Canon G7 X vs Nikon D3100

The Canon PowerShot G7 X and the Nikon D3100 are two digital cameras that were officially introduced, respectively, in September 2014 and August 2010. The G7X is a fixed lens compact, while the D3100 is a DSLR. The cameras are based on an one-inch (G7X) and an APS-C (D3100) sensor. The Canon has a resolution of 20 megapixels, whereas the Nikon provides 14.2 MP.

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

Headline Specifications

Canon G7 X		Nikon D3100
Fixed lens compact camera		Digital single lens reflex
24-100mm f/1.8-2.8		Nikon F mount lenses
20 MP – 1" sensor		14.2 MP – APS-C sensor
1080/60p Video		1080/24p Video
ISO 125-12,800		ISO 100-3,200 (100 - 12,800)
No viewfinder, LCD framing		Optical viewfinder
3.0" LCD – 1040k dots		3.0" LCD – 230k dots
Tilting touchscreen		Fixed screen (not touch-sensitive)
6.5 shutter flaps per second		3 shutter flaps per second
210 shots per battery charge		550 shots per battery charge
103 x 60 x 40 mm, 304 g		124 x 96 x 75 mm, 505 g

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Going beyond this snapshot of core features and characteristics, what are the differences between the Canon PowerShot G7 X and the Nikon D3100? 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 G7 X and the Nikon D3100 are illustrated in the side-by-side display below. 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 D3100 can be obtained in two different colors (black, red), while the G7X 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 Nikon D3100 is considerably larger (93 percent) than the Canon G7 X. In this context, it is worth noting that neither the G7X nor the D3100 are weather-sealed.

The above size and weight comparisons are to some extent incomplete and possibly misleading, as the G7X has a lens built in, whereas the D3100 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 D3100 and their specifications in the Nikon Lens Catalog.

Concerning battery life, the G7X gets 210 shots out of its Canon NB-13L battery, while the D3100 can take 550 images on a single charge of its Nikon EN-EL14 power pack.

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 G7 X	103 mm	60 mm	40 mm	304 g	210	n	Sep 2014	699	ebay.com
2.		Nikon D3100	124 mm	96 mm	75 mm	505 g	550	n	Aug 2010	599	ebay.com
3.		Canon G5 X	112 mm	76 mm	44 mm	353 g	210	n	Oct 2015	799	ebay.com
4.		Canon G7 X Mark II	106 mm	61 mm	42 mm	319 g	265	n	Feb 2016	699	ebay.com
5.		Canon G7 X Mark III	105 mm	61 mm	41 mm	304 g	235	n	Jul 2019	749	amazon.com
6.		Canon G9 X	98 mm	58 mm	31 mm	209 g	220	n	Oct 2015	529	ebay.com
7.		Canon M3	111 mm	68 mm	44 mm	366 g	250	n	Feb 2015	679	ebay.com
8.		Canon M10	108 mm	67 mm	35 mm	301 g	255	n	Oct 2015	499	ebay.com
9.		Canon T6i	132 mm	101 mm	78 mm	555 g	440	n	Feb 2015	749	ebay.com
10.		Nikon D3000	126 mm	97 mm	64 mm	536 g	500	n	Jul 2009	599	ebay.com
11.		Nikon D3200	125 mm	96 mm	77 mm	505 g	540	n	Apr 2012	599	ebay.com
12.		Nikon D5000	127 mm	104 mm	80 mm	590 g	510	n	Apr 2009	749	ebay.com
13.		Nikon D5100	128 mm	97 mm	79 mm	560 g	660	n	Apr 2011	749	ebay.com
14.		Nikon D7000	132 mm	105 mm	77 mm	780 g	1050	Y	Sep 2010	1,499	ebay.com
15.		Sony RX100 II	102 mm	58 mm	38 mm	281 g	350	n	Jun 2013	749	ebay.com
16.		Sony RX100 III	102 mm	58 mm	41 mm	290 g	320	n	May 2014	799	ebay.com
17.		Sony RX100 IV	102 mm	58 mm	41 mm	298 g	280	n	Jun 2015	999	ebay.com
Note: Measurements and pricing do not include easily detachable parts, such as add-on or interchangeable lenses or optional viewfinders.
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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. 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.

Sensor comparison

The size of the sensor inside a digital camera is one of the key determinants 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. 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 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 features an one-inch sensor and the Nikon D3100 an APS-C sensor. The sensor area in the D3100 is 207 percent bigger. As a result of these sensor size differences, the cameras have a format factor of, respectively, 2.7 and 1.5. Both cameras have a native aspect ratio (sensor width to sensor height) of 3:2.

