Nikon D6 vs Pentax 645Z

The Nikon D6 and the Pentax 645Z are two professional cameras that were officially introduced, respectively, in February 2020 and April 2014. Both are DSLR (Digital Single Lens Reflex) cameras that are based on a full frame (D6) and a medium format (645Z) sensor. The Nikon has a resolution of 20.7 megapixels, whereas the Pentax provides 51.1 MP.

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

Headline Specifications

Nikon D6		Pentax 645Z
Digital single lens reflex		Digital single lens reflex
Nikon F mount lenses		Pentax 645 mount lenses
20.7 MP – Full Frame sensor		51.1 MP – Medium Format sensor
4K/30p Video		1080/60i Video
ISO 100-102,400 (50 - 3,280,000)		ISO 100-204,800
Optical viewfinder		Optical viewfinder
3.2" LCD – 2359k dots		3.2" LCD – 1037k dots
Fixed touchscreen		Tilting screen (no touchscreen)
14 shutter flaps per second		3 shutter flaps per second
Weathersealed body		Weathersealed body
3580 shots per battery charge		650 shots per battery charge
160 x 163 x 92 mm, 1270 g		156 x 117 x 123 mm, 1550 g

Check D6 price at
amazon.com
Check 645Z offers at
ebay.com

Going beyond this snapshot of core features and characteristics, what are the differences between the Nikon D6 and the Pentax 645Z? 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 D6 and the Pentax 645Z is provided in the side-by-side display below. The two cameras are presented according to their relative size. Three consecutive views from the front, the top, and the rear side are shown. All size dimensions are rounded to the nearest millimeter.

If the front view area (width x height) of the cameras is taken as an aggregate measure of their size, the Pentax 645Z is considerably smaller (30 percent) than the Nikon D6. However, the 645Z is markedly heavier (22 percent) than the D6. 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 D6 gets 3580 shots out of its Nikon EN-EL18c battery, while the 645Z can take 650 images on a single charge of its Pentax D-LI90 power pack. As can be seen in the images above, the D6 has a battery grip built in. This facilitates image-taking in portrait orientation and gives it additional battery power.

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.		Nikon D6	160 mm	163 mm	92 mm	1270 g	3580	Y	Feb 2020	6,499	amazon.com
2.		Pentax 645Z	156 mm	117 mm	123 mm	1550 g	650	Y	Apr 2014	8,499	ebay.com
3.		Canon 1D X Mark II	158 mm	168 mm	83 mm	1530 g	1210	Y	Feb 2016	5,999	ebay.com
4.		Canon 1D X Mark III	158 mm	168 mm	83 mm	1440 g	2850	Y	Jan 2020	6,499	amazon.com
5.		Canon 5DS	152 mm	116 mm	76 mm	930 g	700	Y	Feb 2015	3,699	ebay.com
6.		Canon 5DS R	152 mm	116 mm	76 mm	930 g	700	Y	Feb 2015	3,699	ebay.com
7.		Hasselblad X1D	150 mm	98 mm	71 mm	725 g	..	Y	Jun 2016	8,995	ebay.com
8.		Leica SL	147 mm	104 mm	39 mm	847 g	400	Y	Oct 2015	7,450	ebay.com
9.		Nikon D3X	160 mm	157 mm	88 mm	1260 g	4400	Y	Dec 2008	7,999	ebay.com
10.		Nikon D4	160 mm	157 mm	91 mm	1340 g	2600	Y	Jan 2012	5,999	ebay.com
11.		Nikon D4S	160 mm	157 mm	91 mm	1350 g	3020	Y	Feb 2014	6,499	ebay.com
12.		Nikon D5	160 mm	159 mm	92 mm	1415 g	3780	Y	Jan 2016	6,499	ebay.com
13.		Nikon D600	141 mm	113 mm	82 mm	850 g	900	Y	Sep 2012	2,099	ebay.com
14.		Nikon D610	141 mm	113 mm	82 mm	850 g	900	Y	Oct 2013	1,999	ebay.com
15.		Nikon D750	141 mm	113 mm	78 mm	750 g	1230	Y	Sep 2014	2,299	ebay.com
16.		Nikon D780	144 mm	116 mm	76 mm	840 g	2260	Y	Jan 2020	2,299	amazon.com
17.		Pentax 645D	156 mm	117 mm	119 mm	1480 g	800	Y	Mar 2010	9,995	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 manufacturer’s suggested retail prices give an idea on the placement of the camera in the maker’s lineup and the broader market. The D6 was launched at a somewhat lower price (by 24 percent) than the 645Z, which makes it more attractive for photographers on a tight budget. 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. 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 tend to be associated with larger, more expensive camera bodies and lenses.

