Pentax K-1 vs K-3

The Pentax K-1 and the Pentax K-3 are two enthusiast cameras that were officially introduced, respectively, in February 2016 and October 2013. Both are DSLR (Digital Single Lens Reflex) cameras that are based on a full frame (K-1) and an APS-C (K-3) sensor. The K-1 has a resolution of 36.2 megapixels, whereas the K-3 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

Pentax K-1		Pentax K-3
Digital single lens reflex		Digital single lens reflex
Pentax K mount lenses		Pentax K mount lenses
36.2 MP – Full Frame sensor		24.1 MP – APS-C sensor
1080/60i Video		1080/60i Video
ISO 100-204,800		ISO 100-51,200
Optical viewfinder		Optical viewfinder
3.2" LCD – 1037k dots		3.2" LCD – 1037k dots
Fully flexible screen (no touchscreen)		Fixed screen (not touch-sensitive)
4.4 shutter flaps per second		8.3 shutter flaps per second
In-body stabilization		In-body stabilization
Weathersealed body		Weathersealed body
760 shots per battery charge		560 shots per battery charge
137 x 110 x 86 mm, 1010 g		131 x 100 x 77 mm, 800 g

Check K-1 offers at
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Check K-3 offers at
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Going beyond this snapshot of core features and characteristics, what are the differences between the Pentax K-1 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 Pentax K-1 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 consecutive perspectives from the front, the top, and the back are available. All size dimensions are rounded to the nearest millimeter.

Both cameras are available in two different colors (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 is notably smaller (13 percent) than the Pentax K-1. Moreover, the K-3 is markedly lighter (21 percent) than the K-1. In this context, it is worth noting that both cameras are splash and dust-proof and can, hence, be used in inclement weather conditions or harsh environments.

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.

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	Street Price
1.		Pentax K-1	137 mm	110 mm	86 mm	1010 g	760	Y	Feb 2016	US$ 1 799	ebay.com
2.		Pentax K-3	131 mm	100 mm	77 mm	800 g	560	Y	Oct 2013	US$ 1 299	ebay.com
3.		Canon 5D Mark IV	151 mm	116 mm	76 mm	890 g	900	Y	Aug 2016	US$ 3 499	amazon.com
4.		Canon 70D	139 mm	104 mm	79 mm	755 g	920	Y	Jul 2013	US$ 1 199	ebay.com
5.		Nikon D500	147 mm	115 mm	81 mm	860 g	1240	Y	Jan 2016	US$ 1 999	ebay.com
6.		Olympus E-M1 II	134 mm	91 mm	67 mm	574 g	440	Y	Sep 2016	US$ 1 999	ebay.com
7.		Pentax K-1 II	137 mm	110 mm	86 mm	1010 g	670	Y	Feb 2018	US$ 1 999	amazon.com
8.		Pentax K-3 II	131 mm	100 mm	77 mm	800 g	720	Y	Apr 2015	US$ 1 099	ebay.com
9.		Pentax K-5	131 mm	97 mm	73 mm	760 g	740	Y	Sep 2010	US$ 1 099	ebay.com
10.		Pentax K-5 II	131 mm	97 mm	73 mm	760 g	740	Y	Sep 2012	US$ 1 099	ebay.com
11.		Pentax KP	132 mm	101 mm	76 mm	703 g	390	Y	Jan 2017	US$ 1 099	ebay.com
12.		Sony A7R II	127 mm	96 mm	60 mm	625 g	290	Y	Jun 2015	US$ 3 199	ebay.com
13.		Sony A7R III	127 mm	96 mm	74 mm	650 g	650	Y	Oct 2017	US$ 3 199	ebay.com
14.		Sony A7R IIIA	127 mm	96 mm	74 mm	650 g	650	Y	Apr 2021	US$ 3 199	amazon.com
15.		Sony A99 II	143 mm	104 mm	76 mm	849 g	490	Y	Sep 2016	US$ 3 199	ebay.com
16.		Sony A850	156 mm	117 mm	82 mm	895 g	880	Y	Aug 2009	US$ 1 999	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

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 K-3 was launched at a markedly lower price (by 28 percent) than the K-1, which puts it into a different 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. Then, after the new model is out, very good deals can frequently be found on the pre-owned market.

