Sony A7 III vs A7 IV

The Sony Alpha A7 III and the Sony Alpha A7 IV are two enthusiast cameras that were announced, respectively, in February 2018 and October 2021. Both the A7 III and the A7 IV are mirrorless interchangeable lens cameras that are equipped with a full frame sensor. The A7 III has a resolution of 24 megapixels, whereas the A7 IV provides 32.7 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 A7 IV
Mirrorless system camera		Mirrorless system camera
Sony E mount lenses		Sony E mount lenses
24 MP – Full Frame sensor		32.7 MP – Full Frame sensor
4K/30p Video		4K/60p Video
ISO 100-51,200 (50 - 204,800)		ISO 100-51,200 (50 - 204,800)
Electronic viewfinder (2359k dots)		Electronic viewfinder (3686k dots)
3.0" LCD – 922k dots		3.0" LCD – 1037k dots
Tilting touchscreen		Swivel touchscreen
10 shutter flaps per second		10 shutter flaps per second
In-body stabilization		In-body stabilization
Weathersealed body		Weathersealed body
610 shots per battery charge		580 shots per battery charge
127 x 96 x 74 mm, 650 g		131 x 96 x 80 mm, 659 g

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

Going beyond this snapshot of core features and characteristics, what are the differences between the Sony Alpha A7 III and the Sony Alpha A7 IV? 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 A7 IV 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 A7 IV is somewhat larger (3 percent) than the Sony A7 III. Moreover, the A7 IV is slightly heavier (1 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.

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. 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 A7 III	127 mm	96 mm	74 mm	650 g	610	Y	Feb 2018	1,999	amazon.com
2.		Sony A7 IV	131 mm	96 mm	80 mm	659 g	580	Y	Oct 2021	2,499	amazon.com
3.		Nikon Z6	134 mm	101 mm	67 mm	675 g	310	Y	Aug 2018	1,999	ebay.com
4.		Panasonic GH5	139 mm	98 mm	87 mm	725 g	410	Y	Jan 2017	1,999	ebay.com
5.		Sony A7R V	131 mm	97 mm	82 mm	723 g	530	Y	Oct 2022	3,899	amazon.com
6.		Sony A1	129 mm	97 mm	81 mm	737 g	530	Y	Jan 2021	6,499	amazon.com
7.		Sony A7R IIIA	127 mm	96 mm	74 mm	650 g	650	Y	Apr 2021	3,199	amazon.com
8.		Sony A7S III	127 mm	97 mm	81 mm	699 g	600	Y	Jul 2020	3,499	amazon.com
9.		Sony A7C	124 mm	71 mm	60 mm	509 g	740	Y	Sep 2020	1,799	amazon.com
10.		Sony A9 II	129 mm	96 mm	76 mm	678 g	690	Y	Oct 2019	4,499	amazon.com
11.		Sony A7R IV	129 mm	96 mm	78 mm	665 g	670	Y	Jul 2019	3,499	ebay.com
12.		Sony A7R III	127 mm	96 mm	74 mm	650 g	650	Y	Oct 2017	3,199	ebay.com
13.		Sony A9	127 mm	96 mm	63 mm	673 g	650	Y	Apr 2017	4,499	ebay.com
14.		Sony A7 II	127 mm	96 mm	60 mm	599 g	350	Y	Nov 2014	1,999	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 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 A7 IV, 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 imaging sensor is a crucial determinant of image quality. A large sensor will tend to have larger individual pixels that provide better low-light sensitivity, wider dynamic range, and richer color-depth than smaller pixel-units in a sensor of the same technological generation. Moreover, a large sensor camera will give the photographer more control over depth-of-field in the image and, thus, the ability to better isolate a subject from the 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 A7 IV 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.

Technology-wise, the A7 IV uses a more advanced image processing engine (BIONZ XR) than the A7 III (BIONZ X), with benefits for noise reduction, color accuracy, and processing speed.

With 32.7MP, the A7 IV offers a higher resolution than the A7 III (24MP), but the A7 IV has smaller individual pixels (pixel pitch of 5.12μm versus 5.94μm for the A7 III). Yet, the A7 IV is a much more recent model (by 3 years and 7 months) than the A7 III, and its sensor will have benefitted from technological advances during this time that enhance the light gathering capacity of its pixel-units. 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 A7 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 III has a native sensitivity range from ISO 100 to ISO 51200, which can be extended to ISO 50-204800. The Sony Alpha A7 IV offers exactly the same ISO settings.