Of the two cameras under consideration, the Nikon D6 features a full frame sensor and the Pentax 645Z a medium format sensor. The sensor area in the 645Z is 67 percent bigger. As a result of these sensor size differences, the cameras have a format factor of, respectively, 1.0 and 0.79. The sensor in the D6 has a native 3:2 aspect ratio, while the one in the 645Z offers a 4:3 aspect.

With 51.1MP, the 645Z offers a higher resolution than the D6 (20.7MP), but the 645Z has smaller individual pixels (pixel pitch of 5.30μm versus 6.44μm for the D6). Yet, the D6 is a much more recent model (by 5 years and 9 months) than the 645Z, and its sensor will have benefitted from technological advances during this time that further enhance the light gathering capacity of its pixel-units. Coming back to sensor resolution, it should be mentioned that the 645Z has no anti-alias filter installed, so that it can capture all the detail its sensor resolves.

The resolution advantage of the Pentax 645Z implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the 645Z for good quality output (200 dots per inch) amounts to 41.3 x 31 inches or 104.9 x 78.6 cm, for very good quality (250 dpi) 33 x 24.8 inches or 83.9 x 62.9 cm, and for excellent quality (300 dpi) 27.5 x 20.6 inches or 69.9 x 52.4 cm. The corresponding values for the Nikon D6 are 27.8 x 18.6 inches or 70.7 x 47.1 cm for good quality, 22.3 x 14.8 inches or 56.6 x 37.7 cm for very good quality, and 18.6 x 12.4 inches or 47.1 x 31.4 cm for excellent quality prints.

The Nikon D6 has a native sensitivity range from ISO 100 to ISO 102400, which can be extended to ISO 50-3280000. The corresponding ISO settings for the Pentax 645Z are ISO 100 to ISO 204800 (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 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.		Nikon D6	Full Frame	20.7	5568	3712	4K/30p	25.3	14.3	2886	95
2.		Pentax 645Z	Medium Format	51.1	8256	6192	1080/60i	26.0	14.7	4505	101
3.		Canon 1D X Mark II	Full Frame	20.0	5472	3648	4K/60p	24.1	13.5	3207	88
4.		Canon 1D X Mark III	Full Frame	20.0	5472	3648	4K/60p	24.2	14.5	3248	91
5.		Canon 5DS	Full Frame	50.3	8688	5792	1080/30p	24.7	12.4	2381	87
6.		Canon 5DS R	Full Frame	50.3	8688	5792	1080/30p	24.6	12.4	2308	86
7.		Hasselblad X1D	Medium Format	51.3	8272	6200	1080/25p	26.2	14.8	4489	102
8.		Leica SL	Full Frame	24.0	6000	4000	4K/30p	25.0	13.4	1821	88
9.		Nikon D3X	Full Frame	24.4	6048	4032	none	24.7	13.7	1992	88
10.		Nikon D4	Full Frame	16.2	4928	3280	1080/30p	24.7	13.1	2965	89
11.		Nikon D4S	Full Frame	16.2	4928	3280	1080/60p	24.4	13.3	3074	89
12.		Nikon D5	Full Frame	20.7	5588	3712	4K/30p	25.1	12.3	2343	88
13.		Nikon D600	Full Frame	24.2	6016	4016	1080/30p	25.1	14.2	2980	94
14.		Nikon D610	Full Frame	24.2	6016	4016	1080/30p	25.1	14.4	2925	94
15.		Nikon D750	Full Frame	24.2	6016	4016	1080/60p	24.8	14.5	2956	93
16.		Nikon D780	Full Frame	24.3	6048	4024	4K/30p	25.3	14.3	2877	95
17.		Pentax 645D	Medium Format	39.5	7264	5440	none	24.6	12.6	1262	82
Note: DXO values in italics represent estimates based on sensor size and age.

Many modern cameras cannot only take still pictures, but also record videos. Both cameras under consideration are equipped with sensors that have a sufficiently high read-out speed for moving images, but the D6 provides a higher video resolution than the 645Z. It can shoot video footage at 4K/30p, while the Pentax is limited to 1080/60i.

