Canon G7 X Mark III vs Sony A7S III
The Canon PowerShot G7 X Mark III and the Sony Alpha 7S III are two digital cameras that were officially introduced, respectively, in July 2019 and July 2020. The G7X Mark III is a fixed lens compact, while the A7S III is a mirrorless interchangeable lens camera. The cameras are based on an one-inch (G7X Mark III) and a full frame (A7S III) sensor. The Canon has a resolution of 20 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.
Going beyond this snapshot of core features and characteristics, what are the differences between the Canon PowerShot G7 X Mark III 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.
The physical size and weight of the Canon G7 X Mark III and the Sony A7S 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 width, height and depth measures are rounded to the nearest millimeter.
The G7X Mark III 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 (92 percent) than the Canon G7 X Mark III. It is noteworthy in this context that the A7S III is splash and dust-proof, while the G7X Mark III does not feature any corresponding weather-sealing.
The above size and weight comparisons are to some extent incomplete and possibly misleading, as the G7X Mark III has a lens built in, whereas the A7S III is an interchangeable lens camera that requires a separate lens. Attaching the latter will add extra weight and bulk to the setup. You can compare the optics available for the A7S III and their specifications in the Sony FE Lens Catalog.
Concerning battery life, the G7X Mark III gets 235 shots out of its NB-13L battery, while the A7S III can take 600 images on a single charge of its NP-FZ100 power pack. The battery packs of both cameras can be charged via USB, 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. 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.
|1.||Canon G7 X Mark III||105 mm||61 mm||41 mm||304 g||235||n||Jul 2019||749|
|2.||Sony A7S III||127 mm||97 mm||81 mm||699 g||600||Y||Jul 2020||3,499|
|3.||Canon G5 X Mark II||111 mm||61 mm||46 mm||340 g||230||n||Jul 2019||899|
|4.||Canon SX740||110 mm||64 mm||40 mm||299 g||265||n||Jul 2018||399|
|5.||Canon G7 X Mark II||106 mm||61 mm||42 mm||319 g||265||n||Feb 2016||699|
|6.||Canon G5 X||112 mm||76 mm||44 mm||353 g||210||n||Oct 2015||799|
|7.||Canon G7 X||103 mm||60 mm||40 mm||304 g||210||n||Sep 2014||699|
|8.||Leica C-LUX||113 mm||67 mm||46 mm||340 g||370||n||Jun 2018||1,049|
|9.||Panasonic FZ1000 II||136 mm||97 mm||131 mm||810 g||350||n||Feb 2019||899|
|10.||Panasonic ZS200||111 mm||65 mm||45 mm||340 g||370||n||Feb 2018||799|
|11.||Sony ZV-1||105 mm||60 mm||44 mm||294 g||260||n||May 2020||799|
|12.||Sony A7R IV||129 mm||96 mm||78 mm||665 g||670||Y||Jul 2019||3,499|
|13.||Sony RX100 VI||102 mm||58 mm||43 mm||301 g||240||n||Jun 2018||1,199|
|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 A7R II||127 mm||96 mm||60 mm||625 g||290||Y||Jun 2015||3,199|
|17.||Sony A7S II||127 mm||96 mm||60 mm||627 g||370||Y||Sep 2015||2,999|
|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 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 G7X Mark III was launched at a lower price than the A7S III, despite having a lens built in. 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.
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 are more costly to manufacture and tend to lead to bigger and heavier cameras and lenses.
Of the two cameras under consideration, the Canon G7 X Mark III features an one-inch sensor and the Sony A7S III a full frame sensor. The sensor area in the A7S III is 630 percent bigger. As a result of these sensor size differences, the cameras have a format factor of, respectively, 2.7 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 G7 X Mark III offers a higher resolution of 20 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 2.41μm versus 8.40μm for the A7S III). Moreover, it should be noted that the A7S III is a somewhat more recent model (by 1 year) than the G7X Mark III, and its sensor might 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 G7 X Mark III implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the G7X Mark III for good quality output (200 dots per inch) amounts to 27.4 x 18.2 inches or 69.5 x 46.3 cm, for very good quality (250 dpi) 21.9 x 14.6 inches or 55.6 x 37.1 cm, and for excellent quality (300 dpi) 18.2 x 12.2 inches or 46.3 x 30.9 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 PowerShot G7 X Mark III has a native sensitivity range from ISO 125 to ISO 12800, which can be extended to ISO 125-25600. 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.
