Canon RP vs Pentax K-3

The Canon EOS RP and the Pentax K-3 are two digital cameras that were revealed to the public, respectively, in February 2019 and October 2013. The RP is a mirrorless interchangeable lens camera, while the K-3 is a DSLR. The cameras are based on a full frame (RP) and an APS-C (K-3) sensor. The Canon has a resolution of 26 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 RP		Pentax K-3
Mirrorless system camera		Digital single lens reflex
Canon RF mount lenses		Pentax K mount lenses
26 MP – Full Frame sensor		24.1 MP – APS-C sensor
4K/30p Video		1080/60i Video
ISO 100-40,000 (50 - 102,400)		ISO 100-51,200
Electronic viewfinder (2360k dots)		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
250 shots per battery charge		560 shots per battery charge
133 x 85 x 70 mm, 485 g		131 x 100 x 77 mm, 800 g

Check RP price at
amazon.com
Check K-3 offers at
ebay.com

Going beyond this snapshot of core features and characteristics, what are the differences between the Canon EOS RP and the Pentax K-3? 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 RP and the Pentax K-3 are illustrated 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 K-3 can be obtained in two different colors (black, silver), while the RP 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 Pentax K-3 is notably larger (16 percent) than the Canon RP. Moreover, the K-3 is substantially heavier (65 percent) than the RP. It is noteworthy in this context that the K-3 is splash and dust-proof, while the RP 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 RP gets 250 shots out of its Canon LP-E17 battery, while the K-3 can take 560 images on a single charge of its Pentax D-LI90 power pack. The power pack in the RP can be charged via the USB port, so that it is not always necessary to take the battery charger along when travelling.

The following table provides a synthesis of the main physical specifications of the two cameras and other similar ones. 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 RP	133 mm	85 mm	70 mm	485 g	250	n	Feb 2019	1,299	amazon.com
2.		Pentax K-3	131 mm	100 mm	77 mm	800 g	560	Y	Oct 2013	1,299	ebay.com
3.		Canon R8	133 mm	86 mm	70 mm	461 g	220	n	Feb 2023	1,499	amazon.com
4.		Canon SL3	122 mm	93 mm	70 mm	449 g	1070	n	Apr 2019	599	amazon.com
5.		Canon T7	129 mm	101 mm	78 mm	475 g	500	n	Feb 2018	449	amazon.com
6.		Canon R	139 mm	98 mm	84 mm	660 g	370	Y	Sep 2018	2,299	ebay.com
7.		Canon SL2	122 mm	93 mm	70 mm	453 g	650	n	Jun 2017	549	ebay.com
8.		Canon M5	116 mm	89 mm	61 mm	427 g	295	n	Sep 2016	979	ebay.com
9.		Canon T6s	132 mm	101 mm	78 mm	565 g	440	n	Feb 2015	649	ebay.com
10.		Nikon D7100	136 mm	107 mm	76 mm	765 g	950	Y	Feb 2013	1,199	ebay.com
11.		Pentax KP	132 mm	101 mm	76 mm	703 g	390	Y	Jan 2017	1,099	ebay.com
12.		Pentax K-3 II	131 mm	100 mm	77 mm	800 g	720	Y	Apr 2015	1,099	ebay.com
13.		Pentax K-5 II	131 mm	97 mm	73 mm	760 g	740	Y	Sep 2012	1,099	ebay.com
14.		Sony RX1R	113 mm	65 mm	70 mm	482 g	270	n	Jun 2013	2,799	ebay.com
15.		Sony RX1	113 mm	65 mm	70 mm	482 g	270	n	Sep 2012	2,799	ebay.com
16.		Sony A77	143 mm	104 mm	81 mm	732 g	470	Y	Aug 2011	1,399	ebay.com
17.		Sony NEX-7	120 mm	67 mm	43 mm	400 g	430	n	Aug 2011	1,349	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 listed launch prices provide an indication of the market segment that the manufacturer of the cameras have been targeting. The two cameras under review were launched at the same price and fall into the same market segment. 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 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 tend to have larger individual pixels that provide better low-light sensitivity, wider dynamic range, and richer color-depth than smaller pixel-units 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 tend to be associated with larger, more expensive camera bodies and lenses.

