Pentax K-1 II vs K-3 II

The Pentax K-1 II and the Pentax K-3 II are two enthusiast cameras that were announced, respectively, in February 2018 and April 2015. Both are DSLR (Digital Single Lens Reflex) cameras that are based on a full frame (K-1 II) and an APS-C (K-3 II) sensor. The K-1 II has a resolution of 36.2 megapixels, whereas the K-3 II 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 II		Pentax K-3 II
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 100-819,200		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
670 shots per battery charge		720 shots per battery charge
137 x 110 x 86 mm, 1010 g		131 x 100 x 77 mm, 800 g

Check K-1 II 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 Pentax K-1 II 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

An illustration of the physical size and weight of the Pentax K-1 II and the Pentax K-3 II 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 width, height and depth 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 II is notably smaller (13 percent) than the Pentax K-1 II. Moreover, the K-3 II is markedly lighter (21 percent) than the K-1 II. 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 adjacent table lists the principal physical characteristics of the two cameras alongside a wider set of alternatives. In case you want to display and compare another camera duo, you can use the CAM-parator app to select your camera combination among a large number of options.

Body Specifications

#		Camera Model	Camera Width	Camera Height	Camera Depth	Camera Weight	Battery Life	Weather Sealing	Camera Launch	Launch Price (USD)	Street Price
1.		Pentax K-1 II	137 mm	110 mm	86 mm	1010 g	670	Y	Feb 2018	1,999	amazon.com
2.		Pentax K-3 II	131 mm	100 mm	77 mm	800 g	720	Y	Apr 2015	1,099	ebay.com
3.		Fujifilm X-H1	140 mm	97 mm	86 mm	673 g	310	Y	Feb 2018	1,899	ebay.com
4.		Olympus E-5	142 mm	117 mm	75 mm	873 g	750	Y	Sep 2010	1,699	ebay.com
5.		Panasonic S1R	149 mm	110 mm	97 mm	1016 g	380	Y	Feb 2019	3,699	amazon.com
6.		Panasonic G9	137 mm	97 mm	92 mm	658 g	400	Y	Nov 2017	1,699	ebay.com
7.		Panasonic GH5	139 mm	98 mm	87 mm	725 g	410	Y	Jan 2017	1,999	ebay.com
8.		Pentax K-3 III	135 mm	104 mm	74 mm	820 g	800	Y	Mar 2021	1,999	amazon.com
9.		Pentax KP	132 mm	101 mm	76 mm	703 g	390	Y	Jan 2017	1,099	ebay.com
10.		Pentax K-1	137 mm	110 mm	86 mm	1010 g	760	Y	Feb 2016	1,799	ebay.com
11.		Pentax K-70	126 mm	93 mm	74 mm	688 g	410	Y	Jun 2016	649	ebay.com
12.		Pentax K-3	131 mm	100 mm	77 mm	800 g	560	Y	Oct 2013	1,299	ebay.com
13.		Pentax K-5	131 mm	97 mm	73 mm	760 g	740	Y	Sep 2010	1,099	ebay.com
14.		Sony A7R III	127 mm	96 mm	74 mm	650 g	650	Y	Oct 2017	3,199	ebay.com
15.		Sony RX10 IV	133 mm	94 mm	145 mm	1095 g	400	Y	Sep 2017	1,699	amazon.com
16.		Sony A99 II	143 mm	104 mm	76 mm	849 g	490	Y	Sep 2016	3,199	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 K-3 II was launched at a markedly lower price (by 45 percent) than the K-1 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 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. 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 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 II features a full frame sensor and the Pentax K-3 II an APS-C sensor. The sensor area in the K-3 II 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 II uses a more advanced image processing engine (PRIME IV) than the K-3 II (PRIME III), with benefits for noise reduction, color accuracy, and processing speed.

With 36.2MP, the K-1 II offers a higher resolution than the K-3 II (24.1MP), but the K-1 II nevertheless has larger individual pixels (pixel pitch of 4.88μm versus 3.90μm for the K-3 II) due to its larger sensor. Moreover, the K-1 II is a much more recent model (by 2 years and 10 months) than the K-3 II, 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 II implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the K-1 II 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 II 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.

Both cameras have the capacity to capture high quality composite images by combining multiple shots after shifting the 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 II has a native sensitivity range from ISO 100 to ISO 819200. 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.

