Sony A7S vs A9 III

The Sony Alpha A7S and the Sony Alpha A9 III are two professional cameras that were revealed to the public, respectively, in April 2014 and November 2023. Both the A7S and the A9 III are mirrorless interchangeable lens cameras that are equipped with a full frame sensor. The A7S has a resolution of 12 megapixels, whereas the A9 III provides 24 MP.

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

Headline Specifications

Sony A7S		Sony A9 III
Mirrorless system camera		Mirrorless system camera
Sony E mount lenses		Sony E mount lenses
12 MP – Full Frame sensor		24 MP – Full Frame sensor
1080/60p Video		4K/120p Video
ISO 100-102,400 (50 - 409,600)		ISO 250-25,600 (125 - 51,200)
Electronic viewfinder (2400k dots)		Electronic viewfinder (9440k dots)
3.0" LCD – 921k dots		3.2" LCD – 2100k dots
Tilting screen (no touchscreen)		Fully flexible touchscreen
5 shutter flaps per second		120 shutter flaps per second
Lens stabilization only		In-body stabilization
Weathersealed body		Weathersealed body
380 shots per battery charge		530 shots per battery charge
127 x 94 x 48 mm, 489 g		136 x 97 x 83 mm, 702 g

Check A7S offers at
ebay.com
Check A9 III price at
amazon.com

Going beyond this snapshot of core features and characteristics, what are the differences between the Sony Alpha A7S and the Sony Alpha A9 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 A7S and the Sony A9 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 A9 III is notably larger (11 percent) than the Sony A7S. Moreover, the A9 III is substantially heavier (44 percent) than the A7S. 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 A7S gets 380 shots out of its Sony NP-FW50 battery, while the A9 III can take 530 images on a single charge of its Sony 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 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	Street Price
1.		Sony A7S	127 mm	94 mm	48 mm	489 g	380	Y	Apr 2014	US$ 2 499	ebay.com
2.		Sony A9 III	136 mm	97 mm	83 mm	702 g	530	Y	Nov 2023	US$ 5 999	amazon.com
3.		Nikon D750	141 mm	113 mm	78 mm	750 g	1230	Y	Sep 2014	US$ 2 299	ebay.com
4.		Nikon Df	144 mm	110 mm	67 mm	760 g	1400	Y	Nov 2013	US$ 2 749	ebay.com
5.		Panasonic GH4	133 mm	93 mm	84 mm	560 g	500	Y	Feb 2014	US$ 1 499	ebay.com
6.		Sony A1 II	136 mm	97 mm	83 mm	743 g	520	Y	Nov 2024	US$ 6 499	amazon.com
7.		Sony A7	127 mm	94 mm	48 mm	474 g	340	Y	Oct 2013	US$ 1 699	ebay.com
8.		Sony A7 II	127 mm	96 mm	60 mm	599 g	350	Y	Nov 2014	US$ 1 999	ebay.com
9.		Sony A7 III	127 mm	96 mm	74 mm	650 g	610	Y	Feb 2018	US$ 1 999	amazon.com
10.		Sony A7R	127 mm	94 mm	48 mm	465 g	340	Y	Oct 2013	US$ 2 299	ebay.com
11.		Sony A7R II	127 mm	96 mm	60 mm	625 g	290	Y	Jun 2015	US$ 3 199	ebay.com
12.		Sony A7S II	127 mm	96 mm	60 mm	627 g	370	Y	Sep 2015	US$ 2 999	ebay.com
13.		Sony A9	127 mm	96 mm	63 mm	673 g	650	Y	Apr 2017	US$ 4 499	ebay.com
14.		Sony A9 II	129 mm	96 mm	76 mm	678 g	690	Y	Oct 2019	US$ 4 499	amazon.com
15.		Sony RX1R	113 mm	65 mm	70 mm	482 g	270	n	Jun 2013	US$ 2 799	ebay.com
16.		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

Any camera decision will naturally be influenced heavily by the price. The listed launch prices provide an indication of the market segment that the manufacturer of the cameras have been targeting. The A7S was launched at a markedly lower price (by 58 percent) than the A9 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 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. 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, but their sensors differ slightly in size. The sensor area in the A9 III is 1 percent smaller. 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.

