Pentax 645Z vs Ricoh WG-6

The Pentax 645Z and the Ricoh WG-6 are two digital cameras that were revealed to the public, respectively, in April 2014 and February 2019. The 645Z is a DSLR, while the WG-6 is a fixed lens compact. The cameras are based on a medium format (645Z) and a 1/2.3-inch (WG-6) sensor. The Pentax has a resolution of 51.1 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 645Z		Ricoh WG-6
Digital single lens reflex		Fixed lens compact camera
Pentax 645 mount lenses		28-140mm f/3.5-5.5
51.1 MP – Medium Format sensor		20.2 MP – 1/2.3" sensor
1080/60i Video		4K/30p Video
ISO 100-204,800		ISO 125-6,400
Optical viewfinder		No viewfinder, LCD framing
3.2" LCD – 1037k dots		3.0" LCD – 1040k dots
Tilting screen (no touchscreen)		Fixed screen (not touch-sensitive)
3 shutter flaps per second		1 shutter flaps per second
Weathersealed body		Waterproof body (20m)
650 shots per battery charge		340 shots per battery charge
156 x 117 x 123 mm, 1550 g		118 x 66 x 33 mm, 246 g

Check 645Z 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 645Z 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 645Z and the Ricoh WG-6. The two cameras are presented according to their relative size. Three consecutive perspectives from the front, the top, and the back are available. All width, height and depth measures are rounded to the nearest millimeter.

The WG-6 can be obtained in two different colors (black, orange), while the 645Z 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 645Z. 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 645Z 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 645Z gets 650 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 adjacent table lists the principal physical characteristics of the two cameras alongside a wider set of alternatives. 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 645Z	156 mm	117 mm	123 mm	1550 g	650	Y	Apr 2014	8,499	ebay.com
2.		Ricoh WG-6	118 mm	66 mm	33 mm	246 g	340	Y	Feb 2019	399	amazon.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 5DS	152 mm	116 mm	76 mm	930 g	700	Y	Feb 2015	3,699	ebay.com
5.		Canon 5DS R	152 mm	116 mm	76 mm	930 g	700	Y	Feb 2015	3,699	ebay.com
6.		Canon SX740	110 mm	64 mm	40 mm	299 g	265	n	Jul 2018	399	amazon.com
7.		Hasselblad X1D	150 mm	98 mm	71 mm	725 g	..	Y	Jun 2016	8,995	ebay.com
8.		Leica M11	139 mm	80 mm	39 mm	640 g	700	Y	Jan 2022	8,995	amazon.com
9.		Leica SL	147 mm	104 mm	39 mm	847 g	400	Y	Oct 2015	7,450	ebay.com
10.		Nikon D4S	160 mm	157 mm	91 mm	1350 g	3020	Y	Feb 2014	6,499	ebay.com
11.		Nikon D5	160 mm	159 mm	92 mm	1415 g	3780	Y	Jan 2016	6,499	ebay.com
12.		Nikon D7200	136 mm	107 mm	76 mm	765 g	1110	Y	Mar 2015	1,199	ebay.com
13.		Panasonic TS7	117 mm	76 mm	37 mm	319 g	300	Y	May 2018	449	ebay.com
14.		Pentax 645D	156 mm	117 mm	119 mm	1480 g	800	Y	Mar 2010	9,995	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 listed launch prices provide an indication of the market segment that the manufacturer of the cameras have been targeting. The WG-6 was launched at a lower price than the 645Z, 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. Then, after the new model is out, very good deals can frequently be found on the pre-owned market.

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. Moreover, a large sensor camera will give the photographer more control over depth-of-field in the image and, thus, the ability to better 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 645Z 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 51.1MP, the 645Z offers a higher resolution than the WG-6 (20.2MP), but the 645Z nevertheless has larger individual pixels (pixel pitch of 5.30μm versus 1.18μm for the WG-6) due to its larger sensor. However, the WG-6 is a much more recent model (by 4 years and 10 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 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 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 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 645Z has a native sensitivity range from ISO 100 to ISO 204800. The corresponding ISO settings for the Ricoh WG-6 are ISO 125 to ISO 6400 (no boost).

