Pentax 645D vs Nikon D750

The Pentax 645D and the Nikon D750 are two digital cameras that were officially introduced, respectively, in March 2010 and September 2014. Both are DSLR (Digital Single Lens Reflex) cameras that are based on a medium format (645D) and a full frame (D750) sensor. The Pentax has a resolution of 39.5 megapixels, whereas the Nikon provides 24.2 MP.

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

Headline Specifications

Pentax 645D		Nikon D750
Digital single lens reflex		Digital single lens reflex
Pentax 645 mount lenses		Nikon F mount lenses
39.5 MP – Medium Format sensor		24.2 MP – Full Frame sensor
no Video		1080/60p Video
ISO 100-1,600		ISO 100-12,800 (50 - 51,200)
Optical viewfinder		Optical viewfinder
3.0" LCD – 921k dots		3.2" LCD – 1229k dots
Fixed screen (not touch-sensitive)		Tilting screen (no touchscreen)
1.1 shutter flaps per second		6 shutter flaps per second
Weathersealed body		Weathersealed body
800 shots per battery charge		1230 shots per battery charge
156 x 117 x 119 mm, 1480 g		141 x 113 x 78 mm, 750 g

Check 645D offers at
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Check D750 offers at
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Going beyond this snapshot of core features and characteristics, what are the differences between the Pentax 645D and the Nikon D750? 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 645D and the Nikon D750 are illustrated 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 Nikon D750 is notably smaller (13 percent) than the Pentax 645D. Moreover, the D750 is substantially lighter (49 percent) than the 645D. 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 645D gets 800 shots out of its Pentax D-LI90 battery, while the D750 can take 1230 images on a single charge of its Nikon EN-EL15 power pack.

The table below summarizes the key physical specs of the two cameras alongside a broader set of comparators. 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.		Pentax 645D	156 mm	117 mm	119 mm	1480 g	800	Y	Mar 2010	9,995	ebay.com
2.		Nikon D750	141 mm	113 mm	78 mm	750 g	1230	Y	Sep 2014	2,299	ebay.com
3.		Canon 1D Mark IV	156 mm	157 mm	80 mm	1230 g	1500	Y	Oct 2009	4,999	ebay.com
4.		Canon 1D X	158 mm	168 mm	83 mm	1551 g	1120	Y	Oct 2011	6,799	ebay.com
5.		Canon 1D X Mark II	158 mm	168 mm	83 mm	1530 g	1210	Y	Feb 2016	5,999	ebay.com
6.		Leica S Typ 006	160 mm	120 mm	80 mm	1260 g	..	Y	Sep 2012	21,950	ebay.com
7.		Nikon D3S	160 mm	157 mm	88 mm	1240 g	4200	Y	Oct 2009	5,199	ebay.com
8.		Nikon D5	160 mm	159 mm	92 mm	1415 g	3780	Y	Jan 2016	6,499	ebay.com
9.		Nikon D600	141 mm	113 mm	82 mm	850 g	900	Y	Sep 2012	2,099	ebay.com
10.		Nikon D610	141 mm	113 mm	82 mm	850 g	900	Y	Oct 2013	1,999	ebay.com
11.		Nikon D700	147 mm	123 mm	77 mm	1074 g	1000	Y	Jul 2008	2,999	ebay.com
12.		Nikon D780	144 mm	116 mm	76 mm	840 g	2260	Y	Jan 2020	2,299	amazon.com
13.		Nikon D810	146 mm	123 mm	82 mm	980 g	1200	Y	Jun 2014	3,299	ebay.com
14.		Nikon D850	146 mm	124 mm	79 mm	1005 g	1840	Y	Jul 2017	3,299	amazon.com
15.		Nikon Df	144 mm	110 mm	67 mm	760 g	1400	Y	Nov 2013	2,749	ebay.com
16.		Pentax 645Z	156 mm	117 mm	123 mm	1550 g	650	Y	Apr 2014	8,499	ebay.com
17.		Sony A7R	127 mm	94 mm	48 mm	465 g	340	Y	Oct 2013	2,299	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 listed launch prices provide an indication of the market segment that the manufacturer of the cameras have been targeting. The D750 was launched at a markedly lower price (by 77 percent) than the 645D, 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 645D features a medium format sensor and the Nikon D750 a full frame sensor. The sensor area in the D750 is 41 percent smaller. As a result of these sensor size differences, the cameras have a format factor of, respectively, 0.79 and 1.0. The sensor in the 645D has a native 4:3 aspect ratio, while the one in the D750 offers a 3:2 aspect.

