Canon R8 vs Sony A7R III

The Canon EOS R8 and the Sony Alpha A7R III are two digital cameras that were revealed to the public, respectively, in February 2023 and October 2017. Both the R8 and the A7R III are mirrorless interchangeable lens cameras that are equipped with a full frame sensor. The Canon has a resolution of 24 megapixels, whereas the Sony provides 42.2 MP.

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

Headline Specifications

Canon R8		Sony A7R III
Mirrorless system camera		Mirrorless system camera
Canon RF mount lenses		Sony E mount lenses
24 MP – Full Frame sensor		42.2 MP – Full Frame sensor
4k/60p Video		4K/30p Video
ISO 100-102,400 (100 - 204,800)		ISO 100-32,000 (50 - 102,400)
Electronic viewfinder (2360k dots)		Electronic viewfinder (3686k dots)
3.0" LCD – 1620k dots		3.0" LCD – 1440k dots
Swivel touchscreen		Tilting touchscreen
6 shutter flaps per second		10 shutter flaps per second
Lens stabilization only		In-body stabilization
not weather sealed		Weathersealed body
220 shots per battery charge		650 shots per battery charge
133 x 86 x 70 mm, 461 g		127 x 96 x 74 mm, 650 g

Check R8 price at
amazon.com
Check A7R III offers at
ebay.com

Going beyond this snapshot of core features and characteristics, what are the differences between the Canon EOS R8 and the Sony Alpha A7R 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 physical size and weight of the Canon R8 and the Sony A7R III are illustrated 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 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 A7R III is notably larger (7 percent) than the Canon R8. Moreover, the A7R III is substantially heavier (41 percent) than the R8. It is noteworthy in this context that the A7R III is splash and dust-proof, while the R8 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 R8 gets 220 shots out of its Canon LP-E17 battery, while the A7R III can take 650 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 table below summarizes the key physical specs of the two cameras alongside a broader set of comparators. 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.		Canon R8	133 mm	86 mm	70 mm	461 g	220	n	Feb 2023	1,499	amazon.com
2.		Sony A7R III	127 mm	96 mm	74 mm	650 g	650	Y	Oct 2017	3,199	ebay.com
3.		Canon 77D	131 mm	100 mm	76 mm	540 g	600	n	Feb 2017	899	ebay.com
4.		Canon M5	116 mm	89 mm	61 mm	427 g	295	n	Sep 2016	979	ebay.com
5.		Canon M6	112 mm	68 mm	45 mm	390 g	295	n	Feb 2017	779	ebay.com
6.		Canon R10	123 mm	88 mm	83 mm	429 g	450	n	May 2022	979	amazon.com
7.		Canon RP	133 mm	85 mm	70 mm	485 g	250	n	Feb 2019	1,299	amazon.com
8.		Canon SL2	122 mm	93 mm	70 mm	453 g	650	n	Jun 2017	549	ebay.com
9.		Sony A7	127 mm	94 mm	48 mm	474 g	340	Y	Oct 2013	1,699	ebay.com
10.		Sony A7 III	127 mm	96 mm	74 mm	650 g	610	Y	Feb 2018	1,999	amazon.com
11.		Sony A7R II	127 mm	96 mm	60 mm	625 g	290	Y	Jun 2015	3,199	ebay.com
12.		Sony A7R IIIA	127 mm	96 mm	74 mm	650 g	650	Y	Apr 2021	3,199	amazon.com
13.		Sony A7R IV	129 mm	96 mm	78 mm	665 g	670	Y	Jul 2019	3,499	ebay.com
14.		Sony A9	127 mm	96 mm	63 mm	673 g	650	Y	Apr 2017	4,499	ebay.com
15.		Sony NEX-7	120 mm	67 mm	43 mm	400 g	430	n	Aug 2011	1,349	ebay.com
16.		Sony RX1	113 mm	65 mm	70 mm	482 g	270	n	Sep 2012	2,799	ebay.com
17.		Sony RX1R	113 mm	65 mm	70 mm	482 g	270	n	Jun 2013	2,799	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 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 R8 was launched at a markedly lower price (by 53 percent) than the A7R 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. 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 are more costly to manufacture and tend to lead to bigger and heavier cameras and lenses.

Both cameras under consideration feature a full frame sensor, but their sensors differ slightly in size. 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.