Feature comparison

Apart from body and sensor, cameras can and do differ across a range of features. The D6 and the 645Z 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 D6 offers a wider field of view (100%) than the one in the 645Z (98%), so that a larger proportion of the captured image is visible in the finder. On the other hand, the viewfinder of the 645Z has a higher magnification (0.78x vs 0.72x), 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 D6 and Pentax 645Z 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 D6	optical	Y	3.2 / 2359	fixed	Y	1/8000s	14.0/s	n	n
2.		Pentax 645Z	optical	Y	3.2 / 1037	tilting	n	1/4000s	3.0/s	n	n
3.		Canon 1D X Mark II	optical	Y	3.2 / 1620	fixed	Y	1/8000s	16.0/s	n	n
4.		Canon 1D X Mark III	optical	Y	3.2 / 2100	fixed	Y	1/8000s	20.0/s	n	n
5.		Canon 5DS	optical	Y	3.2 / 1040	fixed	n	1/8000s	5.0/s	n	n
6.		Canon 5DS R	optical	Y	3.2 / 1040	fixed	n	1/8000s	5.0/s	n	n
7.		Hasselblad X1D	2360	n	3.0 / 920	fixed	Y	1/2000s	2.3/s	n	n
8.		Leica SL	4400	Y	3.0 / 1040	fixed	Y	1/8000s	11.0/s	n	n
9.		Nikon D3X	optical	Y	3.0 / 922	fixed	n	1/8000s	5.0/s	n	n
10.		Nikon D4	optical	Y	3.2 / 921	fixed	n	1/8000s	11.0/s	n	n
11.		Nikon D4S	optical	Y	3.2 / 921	fixed	n	1/8000s	11.0/s	n	n
12.		Nikon D5	optical	Y	3.2 / 2359	fixed	Y	1/8000s	14.0/s	n	n
13.		Nikon D600	optical	Y	3.0 / 921	fixed	n	1/4000s	5.5/s	Y	n
14.		Nikon D610	optical	Y	3.2 / 921	fixed	n	1/4000s	6.0/s	Y	n
15.		Nikon D750	optical	Y	3.2 / 1229	tilting	n	1/4000s	6.0/s	Y	n
16.		Nikon D780	optical	Y	3.2 / 2359	tilting	Y	1/8000s	12.0/s	n	n
17.		Pentax 645D	optical	Y	3.0 / 921	fixed	n	1/4000s	1.1/s	n	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 D6 has a touchscreen, while the 645Z has a conventional panel. Touch control can be particularly helpful, for example, for setting the focus point.

The Nikon D6 and the Pentax 645Z 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 D6 writes its imaging data to CFexpress (type B) or XQD cards, while the 645Z uses SDXC cards. Both cameras feature dual card slots, which can be very useful in case a memory card fails.

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 D6 and Pentax 645Z 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 D6	Y	stereo / mono	Y	Y	mini	3.1	Y	-	Y
2.		Pentax 645Z	Y	stereo / mono	Y	-	mini	3.0	-	-	-
3.		Canon 1D X Mark II	Y	mono / mono	Y	Y	mini	3.0	-	-	-
4.		Canon 1D X Mark III	Y	mono / mono	Y	Y	mini	3.1	Y	-	Y
5.		Canon 5DS	Y	mono / mono	Y	-	mini	3.0	-	-	-
6.		Canon 5DS R	Y	mono / mono	Y	-	mini	3.0	-	-	-
7.		Hasselblad X1D	Y	stereo / mono	Y	Y	mini	3.0	Y	-	-
8.		Leica SL	Y	stereo / mono	Y	Y	full	3.0	Y	-	-
9.		Nikon D3X	Y	- / -	-	-	mini	2.0	-	-	-
10.		Nikon D4	Y	mono / mono	Y	Y	micro	2.0	-	-	-
11.		Nikon D4S	Y	mono / mono	Y	Y	mini	2.0	-	-	-
12.		Nikon D5	Y	stereo / mono	Y	Y	mini	3.0	-	-	-
13.		Nikon D600	Y	mono / mono	Y	Y	mini	2.0	-	-	-
14.		Nikon D610	Y	mono / mono	Y	Y	mini	2.0	-	-	-
15.		Nikon D750	Y	stereo / mono	Y	Y	mini	2.0	Y	-	-
16.		Nikon D780	Y	stereo / mono	Y	Y	mini	3.1	Y	-	Y
17.		Pentax 645D	Y	stereo / -	-	-	-	2.0	-	-	-

It is notable that the D6 has a headphone jack, which is not present on the 645Z This port makes it possible to attach external headphones and monitor the quality of sound during the recording process.