With 39.5MP, the 645D offers a higher resolution than the D750 (24.2MP), but the 645D nevertheless has marginally larger individual pixels (pixel pitch of 6.06μm versus 5.97μm for the D750) due to its larger sensor. However, the D750 is a much more recent model (by 4 years and 6 months) than the 645D, 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 645D has no anti-alias filter installed, so that it can capture all the detail its sensor resolves.

The resolution advantage of the Pentax 645D implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the 645D for good quality output (200 dots per inch) amounts to 36.3 x 27.2 inches or 92.3 x 69.1 cm, for very good quality (250 dpi) 29.1 x 21.8 inches or 73.8 x 55.3 cm, and for excellent quality (300 dpi) 24.2 x 18.1 inches or 61.5 x 46.1 cm. The corresponding values for the Nikon D750 are 30.1 x 20.1 inches or 76.4 x 51 cm for good quality, 24.1 x 16.1 inches or 61.1 x 40.8 cm for very good quality, and 20.1 x 13.4 inches or 50.9 x 34 cm for excellent quality prints.

The Pentax 645D has a native sensitivity range from ISO 100 to ISO 1600. The corresponding ISO settings for the Nikon D750 are ISO 100 to ISO 12800, with the possibility to increase the ISO range to 50-51200.

In terms of underlying technology, the 645D is build around a CCD sensor, while the D750 uses a CMOS imager. 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 consideration, the D750 offers substantially better image quality than the 645D (overall score 11 points higher). The advantage is based on 0.2 bits higher color depth, 1.9 EV in additional dynamic range, and 1.2 stops in additional low light sensitivity. 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.		Pentax 645D	Medium Format	39.5	7264	5440	none	24.6	12.6	1262	82
2.		Nikon D750	Full Frame	24.2	6016	4016	1080/60p	24.8	14.5	2956	93
3.		Canon 1D Mark IV	APS-H	16.0	4896	3264	1080/30p	22.8	12.0	1320	74
4.		Canon 1D X	Full Frame	17.9	5184	3456	1080/30p	23.8	11.8	2786	82
5.		Canon 1D X Mark II	Full Frame	20.0	5472	3648	4K/60p	24.1	13.5	3207	88
6.		Leica S Typ 006	Medium Format	37.5	7500	5000	none	23.9	12.2	824	76
7.		Nikon D3S	Full Frame	12.1	4256	2832	720/24p	23.5	12.0	3253	82
8.		Nikon D5	Full Frame	20.7	5588	3712	4K/30p	25.1	12.3	2343	88
9.		Nikon D600	Full Frame	24.2	6016	4016	1080/30p	25.1	14.2	2980	94
10.		Nikon D610	Full Frame	24.2	6016	4016	1080/30p	25.1	14.4	2925	94
11.		Nikon D700	Full Frame	12.1	4256	2832	none	23.5	12.2	2303	80
12.		Nikon D780	Full Frame	24.3	6048	4024	4K/30p	25.3	14.3	2877	95
13.		Nikon D810	Full Frame	36.2	7360	4912	1080/60p	25.7	14.8	2853	97
14.		Nikon D850	Full Frame	45.4	8256	5504	4K/30p	26.4	14.8	2660	100
15.		Nikon Df	Full Frame	16.2	4928	3280	none	24.6	13.1	3279	89
16.		Pentax 645Z	Medium Format	51.1	8256	6192	1080/60i	26.0	14.7	4505	101
17.		Sony A7R	Full Frame	36.2	7360	4912	1080/60p	25.6	14.1	2746	95
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 D750 indeed provides for movie recording, while the 645D does not. The highest resolution format that the D750 can use is 1080/60p.

