Canon 400D vs G7X Mark III

The Canon EOS 400D (called Canon XTi in some regions) and the Canon PowerShot G7 X Mark III are two digital cameras that were officially introduced, respectively, in August 2006 and July 2019. The 400D is a DSLR, while the G7X Mark III is a fixed lens compact. The cameras are based on an APS-C (400D) and an one-inch (G7X Mark III) sensor. The 400D has a resolution of 10.1 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 400D		Canon G7 X Mark III
Digital single lens reflex		Fixed lens compact camera
Canon EF mount lenses		24-100mm f/1.8-2.8
10.1 MP – APS-C sensor		20 MP – 1" sensor
no Video		4K/30p Video
ISO 100-1,600		ISO 125-12,800 (125 - 25,600)
Optical viewfinder		No viewfinder, LCD framing
2.5" LCD – 230k dots		3.0" LCD – 1040k dots
Fixed screen (not touch-sensitive)		Tilting touchscreen
3 shutter flaps per second		30 shutter flaps per second
370 shots per battery charge		235 shots per battery charge
127 x 84 x 65 mm, 556 g		105 x 61 x 41 mm, 304 g

Check 400D offers at
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Check G7X Mark III price at
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Going beyond this snapshot of core features and characteristics, what are the differences between the Canon EOS 400D 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

An illustration of the physical size and weight of the Canon 400D and the Canon G7 X Mark III is provided 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.

The G7X Mark III can be obtained in two different colors (black, silver), while the 400D 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 Canon G7 X Mark III is considerably smaller (40 percent) than the Canon 400D. In this context, it is worth noting that neither the 400D nor the G7X Mark III are weather-sealed.

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 400D 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 400D and their specifications in the Canon EF Lens Catalog.

Concerning battery life, the 400D gets 370 shots out of its Canon NB-2LH 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 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.

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 400D	127 mm	84 mm	65 mm	556 g	370	n	Aug 2006	799	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 Mark II	111 mm	61 mm	46 mm	340 g	230	n	Jul 2019	899	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 750D	132 mm	101 mm	78 mm	555 g	440	n	Feb 2015	749	ebay.com
6.		Canon 760D	132 mm	101 mm	78 mm	565 g	440	n	Feb 2015	649	ebay.com
7.		Canon G5 X	112 mm	76 mm	44 mm	353 g	210	n	Oct 2015	799	ebay.com
8.		Canon G7 X	103 mm	60 mm	40 mm	304 g	210	n	Sep 2014	699	ebay.com
9.		Canon 650D	133 mm	100 mm	79 mm	575 g	440	n	Jun 2012	849	ebay.com
10.		Canon 1100D	130 mm	100 mm	78 mm	495 g	700	n	Feb 2011	449	ebay.com
11.		Canon 550D	129 mm	98 mm	62 mm	530 g	440	n	Feb 2010	699	ebay.com
12.		Canon 500D	129 mm	98 mm	62 mm	520 g	400	n	Mar 2009	799	ebay.com
13.		Canon 450D	129 mm	98 mm	62 mm	524 g	500	n	Jan 2008	799	ebay.com
14.		Canon 40D	146 mm	108 mm	74 mm	822 g	750	n	Aug 2007	1,299	ebay.com
15.		Canon 350D	127 mm	94 mm	64 mm	540 g	400	n	Feb 2005	899	ebay.com
16.		Nikon D40X	124 mm	94 mm	64 mm	522 g	520	n	Mar 2007	729	ebay.com
17.		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

The price is, of course, an important factor in any camera decision. 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 400D, 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.

Sensor comparison

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. 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 400D features an APS-C sensor and the Canon G7 X Mark III an one-inch sensor. The sensor area in the G7X Mark III is 65 percent smaller. As a result of these sensor size differences, the cameras have a format factor of, respectively, 1.6 and 2.7. Both cameras have a native aspect ratio (sensor width to sensor height) of 3:2.

Technology-wise, the G7X Mark III uses a more advanced image processing engine (DIGIC 8) than the 400D (DIGIC II), with benefits for noise reduction, color accuracy, and processing speed.

Despite having a smaller sensor, the G7X Mark III offers a higher resolution of 20 megapixels, compared with 10.1 MP of the 400D. 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 5.71μm for the 400D). However, it should be noted that the G7X Mark III is much more recent (by 12 years and 10 months) than the 400D, 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 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 Canon 400D are 19.4 x 13 inches or 49.4 x 32.9 cm for good quality, 15.6 x 10.4 inches or 39.5 x 26.3 cm for very good quality, and 13 x 8.6 inches or 32.9 x 21.9 cm for excellent quality prints.

The Canon EOS 400D 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 400D is build around a CMOS 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.

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. The following table provides an overview of the physical sensor characteristics, as well as the sensor quality measurements for a selection of comparators.