Technology-wise, both cameras are equipped with BSI-CMOS (Backside Illuminated Complementary Metal–Oxide–Semiconductor) sensors. 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 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 Overall DXO ratings for the two cameras under consideration are close, suggesting that they provide similar imaging performance. The table below summarizes the physical sensor characteristics and sensor quality findings and compares them across a set of similar 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 A7 IV	Full Frame	32.7	7008	4672	4K/60p	25.4	14.7	3379	97
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 A7R V	Full Frame	60.2	9504	6336	8k/24p	26.5	14.8	3187	100
6.		Sony A1	Full Frame	49.8	8640	5760	8k/30p	25.9	14.5	3163	98
7.		Sony A7R IIIA	Full Frame	42.2	7952	5304	4K/30p	26.0	14.7	3523	100
8.		Sony A7S III	Full Frame	12.0	4240	2832	4K/120p	23.7	13.9	2520	86
9.		Sony A7C	Full Frame	24.0	6000	4000	4K/30p	25.0	14.7	3407	95
10.		Sony A9 II	Full Frame	24.0	6000	4000	4K/30p	25.0	14.0	3434	93
11.		Sony A7R IV	Full Frame	60.2	9504	6336	4K/30p	26.0	14.8	3344	99
12.		Sony A7R III	Full Frame	42.2	7952	5304	4K/30p	26.0	14.7	3523	100
13.		Sony A9	Full Frame	24.0	6000	4000	4K/30p	24.9	13.3	3517	92
14.		Sony A7 II	Full Frame	24.0	6000	4000	1080/60p	24.9	13.6	2449	90

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 IV provides a faster frame rate than the A7 III. It can shoot movie footage at 4K/60p, while the A7 III is limited to 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 A7 IV offers a substantially higher resolution than the one in the A7 III (3686k vs 2359k dots). The adjacent table lists some of the other core features of the Sony A7 III and Sony A7 IV 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 A7 III	2359	n	3.0 / 922	tilting	Y	1/8000s	10.0/s	n	Y
2.		Sony A7 IV	3686	n	3.0 / 1037	swivel	Y	1/8000s	10.0/s	n	Y
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 A7R V	9440	n	3.2 / 2100	full-flex	Y	1/8000s	10.0/s	n	Y
6.		Sony A1	9437	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 A7S III	9440	n	3.0 / 1440	swivel	Y	1/8000s	10.0/s	n	Y
9.		Sony A7C	2360	n	3.0 / 922	swivel	Y	1/4000s	10.0/s	n	Y
10.		Sony A9 II	3686	n	3.0 / 1440	tilting	Y	1/8000s	20.0/s	n	Y
11.		Sony A7R IV	5760	n	3.0 / 1440	tilting	Y	1/8000s	10.0/s	n	Y
12.		Sony A7R III	3686	n	3.0 / 1440	tilting	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 A7 II	2400	n	3.0 / 1230	tilting	n	1/8000s	5.0/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 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.

The A7 III writes its imaging data to SDXC or Memory Stick PRO Duo cards, while the A7 IV uses CFexpress (type A) or SDXC cards. Both cameras feature dual card slots, which can be very useful in case a memory card fails. However, while the A7 IV supports UHS-II cards (Ultra High Speed data transfer of up to 312 MB/s) on both slots, the A7 III supports UHS-II only on its first slot and UHS-I (data transfer speed up to 104 MB/s) on the second one.

