Pentax 645D vs Samsung NX500

The Pentax 645D and the Samsung NX500 are two digital cameras that were announced, respectively, in March 2010 and February 2015. The 645D is a DSLR, while the NX500 is a mirrorless interchangeable lens camera. The cameras are based on a medium format (645D) and an APS-C (NX500) sensor. The Pentax has a resolution of 39.5 megapixels, whereas the Samsung provides 28 MP.

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

Headline Specifications

Pentax 645D		Samsung NX500
Digital single lens reflex		Mirrorless system camera
Pentax 645 mount lenses		Samsung NX mount lenses
39.5 MP – Medium Format sensor		28 MP – APS-C sensor
no Video		4K/30p Video
ISO 100-1,600		ISO 100-25,600 (100 - 51,200)
Optical viewfinder		No viewfinder, LCD framing
3.0" LCD – 921k dots		3.0" LCD – 1036k dots
Fixed screen (not touch-sensitive)		Tilting touchscreen
1.1 shutter flaps per second		9 shutter flaps per second
Weathersealed body		not weather sealed
800 shots per battery charge		370 shots per battery charge
156 x 117 x 119 mm, 1480 g		120 x 64 x 43 mm, 287 g

Check 645D offers at
ebay.com
Check NX500 offers at
ebay.com

Going beyond this snapshot of core features and characteristics, what are the differences between the Pentax 645D and the Samsung NX500? 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 Samsung NX500 are illustrated 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 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 Samsung NX500 is considerably smaller (58 percent) than the Pentax 645D. Moreover, the NX500 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 NX500 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.

The power pack in the NX500 can be charged via the USB port, which can be very convenient when travelling.

The following table provides a synthesis of the main physical specifications of the two cameras and other similar ones. 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 645D	156 mm	117 mm	119 mm	1480 g	800	Y	Mar 2010	9,995	ebay.com
2.		Samsung NX500	120 mm	64 mm	43 mm	287 g	370	n	Feb 2015	799	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 D810	146 mm	123 mm	82 mm	980 g	1200	Y	Jun 2014	3,299	ebay.com
10.		Nikon D850	146 mm	124 mm	79 mm	1005 g	1840	Y	Jul 2017	3,299	amazon.com
11.		Nikon D5500	124 mm	97 mm	70 mm	470 g	820	n	Jan 2015	899	ebay.com
12.		Nikon D5600	124 mm	97 mm	70 mm	465 g	970	n	Nov 2016	699	ebay.com
13.		Pentax 645Z	156 mm	117 mm	123 mm	1550 g	650	Y	Apr 2014	8,499	ebay.com
14.		Ricoh GR II	117 mm	63 mm	35 mm	251 g	320	n	Jun 2015	699	ebay.com
15.		Sony A7R	127 mm	94 mm	48 mm	465 g	340	Y	Oct 2013	2,299	ebay.com
16.		Sony A5100	110 mm	63 mm	36 mm	283 g	400	n	Aug 2014	549	ebay.com
17.		Sony A6000	120 mm	67 mm	45 mm	344 g	360	n	Feb 2014	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 obviously take relative prices into account. 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 NX500 was launched at a markedly lower price (by 92 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 size of the sensor inside a digital camera is one of the key determinants of image quality. A large sensor will generally have larger individual pixels that offer better low-light sensitivity, provide wider dynamic range, and have 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 more expensive and lead to bigger and heavier cameras and lenses.

Of the two cameras under consideration, the Pentax 645D features a medium format sensor and the Samsung NX500 an APS-C sensor. The sensor area in the NX500 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 NX500 offers a 3:2 aspect.

With 39.5MP, the 645D offers a higher resolution than the NX500 (28MP), but the 645D nevertheless has larger individual pixels (pixel pitch of 6.06μm versus 3.63μm for the NX500) due to its larger sensor. However, the NX500 is a much more recent model (by 4 years and 10 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 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 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 Samsung NX500 are 32.4 x 21.6 inches or 82.3 x 54.9 cm for good quality, 25.9 x 17.3 inches or 65.8 x 43.9 cm for very good quality, and 21.6 x 14.4 inches or 54.9 x 36.6 cm for excellent quality prints.

The NX500 has on-sensor phase detect pixels, which results in fast and reliable autofocus acquisition even during live view operation.