Sensor Characteristics

#		Camera Model	Sensor Class	Resolution (MP)	Horiz. Pixels	Vert. Pixels	Video Format	DXO Portrait	DXO Landscape	DXO Sports	DXO Overall
1.		Canon 400D	APS-C	10.1	3888	2592	none	22.1	11.0	664	62
2.		Canon G7 X Mark III	1-inch	20.0	5472	3648	4K/30p	22.2	12.4	583	65
3.		Canon G5 X Mark II	1-inch	20.0	5472	3648	4K/30p	22.2	12.4	583	65
4.		Canon G7 X Mark II	1-inch	20.0	5472	3648	1080/60p	21.8	11.9	260	62
5.		Canon 750D	APS-C	24.0	6000	4000	1080/30p	22.7	12.0	919	71
6.		Canon 760D	APS-C	24.0	6000	4000	1080/30p	22.6	12.0	915	70
7.		Canon G5 X	1-inch	20.0	5472	3648	1080/60p	21.4	12.3	471	62
8.		Canon G7 X	1-inch	20.0	5472	3648	1080/60p	23.0	12.7	556	71
9.		Canon 650D	APS-C	17.9	5184	3456	1080/30p	21.7	11.2	722	62
10.		Canon 1100D	APS-C	12.2	4272	2848	720/30p	21.9	11.0	755	62
11.		Canon 550D	APS-C	17.9	5184	3456	1080/30p	22.1	11.5	784	66
12.		Canon 500D	APS-C	15.1	4752	3168	1080/20p	21.7	11.5	663	63
13.		Canon 450D	APS-C	12.2	4272	2848	none	21.9	10.8	692	61
14.		Canon 40D	APS-C	10.1	3888	2592	none	22.1	11.3	703	64
15.		Canon 350D	APS-C	8.0	3456	2304	none	21.8	10.8	637	60
16.		Nikon D40X	APS-C	10.0	3872	2592	none	22.4	11.4	516	63
17.		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 cannot only take still pictures, but also record videos. The G7X Mark III indeed provides for movie recording, while the 400D does not. The highest resolution format that the G7X Mark III can use is 4K/30p.

Feature comparison

Beyond body and sensor, cameras can and do differ across a range of features. For example, the 400D has an optical viewfinder, which can be very useful when shooting in bright sunlight. In contrast, the G7X Mark III 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 400D, the Canon G7 X Mark III, 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 400D	optical	n	2.5 / 230	fixed	n	1/4000s	3.0/s	Y	n
2.		Canon G7 X Mark III	none	n	3.0 / 1040	tilting	Y	1/2000s	30/s	Y	Y
3.		Canon G5 X Mark II	2360	n	3.0 / 1040	tilting	Y	1/2000s	30/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 750D	optical	n	3.0 / 1040	swivel	Y	1/4000s	5.0/s	Y	n
6.		Canon 760D	optical	Y	3.0 / 1040	swivel	Y	1/4000s	5.0/s	Y	n
7.		Canon G5 X	2360	n	3.0 / 1040	swivel	Y	1/2000s	5.9/s	Y	Y
8.		Canon G7 X	none	n	3.0 / 1040	tilting	Y	1/2000s	6.5/s	Y	Y
9.		Canon 650D	optical	n	3.0 / 1040	swivel	Y	1/4000s	5.0/s	Y	n
10.		Canon 1100D	optical	n	2.7 / 230	fixed	n	1/4000s	3.0/s	Y	n
11.		Canon 550D	optical	n	3.0 / 1040	fixed	n	1/4000s	3.7/s	Y	n
12.		Canon 500D	optical	n	3.0 / 920	fixed	n	1/4000s	3.4/s	Y	n
13.		Canon 450D	optical	n	3.0 / 230	fixed	n	1/4000s	3.5/s	Y	n
14.		Canon 40D	optical	Y	3.0 / 230	fixed	n	1/8000s	6.5/s	Y	n
15.		Canon 350D	optical	n	1.8 / 115	fixed	n	1/4000s	3.0/s	Y	n
16.		Nikon D40X	optical	n	2.5 / 230	fixed	n	1/4000s	3.0/s	Y	n
17.		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 400D 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.

The 400D writes its imaging data to Compact Flash cards, while the G7X Mark III uses SDXC 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 EOS 400D 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 400D	Y	- / -	-	-	-	2.0	-	-	-
2.		Canon G7 X Mark III	-	stereo / mono	Y	-	micro	3.1	Y	-	Y
3.		Canon G5 X Mark II	-	stereo / mono	-	-	micro	3.1	Y	-	Y
4.		Canon G7 X Mark II	-	stereo / mono	-	-	micro	2.0	Y	Y	-
5.		Canon 750D	Y	stereo / mono	Y	-	mini	2.0	Y	Y	-
6.		Canon 760D	Y	stereo / mono	Y	-	mini	2.0	Y	Y	-
7.		Canon G5 X	Y	stereo / mono	-	-	mini	2.0	Y	Y	-
8.		Canon G7 X	-	stereo / mono	-	-	micro	2.0	Y	Y	-
9.		Canon 650D	Y	stereo / mono	Y	-	mini	2.0	-	-	-
10.		Canon 1100D	Y	stereo / mono	-	-	mini	2.0	-	-	-
11.		Canon 550D	Y	stereo / -	Y	-	mini	2.0	-	-	-
12.		Canon 500D	Y	mono / mono	-	-	mini	2.0	-	-	-
13.		Canon 450D	Y	- / -	-	-	mini	2.0	-	-	-
14.		Canon 40D	Y	- / -	-	-	-	2.0	-	-	-
15.		Canon 350D	Y	- / -	-	-	-	2.0	-	-	-
16.		Nikon D40X	Y	- / -	-	-	-	2.0	-	-	-
17.		Sony ZV-1	Y	stereo / mono	Y	-	micro	2.0	Y	-	Y

It is notable that the 400D has a hotshoe, while the G7X Mark III does not. This socket makes it possible to easily attach optional accessories, such as an external flash gun.