Feature comparison

Apart from body and sensor, cameras can and do differ across a variety of features. The 645D and the D750 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 D750 offers a wider field of view (100%) than the one in the 645D (98%), so that a larger proportion of the captured image is visible in the finder. On the other hand, the viewfinder of the 645D has a higher magnification (0.78x vs 0.70x), 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 Pentax 645D and Nikon D750 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.		Pentax 645D	optical	Y	3.0 / 921	fixed	n	1/4000s	1.1/s	n	n
2.		Nikon D750	optical	Y	3.2 / 1229	tilting	n	1/4000s	6.0/s	Y	n
3.		Canon 1D Mark IV	optical	Y	3.0 / 920	fixed	n	1/8000s	10.0/s	n	n
4.		Canon 1D X	optical	Y	3.2 / 1040	fixed	n	1/8000s	14.0/s	n	n
5.		Canon 1D X Mark II	optical	Y	3.2 / 1620	fixed	Y	1/8000s	16.0/s	n	n
6.		Leica S Typ 006	optical	Y	3.0 / 922	fixed	n	1/4000s	1.5/s	n	n
7.		Nikon D3S	optical	Y	3.0 / 921	fixed	n	1/8000s	11.0/s	n	n
8.		Nikon D5	optical	Y	3.2 / 2359	fixed	Y	1/8000s	14.0/s	n	n
9.		Nikon D600	optical	Y	3.0 / 921	fixed	n	1/4000s	5.5/s	Y	n
10.		Nikon D610	optical	Y	3.2 / 921	fixed	n	1/4000s	6.0/s	Y	n
11.		Nikon D700	optical	Y	3.0 / 922	fixed	n	1/8000s	8.0/s	Y	n
12.		Nikon D780	optical	Y	3.2 / 2359	tilting	Y	1/8000s	12.0/s	n	n
13.		Nikon D810	optical	Y	3.2 / 1229	fixed	n	1/8000s	5.0/s	Y	n
14.		Nikon D850	optical	Y	3.2 / 2359	tilting	Y	1/8000s	9.0/s	n	n
15.		Nikon Df	optical	Y	3.2 / 921	fixed	n	1/4000s	5.5/s	n	n
16.		Pentax 645Z	optical	Y	3.2 / 1037	tilting	n	1/4000s	3.0/s	n	n
17.		Sony A7R	2400	n	3.0 / 1230	tilting	n	1/8000s	4.0/s	n	n
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 D750 has one, while the 645D does not. While the built-in flash of the D750 is not very powerful, it can at times be useful as a fill-in light.

The Pentax 645D and the Nikon D750 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 645D and the D750 write their files to SDXC cards. Both cameras feature dual card slots, which can be very useful in case a memory card fails. The D750 supports UHS-I cards (Ultra High Speed data transfer of up to 104 MB/s), while the 645D cannot take advantage of Ultra High Speed SD cards.

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 645D and Nikon D750 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 645D	Y	stereo / -	-	-	-	2.0	-	-	-
2.		Nikon D750	Y	stereo / mono	Y	Y	mini	2.0	Y	-	-
3.		Canon 1D Mark IV	Y	stereo / -	Y	-	mini	2.0	-	-	-
4.		Canon 1D X	Y	mono / -	Y	-	mini	2.0	-	-	-
5.		Canon 1D X Mark II	Y	mono / mono	Y	Y	mini	3.0	-	-	-
6.		Leica S Typ 006	Y	- / -	-	-	mini	2.0	-	-	-
7.		Nikon D3S	Y	stereo / -	-	-	mini	2.0	-	-	-
8.		Nikon D5	Y	stereo / mono	Y	Y	mini	3.0	-	-	-
9.		Nikon D600	Y	mono / mono	Y	Y	mini	2.0	-	-	-
10.		Nikon D610	Y	mono / mono	Y	Y	mini	2.0	-	-	-
11.		Nikon D700	Y	- / -	-	-	mini	2.0	-	-	-
12.		Nikon D780	Y	stereo / mono	Y	Y	mini	3.1	Y	-	Y
13.		Nikon D810	Y	stereo / mono	Y	Y	mini	3.0	Y	-	-
14.		Nikon D850	Y	stereo / mono	Y	Y	mini	3.0	Y	Y	Y
15.		Nikon Df	Y	- / -	-	-	mini	2.0	-	-	-
16.		Pentax 645Z	Y	stereo / mono	Y	-	mini	3.0	-	-	-
17.		Sony A7R	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-

It is notable that the D750 offers wifi support, which can be a very convenient means to transfer image data to an off-camera location. In contrast, the 645D does not provide wifi capability.

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

Both the 645D and the D750 have been discontinued, but can regularly be found used on ebay. The 645D was replaced by the Pentax 645Z, while the D750 was followed by the Nikon D780. Further information on the features and operation of the 645D and D750 can be found, respectively, in the Pentax 645D Manual (free pdf) or the online Nikon D750 Manual.

Review summary

So how do things add up? Is the Pentax 645D better than the Nikon D750 or vice versa? A synthesis of the relative strong points of each of the models is listed below.

Reasons to prefer the Pentax 645D:

• More detail: Offers more megapixels (39.5 vs 24.2MP) with a 25% higher linear resolution.
• 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 0.70x).
• More heavily discounted: Has been available for much longer (launched in March 2010).

