Canon SX420 vs G7X Mark III

The Canon PowerShot SX420 IS and the Canon PowerShot G7 X Mark III are two digital cameras that were revealed to the public, respectively, in January 2016 and July 2019. Both the SX420 and the G7X Mark III are fixed lens compact cameras that are based on a 1/2.3-inch (SX420) and an one-inch (G7X Mark III) sensor. The SX420 has a resolution of 19.9 megapixels, whereas the G7X Mark III provides 20 MP.

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

Headline Specifications

Canon SX420		Canon G7 X Mark III
Fixed lens compact camera		Fixed lens compact camera
24-1008mm f/3.5-6.6		24-100mm f/1.8-2.8
19.9 MP – 1/2.3" sensor		20 MP – 1" sensor
720/25p Video		4K/30p Video
ISO 100-1,600		ISO 125-12,800 (125 - 25,600)
No viewfinder, LCD framing		No viewfinder, LCD framing
3.0" LCD – 230k dots		3.0" LCD – 1040k dots
Fixed screen (not touch-sensitive)		Tilting touchscreen
0.5 shutter flaps per second		30 shutter flaps per second
195 shots per battery charge		235 shots per battery charge
104 x 69 x 85 mm, 325 g		105 x 61 x 41 mm, 304 g

Check SX420 offers at
ebay.com
Check G7X Mark III price at
amazon.com

Going beyond this snapshot of core features and characteristics, what are the differences between the Canon PowerShot SX420 IS and the Canon PowerShot G7 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 side-by-side display below illustrates the physical size and weight of the Canon SX420 and the Canon G7 X Mark III. 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 size dimensions are rounded to the nearest millimeter.

The SX420 can be obtained in two different colors (black, red), while the G7X Mark III is also available in two color-versions, but different ones (black, silver).

If the front view area (width x height) of the cameras is taken as an aggregate measure of their size, the Canon G7 X Mark III is notably smaller (11 percent) than the Canon SX420. Moreover, the G7X Mark III is markedly lighter (6 percent) than the SX420. In this context, it is worth noting that neither the SX420 nor the G7X Mark III are weather-sealed.

Concerning battery life, the SX420 gets 195 shots out of its Canon NB-11LH battery, while the G7X Mark III can take 235 images on a single charge of its Canon NB-13L power pack. The power pack in the G7X Mark 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 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.		Canon SX420	104 mm	69 mm	85 mm	325 g	195	n	Jan 2016	299	ebay.com
2.		Canon G7 X Mark III	105 mm	61 mm	41 mm	304 g	235	n	Jul 2019	749	amazon.com
3.		Canon G5 X	112 mm	76 mm	44 mm	353 g	210	n	Oct 2015	799	ebay.com
4.		Canon G5 X Mark II	111 mm	61 mm	46 mm	340 g	230	n	Jul 2019	899	ebay.com
5.		Canon G7 X	103 mm	60 mm	40 mm	304 g	210	n	Sep 2014	699	ebay.com
6.		Canon G7 X Mark II	106 mm	61 mm	42 mm	319 g	265	n	Feb 2016	699	ebay.com
7.		Canon SX410	104 mm	69 mm	85 mm	325 g	185	n	Feb 2015	279	ebay.com
8.		Canon SX430	104 mm	69 mm	85 mm	323 g	195	n	Jan 2017	299	ebay.com
9.		Canon SX610	105 mm	61 mm	27 mm	191 g	270	n	Jan 2015	249	ebay.com
10.		Canon SX620	97 mm	57 mm	28 mm	182 g	295	n	May 2016	279	ebay.com
11.		Canon SX710	113 mm	66 mm	35 mm	269 g	230	n	Jan 2015	349	ebay.com
12.		Canon SX720	110 mm	64 mm	36 mm	270 g	250	n	Feb 2016	379	ebay.com
13.		Canon SX730	110 mm	64 mm	40 mm	300 g	250	n	Apr 2017	399	ebay.com
14.		Panasonic ZS70	112 mm	67 mm	41 mm	322 g	380	n	Apr 2017	449	ebay.com
15.		Sony ZV-1	105 mm	60 mm	44 mm	294 g	260	n	May 2020	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

Any camera decision will naturally be influenced heavily by the price. 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 SX420 was launched at a markedly lower price (by 60 percent) than the G7X Mark III, which puts it into a different market segment. 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 imaging sensor is a crucial determinant of image quality. A large sensor will tend to have larger individual pixels that provide better low-light sensitivity, wider dynamic range, and richer color-depth than smaller pixel-units 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 SX420 features a 1/2.3-inch sensor and the Canon G7 X Mark III an one-inch sensor. The sensor area in the G7X Mark III is 314 percent bigger. As a result of these sensor size differences, the cameras have a format factor of, respectively, 5.6 and 2.7. The sensor in the SX420 has a native 4:3 aspect ratio, while the one in the G7X Mark III offers a 3:2 aspect.

