Pentax 645D vs Sony NEX-5

The Pentax 645D and the Sony Alpha NEX-5 are two digital cameras that were announced, respectively, in March 2010 and May 2010. The 645D is a DSLR, while the NEX-5 is a mirrorless interchangeable lens camera. The cameras are based on a medium format (645D) and an APS-C (NEX-5) sensor. The Pentax has a resolution of 39.5 megapixels, whereas the Sony provides 14 MP.

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

Headline Specifications

Pentax 645D		Sony NEX-5
Digital single lens reflex		Mirrorless system camera
Pentax 645 mount lenses		Sony E mount lenses
39.5 MP – Medium Format sensor		14 MP – APS-C sensor
no Video		1080/60i Video
ISO 100-1,600		ISO 200-12,800
Optical viewfinder		Viewfinder optional
3.0" LCD – 921k dots		3.0" LCD – 920k dots
Fixed screen (not touch-sensitive)		Tilting screen (no touchscreen)
1.1 shutter flaps per second		7 shutter flaps per second
Weathersealed body		not weather sealed
800 shots per battery charge		330 shots per battery charge
156 x 117 x 119 mm, 1480 g		111 x 59 x 38 mm, 287 g

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Going beyond this snapshot of core features and characteristics, what are the differences between the Pentax 645D and the Sony Alpha NEX-5? 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 Sony NEX-5 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 width, height and depth dimensions are rounded to the nearest millimeter.

The NEX-5 can be obtained in two different colors (black, silver), while the 645D 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 Sony NEX-5 is considerably smaller (64 percent) than the Pentax 645D. Moreover, the NEX-5 is substantially lighter (81 percent) than the 645D. It is worth mentioning in this context that the 645D is splash and dust resistant, while the NEX-5 does not feature any corresponding weather-sealing.

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 NEX-5 can take 330 images on a single charge of its Sony NP-FW50 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.		Pentax 645D	156 mm	117 mm	119 mm	1480 g	800	Y	Mar 2010	9,995	ebay.com
2.		Sony NEX-5	111 mm	59 mm	38 mm	287 g	330	n	May 2010	699	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	158 mm	168 mm	83 mm	1551 g	1120	Y	Oct 2011	6,799	ebay.com
5.		Canon 1D Mark IV	156 mm	157 mm	80 mm	1230 g	1500	Y	Oct 2009	4,999	ebay.com
6.		Leica S Typ 006	160 mm	120 mm	80 mm	1260 g	..	Y	Sep 2012	21,950	ebay.com
7.		Nikon D850	146 mm	124 mm	79 mm	1005 g	1840	Y	Jul 2017	3,299	amazon.com
8.		Nikon D5	160 mm	159 mm	92 mm	1415 g	3780	Y	Jan 2016	6,499	ebay.com
9.		Nikon D810	146 mm	123 mm	82 mm	980 g	1200	Y	Jun 2014	3,299	ebay.com
10.		Nikon D3S	160 mm	157 mm	88 mm	1240 g	4200	Y	Oct 2009	5,199	ebay.com
11.		Pentax 645Z	156 mm	117 mm	123 mm	1550 g	650	Y	Apr 2014	8,499	ebay.com
12.		Sony A7R	127 mm	94 mm	48 mm	465 g	340	Y	Oct 2013	2,299	ebay.com
13.		Sony NEX-5R	111 mm	59 mm	39 mm	276 g	330	n	Aug 2012	749	ebay.com
14.		Sony NEX-F3	117 mm	67 mm	42 mm	314 g	470	n	May 2012	599	ebay.com
15.		Sony NEX-5N	111 mm	59 mm	38 mm	269 g	460	n	Aug 2011	699	ebay.com
16.		Sony NEX-C3	110 mm	60 mm	33 mm	225 g	400	n	Jun 2011	599	ebay.com
17.		Sony NEX-3	117 mm	62 mm	33 mm	297 g	330	n	May 2010	599	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 manufacturer’s suggested retail prices give an idea on the placement of the camera in the maker’s lineup and the broader market. The NEX-5 was launched at a markedly lower price (by 93 percent) than the 645D, 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.

