Sony A7 III vs Canon G1 X Mark III

The Sony Alpha A7 III and the Canon PowerShot G1 X Mark III are two enthusiast cameras that were announced, respectively, in February 2018 and October 2017. The A7 III is a mirrorless interchangeable lens camera, while the G1X Mark III is a fixed lens compact. The cameras are based on a full frame (A7 III) and an APS-C (G1X Mark 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.

Headline Specifications

Sony A7 III		Canon G1 X Mark III
Mirrorless system camera		Fixed lens compact camera
Sony E mount lenses		24-72mm f/2.8-5.6
24 MP – Full Frame sensor		24 MP – APS-C sensor
4K/30p Video		1080/60p Video
ISO 100-51,200 (50 - 204,800)		ISO 100-25,600
Electronic viewfinder (2359k dots)		Electronic viewfinder (2360k dots)
3.0" LCD – 922k dots		3.0" LCD – 1040k dots
Tilting touchscreen		Swivel touchscreen
10 shutter flaps per second		9 shutter flaps per second
In-body stabilization		Lens-based stabilization
Weathersealed body		Weathersealed body
610 shots per battery charge		200 shots per battery charge
127 x 96 x 74 mm, 650 g		115 x 78 x 51 mm, 399 g

Check A7 III price at
amazon.com
Check G1X Mark III offers at
ebay.com

Going beyond this snapshot of core features and characteristics, what are the differences between the Sony Alpha A7 III and the Canon PowerShot G1 X Mark 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 Sony A7 III and the Canon G1 X Mark III are illustrated in the side-by-side display below. The two cameras are presented according to their relative size. Three consecutive views from the front, the top, and the rear side are shown. All width, height and depth measures 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 Canon G1 X Mark III is notably smaller (26 percent) than the Sony 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 and possibly misleading, as the G1X Mark III has a lens built in, whereas the A7 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 A7 III and their specifications in the Sony FE Lens Catalog.

Concerning battery life, the A7 III gets 610 shots out of its Sony NP-FZ100 battery, while the G1X Mark III can take 200 images on a single charge of its Canon NB-13L power pack. The power pack in the A7 III can be charged via the USB port, so that it is not always necessary to take the battery charger along when travelling.

The adjacent table lists the principal physical characteristics of the two cameras alongside a wider set of alternatives. If you want to switch the focus of the display and review another camera pair, you can move across to the CAM-parator tool and choose from the broad selection of possible camera comparisons 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.		Sony A7 III	127 mm	96 mm	74 mm	650 g	610	Y	Feb 2018	1,999	amazon.com
2.		Canon G1 X Mark III	115 mm	78 mm	51 mm	399 g	200	Y	Oct 2017	1,299	ebay.com
3.		Canon 6D Mark II	144 mm	111 mm	75 mm	765 g	1200	Y	Jun 2017	1,999	amazon.com
4.		Canon 80D	139 mm	105 mm	79 mm	730 g	960	Y	Feb 2016	1,199	ebay.com
5.		Fujifilm X100F	127 mm	75 mm	52 mm	469 g	390	n	Jan 2017	1,299	ebay.com
6.		Fujifilm X100V	128 mm	75 mm	53 mm	478 g	420	Y	Feb 2020	1,399	ebay.com
7.		Nikon Z6	134 mm	101 mm	67 mm	675 g	310	Y	Aug 2018	1,999	ebay.com
8.		Sony A7 II	127 mm	96 mm	60 mm	599 g	350	Y	Nov 2014	1,999	ebay.com
9.		Sony A7 IV	131 mm	96 mm	80 mm	659 g	580	Y	Oct 2021	2,499	amazon.com
10.		Sony A7C	124 mm	71 mm	60 mm	509 g	740	Y	Sep 2020	1,799	amazon.com
11.		Sony A7R III	127 mm	96 mm	74 mm	650 g	650	Y	Oct 2017	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 A9 II	129 mm	96 mm	76 mm	678 g	690	Y	Oct 2019	4,499	amazon.com
16.		Sony A6300	120 mm	67 mm	49 mm	404 g	400	Y	Feb 2016	999	ebay.com
17.		Sony A6500	120 mm	67 mm	53 mm	453 g	350	Y	Oct 2016	1,399	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 manufacturer’s suggested retail prices give an idea on the placement of the camera in the maker’s lineup and the broader market. The G1X Mark III was launched at a lower price than the A7 III, despite having a lens built in. 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. Then, after the new model is out, very good deals can frequently be found on the pre-owned market.