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"). The adjacent table reports on the physical sensor characteristics and the outcomes of the DXO sensor quality tests for a sample of comparator-cameras.
| DXO |
|1.||Canon G7 X Mark III||1-inch||20.0||5472||3648||4K/30p||..||..||..||..|
|2.||Sony A7S III||Full Frame||12.0||4240||2832||4K/120p||23.7||13.9||2520||86|
|3.||Canon G5 X Mark II||1-inch||20.0||5472||3648||4K/30p||..||..||..||..|
|5.||Canon G7 X Mark II||1-inch||20.0||5472||3648||1080/60p||..||..||..||..|
|6.||Canon G5 X||1-inch||20.0||5472||3648||1080/60p||..||..||..||..|
|7.||Canon G7 X||1-inch||20.0||5472||3648||1080/60p||23.0||12.7||556||71|
|9.||Panasonic FZ1000 II||1-inch||20.0||5472||3648||4K/30p||..||..||..||..|
|12.||Sony A7R IV||Full Frame||60.2||9504||6336||4K/30p||26.0||14.8||3344||99|
|13.||Sony RX100 VI||1-inch||20.0||5472||3648||4K/30p||..||..||..||..|
|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 A7R II||Full Frame||42.2||7952||5304||4K/30p||26.0||13.9||3434||98|
|17.||Sony A7S II||Full Frame||12.0||4240||2832||4K/30p||23.6||13.3||2993||85|
Many modern cameras are not only capable of taking still images, but can also record movies. The two cameras under consideration both have sensors whose read-out speed is fast enough to capture moving pictures, but the A7S III provides a faster frame rate than the G7X Mark III. It can shoot movie footage at 4K/120p, while the Canon is limited to 4K/30p.
Apart from body and sensor, cameras can and do differ across a variety 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 G7X Mark III relies on live view and the rear LCD for framing. The table below summarizes some of the other core capabilities of the Canon G7 X Mark III and Sony A7S III in connection with corresponding information for a sample of similar cameras.
|1.||Canon G7 X Mark III||none||n||3.0||1040||tilting||Y||1/2000s||30||Y||Y|
|2.||Sony A7S III||9440||n||3.0||1440||swivel||Y||1/8000s||10.0||n||Y|
|3.||Canon G5 X Mark II||2360||n||3.0||1040||tilting||Y||1/2000s||30||Y||Y|
|5.||Canon G7 X Mark II||none||n||3.0||1040||tilting||Y||1/2000s||8.0||Y||Y|
|6.||Canon G5 X||2360||n||3.0||1040||swivel||Y||1/2000s||5.9||Y||Y|
|7.||Canon G7 X||none||n||3.0||1040||tilting||Y||1/2000s||6.5||Y||Y|
|9.||Panasonic FZ1000 II||2360||n||3.0||1240||swivel||Y||1/4000s||12.0||Y||Y|
|12.||Sony A7R IV||5760||n||3.0||1440||tilting||Y||1/8000s||10.0||n||Y|
|13.||Sony RX100 VI||2359||n||3.0||1229||tilting||Y||1/2000s||24.0||Y||Y|
|14.||Sony A7R III||3686||n||3.0||1440||tilting||Y||1/8000s||10.0||n||Y|
|16.||Sony A7R II||2400||n||3.0||1229||tilting||n||1/8000s||5.0||n||Y|
|17.||Sony A7S II||2400||n||3.0||1229||tilting||n||1/8000s||5.0||n||Y|
One difference between the cameras concerns the presence of an on-board flash. The G7X Mark III has one, while the A7S III does not. While the built-in flash of the G7X Mark III is not very powerful, it can at times be useful as a fill-in light.Both cameras have an articulated rear screen that can be turned to be front-facing. This feature will be particularly appreciated by vloggers and photographers who are interested in taking selfies.
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 G7 X Mark 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 G7X Mark III writes its imaging data to SDXC cards, while the A7S III uses CFexpress or SDXC cards. The A7S III features dual card slots, which can be very useful in case a memory card fails. In contrast, the G7X Mark III only has one slot. The A7S III supports UHS-II cards (on both slots), while the G7X Mark III 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 PowerShot G7 X Mark III and Sony Alpha 7S III and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.
