Canon M6 vs Sony A7S III

The Canon EOS M6 and the Sony Alpha 7S III are two digital cameras that were announced, respectively, in February 2017 and July 2020. Both the M6 and the A7S III are mirrorless interchangeable lens cameras that are based on an APS-C (M6) and a full frame (A7S III) sensor. The Canon has a resolution of 24 megapixels, whereas the Sony provides 12 MP.

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

Headline Specifications

Canon M6		Sony A7S III
Mirrorless system camera		Mirrorless system camera
Canon EF-M mount lenses		Sony E mount lenses
24 MP – APS-C sensor		12 MP – Full Frame sensor
1080/60p Video		4K/120p Video
ISO 100-25,600		ISO 80-102,400 (40 - 409,600)
Viewfinder optional		Electronic viewfinder (9440k dots)
3.0" LCD – 1040k dots		3.0" LCD – 1440k dots
Tilting touchscreen		Swivel touchscreen
9 shutter flaps per second		10 shutter flaps per second
Lens stabilization only		In-body stabilization
not weather sealed		Weathersealed body
295 shots per battery charge		600 shots per battery charge
112 x 68 x 45 mm, 390 g		127 x 97 x 81 mm, 699 g

Check M6 offers at
ebay.com
Check A7S III price at
amazon.com

Going beyond this snapshot of core features and characteristics, what are the differences between the Canon EOS M6 and the Sony Alpha 7S 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 Canon M6 and the Sony A7S 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 width, height and depth dimensions are rounded to the nearest millimeter.

The M6 can be obtained in two different colors (black, silver), while the A7S III is only available in black.

If the front view area (width x height) of the cameras is taken as an aggregate measure of their size, the Sony A7S III is considerably larger (62 percent) than the Canon M6. Moreover, the A7S III is substantially heavier (79 percent) than the M6. It is noteworthy in this context that the A7S III is splash and dust-proof, while the M6 does not feature any corresponding weather-sealing.

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. Hence, you might want to study and compare the specifications of available lenses in order to get the full picture of the size and weight of the two camera systems.

Concerning battery life, the M6 gets 295 shots out of its Canon LP-E17 battery, while the A7S III can take 600 images on a single charge of its Sony NP-FZ100 power pack. The power pack in the A7S III can be charged via the USB port, 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.		Canon M6	112 mm	68 mm	45 mm	390 g	295	n	Feb 2017	779	ebay.com
2.		Sony A7S III	127 mm	97 mm	81 mm	699 g	600	Y	Jul 2020	3,499	amazon.com
3.		Canon 77D	131 mm	100 mm	76 mm	540 g	600	n	Feb 2017	899	ebay.com
4.		Canon M3	111 mm	68 mm	44 mm	366 g	250	n	Feb 2015	679	ebay.com
5.		Canon M5	116 mm	89 mm	61 mm	427 g	295	n	Sep 2016	979	ebay.com
6.		Canon M6 Mark II	120 mm	70 mm	49 mm	408 g	305	n	Aug 2019	849	ebay.com
7.		Canon M50	116 mm	88 mm	59 mm	390 g	235	n	Feb 2018	779	ebay.com
8.		Canon M100	108 mm	67 mm	35 mm	302 g	295	n	Aug 2017	499	ebay.com
9.		Canon SL2	122 mm	93 mm	70 mm	453 g	650	n	Jun 2017	549	ebay.com
10.		Canon T6i	132 mm	101 mm	78 mm	555 g	440	n	Feb 2015	749	ebay.com
11.		Canon T6s	132 mm	101 mm	78 mm	565 g	440	n	Feb 2015	649	ebay.com
12.		Nikon D5600	124 mm	97 mm	70 mm	465 g	970	n	Nov 2016	699	ebay.com
13.		Sony A7R III	127 mm	96 mm	74 mm	650 g	650	Y	Oct 2017	3,199	ebay.com
14.		Sony A7R IV	129 mm	96 mm	78 mm	665 g	670	Y	Jul 2019	3,499	ebay.com
15.		Sony A7R IVA	129 mm	96 mm	78 mm	665 g	670	Y	Apr 2021	3,499	amazon.com
16.		Sony A7S II	127 mm	96 mm	60 mm	627 g	370	Y	Sep 2015	2,999	ebay.com
17.		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 retail prices at the time of the camera’s release place the model in the market relative to other models in the producer’s line-up and the competition. The M6 was launched at a markedly lower price (by 78 percent) than the A7S 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. Then, after the new model is out, very good deals can frequently be found on the pre-owned market.

