Pentax 645Z vs Ricoh GR II

The Pentax 645Z and the Ricoh GR II are two digital cameras that were officially introduced, respectively, in April 2014 and June 2015. The 645Z is a DSLR, while the GR II is a fixed lens compact. The cameras are based on a medium format (645Z) and an APS-C (GR II) sensor. The Pentax has a resolution of 51.1 megapixels, whereas the Ricoh provides 16.1 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 GR II
Digital single lens reflex		Fixed lens compact camera
Pentax 645 mount lenses		28mm f/2.8
51.1 MP – Medium Format sensor		16.1 MP – APS-C sensor
1080/60i Video		1080/30p Video
ISO 100-204,800		ISO 100-25,600
Optical viewfinder		Viewfinder optional
3.2" LCD – 1037k dots		3.0" LCD – 1230k dots
Tilting screen (no touchscreen)		Fixed screen (not touch-sensitive)
3 shutter flaps per second		4 shutter flaps per second
Weathersealed body		not weather sealed
650 shots per battery charge		320 shots per battery charge
156 x 117 x 123 mm, 1550 g		117 x 63 x 35 mm, 251 g

Check 645Z offers at
ebay.com
Check GR II offers at
ebay.com

Going beyond this snapshot of core features and characteristics, what are the differences between the Pentax 645Z and the Ricoh GR II? 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 645Z and the Ricoh GR II 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 Ricoh GR II is considerably smaller (60 percent) than the Pentax 645Z. It is worth mentioning in this context that the 645Z is splash and dust resistant, while the GR II does not feature any corresponding weather-sealing.

The above size and weight comparisons are to some extent incomplete and possibly misleading, as the GR II 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 GR II can take 320 images on a single charge of its Ricoh DB-65 power pack. The power pack in the GR II 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 645Z	156 mm	117 mm	123 mm	1550 g	650	Y	Apr 2014	8,499	ebay.com
2.		Ricoh GR II	117 mm	63 mm	35 mm	251 g	320	n	Jun 2015	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 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 G7 X	103 mm	60 mm	40 mm	304 g	210	n	Sep 2014	699	ebay.com
7.		Fujifilm X70	113 mm	64 mm	44 mm	340 g	330	n	Jan 2016	799	ebay.com
8.		Hasselblad X1D	150 mm	98 mm	71 mm	725 g	..	Y	Jun 2016	8,995	ebay.com
9.		Leica M11	139 mm	80 mm	39 mm	640 g	700	Y	Jan 2022	8,995	amazon.com
10.		Leica SL	147 mm	104 mm	39 mm	847 g	400	Y	Oct 2015	7,450	ebay.com
11.		Nikon D4S	160 mm	157 mm	91 mm	1350 g	3020	Y	Feb 2014	6,499	ebay.com
12.		Nikon D5	160 mm	159 mm	92 mm	1415 g	3780	Y	Jan 2016	6,499	ebay.com
13.		Nikon D7200	136 mm	107 mm	76 mm	765 g	1110	Y	Mar 2015	1,199	ebay.com
14.		Panasonic GM5	99 mm	60 mm	36 mm	211 g	220	n	Sep 2014	749	ebay.com
15.		Pentax 645D	156 mm	117 mm	119 mm	1480 g	800	Y	Mar 2010	9,995	ebay.com
16.		Ricoh GR	117 mm	61 mm	35 mm	245 g	290	n	Apr 2013	799	ebay.com
17.		Sony RX100 III	102 mm	58 mm	41 mm	290 g	320	n	May 2014	799	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 manufacturer’s suggested retail prices give an idea on the placement of the camera in the maker’s lineup and the broader market. The GR II 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.

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 GR II an APS-C sensor. The sensor area in the GR II is 74 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 645Z has a native 4:3 aspect ratio, while the one in the GR II offers a 3:2 aspect.

With 51.1MP, the 645Z offers a higher resolution than the GR II (16.1MP), but the 645Z nevertheless has larger individual pixels (pixel pitch of 5.30μm versus 4.79μm for the GR II) due to its larger sensor. However, the GR II is a somewhat more recent model (by 1 year and 2 months) than the 645Z, and its sensor might have benefitted from technological advances during this time that 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 GR II are 24.6 x 16.3 inches or 62.6 x 41.5 cm for good quality, 19.7 x 13.1 inches or 50.1 x 33.2 cm for very good quality, and 16.4 x 10.9 inches or 41.7 x 27.6 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 GR II are ISO 100 to ISO 25600 (no boost).

