Pentax 645D vs Ricoh WG-6

The Pentax 645D and the Ricoh WG-6 are two digital cameras that were officially introduced, respectively, in March 2010 and February 2019. The 645D is a DSLR, while the WG-6 is a fixed lens compact. The cameras are based on a medium format (645D) and a 1/2.3-inch (WG-6) sensor. The Pentax has a resolution of 39.5 megapixels, whereas the Ricoh provides 20.2 MP.

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

Headline Specifications

Pentax 645D		Ricoh WG-6
Digital single lens reflex		Fixed lens compact camera
Pentax 645 mount lenses		28-140mm f/3.5-5.5
39.5 MP – Medium Format sensor		20.2 MP – 1/2.3" sensor
no Video		4K/30p Video
ISO 100-1,600		ISO 125-6,400
Optical viewfinder		No viewfinder, LCD framing
3.0" LCD – 921k dots		3.0" LCD – 1040k dots
Fixed screen (not touch-sensitive)		Fixed screen (not touch-sensitive)
1.1 shutter flaps per second		1 shutter flaps per second
Weathersealed body		Waterproof body (20m)
800 shots per battery charge		340 shots per battery charge
156 x 117 x 119 mm, 1480 g		118 x 66 x 33 mm, 246 g

Check 645D offers at
ebay.com
Check WG-6 price at
amazon.com

Going beyond this snapshot of core features and characteristics, what are the differences between the Pentax 645D and the Ricoh WG-6? 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 side-by-side display below illustrates the physical size and weight of the Pentax 645D and the Ricoh WG-6. 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.

The WG-6 can be obtained in two different colors (black, orange), 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 Ricoh WG-6 is considerably smaller (57 percent) than the Pentax 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. More than that, the WG-6 is water-proof up to 20m and can, thus, be used for underwater photography.

The above size and weight comparisons are to some extent incomplete and possibly misleading, as the WG-6 has a lens built in, whereas the 645D is an interchangeable lens camera that requires a separate lens. Attaching the latter will add extra weight and bulk to the setup.

Concerning battery life, the 645D gets 800 shots out of its Pentax D-LI90 battery, while the WG-6 can take 340 images on a single charge of its Ricoh DB-110 power pack. The power pack in the WG-6 can be charged via the USB port, which can be very convenient when travelling.

The table below summarizes the key physical specs of the two cameras alongside a broader set of comparators. If you would like to visualize and compare a different camera combination, you can navigate to the CAM-parator app and make your selection from a broad list of cameras 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.		Ricoh WG-6	118 mm	66 mm	33 mm	246 g	340	Y	Feb 2019	399	amazon.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.		Canon SX740	110 mm	64 mm	40 mm	299 g	265	n	Jul 2018	399	amazon.com
7.		Leica S Typ 006	160 mm	120 mm	80 mm	1260 g	..	Y	Sep 2012	21,950	ebay.com
8.		Nikon D3S	160 mm	157 mm	88 mm	1240 g	4200	Y	Oct 2009	5,199	ebay.com
9.		Nikon D5	160 mm	159 mm	92 mm	1415 g	3780	Y	Jan 2016	6,499	ebay.com
10.		Nikon D810	146 mm	123 mm	82 mm	980 g	1200	Y	Jun 2014	3,299	ebay.com
11.		Nikon D850	146 mm	124 mm	79 mm	1005 g	1840	Y	Jul 2017	3,299	amazon.com
12.		Panasonic TS7	117 mm	76 mm	37 mm	319 g	300	Y	May 2018	449	ebay.com
13.		Pentax 645Z	156 mm	117 mm	123 mm	1550 g	650	Y	Apr 2014	8,499	ebay.com
14.		Sony A7R	127 mm	94 mm	48 mm	465 g	340	Y	Oct 2013	2,299	ebay.com
15.		Sony HX95	102 mm	58 mm	36 mm	242 g	370	n	Aug 2018	429	ebay.com
16.		Sony HX99	102 mm	58 mm	36 mm	242 g	370	n	Aug 2018	449	ebay.com
17.		Sony WX800	102 mm	58 mm	36 mm	233 g	370	n	Oct 2018	399	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 WG-6 was launched at a lower price than the 645D, despite having a lens built in. 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. 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 Ricoh WG-6 a 1/2.3-inch sensor. The sensor area in the WG-6 is 98 percent smaller. As a result of these sensor size differences, the cameras have a format factor of, respectively, 0.79 and 5.6. Both cameras feature a native aspect ratio (sensor width to sensor height) of 4:3.

With 39.5MP, the 645D offers a higher resolution than the WG-6 (20.2MP), but the 645D nevertheless has larger individual pixels (pixel pitch of 6.06μm versus 1.18μm for the WG-6) due to its larger sensor. However, the WG-6 is a much more recent model (by 8 years and 11 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 Ricoh WG-6 are 25.9 x 19.4 inches or 65.8 x 49.4 cm for good quality, 20.7 x 15.6 inches or 52.7 x 39.5 cm for very good quality, and 17.3 x 13 inches or 43.9 x 32.9 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 Ricoh WG-6 are ISO 125 to ISO 6400 (no boost).

