Canon SL3 vs Olympus E-420

The Canon EOS Rebel SL3 (called Canon 250D in some regions) and the Olympus E-420 are two digital cameras that were revealed to the public, respectively, in April 2019 and March 2008. Both are DSLR (Digital Single Lens Reflex) cameras that are based on an APS-C (SL3) and a Four Thirds (E-420) sensor. The Canon has a resolution of 24 megapixels, whereas the Olympus provides 10 MP.

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

Headline Specifications

Canon SL3		Olympus E-420
Digital single lens reflex		Digital single lens reflex
Canon EF mount lenses		Four Thirds lenses
24 MP – APS-C sensor		10 MP – Four Thirds sensor
4K/25p Video		no Video
ISO 100-25,600 (100 - 51,200)		ISO 100-1,600
Optical viewfinder		Optical viewfinder
3.0" LCD – 1040k dots		2.7" LCD – 215k dots
Swivel touchscreen		Fixed screen (not touch-sensitive)
5 shutter flaps per second		3.5 shutter flaps per second
1070 shots per battery charge		500 shots per battery charge
122 x 93 x 70 mm, 449 g		130 x 91 x 53 mm, 440 g

Check SL3 price at
amazon.com
Check E-420 offers at
ebay.com

Going beyond this snapshot of core features and characteristics, what are the differences between the Canon EOS Rebel SL3 and the Olympus E-420? 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 SL3 and the Olympus E-420. 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 SL3 can be obtained in two different colors (black, white), while the E-420 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-420 is somewhat larger (4 percent) than the Canon SL3. However, the E-420 is slightly lighter (2 percent) than the SL3. In this context, it is worth noting that neither the SL3 nor the E-420 are weather-sealed.

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 (SL3) and the Four Thirds Lens Catalog (E-420).

Concerning battery life, the SL3 gets 1070 shots out of its Canon LP-E17 battery, while the E-420 can take 500 images on a single charge of its Olympus BLS-1 power pack.

The following table provides a synthesis of the main physical specifications of the two cameras and other similar ones. 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	Street Price
1.		Canon SL3	122 mm	93 mm	70 mm	449 g	1070	n	Apr 2019	US$ 599	amazon.com
2.		Olympus E-420	130 mm	91 mm	53 mm	440 g	500	n	Mar 2008	US$ 599	ebay.com
3.		Canon 77D	131 mm	100 mm	76 mm	540 g	600	n	Feb 2017	US$ 899	ebay.com
4.		Canon M50	116 mm	88 mm	59 mm	390 g	235	n	Feb 2018	US$ 779	ebay.com
5.		Canon M50 Mark II	116 mm	88 mm	59 mm	387 g	305	n	Oct 2020	US$ 599	ebay.com
6.		Canon SL1	117 mm	91 mm	69 mm	407 g	380	n	Mar 2013	US$ 549	ebay.com
7.		Canon SL2	122 mm	93 mm	70 mm	453 g	650	n	Jun 2017	US$ 549	ebay.com
8.		Canon T2i	129 mm	98 mm	62 mm	530 g	440	n	Feb 2010	US$ 699	ebay.com
9.		Canon T6s	132 mm	101 mm	78 mm	565 g	440	n	Feb 2015	US$ 649	ebay.com
10.		Canon T7	129 mm	101 mm	78 mm	475 g	500	n	Feb 2018	US$ 449	amazon.com
11.		Canon T7i	131 mm	100 mm	76 mm	532 g	600	n	Feb 2017	US$ 749	ebay.com
12.		Canon T8i	131 mm	103 mm	76 mm	515 g	800	n	Feb 2020	US$ 749	ebay.com
13.		Olympus E-400	130 mm	91 mm	53 mm	435 g	500	n	Sep 2006	US$ 699	ebay.com
14.		Olympus E-410	130 mm	91 mm	53 mm	435 g	500	n	Mar 2007	US$ 699	ebay.com
15.		Olympus E-450	130 mm	91 mm	53 mm	440 g	500	n	Mar 2009	US$ 499	ebay.com
16.		Olympus E-520	136 mm	92 mm	68 mm	535 g	750	n	May 2008	US$ 699	ebay.com
17.		Olympus E-620	130 mm	94 mm	60 mm	521 g	500	n	Feb 2009	US$ 699	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 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 two cameras under review were launched at the same price and fall into the same market segment. 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. 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. 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 tend to be associated with larger, more expensive camera bodies and lenses.