Of the two cameras under consideration, the Canon RP features a full frame sensor and the Pentax K-3 an APS-C sensor. The sensor area in the K-3 is 57 percent smaller. As a result of these sensor size differences, the cameras have a format factor of, respectively, 1.0 and 1.5. Both cameras have a native aspect ratio (sensor width to sensor height) of 3:2.

With 26MP, the RP offers a slightly higher resolution than the K-3 (24.1MP), but the RP nevertheless has larger individual pixels (pixel pitch of 5.76μm versus 3.90μm for the K-3) due to its larger sensor. Moreover, the RP is a much more recent model (by 5 years and 4 months) than the K-3, and its sensor will have benefitted from technological advances during this time that further enhance the light gathering capacity of its pixels. Coming back to sensor resolution, it should be mentioned that the K-3 has no anti-alias filter installed, so that it can capture all the detail its sensor resolves.

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

The Canon EOS RP has a native sensitivity range from ISO 100 to ISO 40000, which can be extended to ISO 50-102400. The corresponding ISO settings for the Pentax K-3 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"). Of the two cameras under review, the RP has a notably higher overall DXO score than the K-3 (overall score 5 points higher), which gives it an advantage in terms of imaging quality. This advantage is based on 0.6 bits higher color depth, 1.5 EV of lower dynamic range, and 1.3 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 RP	Full Frame	26.0	6240	4160	4K/30p	24.3	11.9	2977	85
2.		Pentax K-3	APS-C	24.1	6016	4000	1080/60i	23.7	13.4	1216	80
3.		Canon R8	Full Frame	24.0	6000	4000	4k/60p	24.5	14.7	3295	93
4.		Canon SL3	APS-C	24.0	6000	4000	4K/25p	23.9	13.4	1791	82
5.		Canon T7	APS-C	24.0	6000	4000	1080/30p	23.8	13.3	1684	81
6.		Canon R	Full Frame	30.1	6720	4480	4K/30p	24.5	13.5	2742	89
7.		Canon SL2	APS-C	24.0	6000	4000	1080/60p	23.6	13.4	1041	79
8.		Canon M5	APS-C	24.0	6000	4000	1080/60p	23.4	12.4	1262	77
9.		Canon T6s	APS-C	24.0	6000	4000	1080/30p	22.6	12.0	915	70
10.		Nikon D7100	APS-C	24.0	6000	4000	1080/60p	24.2	13.7	1256	83
11.		Pentax KP	APS-C	24.1	6016	4000	1080/60i	23.9	13.2	1699	81
12.		Pentax K-3 II	APS-C	24.1	6016	4000	1080/60i	23.6	13.6	1106	80
13.		Pentax K-5 II	APS-C	16.1	4928	3264	1080/25p	23.8	14.1	1235	82
14.		Sony RX1R	Full Frame	24.0	6000	4000	1080/60p	25.0	13.6	2537	91
15.		Sony RX1	Full Frame	24.0	6000	4000	1080/60p	25.1	14.3	2534	93
16.		Sony A77	APS-C	24.0	6000	4000	1080/60p	24.0	13.2	801	78
17.		Sony NEX-7	APS-C	24.0	6000	4000	1080/60i	24.1	13.4	1016	81
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. Both cameras under consideration have a sensor with sufficiently fast read-out times for moving pictures, but the RP provides a higher video resolution than the K-3. It can shoot video footage at 4K/30p, while the Pentax is limited to 1080/60i.