Despite having a smaller sensor, the Canon G7 X offers a higher resolution of 20 megapixels, compared with 14.2 MP of the Nikon D3100. 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 5.01μm for the D3100). However, it should be noted that the G7X is much more recent (by 4 years) than the D3100, and its sensor will have benefitted from technological advances during this time that make it possible to gather light more efficiently.

The resolution advantage of the Canon G7 X implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the G7X 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 Nikon D3100 are 23 x 15.4 inches or 58.5 x 39 cm for good quality, 18.4 x 12.3 inches or 46.8 x 31.2 cm for very good quality, and 15.4 x 10.2 inches or 39 x 26 cm for excellent quality prints.

The Canon PowerShot G7 X has a native sensitivity range from ISO 125 to ISO 12800. The corresponding ISO settings for the Nikon D3100 are ISO 100 to ISO 3200, with the possibility to increase the ISO range to 100-12800.

In terms of underlying technology, the G7X is build around a BSI-CMOS sensor, while the D3100 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 assesses and scores the color depth ("DXO Portrait"), dynamic range ("DXO Landscape"), and low-light sensitivity ("DXO Sports") of camera sensors, and also publishes an overall camera score. Of the two cameras under review, the G7X has a notably higher overall DXO score than the D3100 (overall score 4 points higher), which gives it an advantage in terms of imaging quality. This advantage is based on 0.5 bits higher color depth, 1.4 EV in additional dynamic range, and 0.7 stops of reduced 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.

Sensor Characteristics

		Camera Model	Sensor Class	Resolution (MP)	Horiz. Pixels	Vert. Pixels	Video Format	DXO Portrait	DXO Landscape	DXO Sports	DXO Overall
1.		Canon G7 X	1-inch	20.0	5472	3648	1080/60p	23.0	12.7	556	71
2.		Nikon D3100	APS-C	14.2	4608	3072	1080/24p	22.5	11.3	919	67
3.		Canon G5 X	1-inch	20.0	5472	3648	1080/60p	21.4	12.3	471	62
4.		Canon G7 X Mark II	1-inch	20.0	5472	3648	1080/60p	21.8	11.9	260	62
5.		Canon G7 X Mark III	1-inch	20.0	5472	3648	4K/30p	22.2	12.4	583	65
6.		Canon G9 X	1-inch	20.0	5472	3648	1080/60p	21.5	12.3	495	63
7.		Canon M3	APS-C	24.0	6000	4000	1080/30p	22.8	11.8	1169	72
8.		Canon M10	APS-C	17.9	5184	3456	1080/30p	22.2	11.4	753	65
9.		Canon T6i	APS-C	24.0	6000	4000	1080/30p	22.7	12.0	919	71
10.		Nikon D3000	APS-C	10.0	3872	2592	none	22.3	11.1	563	62
11.		Nikon D3200	APS-C	24.1	6016	4000	1080/30p	24.1	13.2	1131	81
12.		Nikon D5000	APS-C	12.2	4288	2848	720/24p	22.7	12.5	868	72
13.		Nikon D5100	APS-C	16.1	4928	3264	1080/30p	23.5	13.6	1183	80
14.		Nikon D7000	APS-C	16.1	4928	3264	1080/24p	23.5	13.9	1167	80
15.		Sony RX100 II	1-inch	20.0	5472	3648	1080/60p	22.5	12.4	483	67
16.		Sony RX100 III	1-inch	20.0	5472	3648	1080/60p	22.4	12.3	495	67
17.		Sony RX100 IV	1-inch	20.0	5472	3648	4K/30p	22.8	12.6	591	70
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 can also record movies. Both cameras under consideration are equipped with sensors that have a sufficiently high read-out speed for moving images, but the G7X provides a higher frame rate than the D3100. It can shoot video footage at 1080/60p, while the Nikon is limited to 1080/24p.

