Canon SL3 vs Pentax K-3 II

The Canon EOS Rebel SL3 (called Canon 250D in some regions) and the Pentax K-3 II are two digital cameras that were announced, respectively, in April 2019 and April 2015. Both are DSLR (Digital Single Lens Reflex) cameras that are equipped with an APS-C sensor. The Canon has a resolution of 24 megapixels, whereas the Pentax provides 24.1 MP.

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

Headline Specifications

Canon SL3		Pentax K-3 II
Digital single lens reflex		Digital single lens reflex
Canon EF mount lenses		Pentax K mount lenses
24 MP – APS-C sensor		24.1 MP – APS-C sensor
4K/25p Video		1080/60i Video
ISO 100-25,600 (100 - 51,200)		ISO 100-51,200
Optical viewfinder		Optical viewfinder
3.0" LCD – 1040k dots		3.2" LCD – 1037k dots
Swivel touchscreen		Fixed screen (not touch-sensitive)
5 shutter flaps per second		8.3 shutter flaps per second
Lens stabilization only		In-body stabilization
not weather sealed		Weathersealed body
1070 shots per battery charge		720 shots per battery charge
122 x 93 x 70 mm, 449 g		131 x 100 x 77 mm, 800 g

Check SL3 price at
amazon.com
Check K-3 II 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 Pentax K-3 II? 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 Pentax K-3 II. 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 SL3 can be obtained in two different colors (black, white), while the K-3 II is also available in two color-versions, but different ones (black, silver).

If the front view area (width x height) of the cameras is taken as an aggregate measure of their size, the Pentax K-3 II is notably larger (15 percent) than the Canon SL3. Moreover, the K-3 II is substantially heavier (78 percent) than the SL3. It is noteworthy in this context that the K-3 II is splash and dust-proof, while the SL3 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. Hence, you might want to study and compare the specifications of available lenses in order to get the full picture of the size and weight of the two camera systems.

Concerning battery life, the SL3 gets 1070 shots out of its Canon LP-E17 battery, while the K-3 II can take 720 images on a single charge of its Pentax D-LI90 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 SL3	122 mm	93 mm	70 mm	449 g	1070	n	Apr 2019	599	amazon.com
2.		Pentax K-3 II	131 mm	100 mm	77 mm	800 g	720	Y	Apr 2015	1,099	ebay.com
3.		Canon T8i	131 mm	103 mm	76 mm	515 g	800	n	Feb 2020	749	ebay.com
4.		Canon M50 Mark II	116 mm	88 mm	59 mm	387 g	305	n	Oct 2020	599	ebay.com
5.		Canon M50	116 mm	88 mm	59 mm	390 g	235	n	Feb 2018	779	ebay.com
6.		Canon T7	129 mm	101 mm	78 mm	475 g	500	n	Feb 2018	449	amazon.com
7.		Canon 77D	131 mm	100 mm	76 mm	540 g	600	n	Feb 2017	899	ebay.com
8.		Canon SL2	122 mm	93 mm	70 mm	453 g	650	n	Jun 2017	549	ebay.com
9.		Canon T7i	131 mm	100 mm	76 mm	532 g	600	n	Feb 2017	749	ebay.com
10.		Canon T6s	132 mm	101 mm	78 mm	565 g	440	n	Feb 2015	649	ebay.com
11.		Canon SL1	117 mm	91 mm	69 mm	407 g	380	n	Mar 2013	549	ebay.com
12.		Canon T2i	129 mm	98 mm	62 mm	530 g	440	n	Feb 2010	699	ebay.com
13.		Pentax K-3 III	135 mm	104 mm	74 mm	820 g	800	Y	Mar 2021	1,999	amazon.com
14.		Pentax KP	132 mm	101 mm	76 mm	703 g	390	Y	Jan 2017	1,099	ebay.com
15.		Pentax K-70	126 mm	93 mm	74 mm	688 g	410	Y	Jun 2016	649	ebay.com
16.		Pentax K-3	131 mm	100 mm	77 mm	800 g	560	Y	Oct 2013	1,299	ebay.com
17.		Pentax K-5	131 mm	97 mm	73 mm	760 g	740	Y	Sep 2010	1,099	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 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 SL3 was launched at a markedly lower price (by 45 percent) than the K-3 II, which puts it into a different 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. 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. 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 tend to be more expensive and 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 K-3 II is 11 percent bigger. As a result of these sensor size differences, the cameras have format factors, respectively, of 1.6 (SL3) and 1.5. Both cameras have a native aspect ratio (sensor width to sensor height) of 3:2.