Of the two cameras under consideration, the Canon SL3 features an APS-C sensor and the Olympus E-420 a Four Thirds sensor. The sensor area in the E-420 is 32 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 SL3 has a native 3:2 aspect ratio, while the one in the E-420 offers a 4:3 aspect.

With 24MP, the SL3 offers a higher resolution than the E-420 (10MP), but the SL3 has smaller individual pixels (pixel pitch of 3.72μm versus 4.74μm for the E-420). However, the SL3 is a much more recent model (by 11 years and 1 month) than the E-420, and its sensor will have benefitted from technological advances during this time that enhance the light gathering capacity of its pixels.

The resolution advantage of the Canon SL3 implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the SL3 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 Olympus E-420 are 18.2 x 13.7 inches or 46.3 x 34.7 cm for good quality, 14.6 x 10.9 inches or 37.1 x 27.8 cm for very good quality, and 12.2 x 9.1 inches or 30.9 x 23.2 cm for excellent quality prints.

The SL3 has on-sensor phase detect pixels, which results in fast and reliable autofocus acquisition even during live view operation.

The Canon EOS Rebel SL3 has a native sensitivity range from ISO 100 to ISO 25600, which can be extended to ISO 100-51200. The corresponding ISO settings for the Olympus E-420 are ISO 100 to ISO 1600 (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 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 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 SL3	APS-C	24.0	6000	4000	4K/25p	23.9	13.4	1791	82
2.		Olympus E-420	Four Thirds	10.0	3648	2736	none	21.5	10.4	527	56
3.		Canon 77D	APS-C	24.0	6000	4000	1080/60p	23.6	13.3	971	78
4.		Canon M50	APS-C	24.0	6000	4000	4K/24p	23.8	13.3	1684	81
5.		Canon M50 Mark II	APS-C	24.0	6000	4000	4K/24p	24.0	13.6	1939	83
6.		Canon SL1	APS-C	17.9	5184	3456	1080/30p	21.8	11.3	843	63
7.		Canon SL2	APS-C	24.0	6000	4000	1080/60p	23.6	13.4	1041	79
8.		Canon T2i	APS-C	17.9	5184	3456	1080/30p	22.1	11.5	784	66
9.		Canon T6s	APS-C	24.0	6000	4000	1080/30p	22.6	12.0	915	70
10.		Canon T7	APS-C	24.0	6000	4000	1080/30p	23.8	13.3	1684	81
11.		Canon T7i	APS-C	24.0	6000	4000	1080/60p	23.7	13.1	1586	80
12.		Canon T8i	APS-C	24.0	6000	4000	4K/24p	24.0	13.5	1873	83
13.		Olympus E-400	Four Thirds	10.0	3648	2736	none	21.0	10.6	127	53
14.		Olympus E-410	Four Thirds	10.0	3648	2736	none	21.1	10.0	494	51
15.		Olympus E-450	Four Thirds	10.0	3648	2736	none	21.5	10.5	512	56
16.		Olympus E-520	Four Thirds	10.0	3648	2736	none	21.4	10.4	548	55
17.		Olympus E-620	Four Thirds	12.2	4032	3024	none	21.3	10.3	536	55
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 SL3 indeed provides movie recording capabilities, while the E-420 does not. The highest resolution format that the SL3 can use is 4K/25p.