Sensor comparison

The size of the sensor inside a digital camera is one of the key determinants 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. Further, a large sensor camera will give the photographer additional creative options when using shallow depth-of-field to isolate a subject from its 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 Sony A7 III features a full frame sensor and the Canon G1 X Mark III an APS-C sensor. The sensor area in the G1X Mark III is 61 percent smaller. As a result of these sensor size differences, the cameras have a format factor of, respectively, 1.0 and 1.5. 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 G1X Mark III), which gives it a potential advantage in terms of light gathering capacity. In addition, the A7 III is a somewhat more recent model (by 4 months) than the G1X Mark III, and its sensor might have benefitted from technological advances during this time.

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 corresponding ISO settings for the Canon PowerShot G1 X Mark III are ISO 100 to ISO 25600 (no boost).

In terms of underlying technology, the A7 III is build around a BSI-CMOS sensor, while the G1X Mark III uses a 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 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 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.		Sony A7 III	Full Frame	24.0	6000	4000	4K/30p	25.0	14.7	3730	96
2.		Canon G1 X Mark III	APS-C	24.0	6000	4000	1080/60p	23.8	13.2	1649	81
3.		Canon 6D Mark II	Full Frame	26.0	6240	4160	1080/60p	24.4	11.9	2862	85
4.		Canon 80D	APS-C	24.0	6000	4000	1080/60p	23.6	13.2	1135	79
5.		Fujifilm X100F	APS-C	24.0	6000	4000	1080/60p	23.9	13.2	1704	81
6.		Fujifilm X100V	APS-C	26.0	6240	4160	4K/30p	24.2	13.6	1996	84
7.		Nikon Z6	Full Frame	24.3	6048	4024	4K/30p	25.3	14.3	3299	95
8.		Sony A7 II	Full Frame	24.0	6000	4000	1080/60p	24.9	13.6	2449	90
9.		Sony A7 IV	Full Frame	32.7	7008	4672	4K/60p	25.4	14.7	3379	97
10.		Sony A7C	Full Frame	24.0	6000	4000	4K/30p	25.0	14.7	3407	95
11.		Sony A7R III	Full Frame	42.2	7952	5304	4K/30p	26.0	14.7	3523	100
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 A9 II	Full Frame	24.0	6000	4000	4K/30p	25.0	14.0	3434	93
16.		Sony A6300	APS-C	24.0	6000	4000	4K/30p	24.4	13.7	1437	85
17.		Sony A6500	APS-C	24.0	6000	4000	4K/30p	24.5	13.7	1405	85
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 are equipped with sensors that have a sufficiently high read-out speed for moving images, but the A7 III provides a higher video resolution than the G1X Mark III. It can shoot video footage at 4K/30p, while the Canon is limited to 1080/60p.