With 42.2MP, the A7R III offers a higher resolution than the R8 (24MP), but the A7R III has smaller individual pixels (pixel pitch of 4.52μm versus 5.98μm for the R8). Yet, the R8 is a much more recent model (by 5 years and 3 months) than the A7R III, and its sensor will have benefitted from technological advances during this time that further enhance the light gathering capacity of its pixel-units. Coming back to sensor resolution, it should be mentioned that the A7R III has no anti-alias filter installed, so that it can capture all the detail its sensor resolves.

The resolution advantage of the Sony A7R III implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the A7R III for good quality output (200 dots per inch) amounts to 39.8 x 26.5 inches or 101 x 67.4 cm, for very good quality (250 dpi) 31.8 x 21.2 inches or 80.8 x 53.9 cm, and for excellent quality (300 dpi) 26.5 x 17.7 inches or 67.3 x 44.9 cm. The corresponding values for the Canon R8 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.

Unlike the R8, the A7R III has the capacity to capture high quality composite images by combining multiple shots after shifting its sensor by miniscule distances. This multi-shot, pixel-shift mode is most suitable for photography of stationary objects (landscapes, studio scenes).

The Canon EOS R8 has a native sensitivity range from ISO 100 to ISO 102400, which can be extended to ISO 100-204800. The corresponding ISO settings for the Sony Alpha A7R III are ISO 100 to ISO 32000, with the possibility to increase the ISO range to 50-102400.

In terms of underlying technology, the R8 is build around a CMOS sensor, while the A7R 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.

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"). Of the two cameras under consideration, the A7R III has a markedly higher DXO score than the R8 (overall score 7 points higher), which will translate into better image quality. The advantage is based on 1.5 bits higher color depth, and 0.1 stops in additional low light sensitivity. 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.		Canon R8	Full Frame	24.0	6000	4000	4k/60p	24.5	14.7	3295	93
2.		Sony A7R III	Full Frame	42.2	7952	5304	4K/30p	26.0	14.7	3523	100
3.		Canon 77D	APS-C	24.0	6000	4000	1080/60p	23.6	13.3	971	78
4.		Canon M5	APS-C	24.0	6000	4000	1080/60p	23.4	12.4	1262	77
5.		Canon M6	APS-C	24.0	6000	4000	1080/60p	23.4	12.6	1317	78
6.		Canon R10	APS-C	24.0	6000	4000	4k/60p	24.1	13.8	2085	84
7.		Canon RP	Full Frame	26.0	6240	4160	4K/30p	24.3	11.9	2977	85
8.		Canon SL2	APS-C	24.0	6000	4000	1080/60p	23.6	13.4	1041	79
9.		Sony A7	Full Frame	24.0	6000	4000	1080/60p	24.8	14.2	2248	90
10.		Sony A7 III	Full Frame	24.0	6000	4000	4K/30p	25.0	14.7	3730	96
11.		Sony A7R II	Full Frame	42.2	7952	5304	4K/30p	26.0	13.9	3434	98
12.		Sony A7R IIIA	Full Frame	42.2	7952	5304	4K/30p	26.0	14.7	3523	100
13.		Sony A7R IV	Full Frame	60.2	9504	6336	4K/30p	26.0	14.8	3344	99
14.		Sony A9	Full Frame	24.0	6000	4000	4K/30p	24.9	13.3	3517	92
15.		Sony NEX-7	APS-C	24.0	6000	4000	1080/60i	24.1	13.4	1016	81
16.		Sony RX1	Full Frame	24.0	6000	4000	1080/60p	25.1	14.3	2534	93
17.		Sony RX1R	Full Frame	24.0	6000	4000	1080/60p	25.0	13.6	2537	91
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 have a sensor with sufficiently fast read-out times for moving pictures, but the R8 provides a higher frame rate than the A7R III. It can shoot video footage at 4k/60p, while the Sony 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 A7R III offers a substantially higher resolution than the one in the R8 (3686k vs 2360k dots). The table below summarizes some of the other core capabilities of the Canon R8 and Sony A7R 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.		Canon R8	2360	n	3.0 / 1620	swivel	Y	1/4000s	6.0/s	n	n
2.		Sony A7R III	3686	n	3.0 / 1440	tilting	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 M5	2360	n	3.2 / 1620	tilting	Y	1/4000s	9.0/s	Y	n
5.		Canon M6	optional	n	3.0 / 1040	tilting	Y	1/4000s	9.0/s	Y	n
6.		Canon R10	2360	n	3.0 / 1040	swivel	Y	1/8000s	15.0/s	Y	n
7.		Canon RP	2360	n	3.0 / 1040	swivel	Y	1/4000s	5.0/s	n	n
8.		Canon SL2	optical	n	3.0 / 1040	swivel	Y	1/4000s	5.0/s	Y	n
9.		Sony A7	2400	n	3.0 / 1230	tilting	n	1/8000s	5.0/s	n	n
10.		Sony A7 III	2359	n	3.0 / 922	tilting	Y	1/8000s	10.0/s	n	Y
11.		Sony A7R II	2400	n	3.0 / 1229	tilting	n	1/8000s	5.0/s	n	Y
12.		Sony A7R IIIA	3686	n	3.0 / 2340	tilting	Y	1/8000s	10.0/s	n	Y
13.		Sony A7R IV	5760	n	3.0 / 1440	tilting	Y	1/8000s	10.0/s	n	Y
14.		Sony A9	3686	n	3.0 / 1440	tilting	Y	1/8000s	20.0/s	n	Y
15.		Sony NEX-7	2359	n	3.0 / 921	tilting	n	1/4000s	10.0/s	Y	n
16.		Sony RX1	optional	n	3.0 / 1229	fixed	n	1/4000s	5.0/s	Y	n
17.		Sony RX1R	optional	n	3.0 / 1229	fixed	n	1/4000s	5.0/s	Y	n
Note: *) Information refers to the mechanical shutter, unless the camera only has an electronic one.