In terms of underlying technology, the 645D is build around a CCD sensor, while the WG-6 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.

Since 2007, DXO Mark has published sensor performance measurements that have been derived using a consistent methodology. 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"). The table below summarizes the physical sensor characteristics and sensor quality findings and compares them across a set of similar 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.		Ricoh WG-6	1/2.3	20.2	5184	3888	4K/30p	20.7	12.2	1104	52
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.		Canon SX740	1/2.3	20.2	5184	3888	4K/30p	20.6	12.1	1050	51
7.		Leica S Typ 006	Medium Format	37.5	7500	5000	none	23.9	12.2	824	76
8.		Nikon D3S	Full Frame	12.1	4256	2832	720/24p	23.5	12.0	3253	82
9.		Nikon D5	Full Frame	20.7	5588	3712	4K/30p	25.1	12.3	2343	88
10.		Nikon D810	Full Frame	36.2	7360	4912	1080/60p	25.7	14.8	2853	97
11.		Nikon D850	Full Frame	45.4	8256	5504	4K/30p	26.4	14.8	2660	100
12.		Panasonic TS7	1/2.3	20.2	5184	3888	4K/30p	20.6	12.1	1028	51
13.		Pentax 645Z	Medium Format	51.1	8256	6192	1080/60i	26.0	14.7	4505	101
14.		Sony A7R	Full Frame	36.2	7360	4912	1080/60p	25.6	14.1	2746	95
15.		Sony HX95	1/2.3	18.0	4896	3672	4K/30p	20.6	12.1	1057	51
16.		Sony HX99	1/2.3	18.0	4896	3672	4K/30p	20.6	12.1	1058	51
17.		Sony WX800	1/2.3	18.0	4896	3672	4K/30p	20.6	12.2	1070	51
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 WG-6 indeed provides for movie recording, while the 645D does not. The highest resolution format that the WG-6 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 WG-6 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 Ricoh WG-6 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.		Ricoh WG-6	none	n	3.0 / 1040	fixed	n	1/4000s	1.0/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.		Canon SX740	none	n	3.0 / 922	tilting	n	1/3200s	10.0/s	Y	Y
7.		Leica S Typ 006	optical	Y	3.0 / 922	fixed	n	1/4000s	1.5/s	n	n
8.		Nikon D3S	optical	Y	3.0 / 921	fixed	n	1/8000s	11.0/s	n	n
9.		Nikon D5	optical	Y	3.2 / 2359	fixed	Y	1/8000s	14.0/s	n	n
10.		Nikon D810	optical	Y	3.2 / 1229	fixed	n	1/8000s	5.0/s	Y	n
11.		Nikon D850	optical	Y	3.2 / 2359	tilting	Y	1/8000s	9.0/s	n	n
12.		Panasonic TS7	1170	n	3.0 / 1040	fixed	n	1/1300s	10.0/s	Y	Y
13.		Pentax 645Z	optical	Y	3.2 / 1037	tilting	n	1/4000s	3.0/s	n	n
14.		Sony A7R	2400	n	3.0 / 1230	tilting	n	1/8000s	4.0/s	n	n
15.		Sony HX95	638	n	3.0 / 922	tilting	n	1/2000s	10.0/s	Y	Y
16.		Sony HX99	638	n	3.0 / 922	tilting	Y	1/2000s	10.0/s	Y	Y
17.		Sony WX800	none	n	3.0 / 922	tilting	Y	1/2000s	10.0/s	Y	Y
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 WG-6 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 Ricoh WG-6 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 WG-6 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 WG-6 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 Ricoh WG-6 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.		Ricoh WG-6	-	mono / mono	-	-	micro	3.0	-	-	-
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.		Canon SX740	-	stereo / mono	-	-	micro	2.0	Y	-	Y
7.		Leica S Typ 006	Y	- / -	-	-	mini	2.0	-	-	-
8.		Nikon D3S	Y	stereo / -	-	-	mini	2.0	-	-	-
9.		Nikon D5	Y	stereo / mono	Y	Y	mini	3.0	-	-	-
10.		Nikon D810	Y	stereo / mono	Y	Y	mini	3.0	Y	-	-
11.		Nikon D850	Y	stereo / mono	Y	Y	mini	3.0	Y	Y	Y
12.		Panasonic TS7	-	stereo / mono	-	-	micro	2.0	Y	-	-
13.		Pentax 645Z	Y	stereo / mono	Y	-	mini	3.0	-	-	-
14.		Sony A7R	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
15.		Sony HX95	-	stereo / mono	-	-	micro	2.0	Y	Y	Y
16.		Sony HX99	-	stereo / mono	-	-	micro	2.0	Y	Y	Y
17.		Sony WX800	-	stereo / mono	-	-	micro	2.0	Y	Y	-

It is notable that the 645D has a hotshoe, while the WG-6 does not. This socket makes it possible to easily attach optional accessories, such as an external flash gun.