Technology-wise, the G7X Mark III uses a more advanced image processing engine (DIGIC 8) than the SX420 (DIGIC 4+), with benefits for noise reduction, color accuracy, and processing speed.

With 20MP, the G7X Mark III offers a higher resolution than the SX420 (19.9MP), but the G7X Mark III nevertheless has larger individual pixels (pixel pitch of 2.41μm versus 1.19μm for the SX420) due to its larger sensor. Moreover, the G7X Mark III is a much more recent model (by 3 years and 6 months) than the SX420, 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 SX420 has no anti-alias filter installed, so that it can capture all the detail its sensor resolves.

The Canon PowerShot SX420 IS has a native sensitivity range from ISO 100 to ISO 1600. The corresponding ISO settings for the Canon PowerShot G7 X Mark III are ISO 125 to ISO 12800, with the possibility to increase the ISO range to 125-25600.

In terms of underlying technology, the SX420 is build around a CCD sensor, while the G7X Mark 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 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.		Canon SX420	1/2.3	19.9	5152	3864	720/25p	20.3	11.7	806	48
2.		Canon G7 X Mark III	1-inch	20.0	5472	3648	4K/30p	22.2	12.4	583	65
3.		Canon G5 X	1-inch	20.0	5472	3648	1080/60p	21.4	12.3	471	62
4.		Canon G5 X Mark II	1-inch	20.0	5472	3648	4K/30p	22.2	12.4	583	65
5.		Canon G7 X	1-inch	20.0	5472	3648	1080/60p	23.0	12.7	556	71
6.		Canon G7 X Mark II	1-inch	20.0	5472	3648	1080/60p	21.8	11.9	260	62
7.		Canon SX410	1/2.3	19.9	5152	3864	720/30p	20.2	11.6	720	47
8.		Canon SX430	1/2.3	19.9	5152	3864	720/25p	20.5	11.9	900	49
9.		Canon SX610	1/2.3	20.2	5184	3888	1080/30p	20.2	11.6	712	47
10.		Canon SX620	1/2.3	20.2	5184	3888	1080/30p	20.4	11.8	838	49
11.		Canon SX710	1/2.3	20.2	5184	3888	1080/60p	20.2	11.6	712	47
12.		Canon SX720	1/2.3	20.2	5184	3888	1080/60p	20.3	11.8	817	48
13.		Canon SX730	1/2.3	20.2	5184	3888	1080/60p	20.5	11.9	924	50
14.		Panasonic ZS70	1/2.3	20.2	5184	3888	4K/30p	19.1	10.6	106	36
15.		Sony ZV-1	1-inch	20.0	5472	3648	4K/30p	22.2	12.6	669	66
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. The two cameras under consideration both have sensors whose read-out speed is fast enough to capture moving pictures, but the G7X Mark III provides a better video resolution than the SX420. It can shoot movie footage at 4K/30p, while the SX420 is limited to 720/25p.

Feature comparison

Apart from body and sensor, cameras can and do differ across a range of features. The SX420 and the G7X Mark III are similar in the sense that neither of the two has a viewfinder. The images are, thus, framed using live view on the rear LCD. The adjacent table lists some of the other core features of the Canon SX420 and Canon G7 X Mark III along with similar information for a selection of comparators.