One feature that differentiates the A7R III and the R8 is in-body image stabilization (IBIS). The A7R III reduces the risk of handshake-induced blur with all attached lenses, while the R8 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 Canon R8 and the Sony A7R III both have 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 R8 writes its imaging data to SDXC cards, while the A7R III uses SDXC or Memory Stick PRO Duo cards. The A7R III features dual card slots, which can be very useful in case a memory card fails. In contrast, the R8 only has one slot. Both the R8 and the A7R III support UHS-II cards, which provide for Ultra High Speed data transfer of up to 312 MB/s (the second slot of the A7R III only offers slower UHS-I transfer rates, though).

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 R8 and Sony Alpha A7R 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 R8	Y	stereo / mono	Y	Y	micro	3.2	Y	-	Y
2.		Sony A7R III	Y	stereo / mono	Y	Y	micro	3.1	Y	Y	Y
3.		Canon 77D	Y	stereo / mono	Y	-	mini	2.0	Y	Y	Y
4.		Canon M5	Y	stereo / mono	Y	-	mini	2.0	Y	Y	Y
5.		Canon M6	Y	stereo / mono	Y	-	mini	2.0	Y	Y	Y
6.		Canon R10	Y	stereo / mono	Y	-	micro	2.0	Y	-	Y
7.		Canon RP	Y	stereo / mono	Y	Y	micro	2.0	Y	-	Y
8.		Canon SL2	Y	stereo / mono	Y	-	mini	2.0	Y	Y	Y
9.		Sony A7	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
10.		Sony A7 III	Y	stereo / mono	Y	Y	micro	3.1	Y	Y	Y
11.		Sony A7R II	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
12.		Sony A7R IIIA	Y	stereo / mono	Y	Y	micro	3.2	Y	Y	Y
13.		Sony A7R IV	Y	stereo / mono	Y	Y	micro	3.1	Y	Y	Y
14.		Sony A9	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	Y
15.		Sony NEX-7	Y	stereo / mono	Y	-	mini	2.0	-	-	-
16.		Sony RX1	Y	stereo / mono	Y	-	mini	2.0	-	-	-
17.		Sony RX1R	Y	stereo / mono	Y	-	mini	2.0	-	-	-

Studio photographers will appreciate that the Sony A7R III (unlike the R8) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.

The R8 is a recent model that features in the current product line-up of Canon. In contrast, the A7R III has been discontinued (but can be found pre-owned on ebay). As a replacement in the same line of cameras, the A7R III was succeeded by the Sony A7R IV. Further information on the features and operation of the R8 and A7R III can be found, respectively, in the Canon R8 Manual (free pdf) or the online Sony A7R III Manual.

Review summary

So how do things add up? Is the Canon R8 better than the Sony A7R III or vice versa? Below is a summary of the relative strengths of each of the two contestants.

