Canon 20D vs Olympus E-M5

The Canon EOS 20D and the Olympus OM-D E-M5 are two enthusiast cameras that were announced, respectively, in August 2004 and February 2012. The 20D is a DSLR, while the E-M5 is a mirrorless interchangeable lens camera. The cameras are based on an APS-C (20D) and a Four Thirds (E-M5) sensor. The Canon has a resolution of 8.2 megapixels, whereas the Olympus provides 15.9 MP.

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

Headline Specifications

Canon 20D		Olympus E-M5
Digital single lens reflex		Mirrorless system camera
Canon EF mount lenses		Micro Four Thirds lenses
8.2 MP – APS-C sensor		15.9 MP – Four Thirds sensor
no Video		1080/60i Video
ISO 100-1,600 (100 - 3,200)		ISO 200-25,600
Optical viewfinder		Electronic viewfinder (1440k dots)
1.8" LCD – 118k dots		3.0" LCD – 610k dots
Fixed screen (not touch-sensitive)		Tilting touchscreen
5 shutter flaps per second		9 shutter flaps per second
Lens stabilization only		In-body stabilization
not weather sealed		Weathersealed body
700 shots per battery charge		360 shots per battery charge
144 x 106 x 72 mm, 770 g		122 x 89 x 43 mm, 425 g

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Going beyond this snapshot of core features and characteristics, what are the differences between the Canon EOS 20D and the Olympus OM-D E-M5? 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 20D and the Olympus E-M5 is provided 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 size dimensions are rounded to the nearest millimeter.

The E-M5 can be obtained in two different colors (black, silver), while the 20D 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 Olympus E-M5 is notably smaller (29 percent) than the Canon 20D. Moreover, the E-M5 is substantially lighter (45 percent) than the 20D. It is noteworthy in this context that the E-M5 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 since they do not consider the interchangeable lenses that both of these cameras require. A larger imaging sensor will tend to go along with bigger and heavier lenses, although exceptions exist. You can compare the optics available for the two cameras in the Canon EF Lens Catalog (20D) and the Micro Four Thirds Lens Catalog (E-M5). Mirrorless cameras, such as the E-M5, have moreover the advantage that they can use many lenses from other systems via adapters, as they have a relatively short flange to focal plane distance.

Concerning battery life, the 20D gets 700 shots out of its Canon BP-511A battery, while the E-M5 can take 360 images on a single charge of its Olympus BLN-1 power pack.

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.		Canon 20D	144 mm	106 mm	72 mm	770 g	700	n	Aug 2004	1,499	ebay.com
2.		Olympus E-M5	122 mm	89 mm	43 mm	425 g	360	Y	Feb 2012	1,299	ebay.com
3.		Canon 7D	148 mm	111 mm	74 mm	860 g	800	Y	Sep 2009	1,699	ebay.com
4.		Canon 7D II	149 mm	112 mm	78 mm	910 g	670	Y	Sep 2014	1,799	ebay.com
5.		Canon 10D	150 mm	107 mm	75 mm	850 g	500	n	Feb 2003	1,999	ebay.com
6.		Canon 30D	144 mm	106 mm	74 mm	785 g	750	n	Feb 2006	1,399	ebay.com
7.		Canon 40D	146 mm	108 mm	74 mm	822 g	750	n	Aug 2007	1,299	ebay.com
8.		Canon 50D	146 mm	108 mm	74 mm	822 g	800	Y	Aug 2008	1,299	ebay.com
9.		Canon 60D	145 mm	106 mm	79 mm	755 g	1100	Y	Aug 2010	1,399	ebay.com
10.		Canon 300D	142 mm	99 mm	72 mm	649 g	400	n	Aug 2003	899	ebay.com
11.		Canon 350D	127 mm	94 mm	64 mm	540 g	400	n	Feb 2005	899	ebay.com
12.		Nikon D200	147 mm	113 mm	74 mm	920 g	400	Y	Nov 2005	1,699	ebay.com
13.		Olympus E-M1	130 mm	94 mm	63 mm	497 g	350	Y	Sep 2013	1,399	ebay.com
14.		Olympus E-M5 II	124 mm	85 mm	45 mm	469 g	310	Y	Feb 2015	1,099	ebay.com
15.		Olympus E-M10	119 mm	82 mm	46 mm	396 g	320	n	Jan 2014	699	ebay.com
16.		Olympus E-M10 II	120 mm	83 mm	47 mm	390 g	320	n	Aug 2015	649	ebay.com
17.		Olympus E-P5	122 mm	69 mm	37 mm	420 g	330	n	May 2013	999	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 E-M5 was launched at a somewhat lower price (by 13 percent) than the 20D, which makes it more attractive for photographers on a tight budget. 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.