Arguments in favor of the Nikon D750:

• Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
• Better image quality: Scores substantially higher (11 points) in the DXO overall evaluation.
• More dynamic range: Captures a broader range of light and dark details (1.9 EV of extra DR).
• Better low-light sensitivity: Can shoot in dim conditions (1.2 stops ISO advantage).
• Broader imaging potential: Can capture not only stills but also 1080/60p video.
• More complete view: Has a viewfinder with a larger field of view (100% vs 98%).
• Larger screen: Has a bigger rear LCD (3.2" vs 3.0") for image review and settings control.
• More detailed LCD: Has a higher resolution rear screen (1229k vs 921k dots).
• More flexible LCD: Has a tilting screen for odd-angle shots in landscape orientation.
• Faster burst: Shoots at higher frequency (6 vs 1.1 flaps/sec) to capture the decisive moment.
• More compact: Is smaller (141x113mm vs 156x117mm) and will fit more readily into a bag.
• Less heavy: Has a lower weight (by 730g or 49 percent) and is thus easier to take along.
• Longer lasting: Gets more shots (1230 versus 800) out of a single battery charge.
• Easier fill-in: Has a small integrated flash to brighten shadows of backlit subjects.
• Easier file upload: Has wifi built in for automatic backup or image transfer to the web.
• Faster buffer clearing: Has an SD card interface that supports the UHS-I standard.
• More affordable: Was introduced into a lower priced category (77 percent cheaper at launch).
• More modern: Reflects 4 years and 6 months of technical progress since the 645D launch.

If the number of relative strengths (bullet points above) is taken as a guide, the D750 is the clear winner of the contest (18 : 4 points). However, the relative importance of the various individual camera aspects will vary according to personal preferences and needs, so that you might like to apply corresponding weights to the particular features before making a decision on a new camera. 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 645D and the Nikon D750 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 partial and cannot reveal, for example, the shooting experience and imaging performance when actually working with the 645D or the D750. 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 expert reviews 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 (USD)	Street Price
1.		Pentax 645D	5/5	..	..	..	..	..	Mar 2010	9,995	ebay.com
2.		Nikon D750	5/5	+ +	4/5	90/100	4.5/5	4.5/5	Sep 2014	2,299	ebay.com
3.		Canon 1D Mark IV	5/5	..	..	89/100	..	..	Oct 2009	4,999	ebay.com
4.		Canon 1D X	5/5	..	..	..	4.5/5	4.5/5	Oct 2011	6,799	ebay.com
5.		Canon 1D X Mark II	..	..	4.5/5	89/100	4.5/5	4.5/5	Feb 2016	5,999	ebay.com
6.		Leica S Typ 006	..	..	..	..	..	..	Sep 2012	21,950	ebay.com
7.		Nikon D3S	5/5	..	..	89/100	4.5/5	5/5	Oct 2009	5,199	ebay.com
8.		Nikon D5	..	..	4/5	89/100	4.5/5	5/5	Jan 2016	6,499	ebay.com
9.		Nikon D600	4/5	+ +	..	87/100	5/5	4.5/5	Sep 2012	2,099	ebay.com
10.		Nikon D610	4/5	+ +	..	87/100	4.5/5	4.5/5	Oct 2013	1,999	ebay.com
11.		Nikon D700	..	89/100	..	+ +	4.5/5	4.5/5	Jul 2008	2,999	ebay.com
12.		Nikon D780	5/5	..	5/5	87/100	4.5/5	4.5/5	Jan 2020	2,299	amazon.com
13.		Nikon D810	5/5	..	5/5	86/100	5/5	4.5/5	Jun 2014	3,299	ebay.com
14.		Nikon D850	4.5/5	+ +	5/5	89/100	4.5/5	5/5	Jul 2017	3,299	amazon.com
15.		Nikon Df	4/5	..	..	81/100	4/5	4/5	Nov 2013	2,749	ebay.com
16.		Pentax 645Z	5/5	..	3.5/5	..	4.5/5	5/5	Apr 2014	8,499	ebay.com
17.		Sony A7R	5/5	+ +	..	82/100	4.5/5	5/5	Oct 2013	2,299	ebay.com
Note: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.

Care should be taken when interpreting the review scores above, though. The ratings are only valid when referring to cameras in the same category and of the same age. Thus, a score needs to be put into the context of the launch date and the launch price of the camera, and comparing ratings of very distinct cameras or ones that are far apart in terms of their release date have little meaning. It should also be noted that some of the review sites have over time altered the way they render their verdicts.

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Other camera comparisons

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