With 24.1MP, the K-3 II offers a higher resolution than the SL3 (24MP), but the K-3 II nevertheless has larger individual pixels (pixel pitch of 3.90μm versus 3.72μm for the SL3) due to its larger sensor. However, the SL3 is a much more recent model (by 3 years and 11 months) than the K-3 II, and its sensor will have benefitted from technological advances during this time that enhance the light gathering capacity of its pixel-units. Coming back to sensor resolution, it should be mentioned that the K-3 II has no anti-alias filter installed, so that it can capture all the detail its sensor resolves.

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

Unlike the SL3, the K-3 II has the capacity to capture high quality composite images by combining multiple shots after shifting its sensor by miniscule distances. This multi-shot, pixel-shift mode is most suitable for photography of stationary objects (landscapes, studio scenes).

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 Pentax K-3 II are ISO 100 to ISO 51200 (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.

Consistent information on actual sensor performance is available from DXO Mark for many cameras. 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 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 SL3	APS-C	24.0	6000	4000	4K/25p	23.9	13.4	1791	82
2.		Pentax K-3 II	APS-C	24.1	6016	4000	1080/60i	23.6	13.6	1106	80
3.		Canon T8i	APS-C	24.0	6000	4000	4K/24p	24.0	13.5	1873	83
4.		Canon M50 Mark II	APS-C	24.0	6000	4000	4K/24p	24.0	13.6	1939	83
5.		Canon M50	APS-C	24.0	6000	4000	4K/24p	23.8	13.3	1684	81
6.		Canon T7	APS-C	24.0	6000	4000	1080/30p	23.8	13.3	1684	81
7.		Canon 77D	APS-C	24.0	6000	4000	1080/60p	23.6	13.3	971	78
8.		Canon SL2	APS-C	24.0	6000	4000	1080/60p	23.6	13.4	1041	79
9.		Canon T7i	APS-C	24.0	6000	4000	1080/60p	23.7	13.1	1586	80
10.		Canon T6s	APS-C	24.0	6000	4000	1080/30p	22.6	12.0	915	70
11.		Canon SL1	APS-C	17.9	5184	3456	1080/30p	21.8	11.3	843	63
12.		Canon T2i	APS-C	17.9	5184	3456	1080/30p	22.1	11.5	784	66
13.		Pentax K-3 III	APS-C	25.6	6192	4128	4K/30p	24.2	13.7	2083	85
14.		Pentax KP	APS-C	24.1	6016	4000	1080/60i	23.9	13.2	1699	81
15.		Pentax K-70	APS-C	24.0	6000	4000	1080/60i	23.8	13.1	1639	80
16.		Pentax K-3	APS-C	24.1	6016	4000	1080/60i	23.7	13.4	1216	80
17.		Pentax K-5	APS-C	16.1	4928	3264	1080/25p	23.7	14.1	1162	82
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 two cameras under consideration both have sensors whose read-out speed is fast enough to capture moving pictures, but the SL3 provides a higher video resolution than the K-3 II. It can shoot video footage at 4K/25p, while the Pentax is limited to 1080/60i.