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 SX420	none	n	3.0 / 230	fixed	n	1/4000s	0.5/s	Y	Y
2.		Canon G7 X Mark III	none	n	3.0 / 1040	tilting	Y	1/2000s	30/s	Y	Y
3.		Canon G5 X	2360	n	3.0 / 1040	swivel	Y	1/2000s	5.9/s	Y	Y
4.		Canon G5 X Mark II	2360	n	3.0 / 1040	tilting	Y	1/2000s	30/s	Y	Y
5.		Canon G7 X	none	n	3.0 / 1040	tilting	Y	1/2000s	6.5/s	Y	Y
6.		Canon G7 X Mark II	none	n	3.0 / 1040	tilting	Y	1/2000s	8.0/s	Y	Y
7.		Canon SX410	none	n	3.0 / 230	fixed	n	1/4000s	0.5/s	Y	Y
8.		Canon SX430	none	n	3.0 / 230	fixed	n	1/4000s	0.5/s	Y	Y
9.		Canon SX610	none	n	3.0 / 922	fixed	n	1/2000s	2.5/s	Y	Y
10.		Canon SX620	none	n	3.0 / 922	fixed	n	1/2000s	2.5/s	Y	Y
11.		Canon SX710	none	n	3.0 / 922	fixed	n	1/3200s	6.0/s	Y	Y
12.		Canon SX720	none	n	3.0 / 922	fixed	n	1/3200s	5.9/s	Y	Y
13.		Canon SX730	none	n	3.0 / 922	tilting	n	1/3200s	5.9/s	Y	Y
14.		Panasonic ZS70	1166	n	3.0 / 1040	tilting	Y	1/2000s	10.0/s	Y	Y
15.		Sony ZV-1	none	n	3.0 / 922	swivel	Y	1/2000s	24.0/s	n	n
Note: *) Information refers to the mechanical shutter, unless the camera only has an electronic one.

One differentiating feature between the two cameras concerns the touch sensitivity of the rear screen. The G7X Mark III has a touchscreen, while the SX420 has a conventional panel. Touch control can be particularly helpful, for example, for setting the focus point.

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 G7X Mark 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 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.

Both the SX420 and the G7X Mark III have zoom lenses built in. The SX420 has a 24-1008mm f/3.5-6.6 optic and the G7X Mark III offers a 24-100mm f/1.8-2.8 (focal lengths in full frame equivalent terms). Hence, the SX420 and G7X Mark III provide the same view at the wide-angle end, but the G7X Mark III has less tele-photo reach at the long end. The G7X Mark III offers the faster maximum aperture.

Concerning the storage of imaging data, both the SX420 and the G7X Mark III write their files to SDXC cards. The G7X Mark III supports UHS-I cards (Ultra High Speed data transfer of up to 104 MB/s), while the SX420 cannot take advantage of Ultra High Speed SD 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 PowerShot SX420 IS and Canon PowerShot G7 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.		Canon SX420	-	mono / mono	-	-	-	2.0	Y	Y	-
2.		Canon G7 X Mark III	-	stereo / mono	Y	-	micro	3.1	Y	-	Y
3.		Canon G5 X	Y	stereo / mono	-	-	mini	2.0	Y	Y	-
4.		Canon G5 X Mark II	-	stereo / mono	-	-	micro	3.1	Y	-	Y
5.		Canon G7 X	-	stereo / mono	-	-	micro	2.0	Y	Y	-
6.		Canon G7 X Mark II	-	stereo / mono	-	-	micro	2.0	Y	Y	-
7.		Canon SX410	-	stereo / mono	-	-	-	2.0	-	-	-
8.		Canon SX430	-	mono / mono	-	-	-	2.0	Y	Y	-
9.		Canon SX610	-	- / -	-	-	micro	2.0	Y	Y	-
10.		Canon SX620	-	mono / mono	-	-	micro	2.0	Y	Y	-
11.		Canon SX710	-	stereo / mono	-	-	micro	2.0	Y	Y	-
12.		Canon SX720	-	stereo / mono	-	-	micro	2.0	Y	Y	-
13.		Canon SX730	-	stereo / mono	-	-	micro	2.0	Y	Y	Y
14.		Panasonic ZS70	-	stereo / mono	-	-	micro	2.0	Y	-	-
15.		Sony ZV-1	Y	stereo / mono	Y	-	micro	2.0	Y	-	Y

It is notable that the G7X Mark III has a microphone port, which can help to improve the quality of audio recordings by attaching an external microphone. The SX420 does not feature such a mic input.

The G7X Mark III is a recent model that features in the current product line-up of Canon. In contrast, the SX420 has been discontinued (but can be found pre-owned on ebay). As a replacement in the same line of cameras, the SX420 was succeeded by the Canon SX430. Further information on the features and operation of the SX420 and G7X Mark III can be found, respectively, in the Canon SX420 Manual (free pdf) or the online Canon G7 X Mark III Manual.

Review summary

So what conclusions can be drawn? Is the Canon SX420 better than the Canon G7 X Mark III or vice versa? A synthesis of the relative strong points of each of the models is listed below.