The G7X Mark III is a recent model that features in the current product line-up of Canon. In contrast, the 400D has been discontinued (but can be found pre-owned on ebay). As a replacement in the same line of cameras, the 400D was succeeded by the Canon 450D. Further information on the features and operation of the 400D and G7X Mark III can be found, respectively, in the Canon 400D Manual (free pdf) or the online Canon G7 X Mark III Manual.

Review summary

So what conclusions can be drawn? Which of the two cameras – the Canon 400D or the Canon G7 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.

Arguments in favor of the Canon EOS 400D:

• 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: Can take a variety of interchangeable lenses, including specialty optics.
• Longer lasting: Can take more shots (370 versus 235) on a single battery charge.
• Better lighting: Features a hotshoe and can thus hold and trigger an external flash gun.
• More heavily discounted: Has been available for much longer (launched in August 2006).

Reasons to prefer the Canon PowerShot G7 X Mark III:

• More detail: Has more megapixels (20 vs 10.1MP), which boosts linear resolution by 41%.
• Better jpgs: Has a more modern image processing engine (DIGIC 8 vs DIGIC II).
• Broader imaging potential: Can capture not only stills but also 4K/30p video.
• Larger screen: Has a bigger rear LCD (3.0" vs 2.5") for image review and settings control.
• 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 3 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.
• Ready to shoot: Comes with an integrated lens, while the 400D requires a separate lens.
• More compact: Is smaller (105x61mm vs 127x84mm) and will fit more readily into a bag.
• Less heavy: Has a lower weight even though it has a lens built in (unlike the 400D).
• Easier travel charging: Can be conveniently charged via its USB port.
• 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 file upload: Has wifi built in for automatic backup or image transfer to the web.
• Easier wireless transfer: Supports Bluetooth for image sharing without cables.
• More affordable: Was introduced at a lower price, despite coming with a built-in lens.
• More modern: Reflects 12 years and 10 months of technical progress since the 400D launch.

If the number of relative strengths (bullet points above) is taken as a guide, the G7X Mark III is the clear winner of the contest (21 : 6 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 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 400D and the Canon G7 X Mark III place the cameras among the top in their class? Find out in the latest Best DSLR 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 incomplete and does no justice, for example, to the way the 400D or the G7X Mark 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.

Expert reviews

This is why expert reviews 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 400D	..	+ +	..	+ +	o	4/5	Aug 2006	799	ebay.com
2.		Canon G7 X Mark III	..	+ +	4/5	81/100	4/5	..	Jul 2019	749	amazon.com
3.		Canon G5 X Mark II	4/5	+	4/5	82/100	..	4/5	Jul 2019	899	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 750D	5/5	..	..	75/100	4.5/5	4.5/5	Feb 2015	749	ebay.com
6.		Canon 760D	5/5	+	..	77/100	4.5/5	4.5/5	Feb 2015	649	ebay.com
7.		Canon G5 X	5/5	+ +	..	78/100	4.5/5	4.5/5	Oct 2015	799	ebay.com
8.		Canon G7 X	4/5	+ +	..	77/100	4.5/5	4.5/5	Sep 2014	699	ebay.com
9.		Canon 650D	4/5	+ +	..	77/100	4.5/5	4.5/5	Jun 2012	849	ebay.com
10.		Canon 1100D	..	80/100	..	69/100	4/5	4.5/5	Feb 2011	449	ebay.com
11.		Canon 550D	..	+ +	..	77/100	4/5	4.5/5	Feb 2010	699	ebay.com
12.		Canon 500D	..	+ +	..	74/100	4.5/5	4.5/5	Mar 2009	799	ebay.com
13.		Canon 450D	..	+ +	..	+ +	4/5	4.5/5	Jan 2008	799	ebay.com
14.		Canon 40D	..	+ +	..	+ +	4.5/5	4.5/5	Aug 2007	1,299	ebay.com
15.		Canon 350D	..	80/100	..	+ +	o	..	Feb 2005	899	ebay.com
16.		Nikon D40X	..	79/100	..	+ +	4/5	4/5	Mar 2007	729	ebay.com
17.		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 assessments were made in relation to similar cameras of the same technological generation. 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. Also, please note that some of the review sites have changed their methodology and reporting over time.

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Other camera comparisons

Did this review help to inform your camera decision process? If you would like to see a different side-by-side camera review, just use the search menu below. There is also a set of direct links to comparison reviews that other users of the CAM-parator app explored.

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