Nikon D810 vs Pentax K-3 II

The Nikon D810 and the Pentax K-3 II are two digital cameras that were revealed to the public, respectively, in June 2014 and April 2015. Both are DSLR (Digital Single Lens Reflex) cameras that are based on a full frame (D810) and an APS-C (K-3 II) sensor. The Nikon has a resolution of 36.2 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

Nikon D810		Pentax K-3 II
Digital single lens reflex		Digital single lens reflex
Nikon F mount lenses		Pentax K mount lenses
36.2 MP – Full Frame sensor		24.1 MP – APS-C sensor
1080/60p Video		1080/60i Video
ISO 64-12,800 (32 - 51,200)		ISO 100-51,200
Optical viewfinder		Optical viewfinder
3.2" LCD – 1229k dots		3.2" LCD – 1037k dots
Fixed screen (not touch-sensitive)		Fixed screen (not touch-sensitive)
5 shutter flaps per second		8.3 shutter flaps per second
Lens stabilization only		In-body stabilization
Weathersealed body		Weathersealed body
1200 shots per battery charge		720 shots per battery charge
146 x 123 x 82 mm, 980 g		131 x 100 x 77 mm, 800 g

Check D810 offers at
ebay.com
Check K-3 II offers at
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Going beyond this snapshot of core features and characteristics, what are the differences between the Nikon D810 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 Nikon D810 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 measures are rounded to the nearest millimeter.

The K-3 II can be obtained in two different colors (black, silver), while the D810 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 II is notably smaller (27 percent) than the Nikon D810. Moreover, the K-3 II is markedly lighter (18 percent) than the D810. 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.

Concerning battery life, the D810 gets 1200 shots out of its Nikon EN-EL15 battery, while the K-3 II can take 720 images on a single charge of its Pentax D-LI90 power pack.

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.		Nikon D810	146 mm	123 mm	82 mm	980 g	1200	Y	Jun 2014	3,299	ebay.com
2.		Pentax K-3 II	131 mm	100 mm	77 mm	800 g	720	Y	Apr 2015	1,099	ebay.com
3.		Canon 5DS	152 mm	116 mm	76 mm	930 g	700	Y	Feb 2015	3,699	ebay.com
4.		Nikon D4S	160 mm	157 mm	91 mm	1350 g	3020	Y	Feb 2014	6,499	ebay.com
5.		Nikon D600	141 mm	113 mm	82 mm	850 g	900	Y	Sep 2012	2,099	ebay.com
6.		Nikon D610	141 mm	113 mm	82 mm	850 g	900	Y	Oct 2013	1,999	ebay.com
7.		Nikon D700	147 mm	123 mm	77 mm	1074 g	1000	Y	Jul 2008	2,999	ebay.com
8.		Nikon D750	141 mm	113 mm	78 mm	750 g	1230	Y	Sep 2014	2,299	ebay.com
9.		Nikon D800	146 mm	123 mm	82 mm	1000 g	900	Y	Feb 2012	2,999	ebay.com
10.		Nikon D800E	146 mm	123 mm	82 mm	1000 g	900	Y	Feb 2012	3,299	ebay.com
11.		Nikon D850	146 mm	124 mm	79 mm	1005 g	1840	Y	Jul 2017	3,299	amazon.com
12.		Nikon D7200	136 mm	107 mm	76 mm	765 g	1110	Y	Mar 2015	1,199	ebay.com
13.		Nikon Df	144 mm	110 mm	67 mm	760 g	1400	Y	Nov 2013	2,749	ebay.com
14.		Pentax K-3	131 mm	100 mm	77 mm	800 g	560	Y	Oct 2013	1,299	ebay.com
15.		Pentax K-3 III	135 mm	104 mm	74 mm	820 g	800	Y	Mar 2021	1,999	amazon.com
16.		Pentax K-5 II	131 mm	97 mm	73 mm	760 g	740	Y	Sep 2012	1,099	ebay.com
17.		Pentax K-S2	123 mm	91 mm	73 mm	678 g	410	Y	Feb 2015	749	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

The price is, of course, an important factor in any camera decision. 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 67 percent) than the D810, 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. 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 sensor inside a digital camera is one of the key determinants 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. 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 more expensive and lead to bigger and heavier cameras and lenses.