In terms of underlying technology, the 645Z is build around a CMOS 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 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 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 645Z	Medium Format	51.1	8256	6192	1080/60i	26.0	14.7	4505	101
2.		Ricoh WG-6	1/2.3	20.2	5184	3888	4K/30p	20.7	12.2	1104	52
3.		Canon 1D X Mark II	Full Frame	20.0	5472	3648	4K/60p	24.1	13.5	3207	88
4.		Canon 5DS	Full Frame	50.3	8688	5792	1080/30p	24.7	12.4	2381	87
5.		Canon 5DS R	Full Frame	50.3	8688	5792	1080/30p	24.6	12.4	2308	86
6.		Canon SX740	1/2.3	20.2	5184	3888	4K/30p	20.6	12.1	1050	51
7.		Hasselblad X1D	Medium Format	51.3	8272	6200	1080/25p	26.2	14.8	4489	102
8.		Leica M11	Full Frame	60.3	9528	6328	none	26.3	14.8	3376	100
9.		Leica SL	Full Frame	24.0	6000	4000	4K/30p	25.0	13.4	1821	88
10.		Nikon D4S	Full Frame	16.2	4928	3280	1080/60p	24.4	13.3	3074	89
11.		Nikon D5	Full Frame	20.7	5588	3712	4K/30p	25.1	12.3	2343	88
12.		Nikon D7200	APS-C	24.0	6000	4000	1080/60p	24.5	14.6	1333	87
13.		Panasonic TS7	1/2.3	20.2	5184	3888	4K/30p	20.6	12.1	1028	51
14.		Pentax 645D	Medium Format	39.5	7264	5440	none	24.6	12.6	1262	82
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. Both cameras under consideration have a sensor with sufficiently fast read-out times for moving pictures, but the WG-6 provides a better video resolution than the 645Z. It can shoot movie 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 variety of features. For example, the 645Z 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 table below summarizes some of the other core capabilities of the Pentax 645Z and Ricoh WG-6 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 645Z	optical	Y	3.2 / 1037	tilting	n	1/4000s	3.0/s	n	n
2.		Ricoh WG-6	none	n	3.0 / 1040	fixed	n	1/4000s	1.0/s	Y	n
3.		Canon 1D X Mark II	optical	Y	3.2 / 1620	fixed	Y	1/8000s	16.0/s	n	n
4.		Canon 5DS	optical	Y	3.2 / 1040	fixed	n	1/8000s	5.0/s	n	n
5.		Canon 5DS R	optical	Y	3.2 / 1040	fixed	n	1/8000s	5.0/s	n	n
6.		Canon SX740	none	n	3.0 / 922	tilting	n	1/3200s	10.0/s	Y	Y
7.		Hasselblad X1D	2360	n	3.0 / 920	fixed	Y	1/2000s	2.3/s	n	n
8.		Leica M11	optical	n	3.0 / 2333	fixed	Y	1/4000s	4.5/s	n	n
9.		Leica SL	4400	Y	3.0 / 1040	fixed	Y	1/8000s	11.0/s	n	n
10.		Nikon D4S	optical	Y	3.2 / 921	fixed	n	1/8000s	11.0/s	n	n
11.		Nikon D5	optical	Y	3.2 / 2359	fixed	Y	1/8000s	14.0/s	n	n
12.		Nikon D7200	optical	Y	3.2 / 1229	fixed	n	1/8000s	6.0/s	Y	n
13.		Panasonic TS7	1170	n	3.0 / 1040	fixed	n	1/1300s	10.0/s	Y	Y
14.		Pentax 645D	optical	Y	3.0 / 921	fixed	n	1/4000s	1.1/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 645Z, 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 645Z 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 645Z and the WG-6 write their files to SDXC cards. The 645Z features dual card slots, which can be very useful in case a memory card fails. In contrast, the WG-6 only has one slot. The 645Z supports UHS-I cards (Ultra High Speed data transfer of up to 104 MB/s), while the WG-6 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 645Z 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 645Z	Y	stereo / mono	Y	-	mini	3.0	-	-	-
2.		Ricoh WG-6	-	mono / mono	-	-	micro	3.0	-	-	-
3.		Canon 1D X Mark II	Y	mono / mono	Y	Y	mini	3.0	-	-	-
4.		Canon 5DS	Y	mono / mono	Y	-	mini	3.0	-	-	-
5.		Canon 5DS R	Y	mono / mono	Y	-	mini	3.0	-	-	-
6.		Canon SX740	-	stereo / mono	-	-	micro	2.0	Y	-	Y
7.		Hasselblad X1D	Y	stereo / mono	Y	Y	mini	3.0	Y	-	-
8.		Leica M11	Y	- / -	-	-	-	3.2	Y	-	Y
9.		Leica SL	Y	stereo / mono	Y	Y	full	3.0	Y	-	-
10.		Nikon D4S	Y	mono / mono	Y	Y	mini	2.0	-	-	-
11.		Nikon D5	Y	stereo / mono	Y	Y	mini	3.0	-	-	-
12.		Nikon D7200	Y	stereo / mono	Y	Y	mini	2.0	Y	Y	-
13.		Panasonic TS7	-	stereo / mono	-	-	micro	2.0	Y	-	-
14.		Pentax 645D	Y	stereo / -	-	-	-	2.0	-	-	-
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 645Z 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 645Z (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 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 645Z and WG-6 can be found, respectively, in the Pentax 645Z Manual (free pdf) or the online Ricoh WG-6 Manual.

