Canon 20D vs G1X Mark III

The Canon EOS 20D and the Canon PowerShot G1 X Mark III are two enthusiast cameras that were officially introduced, respectively, in August 2004 and October 2017. The 20D is a DSLR, while the G1X Mark III is a fixed lens compact. Both cameras are equipped with an APS-C sensor. The 20D has a resolution of 8.2 megapixels, whereas the G1X Mark III provides 24 MP.

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

Headline Specifications

Canon 20D		Canon G1 X Mark III
Digital single lens reflex		Fixed lens compact camera
Canon EF mount lenses		24-72mm f/2.8-5.6
8.2 MP – APS-C sensor		24 MP – APS-C sensor
no Video		1080/60p Video
ISO 100-1,600 (100 - 3,200)		ISO 100-25,600
Optical viewfinder		Electronic viewfinder (2360k dots)
1.8" LCD – 118k dots		3.0" LCD – 1040k dots
Fixed screen (not touch-sensitive)		Swivel touchscreen
5 shutter flaps per second		9 shutter flaps per second
not weather sealed		Weathersealed body
700 shots per battery charge		200 shots per battery charge
144 x 106 x 72 mm, 770 g		115 x 78 x 51 mm, 399 g

Check 20D offers at
ebay.com
Check G1X Mark III price at
amazon.com

Going beyond this snapshot of core features and characteristics, what are the differences between the Canon EOS 20D 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 Canon 20D 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 size dimensions 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 considerably smaller (41 percent) than the Canon 20D. It is noteworthy in this context that the G1X Mark III is splash and dust-proof, while the 20D does not feature any corresponding weather-sealing.

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 20D 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 20D and their specifications in the Canon EF Lens Catalog.

Concerning battery life, the 20D gets 700 shots out of its BP-511A battery, while the G1X Mark III can take 200 images on a single charge of its NB-13L power pack.

The table below summarizes the key physical specs of the two cameras alongside a broader set of comparators. 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.

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 20D	144 mm	106 mm	72 mm	770 g	700	n	Aug 2004	1,499	ebay.com
2.		Canon G1 X Mark III	115 mm	78 mm	51 mm	399 g	200	Y	Oct 2017	1,299	amazon.com
3.		Canon 80D	139 mm	105 mm	79 mm	730 g	960	Y	Feb 2016	1,199	ebay.com
4.		Canon 7D II	149 mm	112 mm	78 mm	910 g	670	Y	Sep 2014	1,799	ebay.com
5.		Canon 60D	145 mm	106 mm	79 mm	755 g	1100	Y	Aug 2010	1,399	ebay.com
6.		Canon 7D	148 mm	111 mm	74 mm	860 g	800	Y	Sep 2009	1,699	ebay.com
7.		Canon 50D	146 mm	108 mm	74 mm	822 g	800	Y	Aug 2008	1,299	ebay.com
8.		Canon 40D	146 mm	108 mm	74 mm	822 g	750	n	Aug 2007	1,299	ebay.com
9.		Canon 30D	144 mm	106 mm	74 mm	785 g	750	n	Feb 2006	1,399	ebay.com
10.		Canon XT	127 mm	94 mm	64 mm	540 g	400	n	Feb 2005	899	ebay.com
11.		Canon 10D	150 mm	107 mm	75 mm	850 g	500	n	Feb 2003	1,999	ebay.com
12.		Canon Rebel	142 mm	99 mm	72 mm	649 g	400	n	Aug 2003	899	ebay.com
13.		Fujifilm X100V	128 mm	75 mm	53 mm	478 g	420	Y	Feb 2020	1,399	amazon.com
14.		Fujifilm X100F	127 mm	75 mm	52 mm	469 g	390	n	Jan 2017	1,299	ebay.com
15.		Nikon D200	147 mm	113 mm	74 mm	920 g	400	Y	Nov 2005	1,699	ebay.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

Any camera decision will obviously take relative prices into account. 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 20D, 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 size of the imaging sensor is a crucial determinant 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. 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.

Both cameras under consideration feature an APS-C sensor, but their sensors differ slightly in size. The sensor area in the G1X Mark III is 2 percent smaller. As a result of these sensor size differences, the cameras have format factors, respectively, of 1.6 (20D) and 1.5. Both cameras have a native aspect ratio (sensor width to sensor height) of 3:2.