Of the two cameras under consideration, the Nikon D810 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.

With 36.2MP, the D810 offers a higher resolution than the K-3 II (24.1MP), but the D810 nevertheless has larger individual pixels (pixel pitch of 4.88μm versus 3.90μm for the K-3 II) due to its larger sensor. However, the K-3 II is a somewhat more recent model (by 9 months) than the D810, and its sensor might have benefitted from technological advances during this time that 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 Nikon D810 implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the D810 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.

Unlike the D810, 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 Nikon D810 has a native sensitivity range from ISO 64 to ISO 12800, which can be extended to ISO 32-51200. 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.

For many cameras, data on sensor performance has been reported by DXO Mark. 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 D810 provides substantially higher image quality than the K-3 II, with an overall score that is 17 points higher. This advantage is based on 2.1 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.		Nikon D810	Full Frame	36.2	7360	4912	1080/60p	25.7	14.8	2853	97
2.		Pentax K-3 II	APS-C	24.1	6016	4000	1080/60i	23.6	13.6	1106	80
3.		Canon 5DS	Full Frame	50.3	8688	5792	1080/30p	24.7	12.4	2381	87
4.		Nikon D4S	Full Frame	16.2	4928	3280	1080/60p	24.4	13.3	3074	89
5.		Nikon D600	Full Frame	24.2	6016	4016	1080/30p	25.1	14.2	2980	94
6.		Nikon D610	Full Frame	24.2	6016	4016	1080/30p	25.1	14.4	2925	94
7.		Nikon D700	Full Frame	12.1	4256	2832	none	23.5	12.2	2303	80
8.		Nikon D750	Full Frame	24.2	6016	4016	1080/60p	24.8	14.5	2956	93
9.		Nikon D800	Full Frame	36.2	7360	4912	1080/30p	25.3	14.4	2853	95
10.		Nikon D800E	Full Frame	36.2	7360	4912	1080/30p	25.6	14.3	2979	96
11.		Nikon D850	Full Frame	45.4	8256	5504	4K/30p	26.4	14.8	2660	100
12.		Nikon D7200	APS-C	24.0	6000	4000	1080/60p	24.5	14.6	1333	87
13.		Nikon Df	Full Frame	16.2	4928	3280	none	24.6	13.1	3279	89
14.		Pentax K-3	APS-C	24.1	6016	4000	1080/60i	23.7	13.4	1216	80
15.		Pentax K-3 III	APS-C	25.6	6192	4128	4K/30p	24.2	13.7	2083	85
16.		Pentax K-5 II	APS-C	16.1	4928	3264	1080/25p	23.8	14.1	1235	82
17.		Pentax K-S2	APS-C	20.0	5472	3648	1080/30p	23.6	12.9	1514	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 also of capturing video footage. Both cameras under consideration have a sensor with sufficiently fast read-out times for moving pictures, but the D810 provides a higher frame rate than the K-3 II. It can shoot video footage at 1080/60p, while the Pentax is limited to 1080/60i.