Studio photographers will appreciate that the Pentax 645D (unlike the WG-6) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.

Travel and landscape photographers will find it useful that the WG-6 has an internal geolocalization sensor and can record GPS coordinates in its EXIF data.

The WG-6 is a recent model that features in the current product line-up of Ricoh. In contrast, the 645D has been discontinued (but can be found pre-owned on ebay). As a replacement in the same line of cameras, the 645D was succeeded by the Pentax 645Z. Further information on the features and operation of the 645D and WG-6 can be found, respectively, in the Pentax 645D Manual (free pdf) or the online Ricoh WG-6 Manual.

Review summary

So how do things add up? Is there a clear favorite between the Pentax 645D and the Ricoh WG-6? Which camera is better? A synthesis of the relative strong points of each of the models is listed below.

Arguments in favor of the Pentax 645D:

• More detail: Offers more megapixels (39.5 vs 20.2MP) with a 40% higher linear resolution.
• Better image quality: Features bigger pixels on a larger sensor for higher quality imaging.
• Richer colors: The pixel size advantage translates into images with better, more accurate colors.
• More dynamic range: Larger pixels capture a wider spectrum of light and dark details.
• Better low-light sensitivity: Larger pixels means good image quality even under poor lighting.
• 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.
• More flexible: Can take a variety of interchangeable lenses, including specialty optics.
• Longer lasting: Can take more shots (800 versus 340) on a single battery charge.
• Better lighting: Features a hotshoe and can thus hold and trigger an external flash gun.
• 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 Ricoh WG-6:

• Broader imaging potential: Can capture not only stills but also 4K/30p video.
• More detailed LCD: Has a higher resolution rear screen (1040k vs 921k dots).
• Ready to shoot: Comes with an integrated lens, while the 645D requires a separate lens.
• More compact: Is smaller (118x66mm vs 156x117mm) and will fit more readily into a bag.
• Less heavy: Has a lower weight even though it has a lens built in (unlike the 645D).
• Easier travel charging: Can be conveniently charged via its USB port.
• Water-proof: Is rugged and sealed and can thus be used for underwater photography (up to 20m).
• Easier fill-in: Has a small integrated flash to brighten shadows of backlit subjects.
• Easier geotagging: Features an internal GPS sensor to log localization data.
• Faster data transfer: Supports a more advanced USB protocol (3.0 vs 2.0).
• More affordable: Was introduced at a lower price, despite coming with a built-in lens.
• More modern: Reflects 8 years and 11 months of technical progress since the 645D launch.

If the count of individual advantages (bullet points above) is taken as a guide, the 645D comes out slightly ahead of the WG-6 (13 : 12 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 Pentax 645D and the Ricoh WG-6 place the cameras among the top in their class? Find out in the latest Best DSLR Camera and Best Travel-Zoom Camera listings 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 incomplete and does no justice, for example, to the way the 645D or the WG-6 perform in practice. At times, user reviews, such as those published at amazon, address these issues in a useful manner, but such feedback is on many occasions incomplete, inconsistent, and unreliable.

Expert reviews

This is why hands-on reviews by experts are important. 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.		Pentax 645D	5/5	..	..	..	..	..	Mar 2010	9,995	ebay.com
2.		Ricoh WG-6	..	..	..	..	3.5/5	3.5/5	Feb 2019	399	amazon.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.		Canon SX740	..	+	3.5/5	..	4/5	4/5	Jul 2018	399	amazon.com
7.		Leica S Typ 006	..	..	..	..	..	..	Sep 2012	21,950	ebay.com
8.		Nikon D3S	5/5	..	..	89/100	4.5/5	5/5	Oct 2009	5,199	ebay.com
9.		Nikon D5	..	..	4/5	89/100	4.5/5	5/5	Jan 2016	6,499	ebay.com
10.		Nikon D810	5/5	..	5/5	86/100	5/5	4.5/5	Jun 2014	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.		Panasonic TS7	..	+	..	..	..	3.5/5	May 2018	449	ebay.com
13.		Pentax 645Z	5/5	..	3.5/5	..	4.5/5	5/5	Apr 2014	8,499	ebay.com
14.		Sony A7R	5/5	+ +	..	82/100	4.5/5	5/5	Oct 2013	2,299	ebay.com
15.		Sony HX95	..	..	..	..	..	..	Aug 2018	429	ebay.com
16.		Sony HX99	..	..	..	..	4/5	4.5/5	Aug 2018	449	ebay.com
17.		Sony WX800	..	..	..	..	..	..	Oct 2018	399	ebay.com
Note: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.

The above review scores should be interpreted with care, though. The ratings are only valid when referring to cameras in the same category and of the same age. Hence, a score should always be seen in the context of the camera's market launch date and its price, 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

Did this review help to inform your camera decision process? If you would like to see a different side-by-side camera review, just use the search menu below. There is also a set of direct links to comparison reviews that other users of the CAM-parator app explored.

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