Sensor comparison

The size of the imaging sensor is a crucial determinant 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 are more costly to manufacture and tend to lead to bigger and heavier cameras and lenses.

Of the two cameras under consideration, the Pentax K-1 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.

In terms of chip-set technology, the K-1 uses a more advanced image processing engine (PRIME IV) than the K-3 (PRIME III), with benefits for noise reduction, color accuracy, and processing speed.

With 36.2MP, the K-1 offers a higher resolution than the K-3 (24.1MP), but the K-1 nevertheless has larger individual pixels (pixel pitch of 4.88μm versus 3.90μm for the K-3) due to its larger sensor. Moreover, the K-1 is a much more recent model (by 2 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 neither of the two cameras has an anti-alias filter installed, so they are able to capture all the detail the sensor resolves.

The resolution advantage of the Pentax K-1 implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the K-1 for good quality output (200 dots per inch) amounts to 36.8 x 24.6 inches or 93.5 x 62.4 cm, for very good quality (250 dpi) 29.4 x 19.6 inches or 74.8 x 49.9 cm, and for excellent quality (300 dpi) 24.5 x 16.4 inches or 62.3 x 41.6 cm. The corresponding values for the Pentax K-3 are 30.1 x 20 inches or 76.4 x 50.8 cm for good quality, 24.1 x 16 inches or 61.1 x 40.6 cm for very good quality, and 20.1 x 13.3 inches or 50.9 x 33.9 cm for excellent quality prints.

Unlike the K-3, the K-1 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 Pentax K-1 has a native sensitivity range from ISO 100 to ISO 204800. 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.

Since 2007, DXO Mark has published sensor performance measurements that have been derived using a consistent methodology. 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 review, the K-1 provides substantially higher image quality than the K-3, with an overall score that is 16 points higher. This advantage is based on 1.7 bits higher color depth, 1.2 EV in additional dynamic range, and 1.4 stops in additional low light sensitivity. 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.		Pentax K-1	Full Frame	36.2	7360	4912	1080/60i	25.4	14.6	3280	96
2.		Pentax K-3	APS-C	24.1	6016	4000	1080/60i	23.7	13.4	1216	80
3.		Canon 5D Mark IV	Full Frame	30.1	6720	4480	4K/30p	24.8	13.6	2995	91
4.		Canon 70D	APS-C	20.0	5472	3648	1080/30p	22.5	11.6	926	68
5.		Nikon D500	APS-C	20.7	5568	3712	4K/30p	24.0	14.0	1324	83
6.		Olympus E-M1 II	Four Thirds	20.2	5184	3888	4K/30p	23.7	12.8	1312	80
7.		Pentax K-1 II	Full Frame	36.2	7360	4912	1080/60i	25.1	14.0	2698	93
8.		Pentax K-3 II	APS-C	24.1	6016	4000	1080/60i	23.6	13.6	1106	80
9.		Pentax K-5	APS-C	16.1	4928	3264	1080/25p	23.7	14.1	1162	82
10.		Pentax K-5 II	APS-C	16.1	4928	3264	1080/25p	23.8	14.1	1235	82
11.		Pentax KP	APS-C	24.1	6016	4000	1080/60i	23.9	13.2	1699	81
12.		Sony A7R II	Full Frame	42.2	7952	5304	4K/30p	26.0	13.9	3434	98
13.		Sony A7R III	Full Frame	42.2	7952	5304	4K/30p	26.0	14.7	3523	100
14.		Sony A7R IIIA	Full Frame	42.2	7952	5304	4K/30p	26.0	14.7	3523	100
15.		Sony A99 II	Full Frame	42.2	7952	5304	4K/30p	25.4	13.4	2317	92
16.		Sony A850	Full Frame	24.4	6048	4032	none	23.8	12.2	1415	79
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, and both provide the same movie specifications (1080/60i).

