Sony A7 IV vs A9 III

The Sony Alpha A7 IV and the Sony Alpha A9 III are two digital cameras that were officially introduced, respectively, in October 2021 and November 2023. Both the A7 IV and the A9 III are mirrorless interchangeable lens cameras that are equipped with a full frame sensor. The A7 IV has a resolution of 32.7 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 A7 IV		Sony A9 III
Mirrorless system camera		Mirrorless system camera
Sony E mount lenses		Sony E mount lenses
32.7 MP – Full Frame sensor		24 MP – Full Frame sensor
4K/60p Video		4K/120p Video
ISO 100-51,200 (50 - 204,800)		ISO 250-25,600 (125 - 51,200)
Electronic viewfinder (3686k dots)		Electronic viewfinder (9440k dots)
3.0" LCD – 1037k dots		3.2" LCD – 2100k dots
Swivel touchscreen		Fully flexible touchscreen
10 shutter flaps per second		120 shutter flaps per second
In-body stabilization		In-body stabilization
Weathersealed body		Weathersealed body
580 shots per battery charge		530 shots per battery charge
131 x 96 x 80 mm, 659 g		136 x 97 x 83 mm, 702 g

Check A7 IV price at
amazon.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 A7 IV 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

An illustration of the physical size and weight of the Sony A7 IV and the Sony A9 III is provided 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 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 A9 III is somewhat larger (5 percent) than the Sony A7 IV. Moreover, the A9 III is markedly heavier (7 percent) than the A7 IV. 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.

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 (USD)	Street Price
1.		Sony A7 IV	131 mm	96 mm	80 mm	659 g	580	Y	Oct 2021	2,499	amazon.com
2.		Sony A9 III	136 mm	97 mm	83 mm	702 g	530	Y	Nov 2023	5,999	amazon.com
3.		Sony A1	129 mm	97 mm	81 mm	737 g	530	Y	Jan 2021	6,499	amazon.com
4.		Sony A7 II	127 mm	96 mm	60 mm	599 g	350	Y	Nov 2014	1,999	ebay.com
5.		Sony A7 III	127 mm	96 mm	74 mm	650 g	610	Y	Feb 2018	1,999	amazon.com
6.		Sony A7R III	127 mm	96 mm	74 mm	650 g	650	Y	Oct 2017	3,199	ebay.com
7.		Sony A7R IIIA	127 mm	96 mm	74 mm	650 g	650	Y	Apr 2021	3,199	amazon.com
8.		Sony A7R IV	129 mm	96 mm	78 mm	665 g	670	Y	Jul 2019	3,499	ebay.com
9.		Sony A7R IVA	129 mm	96 mm	78 mm	665 g	670	Y	Apr 2021	3,499	amazon.com
10.		Sony A7R V	131 mm	97 mm	82 mm	723 g	530	Y	Oct 2022	3,899	amazon.com
11.		Sony A7S II	127 mm	96 mm	60 mm	627 g	370	Y	Sep 2015	2,999	ebay.com
12.		Sony A7S III	127 mm	97 mm	81 mm	699 g	600	Y	Jul 2020	3,499	amazon.com
13.		Sony A9	127 mm	96 mm	63 mm	673 g	650	Y	Apr 2017	4,499	ebay.com
14.		Sony A9 II	129 mm	96 mm	76 mm	678 g	690	Y	Oct 2019	4,499	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 obviously take relative prices into account. The listed launch prices provide an indication of the market segment that the manufacturer of the cameras have been targeting. The A7 IV was launched at a markedly lower price (by 58 percent) than the A9 III, which puts it into a different market segment. 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. 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. 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 A7 IV (BIONZ XR), with benefits for noise reduction, color accuracy, and processing speed.

With 32.7MP, the A7 IV offers a higher resolution than the A9 III (24MP), but the A7 IV has smaller individual pixels (pixel pitch of 5.12μm versus 5.94μm for the A9 III). Moreover, the A9 III is a much more recent model (by 2 years) than the A7 IV, and its sensor will have benefitted from technological advances during this time that enhance the light gathering capacity of its pixels. Coming back to sensor resolution, it should be mentioned that the A7 IV has no anti-alias filter installed, so that it can capture all the detail its sensor resolves.

The resolution advantage of the Sony A7 IV implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the A7 IV for good quality output (200 dots per inch) amounts to 35 x 23.4 inches or 89 x 59.3 cm, for very good quality (250 dpi) 28 x 18.7 inches or 71.2 x 47.5 cm, and for excellent quality (300 dpi) 23.4 x 15.6 inches or 59.3 x 39.6 cm. The corresponding values for the Sony A9 III are 30 x 20 inches or 76.2 x 50.8 cm for good quality, 24 x 16 inches or 61 x 40.6 cm for very good quality, and 20 x 13.3 inches or 50.8 x 33.9 cm for excellent quality prints.