Technology-wise, the A9 III uses a more advanced image processing engine (Dual BIONZ XR) than the A7S (BIONZ X), with benefits for noise reduction, color accuracy, and processing speed.

Despite having a slightly smaller sensor, the A9 III offers a higher resolution of 24 megapixels, compared with 12 MP of the 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 A9 III is much more recent (by 9 years and 7 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 A9 III implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the A9 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 A9 III has on-sensor phase detect pixels, which results in fast and reliable autofocus acquisition even during live view operation.

The Sony Alpha A7S has a native sensitivity range from ISO 100 to ISO 102400, which can be extended to ISO 50-409600. The corresponding ISO settings for the Sony Alpha A9 III are ISO 250 to ISO 25600, with the possibility to increase the ISO range to 125-51200.

In terms of underlying technology, the A7S is build around a CMOS sensor, while the A9 III uses a Stacked 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"). 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 A7S	Full Frame	12.0	4240	2832	1080/60p	23.9	13.2	3702	87
2.		Sony A9 III	Full Frame	24.0	6000	4000	4K/120p	25.4	14.7	3243	96
3.		Nikon D750	Full Frame	24.2	6016	4016	1080/60p	24.8	14.5	2956	93
4.		Nikon Df	Full Frame	16.2	4928	3280	none	24.6	13.1	3279	89
5.		Panasonic GH4	Four Thirds	15.9	4608	3456	4K/30p	23.2	12.8	791	74
6.		Sony A1 II	Full Frame	49.8	8640	5760	8k/30p	25.4	14.8	3363	97
7.		Sony A7	Full Frame	24.0	6000	4000	1080/60p	24.8	14.2	2248	90
8.		Sony A7 II	Full Frame	24.0	6000	4000	1080/60p	24.9	13.6	2449	90
9.		Sony A7 III	Full Frame	24.0	6000	4000	4K/30p	25.0	14.7	3730	96
10.		Sony A7R	Full Frame	36.2	7360	4912	1080/60p	25.6	14.1	2746	95
11.		Sony A7R II	Full Frame	42.2	7952	5304	4K/30p	26.0	13.9	3434	98
12.		Sony A7S II	Full Frame	12.0	4240	2832	4K/30p	23.6	13.3	2993	85
13.		Sony A9	Full Frame	24.0	6000	4000	4K/30p	24.9	13.3	3517	92
14.		Sony A9 II	Full Frame	24.0	6000	4000	4K/30p	25.0	14.0	3434	93
15.		Sony RX1R	Full Frame	24.0	6000	4000	1080/60p	25.0	13.6	2537	91
16.		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 are not only capable of taking still images, but can also record movies. Both cameras under consideration are equipped with sensors that have a sufficiently high read-out speed for moving images, but the A9 III provides a better video resolution than the A7S. It can shoot movie footage at 4K/120p, 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 A9 III offers a substantially higher resolution than the one in the A7S (9440k vs 2400k dots). The table below summarizes some of the other core capabilities of the Sony A7S and Sony A9 III in connection with corresponding information for a sample of similar 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 A7S	2400	n	3.0 / 921	tilting	n	1/8000s	5.0/s	n	n
2.		Sony A9 III	9440	n	3.2 / 2100	full-flex	Y	1/80000s	120.0/s	n	Y
3.		Nikon D750	optical	Y	3.2 / 1229	tilting	n	1/4000s	6.0/s	Y	n
4.		Nikon Df	optical	Y	3.2 / 921	fixed	n	1/4000s	5.5/s	n	n
5.		Panasonic GH4	2359	n	3.0 / 1036	swivel	Y	1/8000s	12.0/s	Y	n
6.		Sony A1 II	9437	n	3.2 / 2100	full-flex	Y	1/8000s	30.0/s	n	Y
7.		Sony A7	2400	n	3.0 / 1230	tilting	n	1/8000s	5.0/s	n	n
8.		Sony A7 II	2400	n	3.0 / 1230	tilting	n	1/8000s	5.0/s	n	Y
9.		Sony A7 III	2359	n	3.0 / 922	tilting	Y	1/8000s	10.0/s	n	Y
10.		Sony A7R	2400	n	3.0 / 1230	tilting	n	1/8000s	4.0/s	n	n
11.		Sony A7R II	2400	n	3.0 / 1229	tilting	n	1/8000s	5.0/s	n	Y
12.		Sony A7S II	2400	n	3.0 / 1229	tilting	n	1/8000s	5.0/s	n	Y
13.		Sony A9	3686	n	3.0 / 1440	tilting	Y	1/8000s	20.0/s	n	Y
14.		Sony A9 II	3686	n	3.0 / 1440	tilting	Y	1/8000s	20.0/s	n	Y
15.		Sony RX1R	optional	n	3.0 / 1229	fixed	n	1/4000s	5.0/s	Y	n
16.		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 differentiating feature between the two cameras concerns the touch sensitivity of the rear screen. The A9 III has a touchscreen, while the A7S 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 A9 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.