Feature comparison

Apart from body and sensor, cameras can and do differ across a variety of features. For example, the D3100 has an optical viewfinder, which can be very useful when shooting in bright sunlight. In contrast, the G7X relies on live view and the rear LCD for framing. The following table reports on some other key feature differences and similarities of the Canon G7 X, the Nikon D3100, and comparable 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 G7 X	none	n	3.0 / 1040	tilting	Y	1/2000s	6.5/s	Y	Y
2.		Nikon D3100	optical	n	3.0 / 230	fixed	n	1/4000s	3.0/s	Y	n
3.		Canon G5 X	2360	n	3.0 / 1040	swivel	Y	1/2000s	5.9/s	Y	Y
4.		Canon G7 X Mark II	none	n	3.0 / 1040	tilting	Y	1/2000s	8.0/s	Y	Y
5.		Canon G7 X Mark III	none	n	3.0 / 1040	tilting	Y	1/2000s	30/s	Y	Y
6.		Canon G9 X	none	n	3.0 / 1040	fixed	Y	1/2000s	6.0/s	Y	Y
7.		Canon M3	optional	n	3.0 / 1040	tilting	Y	1/4000s	4.2/s	Y	n
8.		Canon M10	none	n	3.0 / 1040	tilting	Y	1/4000s	4.6/s	Y	n
9.		Canon T6i	optical	n	3.0 / 1040	swivel	Y	1/4000s	5.0/s	Y	n
10.		Nikon D3000	optical	n	3.0 / 230	fixed	n	1/4000s	3.0/s	Y	n
11.		Nikon D3200	optical	n	3.0 / 921	fixed	n	1/4000s	4.0/s	Y	n
12.		Nikon D5000	optical	n	2.7 / 230	full-flex	n	1/4000s	4.0/s	Y	n
13.		Nikon D5100	optical	n	3.0 / 921	swivel	n	1/4000s	4.0/s	Y	n
14.		Nikon D7000	optical	Y	3.0 / 921	fixed	n	1/8000s	6.0/s	Y	n
15.		Sony RX100 II	optional	n	3.0 / 1229	tilting	n	1/2000s	10.0/s	Y	Y
16.		Sony RX100 III	1440	n	3.0 / 1229	tilting	n	1/2000s	10.0/s	Y	Y
17.		Sony RX100 IV	2359	n	3.0 / 1228	tilting	n	1/2000s	16.0/s	Y	Y
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 has a touchscreen, while the D3100 has a conventional panel. Touch control can be particularly helpful, for example, for setting the focus point.

The Canon G7 X 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.

Concerning the storage of imaging data, both the G7X and the D3100 write their files to SDXC cards. The G7X supports UHS-I cards (Ultra High Speed data transfer of up to 104 MB/s), while the D3100 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 G7 X and Nikon D3100 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 G7 X	-	stereo / mono	-	-	micro	2.0	Y	Y	-
2.		Nikon D3100	Y	mono / mono	-	-	mini	2.0	-	-	-
3.		Canon G5 X	Y	stereo / mono	-	-	mini	2.0	Y	Y	-
4.		Canon G7 X Mark II	-	stereo / mono	-	-	micro	2.0	Y	Y	-
5.		Canon G7 X Mark III	-	stereo / mono	Y	-	micro	3.1	Y	-	Y
6.		Canon G9 X	-	stereo / mono	-	-	micro	2.0	Y	Y	-
7.		Canon M3	Y	stereo / mono	Y	-	mini	2.0	Y	Y	-
8.		Canon M10	-	stereo / mono	-	-	mini	2.0	Y	Y	-
9.		Canon T6i	Y	stereo / mono	Y	-	mini	2.0	Y	Y	-
10.		Nikon D3000	Y	- / -	-	-	-	2.0	-	-	-
11.		Nikon D3200	Y	mono / mono	Y	-	mini	2.0	-	-	-
12.		Nikon D5000	Y	mono / mono	-	-	mini	2.0	-	-	-
13.		Nikon D5100	Y	mono / mono	Y	-	mini	2.0	-	-	-
14.		Nikon D7000	Y	mono / mono	Y	-	mini	2.0	-	-	-
15.		Sony RX100 II	Y	stereo / mono	-	-	micro	2.0	Y	Y	-
16.		Sony RX100 III	-	stereo / mono	-	-	micro	2.0	Y	Y	-
17.		Sony RX100 IV	-	stereo / mono	-	-	micro	2.0	Y	Y	-

It is notable that the G7X offers wifi support, while the D3100 does not. Wifi can be a very convenient means to transfer image data to an off-camera location.

Both the G7X and the D3100 have been discontinued, but can regularly be found used on ebay. The D3100 was replaced by the Nikon D3200, while the G7X was followed by the Canon G7 X Mark II. Further information on the features and operation of the G7X and D3100 can be found, respectively, in the Canon G7 X Manual (free pdf) or the online Nikon D3100 Manual.

Review summary

So how do things add up? Is the Canon G7 X better than the Nikon D3100 or vice versa? Below is a summary of the relative strengths of each of the two contestants.