Since 2007, DXO Mark has published sensor performance measurements that have been derived using a consistent methodology. 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 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.		Pentax K-1 II	Full Frame	36.2	7360	4912	1080/60i	25.1	14.0	2698	93
2.		Pentax K-3 II	APS-C	24.1	6016	4000	1080/60i	23.6	13.6	1106	80
3.		Fujifilm X-H1	APS-C	24.0	6000	4000	4K/30p	24.0	13.3	1806	82
4.		Olympus E-5	Four Thirds	12.2	4032	3024	720/30p	21.6	10.5	519	56
5.		Panasonic S1R	Full Frame	46.7	8368	5584	4K/60p	26.4	14.1	3525	100
6.		Panasonic G9	Four Thirds	20.2	5184	3888	4K/60p	23.1	12.8	1138	74
7.		Panasonic GH5	Four Thirds	20.2	5184	3888	4K/60p	23.9	13.0	807	77
8.		Pentax K-3 III	APS-C	25.6	6192	4128	4K/30p	24.2	13.7	2083	85
9.		Pentax KP	APS-C	24.1	6016	4000	1080/60i	23.9	13.2	1699	81
10.		Pentax K-1	Full Frame	36.2	7360	4912	1080/60i	25.4	14.6	3280	96
11.		Pentax K-70	APS-C	24.0	6000	4000	1080/60i	23.8	13.1	1639	80
12.		Pentax K-3	APS-C	24.1	6016	4000	1080/60i	23.7	13.4	1216	80
13.		Pentax K-5	APS-C	16.1	4928	3264	1080/25p	23.7	14.1	1162	82
14.		Sony A7R III	Full Frame	42.2	7952	5304	4K/30p	26.0	14.7	3523	100
15.		Sony RX10 IV	1-inch	20.0	5472	3648	4K/30p	22.0	12.2	408	63
16.		Sony A99 II	Full Frame	42.2	7952	5304	4K/30p	25.4	13.4	2317	92
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 also of capturing video footage. The two cameras under consideration both have sensors whose read-out speed is fast enough to capture moving pictures, and both provide the same movie specifications (1080/60i).

Feature comparison

Beyond body and sensor, cameras can and do differ across a range of features. The K-1 II 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 viewfinders of both cameras offer the same field of view (100%), but the viewfinder of the K-1 II has a higher magnification than the one of the K-3 II (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 II 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.		Pentax K-1 II	optical	Y	3.2 / 1037	full-flex	n	1/8000s	4.4/s	n	Y
2.		Pentax K-3 II	optical	Y	3.2 / 1037	fixed	n	1/8000s	8.3/s	n	Y
3.		Fujifilm X-H1	3690	Y	3.0 / 1040	full-flex	Y	1/8000s	14.0/s	n	Y
4.		Olympus E-5	optical	Y	3.0 / 920	swivel	n	1/8000s	5.0/s	Y	Y
5.		Panasonic S1R	5760	Y	3.2 / 2100	full-flex	Y	1/8000s	9.0/s	n	Y
6.		Panasonic G9	3680	Y	3.0 / 1040	swivel	Y	1/8000s	20.0/s	n	Y
7.		Panasonic GH5	3680	n	3.2 / 1620	swivel	Y	1/8000s	12.0/s	n	Y
8.		Pentax K-3 III	optical	Y	3.2 / 1620	fixed	Y	1/8000s	12.0/s	n	Y
9.		Pentax KP	optical	n	3.0 / 921	tilting	n	1/6000s	7.0/s	Y	Y
10.		Pentax K-1	optical	Y	3.2 / 1037	full-flex	n	1/8000s	4.4/s	n	Y
11.		Pentax K-70	optical	n	3.0 / 921	swivel	n	1/6000s	6.0/s	Y	Y
12.		Pentax K-3	optical	Y	3.2 / 1037	fixed	n	1/8000s	8.3/s	Y	Y
13.		Pentax K-5	optical	Y	3.0 / 921	fixed	n	1/8000s	7.0/s	Y	Y
14.		Sony A7R III	3686	n	3.0 / 1440	tilting	Y	1/8000s	10.0/s	n	Y
15.		Sony RX10 IV	2359	Y	3.0 / 1440	tilting	Y	1/2000s	24.0/s	Y	Y
16.		Sony A99 II	2400	Y	3.0 / 1229	full-flex	n	1/8000s	12.0/s	n	Y
Note: *) Information refers to the mechanical shutter, unless the camera only has an electronic one.