The Sony Alpha A7 IV 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 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 A7 IV is build around a BSI-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.

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"). 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 IV	Full Frame	32.7	7008	4672	4K/60p	25.4	14.7	3379	97
2.		Sony A9 III	Full Frame	24.0	6000	4000	4K/120p	25.4	14.7	3243	96
3.		Sony A1	Full Frame	49.8	8640	5760	8k/30p	25.9	14.5	3163	98
4.		Sony A7 II	Full Frame	24.0	6000	4000	1080/60p	24.9	13.6	2449	90
5.		Sony A7 III	Full Frame	24.0	6000	4000	4K/30p	25.0	14.7	3730	96
6.		Sony A7R III	Full Frame	42.2	7952	5304	4K/30p	26.0	14.7	3523	100
7.		Sony A7R IIIA	Full Frame	42.2	7952	5304	4K/30p	26.0	14.7	3523	100
8.		Sony A7R IV	Full Frame	60.2	9504	6336	4K/30p	26.0	14.8	3344	99
9.		Sony A7R IVA	Full Frame	60.2	9504	6336	4K/30p	26.0	14.8	3344	99
10.		Sony A7R V	Full Frame	60.2	9504	6336	8k/24p	26.5	14.8	3187	100
11.		Sony A7S II	Full Frame	12.0	4240	2832	4K/30p	23.6	13.3	2993	85
12.		Sony A7S III	Full Frame	12.0	4240	2832	4K/120p	23.7	13.9	2520	86
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
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 have a sensor with sufficiently fast read-out times for moving pictures, but the A9 III provides a faster frame rate than the A7 IV. It can shoot movie footage at 4K/120p, while the A7 IV is limited to 4K/60p.

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 A9 III offers a substantially higher resolution than the one in the A7 IV (9440k vs 3686k dots). The following table reports on some other key feature differences and similarities of the Sony A7 IV, the Sony A9 III, 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 IV	3686	n	3.0 / 1037	swivel	Y	1/8000s	10.0/s	n	Y
2.		Sony A9 III	9440	n	3.2 / 2100	full-flex	Y	1/80000s	120.0/s	n	Y
3.		Sony A1	9437	n	3.0 / 1440	tilting	Y	1/8000s	10.0/s	n	Y
4.		Sony A7 II	2400	n	3.0 / 1230	tilting	n	1/8000s	5.0/s	n	Y
5.		Sony A7 III	2359	n	3.0 / 922	tilting	Y	1/8000s	10.0/s	n	Y
6.		Sony A7R III	3686	n	3.0 / 1440	tilting	Y	1/8000s	10.0/s	n	Y
7.		Sony A7R IIIA	3686	n	3.0 / 2340	tilting	Y	1/8000s	10.0/s	n	Y
8.		Sony A7R IV	5760	n	3.0 / 1440	tilting	Y	1/8000s	10.0/s	n	Y
9.		Sony A7R IVA	5760	n	3.0 / 2340	tilting	Y	1/8000s	10.0/s	n	Y
10.		Sony A7R V	9440	n	3.2 / 2100	full-flex	Y	1/8000s	10.0/s	n	Y
11.		Sony A7S II	2400	n	3.0 / 1229	tilting	n	1/8000s	5.0/s	n	Y
12.		Sony A7S III	9440	n	3.0 / 1440	swivel	Y	1/8000s	10.0/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
Note: *) Information refers to the mechanical shutter, unless the camera only has an electronic one.

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.

Concerning the storage of imaging data, both the A7 IV and the A9 III write their files to CFexpress (type A) or SDXC cards. Both cameras feature dual card slots, which can be very useful in case a memory card fails. Both cameras support UHS-II cards, which provide for Ultra High Speed data transfer of up to 312 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 A7 IV 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 A7 IV	Y	stereo / mono	Y	Y	full	3.2	Y	-	Y
2.		Sony A9 III	Y	stereo / mono	Y	Y	full	3.2	Y	-	Y
3.		Sony A1	Y	stereo / mono	Y	Y	full	3.2	Y	-	Y
4.		Sony A7 II	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
5.		Sony A7 III	Y	stereo / mono	Y	Y	micro	3.1	Y	Y	Y
6.		Sony A7R III	Y	stereo / mono	Y	Y	micro	3.1	Y	Y	Y
7.		Sony A7R IIIA	Y	stereo / mono	Y	Y	micro	3.2	Y	Y	Y
8.		Sony A7R IV	Y	stereo / mono	Y	Y	micro	3.1	Y	Y	Y
9.		Sony A7R IVA	Y	stereo / mono	Y	Y	micro	3.2	Y	Y	Y
10.		Sony A7R V	Y	stereo / mono	Y	Y	full	3.2	Y	-	Y
11.		Sony A7S II	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
12.		Sony A7S III	Y	stereo / mono	Y	Y	full	3.2	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

Studio photographers will appreciate that the Sony A9 III (unlike the A7 IV) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.