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. A large sensor will tend to have larger individual pixels that provide better low-light sensitivity, wider dynamic range, and richer color-depth than smaller pixel-units 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 645D features a medium format sensor and the Sony NEX-5 an APS-C sensor. The sensor area in the NEX-5 is 75 percent smaller. As a result of these sensor size differences, the cameras have a format factor of, respectively, 0.79 and 1.5. The sensor in the 645D has a native 4:3 aspect ratio, while the one in the NEX-5 offers a 3:2 aspect.

With 39.5MP, the 645D offers a higher resolution than the NEX-5 (14MP), but the 645D nevertheless has larger individual pixels (pixel pitch of 6.06μm versus 5.11μm for the NEX-5) due to its larger sensor. It is noteworthy in this context that the two cameras were released in close succession, so that their sensors are from the same technological generation. 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 Sony NEX-5 are 23 x 15.3 inches or 58.3 x 38.8 cm for good quality, 18.4 x 12.2 inches or 46.7 x 31 cm for very good quality, and 15.3 x 10.2 inches or 38.9 x 25.9 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 Sony Alpha NEX-5 are ISO 200 to ISO 12800 (no boost).

In terms of underlying technology, the 645D is build around a CCD sensor, while the NEX-5 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 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"). Of the two cameras under review, the 645D provides substantially higher image quality than the NEX-5, with an overall score that is 13 points higher. This advantage is based on 2.4 bits higher color depth, 0.4 EV in additional dynamic range, and 0.7 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 645D	Medium Format	39.5	7264	5440	none	24.6	12.6	1262	82
2.		Sony NEX-5	APS-C	14.0	4592	3056	1080/60i	22.2	12.2	796	69
3.		Canon 1D X Mark II	Full Frame	20.0	5472	3648	4K/60p	24.1	13.5	3207	88
4.		Canon 1D X	Full Frame	17.9	5184	3456	1080/30p	23.8	11.8	2786	82
5.		Canon 1D Mark IV	APS-H	16.0	4896	3264	1080/30p	22.8	12.0	1320	74
6.		Leica S Typ 006	Medium Format	37.5	7500	5000	none	23.9	12.2	824	76
7.		Nikon D850	Full Frame	45.4	8256	5504	4K/30p	26.4	14.8	2660	100
8.		Nikon D5	Full Frame	20.7	5588	3712	4K/30p	25.1	12.3	2343	88
9.		Nikon D810	Full Frame	36.2	7360	4912	1080/60p	25.7	14.8	2853	97
10.		Nikon D3S	Full Frame	12.1	4256	2832	720/24p	23.5	12.0	3253	82
11.		Pentax 645Z	Medium Format	51.1	8256	6192	1080/60i	26.0	14.7	4505	101
12.		Sony A7R	Full Frame	36.2	7360	4912	1080/60p	25.6	14.1	2746	95
13.		Sony NEX-5R	APS-C	16.0	4912	3264	1080/60i	23.7	13.1	910	78
14.		Sony NEX-F3	APS-C	16.0	4912	3264	1080/60i	22.7	12.3	1114	73
15.		Sony NEX-5N	APS-C	16.0	4912	3264	1080/60i	23.6	12.7	1079	77
16.		Sony NEX-C3	APS-C	16.0	4912	3264	720/30p	22.7	12.2	1083	73
17.		Sony NEX-3	APS-C	14.0	4592	3056	720/30p	22.1	12.0	830	68

Many modern cameras are not only capable of taking still images, but also of capturing video footage. The NEX-5 indeed provides for movie recording, while the 645D does not. The highest resolution format that the NEX-5 can use is 1080/60i.