Arguments in favor of the Canon PowerShot G7 X:

• More detail: Offers more megapixels (20 vs 14.2MP) with a 19% higher linear resolution.
• Better image quality: Scores markedly higher (4 points) in the DXO overall assessment.
• More dynamic range: Captures a larger spectrum of light and dark details (1.4 EV of extra DR).
• Better video: Provides higher movie framerates (1080/60p versus 1080/24p).
• 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: Is equipped with a touch-sensitive rear screen to facilitate handling.
• More selfie-friendly: Has an articulated screen that can be turned to be front-facing.
• Faster burst: Shoots at higher frequency (6.5 vs 3 flaps/sec) to capture the decisive moment.
• Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
• Ready to shoot: Comes with a built-in lens, while the D3100 requires a separate lens.
• More compact: Is smaller (103x60mm vs 124x96mm) and thus needs less room in the bag.
• Less heavy: Is lighter even though it comes with a built-in lens (unlike the D3100).
• Sharper images: Has hand-shake reducing image stabilization built-in.
• Easier file upload: Has wifi built in for automatic backup or image transfer to the web.
• Easier device pairing: Supports NFC for fast wireless image transfer over short distances.
• Faster buffer clearing: Has an SD card interface that supports the UHS-I standard.
• More modern: Reflects 4 years of technical progress since the D3100 launch.

Reasons to prefer the Nikon D3100:

• Better low-light sensitivity: Can shoot in dim conditions (0.7 stops ISO advantage).
• Easier framing: Has an optical viewfinder for image composition and settings control.
• Faster shutter: Has higher mechanical shutter speed (1/4000s vs 1/2000s) to freeze action.
• More flexible: Makes it possible to change lenses and thus to use specialty optics.
• Longer lasting: Gets more shots (550 versus 210) out of a single battery charge.
• Better lighting: Features a hotshoe and can thus hold and trigger an external flash gun.
• More heavily discounted: Has been around for much longer (launched in August 2010).

If the count of relative strengths (bullet points above) is taken as a measure, the G7X is the clear winner of the match-up (18 : 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 G7 X and the Nikon D3100 place the cameras among the top in their class? Find out in the latest Best Travel-Zoom Camera and Best DSLR 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 G7X or the D3100. 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 hands-on reviews by experts 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 G7 X	4/5	+ +	..	77/100	4.5/5	4.5/5	Sep 2014	699	ebay.com
2.		Nikon D3100	5/5	+ +	..	72/100	4.5/5	4.5/5	Aug 2010	599	ebay.com
3.		Canon G5 X	5/5	+ +	..	78/100	4.5/5	4.5/5	Oct 2015	799	ebay.com
4.		Canon G7 X Mark II	4.5/5	+ +	..	81/100	4.5/5	4.5/5	Feb 2016	699	ebay.com
5.		Canon G7 X Mark III	..	+ +	4/5	81/100	4/5	..	Jul 2019	749	amazon.com
6.		Canon G9 X	3.5/5	+ +	..	..	4.5/5	4.5/5	Oct 2015	529	ebay.com
7.		Canon M3	4/5	o	..	75/100	4.5/5	4/5	Feb 2015	679	ebay.com
8.		Canon M10	..	..	..	..	..	4/5	Oct 2015	499	ebay.com
9.		Canon T6i	5/5	..	..	75/100	4.5/5	4.5/5	Feb 2015	749	ebay.com
10.		Nikon D3000	..	+	..	72/100	4/5	4.5/5	Jul 2009	599	ebay.com
11.		Nikon D3200	5/5	+ +	..	73/100	4.5/5	4.5/5	Apr 2012	599	ebay.com
12.		Nikon D5000	..	+ +	..	75/100	4/5	4.5/5	Apr 2009	749	ebay.com
13.		Nikon D5100	5/5	+ +	..	76/100	4.5/5	4.5/5	Apr 2011	749	ebay.com
14.		Nikon D7000	4/5	..	..	80/100	4.5/5	4.5/5	Sep 2010	1,499	ebay.com
15.		Sony RX100 II	5/5	+ +	..	79/100	4.5/5	4.5/5	Jun 2013	749	ebay.com
16.		Sony RX100 III	5/5	+ +	..	82/100	4.5/5	5/5	May 2014	799	ebay.com
17.		Sony RX100 IV	4.5/5	+ +	..	85/100	4/5	4.5/5	Jun 2015	999	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. Hence, a score should always be seen in the context of the camera's market launch date and its price, 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.

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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. There is also a set of direct links to comparison reviews that other users of the CAM-parator app explored.

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