Canon M3 vs Sony A7 III
The Canon EOS M3 and the Sony Alpha A7 III are two digital cameras that were officially introduced, respectively, in February 2015 and February 2018. Both the M3 and the A7 III are mirrorless interchangeable lens cameras that are based on an APS-C (M3) and a full frame (A7 III) sensor. Both cameras offer a resolution of 24 megapixels.
Below is an overview of the main specs of the two cameras as a starting point for the comparison.
Going beyond this snapshot of core features and characteristics, what are the differences between the Canon EOS M3 and the Sony Alpha A7 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.
The side-by-side display below illustrates the physical size and weight of the Canon M3 and the Sony A7 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 M3 can be obtained in two different colors (black, white), while the A7 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 A7 III is considerably larger (62 percent) than the Canon M3. Moreover, the A7 III is substantially heavier (78 percent) than the M3. It is noteworthy in this context that the A7 III is splash and dust-proof, while the M3 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 M3 gets 250 shots out of its LP-E17 battery, while the A7 III can take 610 images on a single charge of its NP-FZ100 power pack. The power pack in the A7 III can be charged via the USB port, which can be very convenient when travelling.
The following table provides a synthesis of the main physical specifications of the two cameras and other similar ones. 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.
|1.||Canon M3||111 mm||68 mm||44 mm||366 g||250||n||Feb 2015||679|
|2.||Sony A7 III||127 mm||96 mm||74 mm||650 g||610||Y||Feb 2018||1,999|
|3.||Canon M6||112 mm||68 mm||45 mm||390 g||295||n||Feb 2017||779|
|4.||Canon M100||108 mm||67 mm||35 mm||302 g||295||n||Aug 2017||499|
|5.||Canon G7 X Mark II||106 mm||61 mm||42 mm||319 g||265||n||Feb 2016||699|
|6.||Canon M5||116 mm||89 mm||61 mm||427 g||295||n||Sep 2016||979|
|7.||Canon 750D||132 mm||101 mm||78 mm||555 g||440||n||Feb 2015||749|
|8.||Canon G5 X||112 mm||76 mm||44 mm||353 g||210||n||Oct 2015||799|
|9.||Canon M10||108 mm||67 mm||35 mm||301 g||255||n||Oct 2015||499|
|10.||Canon G7 X||103 mm||60 mm||40 mm||304 g||210||n||Sep 2014||699|
|11.||Canon M||109 mm||66 mm||32 mm||298 g||230||n||Jul 2012||599|
|12.||Nikon Z6||134 mm||101 mm||67 mm||675 g||310||Y||Aug 2018||1,999|
|13.||Sony A7R IV||129 mm||96 mm||78 mm||665 g||670||Y||Jul 2019||3,499|
|14.||Sony A7R III||127 mm||96 mm||74 mm||650 g||650||Y||Oct 2017||3,199|
|15.||Sony A9||127 mm||96 mm||63 mm||673 g||650||Y||Apr 2017||4,499|
|16.||Sony A7 II||127 mm||96 mm||60 mm||599 g||350||Y||Nov 2014||1,999|
|17.||Sony A6000||120 mm||67 mm||45 mm||344 g||360||n||Feb 2014||599|
|Notes: Measurements and pricing do not include easily detachable parts, such as add-on or interchangeable lenses or optional viewfinders.|
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 M3 was launched at a markedly lower price (by 66 percent) than the A7 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.
The size of the imaging sensor is a crucial determinant of image quality. A large sensor will generally have larger individual pixels that offer better low-light sensitivity, provide wider dynamic range, and have 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.
Of the two cameras under consideration, the Canon M3 features an APS-C sensor and the Sony A7 III a full frame sensor. The sensor area in the A7 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.
Even though the A7 III has a larger sensor, both cameras offer the same resolution of 24 megapixels. This implies that the A7 III has a lower pixel density and larger individual pixels (with a pixel pitch of 5.94μm versus 3.72μm for the M3), which gives it a potential advantage in terms of light gathering capacity. In addition, the A7 III is much more recent (by 3 years) than the M3, and its sensor will have benefitted from technological advances during this time.