Both the A7 IV and the A9 III are recent models that are part of the current product line-up. The A7 IV replaced the earlier Sony A7 III, while the A9 III followed on from the Sony A9 II. Further information on the features and operation of the A7 IV and A9 III can be found, respectively, in the Sony A7 IV Manual (free pdf) or the online Sony A9 III Manual.

Review summary

So what is the bottom line? Is there a clear favorite between the Sony A7 IV and the Sony A9 III? Which camera is better? Below is a summary of the relative strengths of each of the two contestants.

Reasons to prefer the Sony Alpha A7 IV:

• More detail: Offers more megapixels (32.7 vs 24MP) with a 17% higher linear resolution.
• Maximized detail: Lacks an anti-alias filter to exploit the sensor's full resolution potential.
• 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 October 2021).

Arguments in favor of the Sony Alpha A9 III:

• Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
• Better jpgs: Has a more modern image processing engine (Dual BIONZ XR vs BIONZ XR).
• Better video: Provides higher movie framerates (4K/120p versus 4K/60p).
• More detailed viewfinder: Has higher resolution electronic viewfinder (9440k vs 3686k dots).
• Larger viewfinder image: Features a viewfinder with a higher magnification (0.9x vs 0.78x).
• 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 1037k dots).
• Faster shutter: Has higher mechanical shutter speed (1/80000s vs 1/8000s) to freeze action.
• Faster burst: Shoots at higher frequency (120 vs 10 flaps/sec) to capture the decisive moment.
• Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
• Better studio light control: Has a PC Sync socket to connect to professional strobe lights.
• More modern: Reflects 2 years of technical progress since the A7 IV launch.

If the count of relative strengths (bullet points above) is taken as a measure, the A9 III is the clear winner of the contest (12 : 4 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 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 IV 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 A7 IV 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 where reviews by experts come in. 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 (USD)	Street Price
1.		Sony A7 IV	5/5	+ +	4.5/5	89/100	4.5/5	4.5/5	Oct 2021	2,499	amazon.com
2.		Sony A9 III	4.5/5	..	..	..	..	..	Nov 2023	5,999	amazon.com
3.		Sony A1	5/5	o	4.5/5	93/100	4.5/5	5/5	Jan 2021	6,499	amazon.com
4.		Sony A7 II	5/5	+	4/5	82/100	4.5/5	5/5	Nov 2014	1,999	ebay.com
5.		Sony A7 III	..	+ +	4.5/5	89/100	5/5	5/5	Feb 2018	1,999	amazon.com
6.		Sony A7R III	..	+ +	4/5	90/100	4.5/5	5/5	Oct 2017	3,199	ebay.com
7.		Sony A7R IIIA	..	+ +	4/5	90/100	4.5/5	5/5	Apr 2021	3,199	amazon.com
8.		Sony A7R IV	5/5	+	4.5/5	91/100	4.5/5	5/5	Jul 2019	3,499	ebay.com
9.		Sony A7R IVA	5/5	+	4.5/5	91/100	4.5/5	5/5	Apr 2021	3,499	amazon.com
10.		Sony A7R V	5/5	+ +	4.5/5	92/100	..	..	Oct 2022	3,899	amazon.com
11.		Sony A7S II	5/5	+	..	..	4.5/5	5/5	Sep 2015	2,999	ebay.com
12.		Sony A7S III	4.5/5	+ +	5/5	91/100	4.5/5	5/5	Jul 2020	3,499	amazon.com
13.		Sony A9	5/5	+ +	4.8/5	89/100	5/5	5/5	Apr 2017	4,499	ebay.com
14.		Sony A9 II	..	..	5/5	90/100	5/5	5/5	Oct 2019	4,499	amazon.com
Note: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.

The above review scores should be interpreted with care, 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 comparisons of ratings among very different cameras or across long time periods have little meaning. Also, kindly note that some of the listed sites have over time developped their review approaches and their reporting style.

Check A7 IV price at
amazon.com
Check A9 III price at
amazon.com

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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Check A7 IV price at
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Check A9 III price at
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