Sensor comparison

The imaging sensor is at the core of digital cameras and its size is one of the main determining factors 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. Furthermore, a large sensor camera will give the photographer more possibilities to use shallow depth-of-field in order to isolate a subject from the background. On the downside, larger sensors tend to be associated with larger, more expensive camera bodies and lenses.

Of the two cameras under consideration, the Canon M6 features an APS-C sensor and the Sony A7S III a full frame sensor. The sensor area in the A7S III is 155 percent bigger. As a result of these sensor size differences, the cameras have a format factor of, respectively, 1.6 and 1.0. Both cameras have a native aspect ratio (sensor width to sensor height) of 3:2.

Despite having a smaller sensor, the Canon M6 offers a higher resolution of 24 megapixels, compared with 12 MP of the Sony A7S III. 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 3.72μm versus 8.40μm for the A7S III). Moreover, it should be noted that the A7S III is much more recent (by 3 years and 5 months) than the M6, and its sensor will have benefitted from technological advances during this time that further enhance the light gathering capacity of its pixel-units.

The resolution advantage of the Canon M6 implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the M6 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 III 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 Canon EOS M6 has a native sensitivity range from ISO 100 to ISO 25600. The corresponding ISO settings for the Sony Alpha 7S III are ISO 80 to ISO 102400, with the possibility to increase the ISO range to 40-409600.

In terms of underlying technology, the M6 is build around a CMOS sensor, while the A7S III uses a BSI-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 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 consideration, the A7S III has a markedly higher DXO score than the M6 (overall score 8 points higher), which will translate into better image quality. The advantage is based on 0.3 bits higher color depth, 1.3 EV in additional dynamic range, and 0.9 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.		Canon M6	APS-C	24.0	6000	4000	1080/60p	23.4	12.6	1317	78
2.		Sony A7S III	Full Frame	12.0	4240	2832	4K/120p	23.7	13.9	2520	86
3.		Canon 77D	APS-C	24.0	6000	4000	1080/60p	23.6	13.3	971	78
4.		Canon M3	APS-C	24.0	6000	4000	1080/30p	22.8	11.8	1169	72
5.		Canon M5	APS-C	24.0	6000	4000	1080/60p	23.4	12.4	1262	77
6.		Canon M6 Mark II	APS-C	32.3	6960	4640	4K/30p	24.0	13.5	1848	83
7.		Canon M50	APS-C	24.0	6000	4000	4K/24p	23.8	13.3	1684	81
8.		Canon M100	APS-C	24.0	6000	4000	1080/60p	23.5	12.9	1272	78
9.		Canon SL2	APS-C	24.0	6000	4000	1080/60p	23.6	13.4	1041	79
10.		Canon T6i	APS-C	24.0	6000	4000	1080/30p	22.7	12.0	919	71
11.		Canon T6s	APS-C	24.0	6000	4000	1080/30p	22.6	12.0	915	70
12.		Nikon D5600	APS-C	24.0	6000	4000	1080/60p	24.1	14.0	1306	84
13.		Sony A7R III	Full Frame	42.2	7952	5304	4K/30p	26.0	14.7	3523	100
14.		Sony A7R IV	Full Frame	60.2	9504	6336	4K/30p	26.0	14.8	3344	99
15.		Sony A7R IVA	Full Frame	60.2	9504	6336	4K/30p	26.0	14.8	3344	99
16.		Sony A7S II	Full Frame	12.0	4240	2832	4K/30p	23.6	13.3	2993	85
17.		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 A7S III provides a better video resolution than the M6. It can shoot movie footage at 4K/120p, while the Canon is limited to 1080/60p.