The Canon EOS M3 has a native sensitivity range from ISO 100 to ISO 12800, which can be extended to ISO 100-25600. The corresponding ISO settings for the Sony Alpha A7 III are ISO 100 to ISO 51200, with the possibility to increase the ISO range to 50-204800.
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 A7 III offers substantially better image quality than the M3 (overall score 24 points higher). The advantage is based on 2.2 bits higher color depth, 2.9 EV in additional dynamic range, and 1.7 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.
|2.||Sony A7 III||Full Frame||24.0||6000||4000||4K/30p||25.0||14.7||3730||96|
|5.||Canon G7 X Mark II||1-inch||20.0||5472||3648||1080/60p||21.8||11.9||260||62|
|8.||Canon G5 X||1-inch||20.0||5472||3648||1080/60p||21.8||11.9||227||61|
|10.||Canon G7 X||1-inch||20.0||5472||3648||1080/60p||23.0||12.7||556||71|
|12.||Nikon Z6||Full Frame||24.3||6048||4024||4K/30p||25.3||14.3||3299||95|
|13.||Sony A7R IV||Full Frame||60.2||9504||6336||4K/30p||26.0||14.8||3344||99|
|14.||Sony A7R III||Full Frame||42.2||7952||5304||4K/30p||26.0||14.7||3523||100|
|15.||Sony A9||Full Frame||24.0||6000||4000||4K/30p||24.9||13.3||3517||92|
|16.||Sony A7 II||Full Frame||24.0||6000||4000||1080/60p||24.9||13.6||2449||90|
|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 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 III provides a better video resolution than the M3. It can shoot movie footage at 4K/30p, while the Canon is limited to 1080/30p.
Apart from body and sensor, cameras can and do differ across a range of features. For example, the A7 III has an electronic viewfinder (2359k dots), which can be very helpful when shooting in bright sunlight. In contrast, the M3 relies on live view and the rear LCD for framing. That said, the M3 can be equipped with an optional viewfinder – the EVF-DC1. The following table reports on some other key feature differences and similarities of the Canon M3, the Sony A7 III, and comparable cameras.
|1.||Canon M3||optional||n||3.0 / 1040||tilting||Y||1/4000s||4.2||Y||n|
|2.||Sony A7 III||2359||n||3.0 / 922||tilting||Y||1/8000s||10.0||n||Y|
|3.||Canon M6||optional||n||3.0 / 1040||tilting||Y||1/4000s||9.0||Y||n|
|4.||Canon M100||none||n||3.0 / 1040||tilting||Y||1/4000s||6.1||Y||n|
|5.||Canon G7 X Mark II||none||n||3.0 / 1040||tilting||Y||1/2000s||8.0||Y||Y|
|6.||Canon M5||2360||n||3.2 / 1620||tilting||Y||1/4000s||9.0||Y||n|
|7.||Canon 750D||optical||n||3.0 / 1040||swivel||Y||1/4000s||5.0||Y||n|
|8.||Canon G5 X||2360||n||3.0 / 1040||swivel||Y||1/2000s||5.9||Y||Y|
|9.||Canon M10||none||n||3.0 / 1040||tilting||Y||1/4000s||4.6||Y||n|
|10.||Canon G7 X||none||n||3.0 / 1040||tilting||Y||1/2000s||6.5||Y||Y|
|11.||Canon M||none||n||3.0 / 1040||fixed||Y||1/4000s||4.3||n||n|
|12.||Nikon Z6||3690||Y||3.2 / 2100||tilting||Y||1/8000s||12.0||n||Y|
|13.||Sony A7R IV||5760||n||3.0 / 1440||tilting||Y||1/8000s||10.0||n||Y|
|14.||Sony A7R III||3686||n||3.0 / 1440||tilting||Y||1/8000s||10.0||n||Y|
|15.||Sony A9||3686||n||3.0 / 1440||tilting||Y||1/8000s||20.0||n||Y|
|16.||Sony A7 II||2400||n||3.0 / 1230||tilting||n||1/8000s||5.0||n||Y|
|17.||Sony A6000||1440||n||3.0 / 922||tilting||n||1/4000s||11.0||Y||n|
One difference between the cameras concerns the presence of an on-board flash. The M3 has one, while the A7 III does not. While the built-in flash of the M3 is not very powerful, it can at times be useful as a fill-in light.The M3 has an articulated LCD that can be turned to be front-facing. This characteristic will be appreciated by vloggers and photographers who are interested in snapping selfies. In contrast, the A7 III does not have a selfie-screen.