Feature comparison

Beyond body and sensor, cameras can and do differ across a range of features. For example, the RP has an electronic viewfinder (2360k dots), while the K-3 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 viewfinders of both cameras offer the same field of view (100%), but the viewfinder of the RP has a higher magnification than the one of the K-3 (0.70x vs 0.63x), so that the size of the image transmitted appears closer to the size seen with the naked human eye. The table below summarizes some of the other core capabilities of the Canon RP and Pentax K-3 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 RP	2360	n	3.0 / 1040	swivel	Y	1/4000s	5.0/s	n	n
2.		Pentax K-3	optical	Y	3.2 / 1037	fixed	n	1/8000s	8.3/s	Y	Y
3.		Canon R8	2360	n	3.0 / 1620	swivel	Y	1/4000s	6.0/s	n	n
4.		Canon SL3	optical	n	3.0 / 1040	swivel	Y	1/4000s	5.0/s	Y	n
5.		Canon T7	optical	n	3.0 / 920	fixed	n	1/4000s	3.0/s	Y	n
6.		Canon R	3690	Y	3.2 / 2100	swivel	Y	1/8000s	8.0/s	n	n
7.		Canon SL2	optical	n	3.0 / 1040	swivel	Y	1/4000s	5.0/s	Y	n
8.		Canon M5	2360	n	3.2 / 1620	tilting	Y	1/4000s	9.0/s	Y	n
9.		Canon T6s	optical	Y	3.0 / 1040	swivel	Y	1/4000s	5.0/s	Y	n
10.		Nikon D7100	optical	Y	3.2 / 1229	fixed	n	1/8000s	6.0/s	Y	n
11.		Pentax KP	optical	n	3.0 / 921	tilting	n	1/6000s	7.0/s	Y	Y
12.		Pentax K-3 II	optical	Y	3.2 / 1037	fixed	n	1/8000s	8.3/s	n	Y
13.		Pentax K-5 II	optical	Y	3.0 / 921	fixed	n	1/8000s	7.0/s	Y	Y
14.		Sony RX1R	optional	n	3.0 / 1229	fixed	n	1/4000s	5.0/s	Y	n
15.		Sony RX1	optional	n	3.0 / 1229	fixed	n	1/4000s	5.0/s	Y	n
16.		Sony A77	2359	Y	3.0 / 921	full-flex	n	1/8000s	12.0/s	Y	Y
17.		Sony NEX-7	2359	n	3.0 / 921	tilting	n	1/4000s	10.0/s	Y	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 RP has a touchscreen, while the K-3 has a conventional panel. Touch control can be particularly helpful, for example, for setting the focus point.

The Canon RP and the Pentax K-3 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 RP and the K-3 write their files to SDXC cards. The K-3 features dual card slots, which can be very useful in case a memory card fails. In contrast, the RP only has one slot. The RP supports UHS-II cards (Ultra High Speed data transfer of up to 312 MB/s), while the K-3 can use UHS-I cards (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 RP and Pentax K-3 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 RP	Y	stereo / mono	Y	Y	micro	2.0	Y	-	Y
2.		Pentax K-3	Y	mono / mono	Y	Y	mini	3.0	-	-	-
3.		Canon R8	Y	stereo / mono	Y	Y	micro	3.2	Y	-	Y
4.		Canon SL3	Y	stereo / mono	Y	-	mini	2.0	Y	-	Y
5.		Canon T7	Y	mono / mono	-	-	mini	2.0	Y	Y	-
6.		Canon R	Y	stereo / mono	Y	Y	mini	3.1	Y	-	Y
7.		Canon SL2	Y	stereo / mono	Y	-	mini	2.0	Y	Y	Y
8.		Canon M5	Y	stereo / mono	Y	-	mini	2.0	Y	Y	Y
9.		Canon T6s	Y	stereo / mono	Y	-	mini	2.0	Y	Y	-
10.		Nikon D7100	Y	stereo / mono	Y	Y	mini	2.0	-	-	-
11.		Pentax KP	Y	stereo / mono	Y	-	-	2.0	Y	-	-
12.		Pentax K-3 II	Y	mono / mono	Y	Y	mini	3.0	-	-	-
13.		Pentax K-5 II	Y	stereo / mono	Y	-	mini	2.0	-	-	-
14.		Sony RX1R	Y	stereo / mono	Y	-	mini	2.0	-	-	-
15.		Sony RX1	Y	stereo / mono	Y	-	mini	2.0	-	-	-
16.		Sony A77	Y	stereo / mono	Y	-	mini	2.0	-	-	-
17.		Sony NEX-7	Y	stereo / mono	Y	-	mini	2.0	-	-	-

It is notable that the RP offers wifi support, while the K-3 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 (unlike the RP) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.

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

Review summary

So how do things add up? Is the Canon RP better than the Pentax K-3 or vice versa? Below is a summary of the relative strengths of each of the two contestants.