Feature comparison

Apart from body and sensor, cameras can and do differ across a variety of features. The SL3 and the K-3 II 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 viewfinder in the K-3 II offers a wider field of view (100%) than the one in the SL3 (95%), so that a larger proportion of the captured image is visible in the finder. In addition, the viewfinder of the K-3 II has a higher magnification (0.63x vs 0.54x), 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 Pentax K-3 II 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.		Pentax K-3 II	optical	Y	3.2 / 1037	fixed	n	1/8000s	8.3/s	n	Y
3.		Canon T8i	optical	n	3.0 / 1040	swivel	Y	1/4000s	7.5/s	Y	n
4.		Canon M50 Mark II	2360	n	3.0 / 1040	swivel	Y	1/4000s	10.0/s	Y	n
5.		Canon M50	2360	n	3.0 / 1040	swivel	Y	1/4000s	10.0/s	Y	n
6.		Canon T7	optical	n	3.0 / 920	fixed	n	1/4000s	3.0/s	Y	n
7.		Canon 77D	optical	Y	3.0 / 1040	swivel	Y	1/4000s	6.0/s	Y	n
8.		Canon SL2	optical	n	3.0 / 1040	swivel	Y	1/4000s	5.0/s	Y	n
9.		Canon T7i	optical	n	3.0 / 1040	swivel	Y	1/4000s	6.0/s	Y	n
10.		Canon T6s	optical	Y	3.0 / 1040	swivel	Y	1/4000s	5.0/s	Y	n
11.		Canon SL1	optical	n	3.0 / 1040	fixed	Y	1/4000s	4.9/s	Y	n
12.		Canon T2i	optical	n	3.0 / 1040	fixed	n	1/4000s	3.7/s	Y	n
13.		Pentax K-3 III	optical	Y	3.2 / 1620	fixed	Y	1/8000s	12.0/s	n	Y
14.		Pentax KP	optical	n	3.0 / 921	tilting	n	1/6000s	7.0/s	Y	Y
15.		Pentax K-70	optical	n	3.0 / 921	swivel	n	1/6000s	6.0/s	Y	Y
16.		Pentax K-3	optical	Y	3.2 / 1037	fixed	n	1/8000s	8.3/s	Y	Y
17.		Pentax K-5	optical	Y	3.0 / 921	fixed	n	1/8000s	7.0/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 SL3 has one, while the K-3 II does not. While the built-in flash of the SL3 is not very powerful, it can at times be useful as a fill-in light.

The Canon SL3 and the Pentax K-3 II both have 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 SL3 and the K-3 II write their files to SDXC cards. The K-3 II features dual card slots, which can be very useful in case a memory card fails. In contrast, the SL3 only has one slot. Both cameras can use UHS-I cards, which provide for Ultra High Speed data transfer of up to 104 MB/s.

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 Pentax K-3 II 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.		Pentax K-3 II	Y	mono / mono	Y	Y	mini	3.0	-	-	-
3.		Canon T8i	Y	stereo / mono	Y	-	mini	2.0	Y	-	Y
4.		Canon M50 Mark II	Y	stereo / mono	Y	-	micro	2.0	Y	-	Y
5.		Canon M50	Y	stereo / mono	Y	-	micro	2.0	Y	-	Y
6.		Canon T7	Y	mono / mono	-	-	mini	2.0	Y	Y	-
7.		Canon 77D	Y	stereo / mono	Y	-	mini	2.0	Y	Y	Y
8.		Canon SL2	Y	stereo / mono	Y	-	mini	2.0	Y	Y	Y
9.		Canon T7i	Y	stereo / mono	Y	-	mini	2.0	Y	Y	Y
10.		Canon T6s	Y	stereo / mono	Y	-	mini	2.0	Y	Y	-
11.		Canon SL1	Y	mono / mono	Y	-	mini	2.0	-	-	-
12.		Canon T2i	Y	stereo / -	Y	-	mini	2.0	-	-	-
13.		Pentax K-3 III	Y	stereo / mono	Y	Y	micro	3.2	Y	-	Y
14.		Pentax KP	Y	stereo / mono	Y	-	-	2.0	Y	-	-
15.		Pentax K-70	Y	stereo / mono	Y	-	mini	2.0	Y	-	-
16.		Pentax K-3	Y	mono / mono	Y	Y	mini	3.0	-	-	-
17.		Pentax K-5	Y	stereo / mono	Y	-	mini	2.0	-	-	-

It is notable that the SL3 offers wifi support, while the K-3 II does not. Wifi can be a very convenient means to transfer image data to an off-camera location.

Studio photographers will appreciate that the Pentax K-3 II (unlike the SL3) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.

Travel and landscape photographers will find it useful that the K-3 II has an internal geolocalization sensor and can record GPS coordinates in its EXIF data.

The SL3 is a recent model that features in the current product line-up of Canon. In contrast, the K-3 II has been discontinued (but can be found pre-owned on ebay). As a replacement in the same line of cameras, the K-3 II was succeeded by the Pentax K-3 III. Further information on the features and operation of the SL3 and K-3 II can be found, respectively, in the Canon SL3 Manual (free pdf) or the online Pentax K-3 II Manual.