Feature comparison

Apart from body and sensor, cameras can and do differ across a variety of features. The two cameras under review are similar with respect to both having an electronic viewfinder. However, the one in the G1X Mark III offers a slightly higher resolution than the one in the A7 III (2360k vs 2359k dots). The table below summarizes some of the other core capabilities of the Sony A7 III and Canon G1 X Mark 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.		Sony A7 III	2359	n	3.0 / 922	tilting	Y	1/8000s	10.0/s	n	Y
2.		Canon G1 X Mark III	2360	n	3.0 / 1040	swivel	Y	1/2000s	9.0/s	Y	Y
3.		Canon 6D Mark II	optical	Y	3.0 / 1040	swivel	Y	1/4000s	6.5/s	n	n
4.		Canon 80D	optical	Y	3.0 / 1040	swivel	Y	1/8000s	7.0/s	Y	n
5.		Fujifilm X100F	2360	n	3.0 / 1040	fixed	n	1/4000s	8.0/s	Y	n
6.		Fujifilm X100V	3690	n	3.0 / 1620	tilting	Y	1/4000s	11.0/s	n	n
7.		Nikon Z6	3690	Y	3.2 / 2100	tilting	Y	1/8000s	12.0/s	n	Y
8.		Sony A7 II	2400	n	3.0 / 1230	tilting	n	1/8000s	5.0/s	n	Y
9.		Sony A7 IV	3686	n	3.0 / 1037	swivel	Y	1/8000s	10.0/s	n	Y
10.		Sony A7C	2360	n	3.0 / 922	swivel	Y	1/4000s	10.0/s	n	Y
11.		Sony A7R III	3686	n	3.0 / 1440	tilting	Y	1/8000s	10.0/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 A9 II	3686	n	3.0 / 1440	tilting	Y	1/8000s	20.0/s	n	Y
16.		Sony A6300	2359	n	3.0 / 922	tilting	n	1/4000s	11.0/s	Y	n
17.		Sony A6500	2359	n	3.0 / 922	tilting	Y	1/4000s	11.0/s	Y	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 G1X Mark III has one, while the A7 III does not. While the built-in flash of the G1X Mark III 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 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 and the Canon G1 X Mark 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 A7 III writes its imaging data to SDXC or Memory Stick PRO Duo cards, while the G1X Mark III uses SDXC cards. The A7 III features dual card slots, which can be very useful in case a memory card fails. In contrast, the G1X Mark III only has one slot. The A7 III supports UHS-II cards (on its first slot), while the G1X Mark III 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 Sony Alpha A7 III and Canon PowerShot G1 X Mark 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.		Sony A7 III	Y	stereo / mono	Y	Y	micro	3.1	Y	Y	Y
2.		Canon G1 X Mark III	Y	stereo / mono	-	-	micro	2.0	Y	Y	Y
3.		Canon 6D Mark II	Y	stereo / mono	Y	-	mini	2.0	Y	Y	Y
4.		Canon 80D	Y	stereo / mono	Y	Y	mini	2.0	Y	Y	-
5.		Fujifilm X100F	Y	stereo / mono	Y	-	micro	2.0	Y	-	-
6.		Fujifilm X100V	Y	stereo / mono	Y	-	micro	3.1	Y	-	Y
7.		Nikon Z6	Y	stereo / mono	Y	Y	micro	3.1	Y	-	Y
8.		Sony A7 II	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
9.		Sony A7 IV	Y	stereo / mono	Y	Y	full	3.2	Y	-	Y
10.		Sony A7C	Y	stereo / mono	Y	Y	micro	3.2	Y	Y	Y
11.		Sony A7R III	Y	stereo / mono	Y	Y	micro	3.1	Y	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 A9 II	Y	stereo / mono	Y	Y	micro	3.1	Y	Y	Y
16.		Sony A6300	Y	stereo / mono	Y	-	micro	2.0	Y	Y	-
17.		Sony A6500	Y	stereo / mono	Y	-	micro	2.0	Y	Y	-

It is notable that the A7 III has a microphone port, which is missing on the G1X Mark III. Such an external microphone input can help to substantially improve the quality of audio recordings when a good external microphone is used.

The A7 III is a recent model that features in the current product line-up of Sony. In contrast, the G1X Mark III has been discontinued (but can be found pre-owned on ebay). There has not been a direct replacement model for the G1X Mark III from Canon. Further information on the features and operation of the A7 III and G1X Mark III can be found, respectively, in the Sony A7 III Manual (free pdf) or the online Canon G1 X Mark III Manual.