Reasons to prefer the Canon EOS RP:

• Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
• Better image quality: Scores markedly higher (5 points) in the DXO overall assessment.
• Better low-light sensitivity: Requires less light for good images (1.3 stops ISO advantage).
• Better video: Provides higher definition movie capture (4K/30p vs 1080/60i).
• 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 viewfinder image: Features a viewfinder with a higher magnification (0.70x vs 0.63x).
• 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 (133x85mm vs 131x100mm) and thus needs less room in the bag.
• Less heavy: Is lighter (by 315g or 39 percent) and hence easier to carry around.
• Easier travel charging: Can be conveniently charged via its USB port.
• More legacy lens friendly: Can take a broad range of non-native lenses via adapters.
• 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.
• Faster buffer clearing: Supports a more advanced SD data transfer standard (UHS-II vs UHS-I).
• More modern: Reflects 5 years and 4 months of technical progress since the K-3 launch.

Advantages of the Pentax K-3:

• Maximized detail: Lacks an anti-alias filter to exploit the sensor's full resolution potential.
• More dynamic range: Captures a broader range of light and dark details (1.5 EV of extra DR).
• Brighter framing: Features an optical viewfinder for clear, lag-free composition.
• 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.
• Longer lasting: Gets more shots (560 versus 250) out of a single battery charge.
• 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 fill-in: Has a small integrated flash to brighten shadows of backlit subjects.
• 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 October 2013).

If the count of individual advantages (bullet points above) is taken as a guide, the RP emerges as the winner of the contest (18 : 15 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 sports photographer will view the differences between cameras in a way that diverges from the perspective of a street photog, and a person interested in family portraits has distinct needs from a landscape 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 RP and the Pentax K-3 place the cameras among the top in their class? Find out in the latest Best Mirrorless Interchangeable Lens Camera and Best DSLR 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 RP or the K-3 perform in practice. 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 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 RP	4/5	+	4/5	..	4.5/5	4/5	Feb 2019	1,299	amazon.com
2.		Pentax K-3	4/5	..	..	83/100	5/5	5/5	Oct 2013	1,299	ebay.com
3.		Canon R8	4.5/5	+ +	4.5/5	87/100	4/5	4.5/5	Feb 2023	1,499	amazon.com
4.		Canon SL3	4/5	o	4.5/5	79/100	4/5	4/5	Apr 2019	599	amazon.com
5.		Canon T7	..	o	3.5/5	..	3.5/5	3.5/5	Feb 2018	449	amazon.com
6.		Canon R	4/5	o	4/5	79/100	4.5/5	4/5	Sep 2018	2,299	ebay.com
7.		Canon SL2	4/5	+ +	4/5	78/100	4.5/5	4.5/5	Jun 2017	549	ebay.com
8.		Canon M5	4/5	+	4/5	82/100	4/5	4/5	Sep 2016	979	ebay.com
9.		Canon T6s	5/5	+	..	77/100	4.5/5	4.5/5	Feb 2015	649	ebay.com
10.		Nikon D7100	5/5	+ +	..	85/100	4.5/5	4.5/5	Feb 2013	1,199	ebay.com
11.		Pentax KP	4/5	..	3/5	82/100	5/5	4.5/5	Jan 2017	1,099	ebay.com
12.		Pentax K-3 II	4.5/5	..	..	..	5/5	5/5	Apr 2015	1,099	ebay.com
13.		Pentax K-5 II	5/5	..	..	80/100	5/5	4.5/5	Sep 2012	1,099	ebay.com
14.		Sony RX1R	5/5	..	..	..	4/5	4.5/5	Jun 2013	2,799	ebay.com
15.		Sony RX1	5/5	..	..	79/100	4/5	4.5/5	Sep 2012	2,799	ebay.com
16.		Sony A77	5/5	91/100	..	81/100	..	5/5	Aug 2011	1,399	ebay.com
17.		Sony NEX-7	5/5	+ +	..	81/100	4.5/5	5/5	Aug 2011	1,349	ebay.com
Note: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.

The above review scores should be interpreted 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.

Check RP price at
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ebay.com

Other camera comparisons

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