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

The D6 is a recent model that features in the current product line-up of Nikon. In contrast, the 645Z has been discontinued (but can be found pre-owned on ebay). There has not been a direct replacement model for the 645Z from Pentax. Further information on the features and operation of the D6 and 645Z can be found, respectively, in the Nikon D6 Manual (free pdf) or the online Pentax 645Z Manual.

Review summary

So what conclusions can be drawn? Which of the two cameras – the Nikon D6 or the Pentax 645Z – 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.

Reasons to prefer the Nikon D6:

• Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
• Better video: Provides higher definition movie capture (4K/30p vs 1080/60i).
• 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 98%).
• More detailed LCD: Has a higher resolution rear screen (2359k vs 1037k dots).
• Fewer buttons to press: Is equipped with a touch-sensitive rear screen to facilitate handling.
• Faster shutter: Has higher mechanical shutter speed (1/8000s vs 1/4000s) to freeze action.
• Faster burst: Shoots at higher frequency (14 vs 3 flaps/sec) to capture the decisive moment.
• Less heavy: Is lighter (by 280g or 18 percent) and hence easier to carry around.
• More portrait friendly: Features an integrated vertical grip for easier portrait shooting.
• Longer lasting: Can take more shots (3580 versus 650) on a single battery charge.
• 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 segment (24 percent cheaper at launch).
• More modern: Reflects 5 years and 9 months of technical progress since the 645Z launch.

Advantages of the Pentax 645Z:

• More detail: Has more megapixels (51.1 vs 20.7MP), which boosts linear resolution by 54%.
• Maximized detail: Lacks an anti-alias filter to exploit the sensor's full resolution potential.
• Larger viewfinder image: Features a viewfinder with a higher magnification (0.78x vs 0.72x).
• More flexible LCD: Has a tilting screen for odd-angle shots in landscape orientation.
• More compact: Is smaller (156x117mm vs 160x163mm) and will fit more readily into a bag.
• More heavily discounted: Has been around for much longer (launched in April 2014).

If the count of relative strengths (bullet points above) is taken as a measure, the D6 is the clear winner of the match-up (15 : 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 wildlife photographer will view the differences between cameras in a way that diverges from the perspective of a family photog, and a person interested in architecture has distinct needs from a sports 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 D6 and the Pentax 645Z 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 D6 or the 645Z. 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.		Nikon D6	..	..	4/5	..	4.5/5	4.5/5	Feb 2020	6,499	amazon.com
2.		Pentax 645Z	5/5	..	3.5/5	..	4.5/5	5/5	Apr 2014	8,499	ebay.com
3.		Canon 1D X Mark II	..	..	4.5/5	89/100	4.5/5	4.5/5	Feb 2016	5,999	ebay.com
4.		Canon 1D X Mark III	..	+ +	5/5	..	4.5/5	4/5	Jan 2020	6,499	amazon.com
5.		Canon 5DS	..	+	..	83/100	4.5/5	4.5/5	Feb 2015	3,699	ebay.com
6.		Canon 5DS R	5/5	+	..	83/100	5/5	4.5/5	Feb 2015	3,699	ebay.com
7.		Hasselblad X1D	..	o	..	81/100	..	4/5	Jun 2016	8,995	ebay.com
8.		Leica SL	4/5	..	4/5	84/100	4.5/5	4/5	Oct 2015	7,450	ebay.com
9.		Nikon D3X	..	..	..	86/100	4/5	5/5	Dec 2008	7,999	ebay.com
10.		Nikon D4	..	..	..	..	4.5/5	4.5/5	Jan 2012	5,999	ebay.com
11.		Nikon D4S	5/5	..	..	..	4.5/5	4.5/5	Feb 2014	6,499	ebay.com
12.		Nikon D5	..	..	4/5	89/100	4.5/5	5/5	Jan 2016	6,499	ebay.com
13.		Nikon D600	4/5	+ +	..	87/100	5/5	4.5/5	Sep 2012	2,099	ebay.com
14.		Nikon D610	4/5	+ +	..	87/100	4.5/5	4.5/5	Oct 2013	1,999	ebay.com
15.		Nikon D750	5/5	+ +	4/5	90/100	4.5/5	4.5/5	Sep 2014	2,299	ebay.com
16.		Nikon D780	5/5	..	5/5	87/100	4.5/5	4.5/5	Jan 2020	2,299	amazon.com
17.		Pentax 645D	5/5	..	..	..	..	..	Mar 2010	9,995	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. 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, 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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