| WiFi |
| NFC |
|1.||Canon G7 X Mark III||-||stereo||mono||Y||-||micro||3.1||Y||-||Y|
|2.||Sony A7S III||Y||stereo||mono||Y||Y||full||3.2||Y||-||Y|
|3.||Canon G5 X Mark II||-||stereo||mono||-||-||micro||3.1||Y||-||Y|
|5.||Canon G7 X Mark II||-||stereo||mono||-||-||micro||2.0||Y||Y||-|
|6.||Canon G5 X||Y||stereo||mono||-||-||mini||2.0||Y||Y||-|
|7.||Canon G7 X||-||stereo||mono||-||-||micro||2.0||Y||Y||-|
|9.||Panasonic FZ1000 II||Y||stereo||mono||Y||-||micro||2.0||Y||-||Y|
|12.||Sony A7R IV||Y||stereo||mono||Y||Y||micro||3.1||Y||Y||Y|
|13.||Sony RX100 VI||-||stereo||mono||-||-||micro||2.0||Y||Y||Y|
|14.||Sony A7R III||Y||stereo||mono||Y||Y||micro||3.1||Y||Y||Y|
|16.||Sony A7R II||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||-|
|17.||Sony A7S II||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||-|
It is notable that the A7S III has a hotshoe, which makes it possible to easily attach optional accessories, such as an external flash gun. The G7X Mark III does not feature such an accessory-socket.
Both the G7X Mark III and the A7S III are recent models that are part of the current product line-up. The G7X Mark III replaced the earlier Canon G7X Mark II, while the A7S III followed on from the Sony A7S II. 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 how do things add up? Is there a clear favorite between the Canon G7 X Mark III and the Sony A7S III? Which camera is better? The listing below highlights the relative strengths of the two models.
Advantages of the Canon PowerShot G7 X Mark III:
- More detail: Offers more megapixels (20 vs 12MP) with a 29% higher linear resolution.
- Faster burst: Shoots at higher frequency (30 vs 10 flaps/sec) to capture the decisive moment.
- Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
- Ready to shoot: Has a lens built-in, whereas the A7S III requires a separate lens.
- More compact: Is smaller (105x61mm vs 127x97mm) and thus needs less room in the bag.
- Less heavy: Is lighter even though it comes with a built-in lens (unlike the A7S III).
- Easier fill-in: Is equipped with a small onboard flash to brighten deep shadow areas.
- More affordable: Was introduced at a lower price, despite coming with a built-in lens.
- More heavily discounted: Has been on the market for longer (launched in July 2019).
Reasons to prefer the Sony Alpha 7S III:
- Better image quality: Is equipped with a larger and more technologically advanced sensor.
- Richer colors: The sensor size advantage translates into images with better, more accurate colors.
- More dynamic range: Larger sensor captures a wider spectrum of light and dark details.
- Better low-light sensitivity: Larger sensor produces good images even in poorly lit environments.
- Better video: Provides higher movie framerates (4K/120p versus 4K/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.
- 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 1/2000s) to freeze action.
- More flexible: Takes interchangeable lenses and can thus be used with specialty optics.
- Longer lasting: Gets more shots (600 versus 235) out of a single battery charge.
- Better sealing: Is splash and dust sealed for shooting in inclement weather conditions.
- Better lighting: Features a hotshoe and can thus hold and trigger an external flash gun.
- 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.
- 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: Was introduced somewhat (1 year) more recently.
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 : 9 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 G7 X Mark III and the Sony A7S III place the cameras among the top in their class? Find out in the latest Best Travel-Zoom Camera and Best Mirrorless Interchangeable Lens Camera listings 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 remains incomplete and does no justice, for example, to the way the G7X Mark III or the A7S III perform in practice. 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 why hands-on reviews by experts are important. The adjacent summary-table relays the overall verdicts of several of the most popular camera review sites (amateurphotographer [AP], cameralabs [CL], 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 G7 X Mark III||..||+ +||81/100||4/5||..||Jul 2019||749|
|2.||Sony A7S III||..||+ +||91/100||4.5/5||5/5||Jul 2020||3,499|
|3.||Canon G5 X Mark II||4/5||+||82/100||..||4/5||Jul 2019||899|
|4.||Canon SX740||..||+||..||4/5||4/5||Jul 2018||399|
|5.||Canon G7 X Mark II||4.5/5||+ +||81/100||4.5/5||4.5/5||Feb 2016||699|
|6.||Canon G5 X||5/5||+ +||78/100||4.5/5||4.5/5||Oct 2015||799|
|7.||Canon G7 X||4/5||+ +||77/100||4.5/5||4.5/5||Sep 2014||699|
|8.||Leica C-LUX||..||..||..||4.5/5||4/5||Jun 2018||1,049|
|9.||Panasonic FZ1000 II||..||..||83/100||4.5/5||4.5/5||Feb 2019||899|
|10.||Panasonic ZS200||..||+ +||81/100||4.5/5||4.5/5||Feb 2018||799|
|11.||Sony ZV-1||4/5||..||85/100||4/5||4.5/5||May 2020||799|
|12.||Sony A7R IV||5/5||+||91/100||4.5/5||5/5||Jul 2019||3,499|
|13.||Sony RX100 VI||4.5/5||+ +||83/100||4/5||4.5/5||Jun 2018||1,199|
|14.||Sony A7R III||..||+ +||90/100||4.5/5||5/5||Oct 2017||3,199|
|15.||Sony A9||5/5||+ +||89/100||5/5||5/5||Apr 2017||4,499|
|16.||Sony A7R II||5/5||+ +||90/100||5/5||5/5||Jun 2015||3,199|
|17.||Sony A7S II||5/5||+||..||4.5/5||5/5||Sep 2015||2,999|
|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. 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. It should also be noted that some of the review sites have over time altered the way they render their verdicts.