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 A7 IV 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 A7 IV	Y	stereo / mono	Y	Y	full	3.2	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 A7R V	Y	stereo / mono	Y	Y	full	3.2	Y	-	Y
6.		Sony A1	Y	stereo / mono	Y	Y	full	3.2	Y	-	Y
7.		Sony A7R IIIA	Y	stereo / mono	Y	Y	micro	3.2	Y	Y	Y
8.		Sony A7S III	Y	stereo / mono	Y	Y	full	3.2	Y	-	Y
9.		Sony A7C	Y	stereo / mono	Y	Y	micro	3.2	Y	Y	Y
10.		Sony A9 II	Y	stereo / mono	Y	Y	micro	3.1	Y	Y	Y
11.		Sony A7R IV	Y	stereo / mono	Y	Y	micro	3.1	Y	Y	Y
12.		Sony A7R III	Y	stereo / mono	Y	Y	micro	3.1	Y	Y	Y
13.		Sony A9	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	Y
14.		Sony A7 II	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-

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

Review summary

So how do things add up? Is there a clear favorite between the Sony A7 III and the Sony A7 IV? Which camera is better? Below is a summary of the relative strengths of each of the two contestants.

Advantages of the Sony Alpha A7 III:

• Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
• Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
• Easier device pairing: Supports NFC for fast wireless image transfer over short distances.
• More affordable: Was introduced into a lower priced segment (20 percent cheaper at launch).
• More heavily discounted: Has been available for much longer (launched in February 2018).

Arguments in favor of the Sony Alpha A7 IV:

• More detail: Has more megapixels (32.7 vs 24MP), which boosts linear resolution by 17%.
• Maximized detail: Lacks an anti-alias filter to exploit the sensor's full resolution potential.
• Better jpgs: Has a more modern image processing engine (BIONZ XR vs BIONZ X).
• Better video: Provides higher movie framerates (4K/60p versus 4K/30p).
• More detailed viewfinder: Has higher resolution electronic viewfinder (3686k vs 2359k dots).
• More detailed LCD: Has a higher resolution rear screen (1037k vs 922k dots).
• More flexible LCD: Has a swivel 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 data transfer: Supports a more advanced USB protocol (3.2 vs 3.1).
• More solid recording: Has a full-sized HDMI port for a sturdy connection to an external recorder.
• More modern: Reflects 3 years and 7 months of technical progress since the A7 III launch.

If the number of relative strengths (bullet points above) is taken as a guide, the A7 IV is the clear winner of the contest (11 : 5 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 A7 IV 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 III and the A7 IV in practical situations. 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 why hands-on reviews by experts are important. The following table reports the overall ratings of the cameras as published by some of the major 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 III	..	+ +	4.5/5	89/100	5/5	5/5	Feb 2018	1,999	amazon.com
2.		Sony A7 IV	5/5	+ +	4.5/5	89/100	4.5/5	4.5/5	Oct 2021	2,499	amazon.com
3.		Nikon Z6	5/5	..	5/5	89/100	4.5/5	5/5	Aug 2018	1,999	ebay.com
4.		Panasonic GH5	4.5/5	+ +	..	85/100	4.5/5	5/5	Jan 2017	1,999	ebay.com
5.		Sony A7R V	5/5	+ +	4.5/5	92/100	..	..	Oct 2022	3,899	amazon.com
6.		Sony A1	5/5	o	4.5/5	93/100	4.5/5	5/5	Jan 2021	6,499	amazon.com
7.		Sony A7R IIIA	..	+ +	4/5	90/100	4.5/5	5/5	Apr 2021	3,199	amazon.com
8.		Sony A7S III	4.5/5	+ +	5/5	91/100	4.5/5	5/5	Jul 2020	3,499	amazon.com
9.		Sony A7C	3.5/5	..	3.5/5	86/100	4/5	4/5	Sep 2020	1,799	amazon.com
10.		Sony A9 II	..	..	5/5	90/100	5/5	5/5	Oct 2019	4,499	amazon.com
11.		Sony A7R IV	5/5	+	4.5/5	91/100	4.5/5	5/5	Jul 2019	3,499	ebay.com
12.		Sony A7R III	..	+ +	4/5	90/100	4.5/5	5/5	Oct 2017	3,199	ebay.com
13.		Sony A9	5/5	+ +	4.8/5	89/100	5/5	5/5	Apr 2017	4,499	ebay.com
14.		Sony A7 II	5/5	+	4/5	82/100	4.5/5	5/5	Nov 2014	1,999	ebay.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. 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, kindly note that some of the listed sites have over time developped their review approaches and their reporting style.

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

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. Alternatively, you can follow any of the listed hyperlinks for comparisons that others found interesting.

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

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