Feature comparison

Beyond body and sensor, cameras can and do differ across a range of features. For example, the 645D has an optical viewfinder, which can be very useful when shooting in bright sunlight. In contrast, the NEX-5 relies on live view and the rear LCD for framing. That said, the NEX-5 can be equipped with an optional viewfinder – the FDA-SV1. The adjacent table lists some of the other core features of the Pentax 645D and Sony NEX-5 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 645D	optical	Y	3.0 / 921	fixed	n	1/4000s	1.1/s	n	n
2.		Sony NEX-5	optional	n	3.0 / 920	tilting	n	1/4000s	7.0/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	optical	Y	3.2 / 1040	fixed	n	1/8000s	14.0/s	n	n
5.		Canon 1D Mark IV	optical	Y	3.0 / 920	fixed	n	1/8000s	10.0/s	n	n
6.		Leica S Typ 006	optical	Y	3.0 / 922	fixed	n	1/4000s	1.5/s	n	n
7.		Nikon D850	optical	Y	3.2 / 2359	tilting	Y	1/8000s	9.0/s	n	n
8.		Nikon D5	optical	Y	3.2 / 2359	fixed	Y	1/8000s	14.0/s	n	n
9.		Nikon D810	optical	Y	3.2 / 1229	fixed	n	1/8000s	5.0/s	Y	n
10.		Nikon D3S	optical	Y	3.0 / 921	fixed	n	1/8000s	11.0/s	n	n
11.		Pentax 645Z	optical	Y	3.2 / 1037	tilting	n	1/4000s	3.0/s	n	n
12.		Sony A7R	2400	n	3.0 / 1230	tilting	n	1/8000s	4.0/s	n	n
13.		Sony NEX-5R	optional	n	3.0 / 920	tilting	Y	1/4000s	10.0/s	n	n
14.		Sony NEX-F3	optional	n	3.0 / 920	tilting	n	1/4000s	5.5/s	Y	n
15.		Sony NEX-5N	optional	n	3.0 / 920	tilting	Y	1/4000s	10.0/s	n	n
16.		Sony NEX-C3	optional	n	3.0 / 920	tilting	n	1/4000s	5.5/s	n	n
17.		Sony NEX-3	optional	n	3.0 / 920	tilting	n	1/4000s	7.0/s	n	n
Note: *) Information refers to the mechanical shutter, unless the camera only has an electronic one.

One feature that is present on the 645D, but is missing on the NEX-5 is a top-level LCD. While being, of course, smaller than the rear screen, the control panel conveys some of the essential shooting information and can be convenient for quick and easy settings verification.

The Pentax 645D has 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 645D writes its imaging data to SDXC cards, while the NEX-5 uses SDXC or Memory Stick PRO Duo cards. The 645D features dual card slots, which can be very useful in case a memory card fails. In contrast, the NEX-5 only has one slot.

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 Sony Alpha NEX-5 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.		Sony NEX-5	Y	stereo / mono	-	-	mini	2.0	-	-	-
3.		Canon 1D X Mark II	Y	mono / mono	Y	Y	mini	3.0	-	-	-
4.		Canon 1D X	Y	mono / -	Y	-	mini	2.0	-	-	-
5.		Canon 1D Mark IV	Y	stereo / -	Y	-	mini	2.0	-	-	-
6.		Leica S Typ 006	Y	- / -	-	-	mini	2.0	-	-	-
7.		Nikon D850	Y	stereo / mono	Y	Y	mini	3.0	Y	Y	Y
8.		Nikon D5	Y	stereo / mono	Y	Y	mini	3.0	-	-	-
9.		Nikon D810	Y	stereo / mono	Y	Y	mini	3.0	Y	-	-
10.		Nikon D3S	Y	stereo / -	-	-	mini	2.0	-	-	-
11.		Pentax 645Z	Y	stereo / mono	Y	-	mini	3.0	-	-	-
12.		Sony A7R	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
13.		Sony NEX-5R	Y	stereo / mono	-	-	mini	2.0	Y	-	-
14.		Sony NEX-F3	Y	stereo / mono	-	-	mini	2.0	-	-	-
15.		Sony NEX-5N	Y	stereo / mono	-	-	mini	2.0	-	-	-
16.		Sony NEX-C3	Y	stereo / mono	-	-	mini	2.0	-	-	-
17.		Sony NEX-3	Y	stereo / mono	-	-	mini	2.0	-	-	-

Studio photographers will appreciate that the Pentax 645D (unlike the NEX-5) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.

Both the 645D and the NEX-5 have been discontinued, but can regularly be found used on ebay. The 645D was replaced by the Pentax 645Z, while the NEX-5 was followed by the Sony NEX-5N. Further information on the features and operation of the 645D and NEX-5 can be found, respectively, in the Pentax 645D Manual (free pdf) or the online Sony NEX-5 Manual.

Review summary

So what is the bottom line? Which of the two cameras – the Pentax 645D or the Sony NEX-5 – has the upper hand? Is one clearly better than the other? The listing below highlights the relative strengths of the two models.

