr 2017	US$ 4 499	ebay.com
15.		Sony A9 II	..	..	5/5	90/100	5/5	5/5	Oct 2019	US$ 4 499	amazon.com
16.		Sony RX1R	5/5	..	..	..	4/5	4.5/5	Jun 2013	US$ 2 799	ebay.com
17.		Sony ZV-E1	..	+	4/5	..	..	4.5/5	Mar 2023	US$ 2 199	amazon.com
Note: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.

The review scores listed above should be treated with care, though. The assessments were made in relation to similar cameras of the same technological generation. A score, therefore, has to be seen in close connection to the price and market introduction time 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? In case you are interested in seeing how other cameras pair up, just make a corresponding selection in the search boxes 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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