Feature comparison

Apart from body and sensor, cameras can and do differ across a range of features. For example, the A7S III has an electronic viewfinder (9440k dots), which can be very helpful when shooting in bright sunlight. In contrast, the M6 relies on live view and the rear LCD for framing. That said, the M6 can be equipped with an optional viewfinder – the EVF-DC2. The following table reports on some other key feature differences and similarities of the Canon M6, the Sony A7S 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.		Canon M6	optional	n	3.0 / 1040	tilting	Y	1/4000s	9.0/s	Y	n
2.		Sony A7S III	9440	n	3.0 / 1440	swivel	Y	1/8000s	10.0/s	n	Y
3.		Canon 77D	optical	Y	3.0 / 1040	swivel	Y	1/4000s	6.0/s	Y	n
4.		Canon M3	optional	n	3.0 / 1040	tilting	Y	1/4000s	4.2/s	Y	n
5.		Canon M5	2360	n	3.2 / 1620	tilting	Y	1/4000s	9.0/s	Y	n
6.		Canon M6 Mark II	optional	n	3.0 / 1040	tilting	Y	1/4000s	14.0/s	Y	n
7.		Canon M50	2360	n	3.0 / 1040	swivel	Y	1/4000s	10.0/s	Y	n
8.		Canon M100	none	n	3.0 / 1040	tilting	Y	1/4000s	6.1/s	Y	n
9.		Canon SL2	optical	n	3.0 / 1040	swivel	Y	1/4000s	5.0/s	Y	n
10.		Canon T6i	optical	n	3.0 / 1040	swivel	Y	1/4000s	5.0/s	Y	n
11.		Canon T6s	optical	Y	3.0 / 1040	swivel	Y	1/4000s	5.0/s	Y	n
12.		Nikon D5600	optical	n	3.2 / 1037	swivel	Y	1/4000s	5.0/s	Y	n
13.		Sony A7R III	3686	n	3.0 / 1440	tilting	Y	1/8000s	10.0/s	n	Y
14.		Sony A7R IV	5760	n	3.0 / 1440	tilting	Y	1/8000s	10.0/s	n	Y
15.		Sony A7R IVA	5760	n	3.0 / 2340	tilting	Y	1/8000s	10.0/s	n	Y
16.		Sony A7S II	2400	n	3.0 / 1229	tilting	n	1/8000s	5.0/s	n	Y
17.		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.

One difference between the cameras concerns the presence of an on-board flash. The M6 has one, while the A7S III does not. While the built-in flash of the M6 is not very powerful, it can at times be useful as a fill-in light.

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, the A7S III is one of those camera that have an additional 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 Canon M6 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 M6 writes its imaging data to SDXC cards, while the A7S III uses CFexpress (type A) or SDXC cards. The A7S III features dual card slots, which can be very useful in case a memory card fails. In contrast, the M6 only has one slot. The A7S III supports UHS-II cards (on both slots), while the M6 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 Canon EOS M6 and Sony Alpha 7S 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.		Canon M6	Y	stereo / mono	Y	-	mini	2.0	Y	Y	Y
2.		Sony A7S III	Y	stereo / mono	Y	Y	full	3.2	Y	-	Y
3.		Canon 77D	Y	stereo / mono	Y	-	mini	2.0	Y	Y	Y
4.		Canon M3	Y	stereo / mono	Y	-	mini	2.0	Y	Y	-
5.		Canon M5	Y	stereo / mono	Y	-	mini	2.0	Y	Y	Y
6.		Canon M6 Mark II	Y	stereo / mono	Y	-	micro	2.0	Y	-	Y
7.		Canon M50	Y	stereo / mono	Y	-	micro	2.0	Y	-	Y
8.		Canon M100	-	stereo / mono	-	-	micro	2.0	Y	Y	Y
9.		Canon SL2	Y	stereo / mono	Y	-	mini	2.0	Y	Y	Y
10.		Canon T6i	Y	stereo / mono	Y	-	mini	2.0	Y	Y	-
11.		Canon T6s	Y	stereo / mono	Y	-	mini	2.0	Y	Y	-
12.		Nikon D5600	Y	stereo / mono	Y	-	mini	2.0	Y	Y	Y
13.		Sony A7R III	Y	stereo / mono	Y	Y	micro	3.1	Y	Y	Y
14.		Sony A7R IV	Y	stereo / mono	Y	Y	micro	3.1	Y	Y	Y
15.		Sony A7R IVA	Y	stereo / mono	Y	Y	micro	3.2	Y	Y	Y
16.		Sony A7S II	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
17.		Sony A9 II	Y	stereo / mono	Y	Y	micro	3.1	Y	Y	Y

It is notable that the A7S III has a headphone jack, which makes it possible to attach external headphones and monitor the quality of sound during the recording process. The M6 lacks such a headphone port.

The A7S III is a recent model that features in the current product line-up of Sony. In contrast, the M6 has been discontinued (but can be found pre-owned on ebay). As a replacement in the same line of cameras, the M6 was succeeded by the Canon M6 Mark II. Further information on the features and operation of the M6 and A7S III can be found, respectively, in the Canon M6 Manual (free pdf) or the online Sony A7S III Manual.