Feature comparison

Apart from body and sensor, cameras can and do differ across a variety of features. The SL3 and the E-420 are similar in the sense that both have an optical viewfinder. The latter is useful for getting a clear image for framing even in brightly lit environments. The viewfinders of both cameras offer the same field of view (95%), but the viewfinder of the SL3 has a higher magnification than the one of the E-420 (0.54x vs 0.46x), 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 SL3 and Olympus E-420 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 SL3	optical	n	3.0 / 1040	swivel	Y	1/4000s	5.0/s	Y	n
2.		Olympus E-420	optical	n	2.7 / 215	fixed	n	1/4000s	3.5/s	Y	n
3.		Canon 77D	optical	Y	3.0 / 1040	swivel	Y	1/4000s	6.0/s	Y	n
4.		Canon M50	2360	n	3.0 / 1040	swivel	Y	1/4000s	10.0/s	Y	n
5.		Canon M50 Mark II	2360	n	3.0 / 1040	swivel	Y	1/4000s	10.0/s	Y	n
6.		Canon SL1	optical	n	3.0 / 1040	fixed	Y	1/4000s	4.9/s	Y	n
7.		Canon SL2	optical	n	3.0 / 1040	swivel	Y	1/4000s	5.0/s	Y	n
8.		Canon T2i	optical	n	3.0 / 1040	fixed	n	1/4000s	3.7/s	Y	n
9.		Canon T6s	optical	Y	3.0 / 1040	swivel	Y	1/4000s	5.0/s	Y	n
10.		Canon T7	optical	n	3.0 / 920	fixed	n	1/4000s	3.0/s	Y	n
11.		Canon T7i	optical	n	3.0 / 1040	swivel	Y	1/4000s	6.0/s	Y	n
12.		Canon T8i	optical	n	3.0 / 1040	swivel	Y	1/4000s	7.5/s	Y	n
13.		Olympus E-400	optical	n	2.5 / 215	fixed	n	1/4000s	3.0/s	Y	n
14.		Olympus E-410	optical	n	2.5 / 215	fixed	n	1/4000s	3.0/s	Y	n
15.		Olympus E-450	optical	n	2.7 / 215	fixed	n	1/4000s	3.5/s	Y	n
16.		Olympus E-520	optical	n	2.7 / 215	fixed	n	1/4000s	3.5/s	Y	Y
17.		Olympus E-620	optical	n	2.7 / 230	swivel	n	1/4000s	4.0/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 SL3 has a touchscreen, while the E-420 has a conventional panel. Touch control can be particularly helpful, for example, for setting the focus point.

The Canon SL3 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 SL3 writes its imaging data to SDXC cards, while the E-420 uses Compact Flash or xD Picture cards. The E-420 features dual card slots, which can be very useful in case a memory card fails. In contrast, the SL3 only has one slot.

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 Rebel SL3 and Olympus E-420 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 SL3	Y	stereo / mono	Y	-	mini	2.0	Y	-	Y
2.		Olympus E-420	Y	- / -	-	-	-	2.0	-	-	-
3.		Canon 77D	Y	stereo / mono	Y	-	mini	2.0	Y	Y	Y
4.		Canon M50	Y	stereo / mono	Y	-	micro	2.0	Y	-	Y
5.		Canon M50 Mark II	Y	stereo / mono	Y	-	micro	2.0	Y	-	Y
6.		Canon SL1	Y	mono / mono	Y	-	mini	2.0	-	-	-
7.		Canon SL2	Y	stereo / mono	Y	-	mini	2.0	Y	Y	Y
8.		Canon T2i	Y	stereo / -	Y	-	mini	2.0	-	-	-
9.		Canon T6s	Y	stereo / mono	Y	-	mini	2.0	Y	Y	-
10.		Canon T7	Y	mono / mono	-	-	mini	2.0	Y	Y	-
11.		Canon T7i	Y	stereo / mono	Y	-	mini	2.0	Y	Y	Y
12.		Canon T8i	Y	stereo / mono	Y	-	mini	2.0	Y	-	Y
13.		Olympus E-400	Y	- / -	-	-	-	2.0	-	-	-
14.		Olympus E-410	Y	- / -	-	-	-	2.0	-	-	-
15.		Olympus E-450	Y	- / -	-	-	-	2.0	-	-	-
16.		Olympus E-520	Y	- / -	-	-	-	2.0	-	-	-
17.		Olympus E-620	Y	- / -	-	-	-	2.0	-	-	-

It is notable that the SL3 offers wifi support, while the E-420 does not. Wifi can be a very convenient means to transfer image data to an off-camera location.