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 A7 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 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 M3 writes its imaging data to SDXC cards, while the A7 III uses SDXC or Memory Stick PRO Duo cards. The A7 III features dual card slots, which can be very useful in case a memory card fails. In contrast, the M3 only has one slot. The A7 III supports UHS-II cards (on its first slot), while the M3 can use UHS-I cards.
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 M3 and Sony Alpha A7 III and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.
Mic / Speaker
|1.||Canon M3||Y||stereo / mono||Y||-||mini||2.0||Y||Y||-|
|2.||Sony A7 III||Y||stereo / mono||Y||Y||micro||3.1||Y||Y||Y|
|3.||Canon M6||Y||stereo / mono||Y||-||mini||2.0||Y||Y||Y|
|4.||Canon M100||-||stereo / mono||-||-||micro||2.0||Y||Y||Y|
|5.||Canon G7 X Mark II||-||stereo / mono||-||-||micro||2.0||Y||Y||-|
|6.||Canon M5||Y||stereo / mono||Y||-||mini||2.0||Y||Y||Y|
|7.||Canon 750D||Y||stereo / mono||Y||-||mini||2.0||Y||Y||-|
|8.||Canon G5 X||Y||stereo / mono||-||-||mini||2.0||Y||Y||-|
|9.||Canon M10||-||stereo / mono||-||-||mini||2.0||Y||Y||-|
|10.||Canon G7 X||-||stereo / mono||-||-||micro||2.0||Y||Y||-|
|11.||Canon M||Y||stereo / mono||Y||-||mini||2.0||-||-||-|
|12.||Nikon Z6||Y||stereo / mono||Y||Y||micro||3.1||Y||-||Y|
|13.||Sony A7R IV||Y||stereo / mono||Y||Y||micro||3.1||Y||Y||Y|
|14.||Sony A7R III||Y||stereo / mono||Y||Y||micro||3.1||Y||Y||Y|
|15.||Sony A9||Y||stereo / mono||Y||Y||micro||2.0||Y||Y||Y|
|16.||Sony A7 II||Y||stereo / mono||Y||Y||micro||2.0||Y||Y||-|
|17.||Sony A6000||Y||stereo / mono||-||-||micro||2.0||Y||Y||-|
It is notable that the A7 III has a headphone jack, which makes it possible to attach external headphones and monitor the quality of sound during the recording process. The M3 lacks such a headphone port.
The A7 III is a recent model that features in the current product line-up of Sony. In contrast, the M3 has been discontinued (but can be found pre-owned on eBay). As a replacement in the same line of cameras, the M3 was succeeded by the Canon M6. Further information on the two cameras (e.g. user guides, manuals), as well as related accessories, can be found on the official Canon and Sony websites.
So what conclusions can be drawn? Which of the two cameras – the Canon M3 or the Sony A7 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.
Reasons to prefer the Canon EOS M3:
- More detailed LCD: Has a higher resolution rear screen (1040k vs 922k dots).
- More selfie-friendly: Has an articulated screen that can be turned to be front-facing.
- More compact: Is smaller (111x68mm vs 127x96mm) and thus needs less room in the bag.
- Less heavy: Is lighter (by 284g or 44 percent) and hence easier to carry around.
- Easier fill-in: Is equipped with a small onboard flash to brighten deep shadow areas.
- More affordable: Was introduced into a lower priced category (66 percent cheaper at launch).
- More heavily discounted: Has been available for much longer (launched in February 2015).
