Pentax K-3 II vs Ricoh GR III

The Pentax K-3 II and the Ricoh GR III are two digital cameras that were officially introduced, respectively, in April 2015 and February 2019. The K-3 II is a DSLR, while the GR III is a fixed lens compact. Both cameras are equipped with an APS-C sensor. The Pentax has a resolution of 24.1 megapixels, whereas the Ricoh provides 24 MP.

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

Headline Specifications

Pentax K-3 II		Ricoh GR III
Digital single lens reflex		Fixed lens compact camera
Pentax K mount lenses		28mm f/2.8
24.1 MP – APS-C sensor		24 MP – APS-C sensor
1080/60i Video		1080/60p Video
ISO 100-51,200		ISO 100-102,400
Optical viewfinder		Viewfinder optional
3.2" LCD – 1037k dots		3.0" LCD – 1037k dots
Fixed screen (not touch-sensitive)		Fixed touchscreen
8.3 shutter flaps per second		4 shutter flaps per second
In-body stabilization		In-body stabilization
Weathersealed body		not weather sealed
720 shots per battery charge		200 shots per battery charge
131 x 100 x 77 mm, 800 g		109 x 62 x 33 mm, 257 g

Check K-3 II offers at
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Check GR III price at
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Going beyond this snapshot of core features and characteristics, what are the differences between the Pentax K-3 II and the Ricoh GR III? 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

An illustration of the physical size and weight of the Pentax K-3 II and the Ricoh GR III is provided in the side-by-side display below. 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 K-3 II can be obtained in two different colors (black, silver), while the GR III 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 GR III is considerably smaller (48 percent) than the Pentax K-3 II. It is worth mentioning in this context that the K-3 II is splash and dust resistant, while the GR III does not feature any corresponding weather-sealing.

The above size and weight comparisons are to some extent incomplete and possibly misleading, as the GR III has a lens built in, whereas the K-3 II 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 K-3 II gets 720 shots out of its Pentax D-LI90 battery, while the GR III can take 200 images on a single charge of its Ricoh DB-110 power pack. The power pack in the GR III 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. 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 K-3 II	131 mm	100 mm	77 mm	800 g	720	Y	Apr 2015	1,099	ebay.com
2.		Ricoh GR III	109 mm	62 mm	33 mm	257 g	200	n	Feb 2019	899	amazon.com
3.		Fujifilm XF10	113 mm	64 mm	41 mm	279 g	330	n	Jul 2018	499	ebay.com
4.		Nikon D7200	136 mm	107 mm	76 mm	765 g	1110	Y	Mar 2015	1,199	ebay.com
5.		Panasonic ZS200	111 mm	65 mm	45 mm	340 g	370	n	Feb 2018	799	amazon.com
6.		Pentax K-3	131 mm	100 mm	77 mm	800 g	560	Y	Oct 2013	1,299	ebay.com
7.		Pentax K-3 III	135 mm	104 mm	74 mm	820 g	800	Y	Mar 2021	1,999	amazon.com
8.		Pentax K-5	131 mm	97 mm	73 mm	760 g	740	Y	Sep 2010	1,099	ebay.com
9.		Pentax K-5 II	131 mm	97 mm	73 mm	760 g	740	Y	Sep 2012	1,099	ebay.com
10.		Pentax K-70	126 mm	93 mm	74 mm	688 g	410	Y	Jun 2016	649	ebay.com
11.		Pentax KP	132 mm	101 mm	76 mm	703 g	390	Y	Jan 2017	1,099	ebay.com
12.		Pentax K-S1	121 mm	93 mm	70 mm	558 g	410	n	Aug 2014	749	ebay.com
13.		Pentax K-S2	123 mm	91 mm	73 mm	678 g	410	Y	Feb 2015	749	ebay.com
14.		Ricoh GR	117 mm	61 mm	35 mm	245 g	290	n	Apr 2013	799	ebay.com
15.		Ricoh GR II	117 mm	63 mm	35 mm	251 g	320	n	Jun 2015	699	ebay.com
16.		Ricoh GR IIIx	109 mm	62 mm	35 mm	262 g	200	n	Sep 2021	999	amazon.com
17.		Sony A77 II	143 mm	104 mm	81 mm	647 g	480	Y	May 2014	1,199	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 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 GR III was launched at a lower price than the K-3 II, despite having a lens built in. 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. 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 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.