Feature comparison

Beyond body and sensor, cameras can and do differ across a range of features. The D810 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 D810 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 table below summarizes some of the other core capabilities of the Nikon D810 and Pentax K-3 II 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.		Nikon D810	optical	Y	3.2 / 1229	fixed	n	1/8000s	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 5DS	optical	Y	3.2 / 1040	fixed	n	1/8000s	5.0/s	n	n
4.		Nikon D4S	optical	Y	3.2 / 921	fixed	n	1/8000s	11.0/s	n	n
5.		Nikon D600	optical	Y	3.0 / 921	fixed	n	1/4000s	5.5/s	Y	n
6.		Nikon D610	optical	Y	3.2 / 921	fixed	n	1/4000s	6.0/s	Y	n
7.		Nikon D700	optical	Y	3.0 / 922	fixed	n	1/8000s	8.0/s	Y	n
8.		Nikon D750	optical	Y	3.2 / 1229	tilting	n	1/4000s	6.0/s	Y	n
9.		Nikon D800	optical	Y	3.2 / 921	fixed	n	1/8000s	4.0/s	Y	n
10.		Nikon D800E	optical	Y	3.2 / 921	fixed	n	1/8000s	4.0/s	Y	n
11.		Nikon D850	optical	Y	3.2 / 2359	tilting	Y	1/8000s	9.0/s	n	n
12.		Nikon D7200	optical	Y	3.2 / 1229	fixed	n	1/8000s	6.0/s	Y	n
13.		Nikon Df	optical	Y	3.2 / 921	fixed	n	1/4000s	5.5/s	n	n
14.		Pentax K-3	optical	Y	3.2 / 1037	fixed	n	1/8000s	8.3/s	Y	Y
15.		Pentax K-3 III	optical	Y	3.2 / 1620	fixed	Y	1/8000s	12.0/s	n	Y
16.		Pentax K-5 II	optical	Y	3.0 / 921	fixed	n	1/8000s	7.0/s	Y	Y
17.		Pentax K-S2	optical	n	3.0 / 921	swivel	n	1/6000s	5.4/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 D810 has one, while the K-3 II does not. While the built-in flash of the D810 is not very powerful, it can at times be useful as a fill-in light.

The Nikon D810 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.

The D810 writes its imaging data to Compact Flash or SDXC cards, while the K-3 II uses 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 Nikon D810 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.		Nikon D810	Y	stereo / mono	Y	Y	mini	3.0	Y	-	-
2.		Pentax K-3 II	Y	mono / mono	Y	Y	mini	3.0	-	-	-
3.		Canon 5DS	Y	mono / mono	Y	-	mini	3.0	-	-	-
4.		Nikon D4S	Y	mono / mono	Y	Y	mini	2.0	-	-	-
5.		Nikon D600	Y	mono / mono	Y	Y	mini	2.0	-	-	-
6.		Nikon D610	Y	mono / mono	Y	Y	mini	2.0	-	-	-
7.		Nikon D700	Y	- / -	-	-	mini	2.0	-	-	-
8.		Nikon D750	Y	stereo / mono	Y	Y	mini	2.0	Y	-	-
9.		Nikon D800	Y	mono / mono	Y	Y	mini	3.0	-	-	-
10.		Nikon D800E	Y	mono / mono	Y	Y	mini	3.0	-	-	-
11.		Nikon D850	Y	stereo / mono	Y	Y	mini	3.0	Y	Y	Y
12.		Nikon D7200	Y	stereo / mono	Y	Y	mini	2.0	Y	Y	-
13.		Nikon Df	Y	- / -	-	-	mini	2.0	-	-	-
14.		Pentax K-3	Y	mono / mono	Y	Y	mini	3.0	-	-	-
15.		Pentax K-3 III	Y	stereo / mono	Y	Y	micro	3.2	Y	-	Y
16.		Pentax K-5 II	Y	stereo / mono	Y	-	mini	2.0	-	-	-
17.		Pentax K-S2	Y	mono / mono	Y	-	micro	2.0	Y	Y	-

It is notable that the D810 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 the K-3 II has an internal geolocalization sensor and can record GPS coordinates in its EXIF data.

Both the D810 and the K-3 II have been discontinued, but can regularly be found used on ebay. The D810 was replaced by the Nikon D850, while the K-3 II was followed by the Pentax K-3 III. Further information on the features and operation of the D810 and K-3 II can be found, respectively, in the Nikon D810 Manual (free pdf) or the online Pentax K-3 II Manual.

Review summary

So what is the bottom line? Is there a clear favorite between the Nikon D810 and the Pentax K-3 II? Which camera is better? The listing below highlights the relative strengths of the two models.