The SL3 is a recent model that features in the current product line-up of Canon. In contrast, the E-420 has been discontinued (but can be found pre-owned on ebay). There has not been a direct replacement model for the E-420 from Olympus. Further information on the features and operation of the SL3 and E-420 can be found, respectively, in the Canon SL3 Manual (free pdf) or the online Olympus E-420 Manual.

Review summary

So what is the bottom line? Is the Canon SL3 better than the Olympus E-420 or vice versa? A synthesis of the relative strong points of each of the models is listed below.

Arguments in favor of the Canon EOS Rebel SL3:

• More detail: Offers more megapixels (24 vs 10MP) with a 58% higher linear resolution.
• Better image quality: Features a larger and more technologically advanced imaging 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.
• Broader imaging potential: Can record not only still images but also 4K/25p movies.
• Better live-view autofocus: Features on-sensor phase-detection for more confident autofocus.
• Larger viewfinder image: Features a viewfinder with a higher magnification (0.54x vs 0.46x).
• Larger screen: Has a bigger rear LCD (3.0" vs 2.7") for image review and settings control.
• More detailed LCD: Has a higher resolution rear screen (1040k vs 215k dots).
• More flexible LCD: Has a swivel screen for odd-angle shots in portrait or 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 (5 vs 3.5 flaps/sec) to capture the decisive moment.
• Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
• Longer lasting: Can take more shots (1070 versus 500) on a single battery charge.
• 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 modern: Reflects 11 years and 1 month of technical progress since the E-420 launch.

Advantages of the Olympus E-420:

• Greater peace of mind: Features a second card slot as a backup in case of memory card failure.
• More heavily discounted: Has been around for much longer (launched in March 2008).

If the count of relative strengths (bullet points above) is taken as a measure, the SL3 is the clear winner of the match-up (19 : 2 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 SL3 and the Olympus E-420 place the cameras among the top in their class? Find out in the latest Best DSLR Camera listing 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 SL3 or the E-420 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 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	Street Price
1.		Canon SL3	4/5	o	4.5/5	79/100	4/5	4/5	Apr 2019	US$ 599	amazon.com
2.		Olympus E-420	..	85/100	..	+ +	4/5	4.5/5	Mar 2008	US$ 599	ebay.com
3.		Canon 77D	4.5/5	..	4/5	82/100	4.5/5	4/5	Feb 2017	US$ 899	ebay.com
4.		Canon M50	..	+	4/5	79/100	..	3.5/5	Feb 2018	US$ 779	ebay.com
5.		Canon M50 Mark II	4/5	..	4/5	..	4.5/5	3.5/5	Oct 2020	US$ 599	ebay.com
6.		Canon SL1	4/5	+	..	78/100	4/5	4/5	Mar 2013	US$ 549	ebay.com
7.		Canon SL2	4/5	+ +	4/5	78/100	4.5/5	4.5/5	Jun 2017	US$ 549	ebay.com
8.		Canon T2i	..	+ +	..	77/100	4/5	4.5/5	Feb 2010	US$ 699	ebay.com
9.		Canon T6s	5/5	+	..	77/100	4.5/5	4.5/5	Feb 2015	US$ 649	ebay.com
10.		Canon T7	..	o	3.5/5	..	3.5/5	3.5/5	Feb 2018	US$ 449	amazon.com
11.		Canon T7i	4.5/5	..	3.5/5	80/100	4.5/5	4/5	Feb 2017	US$ 749	ebay.com
12.		Canon T8i	4.5/5	+	3/5	80/100	4/5	3.5/5	Feb 2020	US$ 749	ebay.com
13.		Olympus E-400	..	85/100	..	..	4/5	4/5	Sep 2006	US$ 699	ebay.com
14.		Olympus E-410	..	86/100	..	+ +	4/5	4.5/5	Mar 2007	US$ 699	ebay.com
15.		Olympus E-450	..	..	..	..	4/5	4/5	Mar 2009	US$ 499	ebay.com
16.		Olympus E-520	..	87/100	..	+ +	4.5/5	4.5/5	May 2008	US$ 699	ebay.com
17.		Olympus E-620	3/5	88/100	..	72/100	4.5/5	5/5	Feb 2009	US$ 699	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 comparisons of ratings among very different cameras or across long time periods have little meaning. 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 are interested in seeing how other cameras pair up, 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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