Technology-wise, both cameras are equipped with CMOS (Complementary Metal–Oxide–Semiconductor) sensors. 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"). Of the two cameras under review, the 645Z provides substantially higher image quality than the GR II, with an overall score that is 21 points higher. This advantage is based on 2.4 bits higher color depth, 1 EV in additional dynamic range, and 2.1 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 645Z	Medium Format	51.1	8256	6192	1080/60i	26.0	14.7	4505	101
2.		Ricoh GR II	APS-C	16.1	4928	3264	1080/30p	23.6	13.7	1078	80
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 G7 X	1-inch	20.0	5472	3648	1080/60p	23.0	12.7	556	71
7.		Fujifilm X70	APS-C	16.0	4896	3264	1080/60p	23.7	13.0	1608	80
8.		Hasselblad X1D	Medium Format	51.3	8272	6200	1080/25p	26.2	14.8	4489	102
9.		Leica M11	Full Frame	60.3	9528	6328	none	26.3	14.8	3376	100
10.		Leica SL	Full Frame	24.0	6000	4000	4K/30p	25.0	13.4	1821	88
11.		Nikon D4S	Full Frame	16.2	4928	3280	1080/60p	24.4	13.3	3074	89
12.		Nikon D5	Full Frame	20.7	5588	3712	4K/30p	25.1	12.3	2343	88
13.		Nikon D7200	APS-C	24.0	6000	4000	1080/60p	24.5	14.6	1333	87
14.		Panasonic GM5	Four Thirds	15.8	4592	3448	1080/60p	22.1	11.7	721	66
15.		Pentax 645D	Medium Format	39.5	7264	5440	none	24.6	12.6	1262	82
16.		Ricoh GR	APS-C	16.1	4928	3264	1080/30p	23.6	13.5	972	78
17.		Sony RX100 III	1-inch	20.0	5472	3648	1080/60p	22.4	12.3	495	67
Note: DXO values in italics represent estimates based on sensor size and age.

Many modern cameras cannot only take still pictures, but also record videos. The two cameras under consideration both have sensors whose read-out speed is fast enough to capture moving pictures, but the 645Z provides a higher frame rate than the GR II. It can shoot video footage at 1080/60i, while the Ricoh is limited to 1080/30p.

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 GR II relies on live view and the rear LCD for framing. That said, the GR II can be equipped with an optional viewfinder – the GV-1. The table below summarizes some of the other core capabilities of the Pentax 645Z and Ricoh GR II 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 GR II	optional	n	3.0 / 1230	fixed	n	1/4000s	4.0/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 G7 X	none	n	3.0 / 1040	tilting	Y	1/2000s	6.5/s	Y	Y
7.		Fujifilm X70	optional	n	3.0 / 1040	tilting	Y	1/4000s	8.0/s	Y	n
8.		Hasselblad X1D	2360	n	3.0 / 920	fixed	Y	1/2000s	2.3/s	n	n
9.		Leica M11	optical	n	3.0 / 2333	fixed	Y	1/4000s	4.5/s	n	n
10.		Leica SL	4400	Y	3.0 / 1040	fixed	Y	1/8000s	11.0/s	n	n
11.		Nikon D4S	optical	Y	3.2 / 921	fixed	n	1/8000s	11.0/s	n	n
12.		Nikon D5	optical	Y	3.2 / 2359	fixed	Y	1/8000s	14.0/s	n	n
13.		Nikon D7200	optical	Y	3.2 / 1229	fixed	n	1/8000s	6.0/s	Y	n
14.		Panasonic GM5	1166	n	3.0 / 921	fixed	Y	1/500s	5.8/s	n	n
15.		Pentax 645D	optical	Y	3.0 / 921	fixed	n	1/4000s	1.1/s	n	n
16.		Ricoh GR	optional	n	3.0 / 1230	fixed	n	1/4000s	4.0/s	Y	n
17.		Sony RX100 III	1440	n	3.0 / 1229	tilting	n	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 GR II 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 GR II 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 GR II 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 GR II only has one slot. Both cameras can use UHS-I cards, which provide for Ultra High Speed data transfer of up to 104 MB/s.

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 GR II 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 GR II	Y	stereo / mono	-	-	micro	2.0	Y	Y	-
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 G7 X	-	stereo / mono	-	-	micro	2.0	Y	Y	-
7.		Fujifilm X70	Y	stereo / mono	Y	-	micro	2.0	Y	-	-
8.		Hasselblad X1D	Y	stereo / mono	Y	Y	mini	3.0	Y	-	-
9.		Leica M11	Y	- / -	-	-	-	3.2	Y	-	Y
10.		Leica SL	Y	stereo / mono	Y	Y	full	3.0	Y	-	-
11.		Nikon D4S	Y	mono / mono	Y	Y	mini	2.0	-	-	-
12.		Nikon D5	Y	stereo / mono	Y	Y	mini	3.0	-	-	-
13.		Nikon D7200	Y	stereo / mono	Y	Y	mini	2.0	Y	Y	-
14.		Panasonic GM5	Y	stereo / mono	-	-	micro	2.0	Y	-	-
15.		Pentax 645D	Y	stereo / -	-	-	-	2.0	-	-	-
16.		Ricoh GR	Y	mono / mono	-	-	micro	2.0	-	-	-
17.		Sony RX100 III	-	stereo / mono	-	-	micro	2.0	Y	Y	-