The Pentax 645D has a native sensitivity range from ISO 100 to ISO 1600. The corresponding ISO settings for the Samsung NX500 are ISO 100 to ISO 25600, with the possibility to increase the ISO range to 100-51200.

In terms of underlying technology, the 645D is build around a CCD sensor, while the NX500 uses a BSI-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 assesses and scores the color depth ("DXO Portrait"), dynamic range ("DXO Landscape"), and low-light sensitivity ("DXO Sports") of camera sensors, and also publishes an overall camera score. Of the two cameras under consideration, the NX500 has a markedly higher DXO score than the 645D (overall score 5 points higher), which will translate into better image quality. The advantage is based on 0.2 bits higher color depth, 1.3 EV in additional dynamic range, and 0.1 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.		Samsung NX500	APS-C	28.0	6480	4320	4K/30p	24.8	13.9	1379	87
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 D810	Full Frame	36.2	7360	4912	1080/60p	25.7	14.8	2853	97
10.		Nikon D850	Full Frame	45.4	8256	5504	4K/30p	26.4	14.8	2660	100
11.		Nikon D5500	APS-C	24.0	6000	4000	1080/60p	24.1	14.0	1438	84
12.		Nikon D5600	APS-C	24.0	6000	4000	1080/60p	24.1	14.0	1306	84
13.		Pentax 645Z	Medium Format	51.1	8256	6192	1080/60i	26.0	14.7	4505	101
14.		Ricoh GR II	APS-C	16.1	4928	3264	1080/30p	23.6	13.7	1078	80
15.		Sony A7R	Full Frame	36.2	7360	4912	1080/60p	25.6	14.1	2746	95
16.		Sony A5100	APS-C	24.0	6000	4000	1080/60p	23.8	12.7	1347	80
17.		Sony A6000	APS-C	24.0	6000	4000	1080/60p	24.1	13.1	1347	82

Many modern cameras cannot only take still pictures, but also record videos. The NX500 indeed provides for movie recording, while the 645D does not. The highest resolution format that the NX500 can use is 4K/30p.

Feature comparison

Apart from body and sensor, cameras can and do differ across a variety of features. For example, the 645D has an optical viewfinder, which can be very useful when shooting in bright sunlight. In contrast, the NX500 relies on live view and the rear LCD for framing. The adjacent table lists some of the other core features of the Pentax 645D and Samsung NX500 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.		Samsung NX500	none	n	3.0 / 1036	tilting	Y	1/6000s	9.0/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 D810	optical	Y	3.2 / 1229	fixed	n	1/8000s	5.0/s	Y	n
10.		Nikon D850	optical	Y	3.2 / 2359	tilting	Y	1/8000s	9.0/s	n	n
11.		Nikon D5500	optical	n	3.2 / 1037	swivel	Y	1/4000s	5.0/s	Y	n
12.		Nikon D5600	optical	n	3.2 / 1037	swivel	Y	1/4000s	5.0/s	Y	n
13.		Pentax 645Z	optical	Y	3.2 / 1037	tilting	n	1/4000s	3.0/s	n	n
14.		Ricoh GR II	optional	n	3.0 / 1230	fixed	n	1/4000s	4.0/s	Y	n
15.		Sony A7R	2400	n	3.0 / 1230	tilting	n	1/8000s	4.0/s	n	n
16.		Sony A5100	none	n	3.0 / 922	tilting	Y	1/4000s	6.0/s	Y	n
17.		Sony A6000	1440	n	3.0 / 922	tilting	n	1/4000s	11.0/s	Y	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 NX500 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 and the Samsung NX500 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 NX500 write their files to SDXC cards. The 645D features dual card slots, which can be very useful in case a memory card fails. In contrast, the NX500 only has one slot. The NX500 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 Samsung NX500 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.		Samsung NX500	Y	stereo / mono	-	-	micro	2.0	Y	Y	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 D810	Y	stereo / mono	Y	Y	mini	3.0	Y	-	-
10.		Nikon D850	Y	stereo / mono	Y	Y	mini	3.0	Y	Y	Y
11.		Nikon D5500	Y	stereo / mono	Y	-	mini	2.0	Y	-	-
12.		Nikon D5600	Y	stereo / mono	Y	-	mini	2.0	Y	Y	Y
13.		Pentax 645Z	Y	stereo / mono	Y	-	mini	3.0	-	-	-
14.		Ricoh GR II	Y	stereo / mono	-	-	micro	2.0	Y	Y	-
15.		Sony A7R	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
16.		Sony A5100	-	stereo / mono	-	-	micro	2.0	Y	Y	-
17.		Sony A6000	Y	stereo / mono	-	-	micro	2.0	Y	Y	-

It is notable that the NX500 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.