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.
Specifications: Canon G7 X Mark III vs Sony A7S 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 G7 X Mark III||Sony A7S III|
|Camera Type||Fixed lens compact camera||Mirrorless system camera|
|Camera Lens||24-100mm f/1.8-2.8||Sony E mount lenses|
|Launch Date||July 2019||July 2020|
|Launch Price||USD 749||USD 3,499|
|Sensor Specs||Canon G7 X Mark III||Sony A7S III|
|Sensor Format||1" Sensor||Full Frame Sensor|
|Sensor Size||13.2 x 8.8 mm||35.6 x 23.8 mm|
|Sensor Area||116.16 mm2||847.28 mm2|
|Sensor Diagonal||15.9 mm||42.8 mm|
|Sensor Resolution||20 Megapixels||12 Megapixels|
|Image Resolution||5472 x 3648 pixels||4240 x 2832 pixels|
|Pixel Pitch||2.41 μm||8.40 μm|
|Pixel Density||17.18 MP/cm2||1.42 MP/cm2|
|Moiré control||Anti-Alias filter||Anti-Alias filter|
|Movie Capability||4K/30p Video||4K/120p Video|
|ISO Setting||125 - 12,800 ISO||80 - 102,400 ISO|
|ISO Boost||125 - 25,600 ISO||40 - 409,600 ISO|
|Image Processor||DIGIC 8||BIONZ XR|
|DXO Sensor Quality (score)||..||86|
|DXO Color Depth (bits)||..||23.7|
|DXO Dynamic Range (EV)||..||13.9|
|DXO Low Light (ISO)||..||2520|
|Screen Specs||Canon G7 X Mark III||Sony A7S III|
|Viewfinder Type||no viewfinder||Electronic viewfinder|
|Viewfinder Field of View||100%|
|Viewfinder Resolution||9440k dots|
|LCD Framing||Live View||Live View|
|Rear LCD Size||3.0inch||3.0inch|
|LCD Resolution||1040k dots||1440k dots|
|LCD Attachment||Tilting screen||Swivel screen|
|Shooting Specs||Canon G7 X Mark III||Sony A7S III|
|Focus System||Contrast-detect AF||Contrast-detect AF|
|Manual Focusing Aid||Focus Peaking||Focus Peaking|
|Max Shutter Speed (mechanical)||1/2000s||1/8000s|
|Continuous Shooting||30 shutter flaps/s||10 shutter flaps/s|
|Electronic Shutter||up to 1/25600s||YES|
|Time-Lapse Photography||Intervalometer built-in||no Intervalometer|
|Image Stabilization||Lens-based stabilization||In-body stabilization|
|Fill Flash||Build-in Flash||no On-Board Flash|
|Storage Medium||SDXC cards||CFexpress or SDXC cards|
|Second Storage Option||Single card slot||Dual card slots|
|UHS card support||UHS-I||Dual UHS-II|
|Connectivity Specs||Canon G7 X Mark III||Sony A7S III|
|External Flash||no Hotshoe||Hotshoe|
|USB Connector||USB 3.1||USB 3.2|
|HDMI Port||micro HDMI||full HDMI|
|Microphone Port||External MIC port||External MIC port|
|Headphone Socket||no Headphone port||Headphone port|
|Wifi Support||Wifi built-in||Wifi built-in|
|Bluetooth Support||Bluetooth built-in||Bluetooth built-in|
|Body Specs||Canon G7 X Mark III||Sony A7S III|
|Environmental Sealing||not weather sealed||Weathersealed body|
|Battery Life (CIPA)||235 shots per charge||600 shots per charge|
|In-Camera Charging||USB charging||USB charging|
105 x 61 x 41 mm
(4.1 x 2.4 x 1.6 in)
127 x 97 x 81 mm
(5.0 x 3.8 x 3.2 in)
|Camera Weight||304 g (10.7 oz)||699 g (24.7 oz)|
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