Reasons to prefer the Nikon D810:

• More detail: Offers more megapixels (36.2 vs 24.1MP) with a 22% higher linear resolution.
• Better image quality: Scores substantially higher (17 points) in the DXO overall assessment.
• Richer colors: Generates images with noticeably better colors (2.1 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 video: Provides higher movie framerates (1080/60p versus 1080/60i).
• Larger viewfinder image: Features a viewfinder with a higher magnification (0.70x vs 0.63x).
• More detailed LCD: Has a higher resolution rear screen (1229k vs 1037k dots).
• Longer lasting: Can take more shots (1200 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.
• More heavily discounted: Has been on the market for longer (launched in June 2014).

Advantages of the Pentax K-3 II:

• High quality composites: Can combine several shots after pixel-shifting its sensor.
• Faster burst: Shoots at higher frequency (8.3 vs 5 flaps/sec) to capture the decisive moment.
• More compact: Is smaller (131x100mm vs 146x123mm) and will fit more readily into a bag.
• Less heavy: Has a lower weight (by 180g or 18 percent) and is thus easier to take along.
• 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.
• More affordable: Was introduced into a lower priced category (67 percent cheaper at launch).
• More modern: Was introduced somewhat (9 months) more recently.

If the number of relative strengths (bullet points above) is taken as a guide, the D810 is the clear winner of the match-up (12 : 8 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 Nikon D810 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 technical specifications can provide a useful overview of the capabilities of different cameras, it remains partial and cannot reveal, for example, the shooting experience and imaging performance when actually working with the D810 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 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 (USD)	Street Price
1.		Nikon D810	5/5	..	5/5	86/100	5/5	4.5/5	Jun 2014	3,299	ebay.com
2.		Pentax K-3 II	4.5/5	..	..	..	5/5	5/5	Apr 2015	1,099	ebay.com
3.		Canon 5DS	..	+	..	83/100	4.5/5	4.5/5	Feb 2015	3,699	ebay.com
4.		Nikon D4S	5/5	..	..	..	4.5/5	4.5/5	Feb 2014	6,499	ebay.com
5.		Nikon D600	4/5	+ +	..	87/100	5/5	4.5/5	Sep 2012	2,099	ebay.com
6.		Nikon D610	4/5	+ +	..	87/100	4.5/5	4.5/5	Oct 2013	1,999	ebay.com
7.		Nikon D700	..	89/100	..	+ +	4.5/5	4.5/5	Jul 2008	2,999	ebay.com
8.		Nikon D750	5/5	+ +	4/5	90/100	4.5/5	4.5/5	Sep 2014	2,299	ebay.com
9.		Nikon D800	5/5	+ +	..	82/100	5/5	5/5	Feb 2012	2,999	ebay.com
10.		Nikon D800E	..	..	..	84/100	5/5	5/5	Feb 2012	3,299	ebay.com
11.		Nikon D850	4.5/5	+ +	5/5	89/100	4.5/5	5/5	Jul 2017	3,299	amazon.com
12.		Nikon D7200	4/5	+ +	..	84/100	4.5/5	4.5/5	Mar 2015	1,199	ebay.com
13.		Nikon Df	4/5	..	..	81/100	4/5	4/5	Nov 2013	2,749	ebay.com
14.		Pentax K-3	4/5	..	..	83/100	5/5	5/5	Oct 2013	1,299	ebay.com
15.		Pentax K-3 III	4/5	..	3/5	..	4.5/5	..	Mar 2021	1,999	amazon.com
16.		Pentax K-5 II	5/5	..	..	80/100	5/5	4.5/5	Sep 2012	1,099	ebay.com
17.		Pentax K-S2	4.5/5	..	..	..	5/5	4.5/5	Feb 2015	749	ebay.com
Note: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.

The review scores listed above should be treated 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 rating-comparisons among cameras that span long time periods or concern very differently equipped models make little sense. Also, kindly note that some of the listed sites have over time developped their review approaches and their reporting style.

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Other camera comparisons

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