The A7S writes its imaging data to SDXC or Memory Stick PRO Duo cards, while the A9 III uses CFexpress (type A) or SDXC cards. The A9 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 A9 III supports UHS-II cards (Ultra High Speed data transfer of up to 312 MB/s), while the A7S can use UHS-I cards (up to 104 MB/s).

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 A7S and Sony Alpha A9 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 A7S	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
2.		Sony A9 III	Y	stereo / mono	Y	Y	full	3.2	Y	-	Y
3.		Nikon D750	Y	stereo / mono	Y	Y	mini	2.0	Y	-	-
4.		Nikon Df	Y	- / -	-	-	mini	2.0	-	-	-
5.		Panasonic GH4	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
6.		Sony A1 II	Y	stereo / mono	Y	Y	full	3.2	Y	-	Y
7.		Sony A7	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
8.		Sony A7 II	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
9.		Sony A7 III	Y	stereo / mono	Y	Y	micro	3.1	Y	Y	Y
10.		Sony A7R	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
11.		Sony A7R II	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
12.		Sony A7S II	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
13.		Sony A9	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	Y
14.		Sony A9 II	Y	stereo / mono	Y	Y	micro	3.1	Y	Y	Y
15.		Sony RX1R	Y	stereo / mono	Y	-	mini	2.0	-	-	-
16.		Sony ZV-E1	Y	stereo / mono	Y	Y	micro	3.2	Y	-	Y

Studio photographers will appreciate that the Sony A9 III (unlike the A7S) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.

The A9 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 A7S and A9 III can be found, respectively, in the Sony A7S Manual (free pdf) or the online Sony A9 III Manual.

Review summary

So what conclusions can be drawn? Which of the two cameras – the Sony A7S or the Sony A9 III – has the upper hand? Is one clearly better than the other? A synthesis of the relative strong points of each of the models is listed below.

Advantages of the Sony Alpha A7S:

• Less heavy: Is lighter (by 213g or 30 percent) and hence easier to carry around.
• Easier device pairing: Supports NFC for fast wireless image transfer over short distances.
• More affordable: Was introduced into a lower priced category (58 percent cheaper at launch).
• More heavily discounted: Has been available for much longer (launched in April 2014).