Review summary

So what conclusions can be drawn? Is the Pentax 645Z better than the Ricoh WG-6 or vice versa? A synthesis of the relative strong points of each of the models is listed below.

Reasons to prefer the Pentax 645Z:

• More detail: Offers more megapixels (51.1 vs 20.2MP) with a 59% 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.
• Better sound: Can connect to an external microphone for higher quality sound recording.
• 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.
• Larger screen: Has a bigger rear LCD (3.2" vs 3.0") for image review and settings control.
• More flexible LCD: Has a tilting screen for odd-angle shots in landscape orientation.
• Faster burst: Shoots at higher frequency (3 vs 1 flaps/sec) to capture the decisive moment.
• More flexible: Can take a variety of interchangeable lenses, including specialty optics.
• Longer lasting: Can take more shots (650 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.
• Faster buffer clearing: Has an SD card interface that supports the UHS-I standard.
• More heavily discounted: Has been available for much longer (launched in April 2014).

Advantages of the Ricoh WG-6:

• Better video: Provides higher definition movie capture (4K/30p vs 1080/60i).
• Ready to shoot: Comes with an integrated lens, while the 645Z 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 645Z).
• 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.
• More affordable: Was introduced at a lower price, despite coming with a built-in lens.
• More modern: Reflects 4 years and 10 months of technical progress since the 645Z launch.

If the count of relative strengths (bullet points above) is taken as a measure, the 645Z is the clear winner of the match-up (18 : 10 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 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 645Z 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 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 645Z and the WG-6 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 why hands-on reviews by experts 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 645Z	5/5	..	3.5/5	..	4.5/5	5/5	Apr 2014	8,499	ebay.com
2.		Ricoh WG-6	..	..	..	..	3.5/5	3.5/5	Feb 2019	399	amazon.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 5DS	..	+	..	83/100	4.5/5	4.5/5	Feb 2015	3,699	ebay.com
5.		Canon 5DS R	5/5	+	..	83/100	5/5	4.5/5	Feb 2015	3,699	ebay.com
6.		Canon SX740	..	+	3.5/5	..	4/5	4/5	Jul 2018	399	amazon.com
7.		Hasselblad X1D	..	o	..	81/100	..	4/5	Jun 2016	8,995	ebay.com
8.		Leica M11	4.5/5	..	4.5/5	..	4.5/5	4.5/5	Jan 2022	8,995	amazon.com
9.		Leica SL	4/5	..	4/5	84/100	4.5/5	4/5	Oct 2015	7,450	ebay.com
10.		Nikon D4S	5/5	..	..	..	4.5/5	4.5/5	Feb 2014	6,499	ebay.com
11.		Nikon D5	..	..	4/5	89/100	4.5/5	5/5	Jan 2016	6,499	ebay.com
12.		Nikon D7200	4/5	+ +	..	84/100	4.5/5	4.5/5	Mar 2015	1,199	ebay.com
13.		Panasonic TS7	..	+	..	..	..	3.5/5	May 2018	449	ebay.com
14.		Pentax 645D	5/5	..	..	..	..	..	Mar 2010	9,995	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.

Care should be taken when interpreting the review scores above, though. The assessments were made in relation to similar cameras of the same technological generation. A score, therefore, has to be seen in close connection to the price and market introduction time 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

Did this review help to inform your camera decision process? In case you are interested in seeing how other cameras pair up, just make a corresponding selection in the search boxes 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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