It is notable that the 645Z has a microphone port, which is missing on the GR II. Such an external microphone input can help to substantially improve the quality of audio recordings when a good external microphone is used.

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

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

Review summary

So what is the bottom line? Is there a clear favorite between the Pentax 645Z and the Ricoh GR II? Which camera is better? The listing below highlights the relative strengths of the two models.

Advantages of the Pentax 645Z:

• More detail: Offers more megapixels (51.1 vs 16.1MP) with a 75% higher linear resolution.
• Better image quality: Scores substantially higher (21 points) in the DXO overall assessment.
• Richer colors: Generates images with noticeably better colors (2.4 bits more color depth).
• More dynamic range: Captures a larger spectrum of light and dark details (1 EV of extra DR).
• Better low-light sensitivity: Requires less light for good images (2.1 stops ISO advantage).
• Better video: Provides higher movie framerates (1080/60i versus 1080/30p).
• 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.
• More flexible: Can take a variety of interchangeable lenses, including specialty optics.
• Longer lasting: Can take more shots (650 versus 320) on a single battery charge.
• Better sealing: Is weather sealed to enable shooting in dusty or wet environments.
• Faster data transfer: Supports a more advanced USB protocol (3.0 vs 2.0).
• 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 on the market for longer (launched in April 2014).

Reasons to prefer the Ricoh GR II:

• More detailed LCD: Has a higher resolution rear screen (1230k vs 1037k dots).
• Faster burst: Shoots at higher frequency (4 vs 3 flaps/sec) to capture the decisive moment.
• Ready to shoot: Comes with an integrated lens, while the 645Z requires a separate lens.
• More compact: Is smaller (117x63mm 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.
• 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.
• More affordable: Was introduced at a lower price, despite coming with a built-in lens.
• More modern: Was introduced somewhat (1 year and 2 months) more recently.

If the count of individual advantages (bullet points above) is taken as a guide, the 645Z is the clear winner of the match-up (18 : 11 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 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 645Z and the Ricoh GR II place the cameras among the top in their class? Find out in the latest Best DSLR Camera and Best Prime Lens Compact 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 remains incomplete and does no justice, for example, to the way the 645Z or the GR II perform in practice. 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 where reviews by experts come in. The adjacent summary-table relays the overall verdicts of several of the most popular 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 GR II	..	..	..	..	4.5/5	4.5/5	Jun 2015	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 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 G7 X	4/5	+ +	..	77/100	4.5/5	4.5/5	Sep 2014	699	ebay.com
7.		Fujifilm X70	4.5/5	..	..	76/100	4.5/5	4.5/5	Jan 2016	799	ebay.com
8.		Hasselblad X1D	..	o	..	81/100	..	4/5	Jun 2016	8,995	ebay.com
9.		Leica M11	4.5/5	..	4.5/5	..	4.5/5	4.5/5	Jan 2022	8,995	amazon.com
10.		Leica SL	4/5	..	4/5	84/100	4.5/5	4/5	Oct 2015	7,450	ebay.com
11.		Nikon D4S	5/5	..	..	..	4.5/5	4.5/5	Feb 2014	6,499	ebay.com
12.		Nikon D5	..	..	4/5	89/100	4.5/5	5/5	Jan 2016	6,499	ebay.com
13.		Nikon D7200	4/5	+ +	..	84/100	4.5/5	4.5/5	Mar 2015	1,199	ebay.com
14.		Panasonic GM5	3.5/5	+	..	77/100	5/5	4.5/5	Sep 2014	749	ebay.com
15.		Pentax 645D	5/5	..	..	..	..	..	Mar 2010	9,995	ebay.com
16.		Ricoh GR	5/5	..	..	79/100	4.5/5	4.5/5	Apr 2013	799	ebay.com
17.		Sony RX100 III	5/5	+ +	..	82/100	4.5/5	5/5	May 2014	799	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. Hence, a score should always be seen in the context of the camera's market launch date and its price, and comparisons of ratings among very different cameras or across long time periods have little meaning. Also, please note that some of the review sites have changed their methodology and reporting over time.

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Other camera comparisons

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