Advantages of the Canon PowerShot SX420 IS:

• Maximized detail: Lacks an anti-alias filter to exploit the sensor's full resolution potential.
• Faster shutter: Has higher mechanical shutter speed (1/4000s vs 1/2000s) to freeze action.
• More tele-reach: Has a longer tele-lens for perspective compression and subject magnification.
• Easier device pairing: Supports NFC for fast wireless image transfer over short distances.
• More affordable: Was introduced into a lower priced category (60 percent cheaper at launch).
• More heavily discounted: Has been available for much longer (launched in January 2016).

Arguments in favor of the Canon PowerShot G7 X Mark III:

• Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
• 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 jpgs: Has a more modern image processing engine (DIGIC 8 vs DIGIC 4+).
• Better video: Provides higher definition movie capture (4K/30p vs 720/25p).
• Better sound: Can connect to an external microphone for higher quality sound recording.
• More detailed LCD: Has a higher resolution rear screen (1040k vs 230k dots).
• More flexible LCD: Has a tilting screen for odd-angle shots in landscape orientation.
• Fewer buttons to press: Has a touchscreen to facilitate handling and shooting adjustments.
• More selfie-friendly: Has an articulated screen that can be turned to be front-facing.
• Faster burst: Shoots at higher frequency (30 vs 0.5 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.
• Better light gathering: Has a lens with a wider maximum aperture (f/1.8 vs f/3.5).
• More compact: Is smaller (105x61mm vs 104x69mm) and will fit more readily into a bag.
• Longer lasting: Gets more shots (235 versus 195) out of 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).
• Easier wireless transfer: Supports Bluetooth for image sharing without cables.
• Faster buffer clearing: Has an SD card interface that supports the UHS-I standard.
• More modern: Reflects 3 years and 6 months of technical progress since the SX420 launch.

If the count of individual advantages (bullet points above) is taken as a guide, the G7X Mark III is the clear winner of the contest (23 : 6 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 wedding photographer will view the differences between cameras in a way that diverges from the perspective of a travel photog, and a person interested in cityscapes has distinct needs from a macro 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 SX420 and the Canon G7 X Mark III place the cameras among the top in their class? Find out in the latest Best Superzoom Camera and Best Travel-Zoom Camera listings 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 incomplete and does no justice, for example, to the way the SX420 or the G7X Mark 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 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 SX420	..	..	..	..	..	3/5	Jan 2016	299	ebay.com
2.		Canon G7 X Mark III	..	+ +	4/5	81/100	4/5	..	Jul 2019	749	amazon.com
3.		Canon G5 X	5/5	+ +	..	78/100	4.5/5	4.5/5	Oct 2015	799	ebay.com
4.		Canon G5 X Mark II	4/5	+	4/5	82/100	..	4/5	Jul 2019	899	ebay.com
5.		Canon G7 X	4/5	+ +	..	77/100	4.5/5	4.5/5	Sep 2014	699	ebay.com
6.		Canon G7 X Mark II	4.5/5	+ +	..	81/100	4.5/5	4.5/5	Feb 2016	699	ebay.com
7.		Canon SX410	..	o	..	..	..	..	Feb 2015	279	ebay.com
8.		Canon SX430	..	..	..	..	3.5/5	3.5/5	Jan 2017	299	ebay.com
9.		Canon SX610	..	..	..	..	4/5	4/5	Jan 2015	249	ebay.com
10.		Canon SX620	..	..	..	..	..	4/5	May 2016	279	ebay.com
11.		Canon SX710	..	+	..	..	4/5	3.5/5	Jan 2015	349	ebay.com
12.		Canon SX720	..	+	..	..	4/5	4.5/5	Feb 2016	379	ebay.com
13.		Canon SX730	..	+	..	..	4/5	4/5	Apr 2017	399	ebay.com
14.		Panasonic ZS70	..	+ +	..	..	4/5	4/5	Apr 2017	449	ebay.com
15.		Sony ZV-1	4/5	+	4/5	85/100	4/5	4.5/5	May 2020	799	ebay.com
Note: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.

The review scores listed above should be treated with care, though. The ratings were established in reference to similarly priced cameras that were available in the market at the time of the review. 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. It should also be noted that some of the review sites have over time altered the way they render their verdicts.

Check SX420 offers at
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Check G7X Mark III price at
amazon.com

Other camera comparisons

Did this review help to inform your camera decision process? In case you would like to check on the differences and similarities of other camera models, 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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