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.

Of the two cameras under consideration, the Canon 20D features an APS-C sensor and the Olympus E-M5 a Four Thirds sensor. The sensor area in the E-M5 is 33 percent smaller. As a result of these sensor size differences, the cameras have a format factor of, respectively, 1.6 and 2.0. The sensor in the 20D has a native 3:2 aspect ratio, while the one in the E-M5 offers a 4:3 aspect.

Despite having a smaller sensor, the E-M5 offers a higher resolution of 15.9 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 3.76μm versus 6.42μm for the 20D). However, it should be noted that the E-M5 is much more recent (by 7 years and 5 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 Olympus E-M5 implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the E-M5 for good quality output (200 dots per inch) amounts to 23 x 17.3 inches or 58.5 x 43.9 cm, for very good quality (250 dpi) 18.4 x 13.8 inches or 46.8 x 35.1 cm, and for excellent quality (300 dpi) 15.4 x 11.5 inches or 39 x 29.3 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 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 Olympus OM-D E-M5 are ISO 200 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.

For many cameras, data on sensor performance has been reported by DXO Mark. 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"). Of the two cameras under consideration, the E-M5 has a markedly higher DXO score than the 20D (overall score 9 points higher), which will translate into better image quality. The advantage is based on 0.9 bits higher color depth, 1.3 EV in additional dynamic range, and 0.2 stops in additional low light sensitivity. The table below summarizes the physical sensor characteristics and sensor quality findings and compares them across a set of similar 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 20D	APS-C	8.2	3504	2336	none	21.9	11.0	721	62
2.		Olympus E-M5	Four Thirds	15.9	4608	3456	1080/60i	22.8	12.3	826	71
3.		Canon 7D	APS-C	17.9	5184	3456	1080/30p	22.0	11.7	854	66
4.		Canon 7D II	APS-C	20.0	5472	3648	1080/60p	22.4	11.8	1082	70
5.		Canon 10D	APS-C	6.3	3072	2048	none	21.1	10.9	571	57
6.		Canon 30D	APS-C	8.2	3504	2336	none	21.5	10.8	736	59
7.		Canon 40D	APS-C	10.1	3888	2592	none	22.1	11.3	703	64
8.		Canon 50D	APS-C	15.1	4752	3168	none	21.8	11.4	696	63
9.		Canon 60D	APS-C	17.9	5184	3456	1080/30p	22.2	11.5	813	66
10.		Canon 300D	APS-C	6.3	3072	2048	none	21.0	10.8	544	55
11.		Canon 350D	APS-C	8.0	3456	2304	none	21.8	10.8	637	60
12.		Nikon D200	APS-C	10.0	3872	2592	none	22.3	11.5	583	64
13.		Olympus E-M1	Four Thirds	15.9	4608	3456	1080/30p	23.0	12.7	757	73
14.		Olympus E-M5 II	Four Thirds	15.9	4608	3456	1080/60p	23.0	12.5	842	73
15.		Olympus E-M10	Four Thirds	15.9	4608	3456	1080/30p	22.8	12.3	884	72
16.		Olympus E-M10 II	Four Thirds	15.9	4608	3456	1080/60p	23.1	12.5	842	73
17.		Olympus E-P5	Four Thirds	15.9	4608	3456	1080/30p	22.8	12.4	895	72

Many modern cameras cannot only take still pictures, but also record videos. The E-M5 indeed provides for movie recording, while the 20D does not. The highest resolution format that the E-M5 can use is 1080/60i.