Arguments in favor of the Pentax 645D:

• More detail: Offers more megapixels (39.5 vs 14MP) with a 65% higher linear resolution.
• Maximized detail: Lacks an anti-alias filter to exploit the sensor's full resolution potential.
• Better image quality: Scores substantially higher (13 points) in the DXO overall assessment.
• Richer colors: Generates images with noticeably better colors (2.4 bits more color depth).
• Better low-light sensitivity: Requires less light for good images (0.7 stops ISO advantage).
• Easier framing: Has an optical viewfinder for image composition and settings control.
• Easier setting verification: Features an LCD display on top to control shooting parameters.
• Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
• Longer lasting: Can take more shots (800 versus 330) on a single battery charge.
• Better sealing: Is weather sealed to enable shooting in dusty or wet environments.
• Better studio light control: Has a PC Sync socket to connect to professional strobe lights.
• Greater peace of mind: Features a second card slot as a backup in case of memory card failure.

Advantages of the Sony Alpha NEX-5:

• Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
• Broader imaging potential: Can capture not only stills but also 1080/60i video.
• More flexible LCD: Has a tilting screen for odd-angle shots in landscape orientation.
• More selfie-friendly: Has an articulated screen that can be turned to be front-facing.
• Faster burst: Shoots at higher frequency (7 vs 1.1 flaps/sec) to capture the decisive moment.
• More compact: Is smaller (111x59mm vs 156x117mm) and will fit more readily into a bag.
• Less heavy: Has a lower weight (by 1193g or 81 percent) and is thus easier to take along.
• More legacy lens friendly: Can use many non-native lenses via adapters.
• More affordable: Was introduced into a lower priced category (93 percent cheaper at launch).

If the number of relative strengths (bullet points above) is taken as a guide, the 645D emerges as the winner of the contest (12 : 9 points). However, the relevance of individual strengths will vary across photographers, so that you might want to apply your own weighing scheme to the summary points when reflecting and deciding on a new camera. 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 Pentax 645D and the Sony NEX-5 place the cameras among the top in their class? Find out in the latest Best DSLR Camera and Best Mirrorless Interchangeable Lens Camera listings 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 says little about, for example, the shooting experience and imaging performance of the 645D and the NEX-5 in practical situations. 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 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.		Sony NEX-5	3/5	+ +	..	71/100	4.5/5	4/5	May 2010	699	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	5/5	..	..	..	4.5/5	4.5/5	Oct 2011	6,799	ebay.com
5.		Canon 1D Mark IV	5/5	..	..	89/100	..	..	Oct 2009	4,999	ebay.com
6.		Leica S Typ 006	..	..	..	..	..	..	Sep 2012	21,950	ebay.com
7.		Nikon D850	4.5/5	+ +	5/5	89/100	4.5/5	5/5	Jul 2017	3,299	amazon.com
8.		Nikon D5	..	..	4/5	89/100	4.5/5	5/5	Jan 2016	6,499	ebay.com
9.		Nikon D810	5/5	..	5/5	86/100	5/5	4.5/5	Jun 2014	3,299	ebay.com
10.		Nikon D3S	5/5	..	..	89/100	4.5/5	5/5	Oct 2009	5,199	ebay.com
11.		Pentax 645Z	5/5	..	3.5/5	..	4.5/5	5/5	Apr 2014	8,499	ebay.com
12.		Sony A7R	5/5	+ +	..	82/100	4.5/5	5/5	Oct 2013	2,299	ebay.com
13.		Sony NEX-5R	..	..	..	..	4.5/5	4.5/5	Aug 2012	749	ebay.com
14.		Sony NEX-F3	4/5	..	..	74/100	4.5/5	4.5/5	May 2012	599	ebay.com
15.		Sony NEX-5N	3/5	+ +	..	79/100	4.5/5	4.5/5	Aug 2011	699	ebay.com
16.		Sony NEX-C3	3/5	+ +	..	74/100	4.5/5	4/5	Jun 2011	599	ebay.com
17.		Sony NEX-3	..	..	..	70/100	4.5/5	4/5	May 2010	599	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 comparisons of ratings among very different cameras or across long time periods have little meaning. 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

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 make your choice using the following search menu. There is also a set of direct links to comparison reviews that other users of the CAM-parator app explored.

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