Arguments in favor of the Sony Alpha A7 III:
- Better image quality: Scores substantially higher (24 points) in the DXO overall evaluation.
- Richer colors: Generates noticeably more natural colors (2.2 bits more color depth).
- More dynamic range: Captures a broader range of light and dark details (2.9 EV of extra DR).
- Better low-light sensitivity: Can shoot in dim conditions (1.7 stops ISO advantage).
- Better video: Provides higher definition movie capture (4K/30p vs 1080/30p).
- 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.
- Faster shutter: Has higher mechanical shutter speed (1/8000s vs 1/4000s) to freeze action.
- Faster burst: Shoots at higher frequency (10 vs 4.2 flaps/sec) to capture the decisive moment.
- Less disturbing: Has an electronic shutter option for completely silent shooting.
- Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
- Longer lasting: Gets more shots (610 versus 250) 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 (3.1 vs 2.0).
- Easier wireless transfer: Supports Bluetooth for image sharing without cables.
- 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 of technical progress since the M3 launch.
If the count of relative strengths (bullet points above) is taken as a measure, the A7 III is the clear winner of the contest (20 : 7 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 Canon M3 and the Sony A7 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 specs-based evaluation of cameras can be instructive in revealing their potential as photographic tools, it remains partial and cannot reveal, for example, the shooting experience and imaging performance when actually working with the M3 or the A7 III. At times, user reviews, such as those published at amazon, address these issues in a useful manner, but such feedback is on many occasions incomplete, inconsistent, and unreliable.
This is where reviews by experts come in. 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.
|1.||Canon M3||4/5||o||..||75/100||4.5/5||4/5||Feb 2015||679|
|2.||Sony A7 III||..||+ +||4.5/5||89/100||5/5||5/5||Feb 2018||1,999|
|3.||Canon M6||..||..||..||80/100||4/5||4/5||Feb 2017||779|
|4.||Canon M100||3/5||+||..||..||4/5||3.5/5||Aug 2017||499|
|5.||Canon G7 X Mark II||4.5/5||+ +||..||81/100||4.5/5||4.5/5||Feb 2016||699|
|6.||Canon M5||4/5||+||4/5||82/100||4/5||4/5||Sep 2016||979|
|7.||Canon 750D||5/5||..||..||75/100||4.5/5||4.5/5||Feb 2015||749|
|8.||Canon G5 X||5/5||+ +||..||78/100||4.5/5||4.5/5||Oct 2015||799|
|9.||Canon M10||..||..||..||..||..||4/5||Oct 2015||499|
|10.||Canon G7 X||4/5||+ +||..||77/100||4.5/5||4.5/5||Sep 2014||699|
|11.||Canon M||3/5||+||..||..||4/5||4/5||Jul 2012||599|
|12.||Nikon Z6||5/5||..||5/5||89/100||4.5/5||5/5||Aug 2018||1,999|
|13.||Sony A7R IV||5/5||+||4.5/5||91/100||4.5/5||5/5||Jul 2019||3,499|
|14.||Sony A7R III||..||+ +||4/5||90/100||4.5/5||5/5||Oct 2017||3,199|
|15.||Sony A9||5/5||+ +||4.8/5||89/100||5/5||5/5||Apr 2017||4,499|
|16.||Sony A7 II||5/5||+||4/5||82/100||4.5/5||5/5||Nov 2014||1,999|
|17.||Sony A6000||5/5||+||4.5/5||80/100||4.5/5||5/5||Feb 2014||599|
|Notes: (+ +) 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. Thus, a score needs to be put into the context of the launch date and the launch price of the camera, and comparing ratings of very distinct cameras or ones that are far apart in terms of their release date have little meaning. Also, kindly note that some of the listed sites have over time developped their review approaches and their reporting style.
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 your choice using the following search menu. Alternatively, you can follow any of the listed hyperlinks for comparisons that others found interesting.