Technology-wise, the G1X Mark III uses a more advanced image processing engine (DIGIC 7) than the 20D (DIGIC 2), with benefits for noise reduction, color accuracy, and processing speed.

Despite having a slightly smaller sensor, the G1X Mark III offers a higher resolution of 24 megapixels, compared with 8.2 MP of the 20D. 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 3.72μm versus 6.42μm for the 20D). However, it should be noted that the G1X Mark III is much more recent (by 13 years and 2 months) than the 20D, 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 G1 X Mark III implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the G1X Mark III for good quality output (200 dots per inch) amounts to 30 x 20 inches or 76.2 x 50.8 cm, for very good quality (250 dpi) 24 x 16 inches or 61 x 40.6 cm, and for excellent quality (300 dpi) 20 x 13.3 inches or 50.8 x 33.9 cm. The corresponding values for the Canon 20D are 17.5 x 11.7 inches or 44.5 x 29.7 cm for good quality, 14 x 9.3 inches or 35.6 x 23.7 cm for very good quality, and 11.7 x 7.8 inches or 29.7 x 19.8 cm for excellent quality prints.

The G1X Mark III has on-sensor phase detect pixels, which results in fast and reliable autofocus acquisition even during live view operation.

The Canon EOS 20D has a native sensitivity range from ISO 100 to ISO 1600, which can be extended to ISO 100-3200. The corresponding ISO settings for the Canon PowerShot G1 X Mark III are ISO 100 to ISO 25600 (no boost).

Technology-wise, both cameras are equipped with CMOS (Complementary Metal–Oxide–Semiconductor) sensors. 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 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 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 20D	APS-C	8.2	3504	2336	none	21.9	11.0	721	62
2.		Canon G1 X Mark III	APS-C	24.0	6000	4000	1080/60p	23.8	13.2	1649	81
3.		Canon 80D	APS-C	24.0	6000	4000	1080/60p	23.6	13.2	1135	79
4.		Canon 7D II	APS-C	20.0	5472	3648	1080/60p	22.4	11.8	1082	70
5.		Canon 60D	APS-C	17.9	5184	3456	1080/30p	22.2	11.5	813	66
6.		Canon 7D	APS-C	17.9	5184	3456	1080/30p	22.0	11.7	854	66
7.		Canon 50D	APS-C	15.1	4752	3168	none	21.8	11.4	696	63
8.		Canon 40D	APS-C	10.1	3888	2592	none	22.1	11.3	703	64
9.		Canon 30D	APS-C	8.2	3504	2336	none	21.5	10.8	736	59
10.		Canon XT	APS-C	8.0	3456	2304	none	21.8	10.8	637	60
11.		Canon 10D	APS-C	6.3	3072	2048	none	21.1	10.9	571	57
12.		Canon Rebel	APS-C	6.3	3072	2048	none	21.0	10.8	544	55
13.		Fujifilm X100V	APS-C	26.0	6240	4160	4K/30p	24.2	13.6	1996	84
14.		Fujifilm X100F	APS-C	24.0	6000	4000	1080/60p	23.9	13.2	1704	81
15.		Nikon D200	APS-C	10.0	3872	2592	none	22.3	11.5	583	64
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 are not only capable of taking still images, but can also record movies. The G1X Mark III indeed provides for movie recording, while the 20D does not. The highest resolution format that the G1X Mark III can use is 1080/60p.