Feature comparison

Beyond body and sensor, cameras can and do differ across a range of features. For example, the E-M5 has an electronic viewfinder (1440k 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 viewfinder in the E-M5 offers a wider field of view (100%) than the one in the 20D (95%), so that a larger proportion of the captured image is visible in the finder. In addition, the viewfinder of the E-M5 has a higher magnification (0.58x vs 0.56x), so that the size of the image transmitted appears closer to the size seen with the naked human eye. The adjacent table lists some of the other core features of the Canon 20D and Olympus E-M5 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 20D	optical	Y	1.8 / 118	fixed	n	1/8000s	5.0/s	Y	n
2.		Olympus E-M5	1440	n	3.0 / 610	tilting	Y	1/4000s	9.0/s	n	Y
3.		Canon 7D	optical	Y	3.0 / 920	fixed	n	1/8000s	8.0/s	Y	n
4.		Canon 7D II	optical	Y	3.0 / 1040	fixed	n	1/8000s	10.0/s	Y	n
5.		Canon 10D	optical	Y	1.8 / 118	fixed	n	1/4000s	3.0/s	Y	n
6.		Canon 30D	optical	Y	2.5 / 230	fixed	n	1/8000s	5.0/s	Y	n
7.		Canon 40D	optical	Y	3.0 / 230	fixed	n	1/8000s	6.5/s	Y	n
8.		Canon 50D	optical	Y	3.0 / 920	fixed	n	1/8000s	6.3/s	Y	n
9.		Canon 60D	optical	Y	3.0 / 1040	swivel	n	1/8000s	5.3/s	Y	n
10.		Canon 300D	optical	n	1.8 / 118	fixed	n	1/4000s	2.5/s	Y	n
11.		Canon 350D	optical	n	1.8 / 115	fixed	n	1/4000s	3.0/s	Y	n
12.		Nikon D200	optical	Y	2.5 / 230	fixed	n	1/8000s	5.0/s	Y	n
13.		Olympus E-M1	2360	n	3.0 / 1037	tilting	Y	1/8000s	10.0/s	n	Y
14.		Olympus E-M5 II	2360	n	3.0 / 1037	swivel	Y	1/8000s	10.0/s	n	Y
15.		Olympus E-M10	1440	n	3.0 / 1037	tilting	Y	1/4000s	8.0/s	Y	Y
16.		Olympus E-M10 II	2360	n	3.0 / 1040	tilting	Y	1/4000s	8.0/s	Y	Y
17.		Olympus E-P5	optional	n	3.0 / 1037	tilting	Y	1/8000s	9.0/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 20D has one, while the E-M5 does not. While the built-in flash of the 20D is not very powerful, it can at times be useful as a fill-in light.

The 20D writes its imaging data to Compact Flash cards, while the E-M5 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 Olympus OM-D E-M5 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.		Olympus E-M5	Y	stereo / mono	-	-	mini	2.0	-	-	-
3.		Canon 7D	Y	mono / -	Y	-	mini	2.0	-	-	-
4.		Canon 7D II	Y	stereo / mono	Y	Y	mini	3.0	-	-	-
5.		Canon 10D	Y	- / -	-	-	-	1.1	-	-	-
6.		Canon 30D	Y	- / -	-	-	-	2.0	-	-	-
7.		Canon 40D	Y	- / -	-	-	-	2.0	-	-	-
8.		Canon 50D	Y	- / -	-	-	mini	2.0	-	-	-
9.		Canon 60D	Y	mono / mono	Y	-	mini	2.0	-	-	-
10.		Canon 300D	Y	- / -	-	-	-	1.1	-	-	-
11.		Canon 350D	Y	- / -	-	-	-	2.0	-	-	-
12.		Nikon D200	Y	- / -	-	-	-	2.0	-	-	-
13.		Olympus E-M1	Y	stereo / mono	Y	-	micro	2.0	Y	-	-
14.		Olympus E-M5 II	Y	stereo / mono	Y	-	micro	2.0	Y	-	-
15.		Olympus E-M10	Y	stereo / mono	-	-	micro	2.0	Y	-	-
16.		Olympus E-M10 II	Y	stereo / mono	-	-	micro	2.0	Y	-	-
17.		Olympus E-P5	Y	stereo / mono	-	-	micro	2.0	Y	-	-

Studio photographers will appreciate that the Canon 20D (unlike the E-M5) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.

Both the 20D and the E-M5 have been discontinued, but can regularly be found used on ebay. The 20D was replaced by the Canon 30D, while the E-M5 was followed by the Olympus E-M5 II. Further information on the features and operation of the 20D and E-M5 can be found, respectively, in the Canon 20D Manual (free pdf) or the online Olympus E-M5 Manual.