Review summary

So how do things add up? Is the Canon M6 better than the Sony A7S III or vice versa? The listing below highlights the relative strengths of the two models.

Arguments in favor of the Canon EOS M6:

• More detail: Offers more megapixels (24 vs 12MP) with a 41% higher linear resolution.
• Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
• More compact: Is smaller (112x68mm vs 127x97mm) and thus needs less room in the bag.
• Less heavy: Is lighter (by 309g or 44 percent) and hence easier to carry around.
• Easier fill-in: Is equipped with a small onboard flash to brighten deep shadow areas.
• Easier device pairing: Supports NFC for fast wireless image transfer over short distances.
• More affordable: Was introduced into a lower priced category (78 percent cheaper at launch).
• More heavily discounted: Has been available for much longer (launched in February 2017).

Reasons to prefer the Sony Alpha 7S III:

• Better image quality: Scores markedly higher (8 points) in the DXO overall evaluation.
• More dynamic range: Captures a broader range of light and dark details (1.3 EV of extra DR).
• Better low-light sensitivity: Can shoot in dim conditions (0.9 stops ISO advantage).
• Better video: Provides higher definition movie capture (4K/120p vs 1080/60p).
• Better sound control: Has a headphone port that enables audio monitoring while recording.
• Easier framing: Has an electronic viewfinder for image composition and settings control.
• More detailed LCD: Has a higher resolution rear screen (1440k vs 1040k dots).
• More flexible LCD: Has a swivel screen for odd-angle shots in portrait or landscape orientation.
• Faster shutter: Has higher mechanical shutter speed (1/8000s vs 1/4000s) to freeze action.
• Less disturbing: Has an electronic shutter option for completely silent shooting.
• Longer lasting: Gets more shots (600 versus 295) out of a single battery charge.
• Easier travel charging: Can be conveniently charged via its USB port.
• Better sealing: Is splash and dust sealed for shooting in inclement weather conditions.
• 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.
• 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 3 years and 5 months of technical progress since the M6 launch.

If the count of individual advantages (bullet points above) is taken as a guide, the A7S III is the clear winner of the contest (19 : 8 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 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 Canon M6 and the Sony A7S 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 M6 and the A7S 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 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.		Canon M6	..	..	..	80/100	4/5	4/5	Feb 2017	779	ebay.com
2.		Sony A7S III	4.5/5	+ +	5/5	91/100	4.5/5	5/5	Jul 2020	3,499	amazon.com
3.		Canon 77D	4.5/5	..	4/5	82/100	4.5/5	4/5	Feb 2017	899	ebay.com
4.		Canon M3	4/5	o	..	75/100	4.5/5	4/5	Feb 2015	679	ebay.com
5.		Canon M5	4/5	+	4/5	82/100	4/5	4/5	Sep 2016	979	ebay.com
6.		Canon M6 Mark II	..	+	4.5/5	85/100	4/5	4/5	Aug 2019	849	ebay.com
7.		Canon M50	..	+	4/5	79/100	..	3.5/5	Feb 2018	779	ebay.com
8.		Canon M100	3/5	+	..	..	4/5	3.5/5	Aug 2017	499	ebay.com
9.		Canon SL2	4/5	+ +	4/5	78/100	4.5/5	4.5/5	Jun 2017	549	ebay.com
10.		Canon T6i	5/5	..	..	75/100	4.5/5	4.5/5	Feb 2015	749	ebay.com
11.		Canon T6s	5/5	+	..	77/100	4.5/5	4.5/5	Feb 2015	649	ebay.com
12.		Nikon D5600	4/5	..	4/5	79/100	4.5/5	4/5	Nov 2016	699	ebay.com
13.		Sony A7R III	..	+ +	4/5	90/100	4.5/5	5/5	Oct 2017	3,199	ebay.com
14.		Sony A7R IV	5/5	+	4.5/5	91/100	4.5/5	5/5	Jul 2019	3,499	ebay.com
15.		Sony A7R IVA	5/5	+	4.5/5	91/100	4.5/5	5/5	Apr 2021	3,499	amazon.com
16.		Sony A7S II	5/5	+	..	..	4.5/5	5/5	Sep 2015	2,999	ebay.com
17.		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 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

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