Review summary

So what conclusions can be drawn? Which of the two cameras – the Sony A7 III or the Canon G1 X Mark 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 Sony Alpha A7 III:

• Better image quality: Features bigger pixels on a larger sensor for higher quality imaging.
• Richer colors: The pixel size advantage translates into images with better, more accurate colors.
• More dynamic range: Larger pixels capture a wider spectrum of light and dark details.
• Better low-light sensitivity: Larger pixels means good image quality even under poor lighting.
• Better video: Provides higher definition movie capture (4K/30p vs 1080/60p).
• Better sound: Can connect to an external microphone for higher quality sound recording.
• Better sound control: Has a headphone port that enables audio monitoring while recording.
• Faster shutter: Has higher mechanical shutter speed (1/8000s vs 1/2000s) to freeze action.
• Less disturbing: Has an electronic shutter option for completely silent shooting.
• More flexible: Accepts interchangeable lenses, so that lens characteristics can be altered.
• Longer lasting: Can take more shots (610 versus 200) on a single battery charge.
• Easier travel charging: Can be conveniently charged via its USB port.
• Faster data transfer: Supports a more advanced USB protocol (3.1 vs 2.0).
• 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: Is somewhat more recent (announced 4 months after the G1X Mark III).

Advantages of the Canon PowerShot G1 X Mark III:

• More detailed LCD: Has a higher resolution rear screen (1040k 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.
• Ready to shoot: Has an integrated lens, whereas the A7 III necessitates an extra lens.
• More compact: Is smaller (115x78mm vs 127x96mm) and will fit more readily into a bag.
• Less heavy: Has a lower weight even though it has a lens built in (unlike the A7 III).
• Easier fill-in: Has a small integrated flash to brighten shadows of backlit subjects.
• 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 October 2017).

If the count of relative strengths (bullet points above) is taken as a measure, the A7 III is the clear winner of the match-up (16 : 9 points). However, the pertinence of the various camera strengths will differ across photographers, so that you might want to weigh individual camera traits according to their importance for your own imaging needs before making a camera decision. 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 Canon G1 X Mark III place the cameras among the top in their class? Find out in the latest Best Mirrorless Interchangeable Lens Camera and Best Travel-Zoom Camera listings 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 partial and cannot reveal, for example, the shooting experience and imaging performance when actually working with the A7 III or the G1X Mark III. 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 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.

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.		Canon G1 X Mark III	5/5	+	4/5	79/100	4.5/5	4.5/5	Oct 2017	1,299	ebay.com
3.		Canon 6D Mark II	4/5	+	4/5	80/100	4.5/5	4/5	Jun 2017	1,999	amazon.com
4.		Canon 80D	4/5	+ +	4.5/5	84/100	4.5/5	4.5/5	Feb 2016	1,199	ebay.com
5.		Fujifilm X100F	5/5	+	3.9/5	83/100	4.5/5	4.5/5	Jan 2017	1,299	ebay.com
6.		Fujifilm X100V	5/5	+ +	4.5/5	86/100	5/5	4.5/5	Feb 2020	1,399	ebay.com
7.		Nikon Z6	5/5	..	5/5	89/100	4.5/5	5/5	Aug 2018	1,999	ebay.com
8.		Sony A7 II	5/5	+	4/5	82/100	4.5/5	5/5	Nov 2014	1,999	ebay.com
9.		Sony A7 IV	5/5	+ +	4.5/5	89/100	4.5/5	4.5/5	Oct 2021	2,499	amazon.com
10.		Sony A7C	3.5/5	..	3.5/5	86/100	4/5	4/5	Sep 2020	1,799	amazon.com
11.		Sony A7R III	..	+ +	4/5	90/100	4.5/5	5/5	Oct 2017	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 A9 II	..	..	5/5	90/100	5/5	5/5	Oct 2019	4,499	amazon.com
16.		Sony A6300	4.5/5	+	..	85/100	5/5	5/5	Feb 2016	999	ebay.com
17.		Sony A6500	5/5	+ +	3.5/5	85/100	4.5/5	4.5/5	Oct 2016	1,399	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 G1X Mark III offers at
ebay.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 your choice using the following search menu. Alternatively, you can follow any of the listed hyperlinks for comparisons that others found interesting.

~

Check A7 III price at
amazon.com
Check G1X Mark III offers at
ebay.com

Did you notice an error on this page? If so, please get in touch, so that we can correct the information.