Feature comparison

Apart from body and sensor, cameras can and do differ across a variety of features. The K-1 and the K-3 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 (100%), but the viewfinder of the K-1 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 adjacent table lists some of the other core features of the Pentax K-1 and Pentax K-3 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.		Pentax K-1	optical	Y	3.2 / 1037	full-flex	n	1/8000s	4.4/s	n	Y
2.		Pentax K-3	optical	Y	3.2 / 1037	fixed	n	1/8000s	8.3/s	Y	Y
3.		Canon 5D Mark IV	optical	Y	3.2 / 1620	fixed	Y	1/8000s	7.0/s	n	n
4.		Canon 70D	optical	Y	3.0 / 1040	swivel	Y	1/8000s	7.0/s	Y	n
5.		Nikon D500	optical	Y	3.2 / 2359	tilting	Y	1/8000s	10.0/s	n	n
6.		Olympus E-M1 II	2360	n	3.0 / 1037	swivel	Y	1/8000s	18.0/s	n	Y
7.		Pentax K-1 II	optical	Y	3.2 / 1037	full-flex	n	1/8000s	4.4/s	n	Y
8.		Pentax K-3 II	optical	Y	3.2 / 1037	fixed	n	1/8000s	8.3/s	n	Y
9.		Pentax K-5	optical	Y	3.0 / 921	fixed	n	1/8000s	7.0/s	Y	Y
10.		Pentax K-5 II	optical	Y	3.0 / 921	fixed	n	1/8000s	7.0/s	Y	Y
11.		Pentax KP	optical	n	3.0 / 921	tilting	n	1/6000s	7.0/s	Y	Y
12.		Sony A7R II	2400	n	3.0 / 1229	tilting	n	1/8000s	5.0/s	n	Y
13.		Sony A7R III	3686	n	3.0 / 1440	tilting	Y	1/8000s	10.0/s	n	Y
14.		Sony A7R IIIA	3686	n	3.0 / 2340	tilting	Y	1/8000s	10.0/s	n	Y
15.		Sony A99 II	2400	Y	3.0 / 1229	full-flex	n	1/8000s	12.0/s	n	Y
16.		Sony A850	optical	Y	3.0 / 922	fixed	n	1/8000s	3.0/s	n	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 K-3 has one, while the K-1 does not. While the built-in flash of the K-3 is not very powerful, it can at times be useful as a fill-in light.

The Pentax K-1 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 K-1 and the K-3 write their files to SDXC cards. Both cameras feature dual card slots, which can be very useful in case a memory card fails. 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 Pentax K-1 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.		Pentax K-1	Y	stereo / mono	Y	Y	micro	2.0	Y	-	-
2.		Pentax K-3	Y	mono / mono	Y	Y	mini	3.0	-	-	-
3.		Canon 5D Mark IV	Y	mono / mono	Y	Y	mini	3.0	Y	Y	-
4.		Canon 70D	Y	stereo / mono	Y	-	mini	2.0	Y	-	-
5.		Nikon D500	Y	stereo / mono	Y	Y	mini	3.0	Y	Y	Y
6.		Olympus E-M1 II	Y	stereo / mono	Y	Y	micro	3.0	Y	-	-
7.		Pentax K-1 II	Y	stereo / mono	Y	Y	micro	2.0	Y	-	-
8.		Pentax K-3 II	Y	mono / mono	Y	Y	mini	3.0	-	-	-
9.		Pentax K-5	Y	stereo / mono	Y	-	mini	2.0	-	-	-
10.		Pentax K-5 II	Y	stereo / mono	Y	-	mini	2.0	-	-	-
11.		Pentax KP	Y	stereo / mono	Y	-	-	2.0	Y	-	-
12.		Sony A7R II	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
13.		Sony A7R III	Y	stereo / mono	Y	Y	micro	3.1	Y	Y	Y
14.		Sony A7R IIIA	Y	stereo / mono	Y	Y	micro	3.2	Y	Y	Y
15.		Sony A99 II	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	Y
16.		Sony A850	Y	- / -	-	-	mini	2.0	-	-	-

It is notable that the K-1 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.

Both cameras feature a PC Sync terminal to control professional strobe lights, which will be appreciated by studio photographers.

Travel and landscape photographers will find it useful that the K-1 has an internal geolocalization sensor and can record GPS coordinates in its EXIF data.

Both the K-1 and the K-3 have been discontinued, but can regularly be found used on ebay. The K-3 was replaced by the Pentax K-3 II, while the K-1 was followed by the Pentax K-1 II. Further information on the features and operation of the K-1 and K-3 can be found, respectively, in the Pentax K-1 Manual (free pdf) or the online Pentax K-3 Manual.

Review summary

So what is the bottom line? Is the Pentax K-1 better than the Pentax K-3 or vice versa? The listing below highlights the relative strengths of the two models.