Reasons to prefer the Sony Alpha A9 III:

• More detail: Has more megapixels (24 vs 12MP), which boosts linear resolution by 41%.
• Better jpgs: Has a more modern image processing engine (Dual BIONZ XR vs BIONZ X).
• Better video: Provides higher definition movie capture (4K/120p vs 1080/60p).
• Better live-view autofocus: Features on-sensor phase-detection for more confident autofocus.
• More detailed viewfinder: Has higher resolution electronic viewfinder (9440k vs 2400k dots).
• Larger viewfinder image: Features a viewfinder with a higher magnification (0.9x vs 0.71x).
• Larger screen: Has a bigger rear LCD (3.2" vs 3.0") for image review and settings control.
• More detailed LCD: Has a higher resolution rear screen (2100k vs 921k dots).
• More flexible LCD: Has a full-flex screen for odd-angle shots in portrait or landscape orientation.
• Fewer buttons to press: Has a touchscreen to facilitate handling and shooting adjustments.
• More selfie-friendly: Has an articulated screen that can be turned to be front-facing.
• Faster shutter: Has higher mechanical shutter speed (1/80000s vs 1/8000s) to freeze action.
• Faster burst: Shoots at higher frequency (120 vs 5 flaps/sec) to capture the decisive moment.
• Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
• Longer lasting: Gets more shots (530 versus 380) 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.
• Easier wireless transfer: Supports Bluetooth for image sharing without cables.
• Better studio light control: Has a PC Sync socket to connect to professional strobe lights.
• 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 9 years and 7 months of technical progress since the A7S launch.

If the number of relative strengths (bullet points above) is taken as a guide, the A9 III is the clear winner of the contest (23 : 4 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 A7S and the Sony A9 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 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 A7S and the A9 III in practical situations. 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.

Expert reviews

This is why expert reviews are important. The adjacent summary-table relays the overall verdicts of several of the most popular camera 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 A7S	4/5	..	..	86/100	4.5/5	5/5	Apr 2014	US$ 2 499	ebay.com
2.		Sony A9 III	4.5/5	..	..	91/100	..	..	Nov 2023	US$ 5 999	amazon.com
3.		Nikon D750	5/5	+ +	4/5	90/100	4.5/5	4.5/5	Sep 2014	US$ 2 299	ebay.com
4.		Nikon Df	4/5	..	..	81/100	4/5	4/5	Nov 2013	US$ 2 749	ebay.com
5.		Panasonic GH4	5/5	+ +	..	85/100	5/5	5/5	Feb 2014	US$ 1 499	ebay.com
6.		Sony A1 II	..	..	..	..	..	..	Nov 2024	US$ 6 499	amazon.com
7.		Sony A7	5/5	+ +	..	80/100	5/5	5/5	Oct 2013	US$ 1 699	ebay.com
8.		Sony A7 II	5/5	+	4/5	82/100	4.5/5	5/5	Nov 2014	US$ 1 999	ebay.com
9.		Sony A7 III	..	+ +	4.5/5	89/100	5/5	5/5	Feb 2018	US$ 1 999	amazon.com
10.		Sony A7R	5/5	+ +	..	82/100	4.5/5	5/5	Oct 2013	US$ 2 299	ebay.com
11.		Sony A7R II	5/5	+ +	5/5	90/100	5/5	5/5	Jun 2015	US$ 3 199	ebay.com
12.		Sony A7S II	5/5	+	..	..	4.5/5	5/5	Sep 2015	US$ 2 999	ebay.com
13.		Sony A9	5/5	+ +	4.8/5	89/100	5/5	5/5	Apr 2017	US$ 4 499	ebay.com
14.		Sony A9 II	..	..	5/5	90/100	5/5	5/5	Oct 2019	US$ 4 499	amazon.com
15.		Sony RX1R	5/5	..	..	..	4/5	4.5/5	Jun 2013	US$ 2 799	ebay.com
16.		Sony ZV-E1	..	+	4/5	..	..	4.5/5	Mar 2023	US$ 2 199	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. A score, therefore, has to be seen in close connection to the price and market introduction time 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.

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Other camera comparisons

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