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- Canon T3i vs Sony A7 III
- Canon T6i vs Sony A7 III
- Fujifilm X-H1 vs Sony A7 III
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- Olympus E-M10 II vs Sony A7 III
- Panasonic S1H vs Sony A7 III
Specifications: Canon M3 vs Sony A7 III
Below is a side-by-side comparison of the specs of the two cameras to facilitate a quick review of their differences and common features.
|Camera Model||Canon M3||Sony A7 III|
|Camera Type||Mirrorless system camera||Mirrorless system camera|
|Camera Lens||Canon EF-M mount lenses||Sony E mount lenses|
|Launch Date||February 2015||February 2018|
|Launch Price||USD 679||USD 1,999|
|Sensor Specs||Canon M3||Sony A7 III|
|Sensor Format||APS-C Sensor||Full Frame Sensor|
|Sensor Size||22.3 x 14.9 mm||35.6 x 23.8 mm|
|Sensor Area||332.27 mm2||847.28 mm2|
|Sensor Diagonal||26.8 mm||42.8 mm|
|Sensor Resolution||24 Megapixels||24 Megapixels|
|Image Resolution||6000 x 4000 pixels||6000 x 4000 pixels|
|Pixel Pitch||3.72 μm||5.94 μm|
|Pixel Density||7.22 MP/cm2||2.83 MP/cm2|
|Moiré control||Anti-Alias filter||Anti-Alias filter|
|Movie Capability||1080/30p Video||4K/30p Video|
|ISO Setting||100 - 12,800 ISO||100 - 51,200 ISO|
|ISO Boost||100 - 25,600 ISO||50 - 204,800 ISO|
|Image Processor||DIGIC 6||BIONZ X|
|DXO Sensor Quality (score)||72||96|
|DXO Color Depth (bits)||22.8||25.0|
|DXO Dynamic Range (EV)||11.8||14.7|
|DXO Low Light (ISO)||1169||3730|
|Screen Specs||Canon M3||Sony A7 III|
|Viewfinder Type||Viewfinder optional||Electronic viewfinder|
|Viewfinder Field of View||100%|
|Viewfinder Resolution||2359k dots|
|LCD Framing||Live View||Live View|
|Rear LCD Size||3.0inch||3.0inch|
|LCD Resolution||1040k dots||922k dots|
|LCD Attachment||Tilting screen||Tilting screen|
|Shooting Specs||Canon M3||Sony A7 III|
|Focus System||On-Sensor Phase-detect||On-Sensor Phase-detect|
|Manual Focusing Aid||Focus Peaking||Focus Peaking|
|Max Shutter Speed (mechanical)||1/4000s||1/8000s|
|Continuous Shooting||4.2 shutter flaps/s||10 shutter flaps/s|
|Shutter Life Expectancy||100 000 actuations||200 000 actuations|
|Electronic Shutter||no E-Shutter||YES|
|Time-Lapse Photography||no Intervalometer||Intervalometer built-in|
|Image Stabilization||Lens stabilization only||In-body stabilization|
|Fill Flash||Built-in Flash||no On-Board Flash|
|Storage Medium||SDXC cards||MS or SDXC cards|
|Second Storage Option||Single card slot||Dual card slots|
|UHS card support||UHS-I||Single UHS-II|
|Connectivity Specs||Canon M3||Sony A7 III|
|USB Connector||USB 2.0||USB 3.1|
|HDMI Port||mini HDMI||micro HDMI|
|Microphone Port||External MIC port||External MIC port|
|Headphone Socket||no Headphone port||Headphone port|
|Wifi Support||Wifi built-in||Wifi built-in|
|Near-Field Communication||NFC built-in||NFC built-in|
|Bluetooth Support||no Bluetooth||Bluetooth built-in|
|Body Specs||Canon M3||Sony A7 III|
|Environmental Sealing||not weather sealed||Weathersealed body|
|Battery Life (CIPA)||250 shots per charge||610 shots per charge|
|In-Camera Charging||no USB charging||USB charging|
111 x 68 x 44 mm
(4.4 x 2.7 x 1.7 in)
127 x 96 x 74 mm
(5.0 x 3.8 x 2.9 in)
|Camera Weight||366 g (12.9 oz)||650 g (22.9 oz)|
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