Advantages of the Pentax K-1:

• More detail: Offers more megapixels (36.2 vs 24.1MP) with a 22% higher linear resolution.
• High quality composites: Can combine several shots after pixel-shifting its sensor.
• Better image quality: Scores substantially higher (16 points) in the DXO overall assessment.
• Richer colors: Generates images with noticeably better colors (1.7 bits more color depth).
• More dynamic range: Captures a larger spectrum of light and dark details (1.2 EV of extra DR).
• Better low-light sensitivity: Requires less light for good images (1.4 stops ISO advantage).
• Better jpgs: Has a more modern image processing engine (PRIME IV vs PRIME III).
• Larger viewfinder image: Features a viewfinder with a higher magnification (0.70x vs 0.63x).
• More flexible LCD: Has a full-flex screen for odd-angle shots in portrait or landscape orientation.
• Longer lasting: Can take more shots (760 versus 560) on a single battery charge.
• Easier geotagging: Features an internal GPS sensor to log localization data.
• Easier file upload: Has wifi built in for automatic backup or image transfer to the web.
• More modern: Reflects 2 years and 4 months of technical progress since the K-3 launch.

Arguments in favor of the Pentax K-3:

• Faster burst: Shoots at higher frequency (8.3 vs 4.4 flaps/sec) to capture the decisive moment.
• More compact: Is smaller (131x100mm vs 137x110mm) and will fit more readily into a bag.
• Less heavy: Has a lower weight (by 210g or 21 percent) and is thus easier to take along.
• 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).
• More affordable: Was introduced into a lower priced category (28 percent cheaper at launch).
• More heavily discounted: Has been around for much longer (launched in October 2013).

If the count of relative strengths (bullet points above) is taken as a measure, the K-1 is the clear winner of the match-up (13 : 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 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 Pentax K-1 and the Pentax K-3 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 K-1 or the K-3. 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	Street Price
1.		Pentax K-1	5/5	..	..	84/100	5/5	5/5	Feb 2016	US$ 1 799	ebay.com
2.		Pentax K-3	4/5	..	..	83/100	5/5	5/5	Oct 2013	US$ 1 299	ebay.com
3.		Canon 5D Mark IV	4.5/5	+ +	4/5	87/100	4.5/5	4.5/5	Aug 2016	US$ 3 499	amazon.com
4.		Canon 70D	5/5	+ +	..	83/100	4.5/5	5/5	Jul 2013	US$ 1 199	ebay.com
5.		Nikon D500	5/5	+ +	4.7/5	91/100	4.5/5	5/5	Jan 2016	US$ 1 999	ebay.com
6.		Olympus E-M1 II	5/5	+ +	5/5	85/100	4.5/5	4.5/5	Sep 2016	US$ 1 999	ebay.com
7.		Pentax K-1 II	..	..	4.5/5	79/100	4.5/5	4.5/5	Feb 2018	US$ 1 999	amazon.com
8.		Pentax K-3 II	4.5/5	..	..	..	5/5	5/5	Apr 2015	US$ 1 099	ebay.com
9.		Pentax K-5	4/5	..	..	83/100	5/5	4.5/5	Sep 2010	US$ 1 099	ebay.com
10.		Pentax K-5 II	5/5	..	..	80/100	5/5	4.5/5	Sep 2012	US$ 1 099	ebay.com
11.		Pentax KP	4/5	..	3/5	82/100	5/5	4.5/5	Jan 2017	US$ 1 099	ebay.com
12.		Sony A7R II	5/5	+ +	5/5	90/100	5/5	5/5	Jun 2015	US$ 3 199	ebay.com
13.		Sony A7R III	..	+ +	4/5	90/100	4.5/5	5/5	Oct 2017	US$ 3 199	ebay.com
14.		Sony A7R IIIA	..	+ +	4/5	90/100	4.5/5	5/5	Apr 2021	US$ 3 199	amazon.com
15.		Sony A99 II	..	..	4.5/5	85/100	4.5/5	4.5/5	Sep 2016	US$ 3 199	ebay.com
16.		Sony A850	3/5	..	..	75/100	..	4.5/5	Aug 2009	US$ 1 999	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. Thus, a score needs to be put into the context of the launch date and the launch price of the camera, 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.

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Other camera comparisons

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