Reasons to prefer the Canon EOS R8:

• Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
• Better video: Provides higher movie framerates (4k/60p versus 4K/30p).
• More detailed LCD: Has a higher resolution rear screen (1620k vs 1440k 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.
• Less heavy: Is lighter (by 189g or 29 percent) and hence easier to carry around.
• Faster data transfer: Supports a more advanced USB protocol (3.2 vs 3.1).
• More affordable: Was introduced into a lower priced category (53 percent cheaper at launch).
• More modern: Reflects 5 years and 3 months of technical progress since the A7R III launch.

Arguments in favor of the Sony Alpha A7R III:

• More detail: Has more megapixels (42.2 vs 24MP), which boosts linear resolution by 33%.
• Maximized detail: Lacks an anti-alias filter to exploit the sensor's full resolution potential.
• High quality composites: Can combine several shots after pixel-shifting its sensor.
• Better image quality: Scores markedly higher (7 points) in the DXO overall evaluation.
• Richer colors: Generates noticeably more natural colors (1.5 bits more color depth).
• More detailed viewfinder: Has higher resolution electronic viewfinder (3686k vs 2360k dots).
• Larger viewfinder image: Features a viewfinder with a higher magnification (0.78x vs 0.70x).
• Faster shutter: Has higher mechanical shutter speed (1/8000s vs 1/4000s) to freeze action.
• Faster burst: Shoots at higher frequency (10 vs 6 flaps/sec) to capture the decisive moment.
• Longer lasting: Gets more shots (650 versus 220) out of a single battery charge.
• 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.
• Easier device pairing: Supports NFC for fast wireless image transfer over short distances.
• 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.
• More heavily discounted: Has been around for much longer (launched in October 2017).

If the count of individual advantages (bullet points above) is taken as a guide, the A7R III is the clear winner of the contest (16 : 9 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 sports photographer will view the differences between cameras in a way that diverges from the perspective of a street photog, and a person interested in family portraits has distinct needs from a landscape 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 R8 and the Sony A7R 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 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 R8 or the A7R III 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 why expert reviews are important. 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 (USD)	Street Price
1.		Canon R8	4.5/5	+ +	4.5/5	87/100	4/5	4.5/5	Feb 2023	1,499	amazon.com
2.		Sony A7R III	..	+ +	4/5	90/100	4.5/5	5/5	Oct 2017	3,199	ebay.com
3.		Canon 77D	4.5/5	..	4/5	82/100	4.5/5	4/5	Feb 2017	899	ebay.com
4.		Canon M5	4/5	+	4/5	82/100	4/5	4/5	Sep 2016	979	ebay.com
5.		Canon M6	..	..	..	80/100	4/5	4/5	Feb 2017	779	ebay.com
6.		Canon R10	4/5	..	4.5/5	87/100	4/5	4.5/5	May 2022	979	amazon.com
7.		Canon RP	4/5	+	4/5	..	4.5/5	4/5	Feb 2019	1,299	amazon.com
8.		Canon SL2	4/5	+ +	4/5	78/100	4.5/5	4.5/5	Jun 2017	549	ebay.com
9.		Sony A7	5/5	+ +	..	80/100	5/5	5/5	Oct 2013	1,699	ebay.com
10.		Sony A7 III	..	+ +	4.5/5	89/100	5/5	5/5	Feb 2018	1,999	amazon.com
11.		Sony A7R II	5/5	+ +	5/5	90/100	5/5	5/5	Jun 2015	3,199	ebay.com
12.		Sony A7R IIIA	..	+ +	4/5	90/100	4.5/5	5/5	Apr 2021	3,199	amazon.com
13.		Sony A7R IV	5/5	+	4.5/5	91/100	4.5/5	5/5	Jul 2019	3,499	ebay.com
14.		Sony A9	5/5	+ +	4.8/5	89/100	5/5	5/5	Apr 2017	4,499	ebay.com
15.		Sony NEX-7	5/5	+ +	..	81/100	4.5/5	5/5	Aug 2011	1,349	ebay.com
16.		Sony RX1	5/5	..	..	79/100	4/5	4.5/5	Sep 2012	2,799	ebay.com
17.		Sony RX1R	5/5	..	..	..	4/5	4.5/5	Jun 2013	2,799	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. Hence, a score should always be seen in the context of the camera's market launch date and its price, and comparing ratings of very distinct cameras or ones that are far apart in terms of their release date have little meaning. 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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