Review summary

So how do things add up? Which of the two cameras – the Canon SL3 or the Pentax K-3 II – 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 Rebel SL3:

• Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
• Better video: Provides higher definition movie capture (4K/25p vs 1080/60i).
• Better live-view autofocus: Features on-sensor phase-detection for more confident autofocus.
• 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.
• More compact: Is smaller (122x93mm vs 131x100mm) and thus needs less room in the bag.
• Less heavy: Is lighter (by 351g or 44 percent) and hence easier to carry around.
• Longer lasting: Can take more shots (1070 versus 720) on a single battery charge.
• Easier fill-in: Is equipped with a small onboard flash to brighten deep shadow areas.
• 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 into a lower priced category (45 percent cheaper at launch).
• More modern: Reflects 3 years and 11 months of technical progress since the K-3 II launch.

Advantages of the Pentax K-3 II:

• Maximized detail: Lacks an anti-alias filter to exploit the sensor's full resolution potential.
• High quality composites: Can combine several shots after pixel-shifting its sensor.
• Better sound control: Has a headphone port that enables audio monitoring while recording.
• 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 (0.63x vs 0.54x).
• Easier setting verification: Features a control panel on top to check shooting parameters.
• Larger screen: Has a bigger rear LCD (3.2" vs 3.0") for image review and settings control.
• Faster shutter: Has higher mechanical shutter speed (1/8000s vs 1/4000s) to freeze action.
• Faster burst: Shoots at higher frequency (8.3 vs 5 flaps/sec) to capture the decisive moment.
• 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.
• Easier geotagging: Features an internal GPS sensor to log localization data.
• Faster data transfer: Supports a more advanced USB protocol (3.0 vs 2.0).
• Better studio light control: Has a PC Sync socket to connect to professional strobe lights.
• 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 April 2015).

If the count of individual advantages (bullet points above) is taken as a guide, the K-3 II emerges as the winner of the match-up (16 : 14 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 SL3 and the Pentax K-3 II 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 specs-based evaluation of cameras can be instructive in revealing their potential as photographic tools, it remains partial and cannot reveal, for example, the shooting experience and imaging performance when actually working with the SL3 or the K-3 II. 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 where reviews by experts come in. 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 SL3	4/5	o	4.5/5	79/100	4/5	4/5	Apr 2019	599	amazon.com
2.		Pentax K-3 II	4.5/5	..	..	..	5/5	5/5	Apr 2015	1,099	ebay.com
3.		Canon T8i	4.5/5	+	3/5	80/100	4/5	3.5/5	Feb 2020	749	ebay.com
4.		Canon M50 Mark II	4/5	..	4/5	..	4.5/5	3.5/5	Oct 2020	599	ebay.com
5.		Canon M50	..	+	4/5	79/100	..	3.5/5	Feb 2018	779	ebay.com
6.		Canon T7	..	o	3.5/5	..	3.5/5	3.5/5	Feb 2018	449	amazon.com
7.		Canon 77D	4.5/5	..	4/5	82/100	4.5/5	4/5	Feb 2017	899	ebay.com
8.		Canon SL2	4/5	+ +	4/5	78/100	4.5/5	4.5/5	Jun 2017	549	ebay.com
9.		Canon T7i	4.5/5	..	3.5/5	80/100	4.5/5	4/5	Feb 2017	749	ebay.com
10.		Canon T6s	5/5	+	..	77/100	4.5/5	4.5/5	Feb 2015	649	ebay.com
11.		Canon SL1	4/5	+	..	78/100	4/5	4/5	Mar 2013	549	ebay.com
12.		Canon T2i	..	+ +	..	77/100	4/5	4.5/5	Feb 2010	699	ebay.com
13.		Pentax K-3 III	4/5	..	3/5	..	4.5/5	..	Mar 2021	1,999	amazon.com
14.		Pentax KP	4/5	..	3/5	82/100	5/5	4.5/5	Jan 2017	1,099	ebay.com
15.		Pentax K-70	4.5/5	..	4/5	79/100	4.5/5	4.5/5	Jun 2016	649	ebay.com
16.		Pentax K-3	4/5	..	..	83/100	5/5	5/5	Oct 2013	1,299	ebay.com
17.		Pentax K-5	4/5	..	..	83/100	5/5	4.5/5	Sep 2010	1,099	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 comparing ratings of very distinct cameras or ones that are far apart in terms of their release date have little meaning. Also, kindly note that some of the listed sites have over time developped their review approaches and their reporting style.

Check SL3 price at
amazon.com
Check K-3 II offers at
ebay.com

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. As an alternative, you can also directly jump to any one of the listed comparisons that were previously generated by the CAM-parator tool.

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