Studio photographers will appreciate that the Pentax 645D (unlike the NX500) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.

Both the 645D and the NX500 have been discontinued, but can regularly be found used on ebay. The 645D was replaced by the Pentax 645Z, while the NX500 does not have a direct successor. Further information on the features and operation of the 645D and NX500 can be found, respectively, in the Pentax 645D Manual (free pdf) or the online Samsung NX500 Manual.

Review summary

So what conclusions can be drawn? Is there a clear favorite between the Pentax 645D and the Samsung NX500? Which camera is better? Below is a summary of the relative strengths of each of the two contestants.

Arguments in favor of the Pentax 645D:

• More detail: Offers more megapixels (39.5 vs 28MP) with a 17% higher linear resolution.
• 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.
• Longer lasting: Can take more shots (800 versus 370) 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.
• More heavily discounted: Has been available for much longer (launched in March 2010).

Advantages of the Samsung NX500:

• Better image quality: Scores markedly higher (5 points) in the DXO overall evaluation.
• More dynamic range: Captures a broader range of light and dark details (1.3 EV of extra DR).
• Broader imaging potential: Can capture not only stills but also 4K/30p video.
• Better live-view autofocus: Features on-sensor phase-detection for more confident autofocus.
• More detailed LCD: Has a higher resolution rear screen (1036k vs 921k dots).
• More flexible LCD: Has a tilting screen for odd-angle shots in landscape orientation.
• Fewer buttons to press: Has a touchscreen to facilitate handling and shooting adjustments.
• More selfie-friendly: Has an articulated screen that can be turned to be front-facing.
• Faster shutter: Has higher mechanical shutter speed (1/6000s vs 1/4000s) to freeze action.
• Faster burst: Shoots at higher frequency (9 vs 1.1 flaps/sec) to capture the decisive moment.
• More compact: Is smaller (120x64mm 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.
• Easier travel charging: Can be conveniently charged via its USB port.
• More legacy lens friendly: Can use many non-native lenses via adapters.
• 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.
• Easier device pairing: Supports NFC for fast wireless image transfer over short distances.
• Easier wireless transfer: Supports Bluetooth for image sharing without cables.
• Faster buffer clearing: Has an SD card interface that supports the UHS-I standard.
• More affordable: Was introduced into a lower priced category (92 percent cheaper at launch).
• More modern: Reflects 4 years and 10 months of technical progress since the 645D launch.

If the number of relative strengths (bullet points above) is taken as a guide, the NX500 is the clear winner of the contest (21 : 8 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 sports photographer will view the differences between cameras in a way that diverges from the perspective of a street photog, and a person interested in family portraits has distinct needs from a landscape 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 Samsung NX500 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 comparison of the spec-sheets of cameras can offer a general idea of their imaging potential, it says little about, for example, the shooting experience and imaging performance of the 645D and the NX500 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.		Samsung NX500	4.5/5	..	..	81/100	5/5	4.5/5	Feb 2015	799	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 D810	5/5	..	5/5	86/100	5/5	4.5/5	Jun 2014	3,299	ebay.com
10.		Nikon D850	4.5/5	+ +	5/5	89/100	4.5/5	5/5	Jul 2017	3,299	amazon.com
11.		Nikon D5500	5/5	+	..	79/100	4.5/5	4.5/5	Jan 2015	899	ebay.com
12.		Nikon D5600	4/5	..	4/5	79/100	4.5/5	4/5	Nov 2016	699	ebay.com
13.		Pentax 645Z	5/5	..	3.5/5	..	4.5/5	5/5	Apr 2014	8,499	ebay.com
14.		Ricoh GR II	..	..	..	..	4.5/5	4.5/5	Jun 2015	699	ebay.com
15.		Sony A7R	5/5	+ +	..	82/100	4.5/5	5/5	Oct 2013	2,299	ebay.com
16.		Sony A5100	4.5/5	+	..	..	4.5/5	5/5	Aug 2014	549	ebay.com
17.		Sony A6000	5/5	+	4.5/5	80/100	4.5/5	5/5	Feb 2014	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. A score, therefore, has to be seen in close connection to the price and market introduction time 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. 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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