Feature comparison

Apart from body and sensor, cameras can and do differ across a variety of features. For example, the G1X Mark III has an electronic viewfinder (2360k dots), while the 20D has an optical one. Both systems have their advantages, with the electronic viewfinder making it possible to project supplementary shooting information into the framing view, whereas the optical viewfinder offers lag-free viewing and a very clear framing image. The table below summarizes some of the other core capabilities of the Canon 20D 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.		Canon 20D	optical	Y	1.8 / 118	fixed	n	1/8000s	5.0/s	Y	n
2.		Canon G1 X Mark III	2360	n	3.0 / 1040	swivel	Y	1/2000s	9.0/s	Y	Y
3.		Canon 80D	optical	Y	3.0 / 1040	swivel	Y	1/8000s	7.0/s	Y	n
4.		Canon 7D II	optical	Y	3.0 / 1040	fixed	n	1/8000s	10.0/s	Y	n
5.		Canon 60D	optical	Y	3.0 / 1040	swivel	n	1/8000s	5.3/s	Y	n
6.		Canon 7D	optical	Y	3.0 / 920	fixed	n	1/8000s	8.0/s	Y	n
7.		Canon 50D	optical	Y	3.0 / 920	fixed	n	1/8000s	6.3/s	Y	n
8.		Canon 40D	optical	Y	3.0 / 230	fixed	n	1/8000s	6.5/s	Y	n
9.		Canon 30D	optical	Y	2.5 / 230	fixed	n	1/8000s	5.0/s	Y	n
10.		Canon XT	optical	n	1.8 / 115	fixed	n	1/4000s	3.0/s	Y	n
11.		Canon 10D	optical	Y	1.8 / 118	fixed	n	1/4000s	3.0/s	Y	n
12.		Canon Rebel	optical	n	1.8 / 118	fixed	n	1/4000s	2.5/s	Y	n
13.		Fujifilm X100V	3690	n	3.0 / 1620	tilting	Y	1/4000s	11.0/s	Y	n
14.		Fujifilm X100F	2360	n	3.0 / 1040	fixed	n	1/4000s	8.0/s	Y	n
15.		Nikon D200	optical	Y	2.5 / 230	fixed	n	1/8000s	5.0/s	Y	n
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
Notes: *) Information refers to the mechanical shutter, unless the camera only has an electronic one.

One feature that is present on the 20D, but is missing on the G1X Mark III is a top-level LCD. While being, of course, smaller than the rear screen, the control panel conveys some of the essential shooting information and can be convenient for quick and easy settings verification.

The Canon G1 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 20D writes its imaging data to Compact Flash cards, while the G1X 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 20D 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.		Canon 20D	Y	- / -	-	-	-	1.1	-	-	-
2.		Canon G1 X Mark III	Y	stereo / mono	-	-	micro	2.0	Y	Y	Y
3.		Canon 80D	Y	stereo / mono	Y	Y	mini	2.0	Y	Y	-
4.		Canon 7D II	Y	stereo / mono	Y	Y	mini	3.0	-	-	-
5.		Canon 60D	Y	mono / mono	Y	-	mini	2.0	-	-	-
6.		Canon 7D	Y	mono / -	Y	-	mini	2.0	-	-	-
7.		Canon 50D	Y	- / -	-	-	mini	2.0	-	-	-
8.		Canon 40D	Y	- / -	-	-	-	2.0	-	-	-
9.		Canon 30D	Y	- / -	-	-	-	2.0	-	-	-
10.		Canon XT	Y	- / -	-	-	-	2.0	-	-	-
11.		Canon 10D	Y	- / -	-	-	-	1.1	-	-	-
12.		Canon Rebel	Y	- / -	-	-	-	1.1	-	-	-
13.		Fujifilm X100V	Y	stereo / mono	Y	-	micro	3.1	Y	-	Y
14.		Fujifilm X100F	Y	stereo / mono	Y	-	micro	2.0	Y	-	-
15.		Nikon D200	Y	- / -	-	-	-	2.0	-	-	-
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 G1X Mark III offers wifi support, which can be a very convenient means to transfer image data to an off-camera location. In contrast, the 20D does not provide wifi capability.

Studio photographers will appreciate that the Canon 20D (unlike the G1X Mark III) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.

The G1X Mark III is a recent model that features in the current product line-up of Canon. In contrast, the 20D has been discontinued (but can be found pre-owned on ebay). As a replacement in the same line of cameras, the 20D was succeeded by the Canon 30D. Further information on the features and operation of the 20D and G1X Mark III can be found, respectively, in the Canon 20D Manual (free pdf) or the online Canon G1 X Mark III Manual.

Review summary

So what is the bottom line? Is there a clear favorite between the Canon 20D and the Canon G1 X Mark III? Which camera is better? The listing below highlights the relative strengths of the two models.