Review summary

So how do things add up? Is there a clear favorite between the Canon 20D and the Olympus E-M5? Which camera is better? Below is a summary of the relative strengths of each of the two contestants.

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 1/4000s) to freeze action.
• Longer lasting: Can take more shots (700 versus 360) on a single battery charge.
• Easier fill-in: Is equipped with a small onboard flash to brighten deep shadow areas.
• 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).

Arguments in favor of the Olympus OM-D E-M5:

• More detail: Has more megapixels (15.9 vs 8.2MP), which boosts linear resolution by 37%.
• Better image quality: Scores markedly higher (9 points) in the DXO overall evaluation.
• More dynamic range: Captures a broader range of light and dark details (1.3 EV of extra DR).
• Broader imaging potential: Can capture not only stills but also 1080/60i video.
• More framing info: Has an electronic viewfinder that displays shooting data.
• More complete view: Has a viewfinder with a larger field of view (100% vs 95%).
• Larger viewfinder image: Features a viewfinder with a higher magnification (0.58x vs 0.56x).
• 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 (610k vs 118k 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.
• Faster burst: Shoots at higher frequency (9 vs 5 flaps/sec) to capture the decisive moment.
• More compact: Is smaller (122x89mm vs 144x106mm) and will fit more readily into a bag.
• Less heavy: Has a lower weight (by 345g or 45 percent) and is thus easier to take along.
• 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.
• More legacy lens friendly: Can use many non-native lenses via adapters.
• Faster data transfer: Supports a more advanced USB protocol (2.0 vs 1.1).
• More affordable: Was released into a lower priced segment (13 percent cheaper at launch).
• More modern: Reflects 7 years and 5 months of technical progress since the 20D launch.

If the number of relative strengths (bullet points above) is taken as a guide, the E-M5 is the clear winner of the contest (20 : 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 Olympus E-M5 place the cameras among the top in their class? Find out in the latest Best DSLR Camera and Best Mirrorless Interchangeable Lens 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 says little about, for example, the shooting experience and imaging performance of the 20D and the E-M5 in practical situations. 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 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 20D	..	..	..	+ +	..	..	Aug 2004	1,499	ebay.com
2.		Olympus E-M5	4/5	+ +	..	80/100	4.5/5	5/5	Feb 2012	1,299	ebay.com
3.		Canon 7D	5/5	+ +	..	84/100	4.5/5	4.5/5	Sep 2009	1,699	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 10D	..	..	..	+ +	..	..	Feb 2003	1,999	ebay.com
6.		Canon 30D	..	+ +	..	+ +	o	..	Feb 2006	1,399	ebay.com
7.		Canon 40D	..	+ +	..	+ +	4.5/5	4.5/5	Aug 2007	1,299	ebay.com
8.		Canon 50D	..	+ +	..	+ +	4.5/5	4.5/5	Aug 2008	1,299	ebay.com
9.		Canon 60D	5/5	+	..	79/100	4/5	4.5/5	Aug 2010	1,399	ebay.com
10.		Canon 300D	..	..	..	+ +	..	..	Aug 2003	899	ebay.com
11.		Canon 350D	..	80/100	..	+ +	o	..	Feb 2005	899	ebay.com
12.		Nikon D200	..	+ +	..	+ +	o	..	Nov 2005	1,699	ebay.com
13.		Olympus E-M1	5/5	+ +	..	84/100	4.5/5	4.5/5	Sep 2013	1,399	ebay.com
14.		Olympus E-M5 II	5/5	+ +	4.5/5	81/100	5/5	5/5	Feb 2015	1,099	ebay.com
15.		Olympus E-M10	4/5	..	..	80/100	5/5	5/5	Jan 2014	699	ebay.com
16.		Olympus E-M10 II	4.5/5	+ +	..	80/100	5/5	5/5	Aug 2015	649	ebay.com
17.		Olympus E-P5	5/5	+ +	..	78/100	4.5/5	5/5	May 2013	999	ebay.com
Note: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.

The review scores listed above should be treated with care, though. The ratings are only valid when referring to cameras in the same category and of the same age. 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. Also, kindly note that some of the listed sites have over time developped their review approaches and their reporting style.

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Other camera comparisons

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