The Pentax K-1 II 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 K-1 II and the K-3 II 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 II 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.		Pentax K-1 II	Y	stereo / mono	Y	Y	micro	2.0	Y	-	-
2.		Pentax K-3 II	Y	mono / mono	Y	Y	mini	3.0	-	-	-
3.		Fujifilm X-H1	Y	stereo / mono	Y	-	micro	3.0	Y	-	-
4.		Olympus E-5	Y	stereo / -	-	-	mini	2.0	-	-	-
5.		Panasonic S1R	Y	stereo / mono	Y	Y	full	3.1	Y	-	Y
6.		Panasonic G9	Y	stereo / mono	Y	Y	full	3.0	Y	-	Y
7.		Panasonic GH5	Y	stereo / mono	Y	Y	full	3.1	Y	-	Y
8.		Pentax K-3 III	Y	stereo / mono	Y	Y	micro	3.2	Y	-	Y
9.		Pentax KP	Y	stereo / mono	Y	-	-	2.0	Y	-	-
10.		Pentax K-1	Y	stereo / mono	Y	Y	micro	2.0	Y	-	-
11.		Pentax K-70	Y	stereo / mono	Y	-	mini	2.0	Y	-	-
12.		Pentax K-3	Y	mono / mono	Y	Y	mini	3.0	-	-	-
13.		Pentax K-5	Y	stereo / mono	Y	-	mini	2.0	-	-	-
14.		Sony A7R III	Y	stereo / mono	Y	Y	micro	3.1	Y	Y	Y
15.		Sony RX10 IV	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
16.		Sony A99 II	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	Y

It is notable that the K-1 II 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.

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 both cameras feature internal geolocalization sensors and can record GPS coordinates in their EXIF data.

The K-1 II is a recent model that features in the current product line-up of Pentax. 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 K-1 II and K-3 II can be found, respectively, in the Pentax K-1 II Manual (free pdf) or the online Pentax K-3 II Manual.

Review summary

So how do things add up? Is there a clear favorite between the Pentax K-1 II and the Pentax K-3 II? Which camera is better? The listing below highlights the relative strengths of the two models.

Arguments in favor of the Pentax K-1 II:

• More detail: Offers more megapixels (36.2 vs 24.1MP) with a 22% 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.
• 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.
• Easier file upload: Has wifi built in for automatic backup or image transfer to the web.
• More modern: Reflects 2 years and 10 months of technical progress since the K-3 II launch.

Advantages of the Pentax K-3 II:

• 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.
• Faster data transfer: Supports a more advanced USB protocol (3.0 vs 2.0).
• More affordable: Was introduced into a lower priced category (45 percent cheaper at launch).
• More heavily discounted: Has been around for much longer (launched in April 2015).

If the count of relative strengths (bullet points above) is taken as a measure, the K-1 II is the clear winner of the match-up (10 : 6 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 II 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 comparison of the spec-sheets of cameras can offer a general idea of their imaging potential, it remains incomplete and does no justice, for example, to the way the K-1 II or the K-3 II 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 where reviews by experts come in. 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.		Pentax K-1 II	..	..	4.5/5	79/100	4.5/5	4.5/5	Feb 2018	1,999	amazon.com
2.		Pentax K-3 II	4.5/5	..	..	..	5/5	5/5	Apr 2015	1,099	ebay.com
3.		Fujifilm X-H1	..	+	5/5	86/100	4.5/5	4.5/5	Feb 2018	1,899	ebay.com
4.		Olympus E-5	4/5	..	..	75/100	4/5	4.5/5	Sep 2010	1,699	ebay.com
5.		Panasonic S1R	4.5/5	..	4.6/5	89/100	4.5/5	4.5/5	Feb 2019	3,699	amazon.com
6.		Panasonic G9	..	+ +	5/5	85/100	5/5	5/5	Nov 2017	1,699	ebay.com
7.		Panasonic GH5	4.5/5	+ +	..	85/100	4.5/5	5/5	Jan 2017	1,999	ebay.com
8.		Pentax K-3 III	4/5	..	3/5	..	4.5/5	..	Mar 2021	1,999	amazon.com
9.		Pentax KP	4/5	..	3/5	82/100	5/5	4.5/5	Jan 2017	1,099	ebay.com
10.		Pentax K-1	5/5	..	..	84/100	5/5	5/5	Feb 2016	1,799	ebay.com
11.		Pentax K-70	4.5/5	..	4/5	79/100	4.5/5	4.5/5	Jun 2016	649	ebay.com
12.		Pentax K-3	4/5	..	..	83/100	5/5	5/5	Oct 2013	1,299	ebay.com
13.		Pentax K-5	4/5	..	..	83/100	5/5	4.5/5	Sep 2010	1,099	ebay.com
14.		Sony A7R III	..	+ +	4/5	90/100	4.5/5	5/5	Oct 2017	3,199	ebay.com
15.		Sony RX10 IV	5/5	+	3.5/5	84/100	4.5/5	5/5	Sep 2017	1,699	amazon.com
16.		Sony A99 II	..	..	4.5/5	85/100	4.5/5	4.5/5	Sep 2016	3,199	ebay.com
Note: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.

The above review scores should be interpreted with care, though. The ratings were established in reference to similarly priced cameras that were available in the market at the time of the review. 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. Also, please note that some of the review sites have changed their methodology and reporting over time.

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Other camera comparisons

Did this review help to inform your camera decision process? In case you would like to check on the differences and similarities of other camera models, just use the search menu below. 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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