Advantages of the Canon EOS 20D:

• Brighter framing: Features an optical viewfinder for clear, lag-free composition.
• Easier setting verification: Features an LCD display on top to control shooting parameters.
• Faster shutter: Has higher mechanical shutter speed (1/8000s vs 1/2000s) to freeze action.
• More flexible: Can take a variety of interchangeable lenses, including specialty optics.
• Longer lasting: Can take more shots (700 versus 200) on a single battery charge.
• Better studio light control: Has a PC Sync socket to connect to professional strobe lights.
• More heavily discounted: Has been available for much longer (launched in August 2004).

Reasons to prefer the Canon PowerShot G1 X Mark III:

• More detail: Has more megapixels (24 vs 8.2MP), which boosts linear resolution by 71%.
• Better jpgs: Has a more modern image processing engine (DIGIC 7 vs DIGIC 2).
• Broader imaging potential: Can capture not only stills but also 1080/60p video.
• Better live-view autofocus: Features on-sensor phase-detection for more confident autofocus.
• More framing info: Has an electronic viewfinder that displays shooting data.
• Larger screen: Has a bigger rear LCD (3.0" vs 1.8") for image review and settings control.
• More detailed LCD: Has a higher resolution rear screen (1040k vs 118k dots).
• More flexible LCD: Has a swivel screen for odd-angle shots in portrait or 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 (9 vs 5 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 an integrated lens, while the 20D requires a separate lens.
• More compact: Is smaller (115x78mm vs 144x106mm) and will fit more readily into a bag.
• Less heavy: Has a lower weight even though it has a lens built in (unlike the 20D).
• Better sealing: Is splash and dust sealed for shooting in inclement weather conditions.
• Sharper images: Has stabilization technology built-in to reduce the impact of hand-shake.
• Faster data transfer: Supports a more advanced USB protocol (2.0 vs 1.1).
• 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.
• 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 13 years and 2 months of technical progress since the 20D launch.

If the count of individual advantages (bullet points above) is taken as a guide, the G1X Mark III is the clear winner of the contest (23 : 7 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 Canon 20D and the Canon G1 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 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 20D or the G1X Mark III perform in practice. User reviews that are available, for instance, at amazon can sometimes shed light on these issues, but such feedback is all too often partial, inconsistent, and inaccurate.

Expert reviews

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], 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 20D	..	..	..	+ +	..	..	Aug 2004	1,499	ebay.com
2.		Canon G1 X Mark III	5/5	+	4/5	79/100	4.5/5	4.5/5	Oct 2017	1,299	amazon.com
3.		Canon 80D	4/5	+ +	4.5/5	84/100	4.5/5	4.5/5	Feb 2016	1,199	ebay.com
4.		Canon 7D II	4.5/5	+	3.5/5	84/100	4/5	4.5/5	Sep 2014	1,799	ebay.com
5.		Canon 60D	5/5	+	..	79/100	4/5	4.5/5	Aug 2010	1,399	ebay.com
6.		Canon 7D	5/5	+ +	..	84/100	4.5/5	4.5/5	Sep 2009	1,699	ebay.com
7.		Canon 50D	..	+ +	..	+ +	4.5/5	4.5/5	Aug 2008	1,299	ebay.com
8.		Canon 40D	..	+ +	..	+ +	4.5/5	4.5/5	Aug 2007	1,299	ebay.com
9.		Canon 30D	..	+ +	..	+ +	o	..	Feb 2006	1,399	ebay.com
10.		Canon XT	..	80/100	..	+ +	o	..	Feb 2005	899	ebay.com
11.		Canon 10D	..	..	..	+ +	..	..	Feb 2003	1,999	ebay.com
12.		Canon Rebel	..	..	..	+ +	..	..	Aug 2003	899	ebay.com
13.		Fujifilm X100V	5/5	+ +	4.5/5	86/100	5/5	4.5/5	Feb 2020	1,399	amazon.com
14.		Fujifilm X100F	5/5	+	3.9/5	83/100	4.5/5	4.5/5	Jan 2017	1,299	ebay.com
15.		Nikon D200	..	+ +	..	+ +	o	..	Nov 2005	1,699	ebay.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
Notes: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.

Care should be taken when interpreting the review scores above, 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 comparisons of ratings among very different cameras or across long time periods have little meaning. Also, please note that some of the review sites have changed their methodology and reporting over time.

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Other camera comparisons

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