Both cameras under consideration feature an APS-C sensor and have a format factor (sometimes also referred to as "crop factor") of 1.5. Within the spectrum of camera sensors, this places the review cameras among the medium-sized sensor cameras that aim to strike a balance between image quality and portability. Both cameras have a native aspect ratio (sensor width to sensor height) of 3:2.

While the two cameras under review share the same sensor size, the K-3 II offers a slightly higher resolution of 24.1 megapixels, compared with 24 MP of the GR III. This megapixels advantage translates into a 0.3 percent gain in linear resolution. On the other hand, these sensor specs imply that the K-3 II has a higher pixel density and a smaller size of the individual pixel (with a pixel pitch of 3.90μm versus 3.91μm for the GR III). Moreover, it should be noted that the GR III is much more recent (by 3 years and 10 months) than the K-3 II, and its sensor will have benefitted from technological advances during this time that further enhance the light gathering capacity of individual 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 GR III has on-sensor phase detect pixels, which results in fast and reliable autofocus acquisition even during live view operation.

Unlike the GR III, the K-3 II has the capacity to capture high quality composite images by combining multiple shots after shifting its sensor by miniscule distances. This multi-shot, pixel-shift mode is most suitable for photography of stationary objects (landscapes, studio scenes).

The Pentax K-3 II has a native sensitivity range from ISO 100 to ISO 51200. The corresponding ISO settings for the Ricoh GR III are ISO 100 to ISO 102400 (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.

Consistent information on actual sensor performance is available from DXO Mark for many cameras. 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 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 K-3 II	APS-C	24.1	6016	4000	1080/60i	23.6	13.6	1106	80
2.		Ricoh GR III	APS-C	24.0	6000	4000	1080/60p	24.1	13.5	1897	83
3.		Fujifilm XF10	APS-C	24.0	6000	4000	4K/15p	24.0	13.4	1844	83
4.		Nikon D7200	APS-C	24.0	6000	4000	1080/60p	24.5	14.6	1333	87
5.		Panasonic ZS200	1-inch	20.0	5472	3648	4K/30p	22.0	12.2	449	64
6.		Pentax K-3	APS-C	24.1	6016	4000	1080/60i	23.7	13.4	1216	80
7.		Pentax K-3 III	APS-C	25.6	6192	4128	4K/30p	24.2	13.7	2083	85
8.		Pentax K-5	APS-C	16.1	4928	3264	1080/25p	23.7	14.1	1162	82
9.		Pentax K-5 II	APS-C	16.1	4928	3264	1080/25p	23.8	14.1	1235	82
10.		Pentax K-70	APS-C	24.0	6000	4000	1080/60i	23.8	13.1	1639	80
11.		Pentax KP	APS-C	24.1	6016	4000	1080/60i	23.9	13.2	1699	81
12.		Pentax K-S1	APS-C	20.0	5472	3648	1080/30p	23.5	13.0	1061	78
13.		Pentax K-S2	APS-C	20.0	5472	3648	1080/30p	23.6	12.9	1514	79
14.		Ricoh GR	APS-C	16.1	4928	3264	1080/30p	23.6	13.5	972	78
15.		Ricoh GR II	APS-C	16.1	4928	3264	1080/30p	23.6	13.7	1078	80
16.		Ricoh GR IIIx	APS-C	24.0	6000	4000	1080/60p	24.2	13.8	2146	85
17.		Sony A77 II	APS-C	24.0	6000	4000	1080/60p	24.4	13.4	1013	82
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 two cameras under consideration both have sensors whose read-out speed is fast enough to capture moving pictures, but the GR III provides a faster frame rate than the K-3 II. It can shoot movie footage at 1080/60p, while the Pentax is limited to 1080/60i.

Feature comparison

Beyond body and sensor, cameras can and do differ across a range of features. For example, the K-3 II has an optical viewfinder, which can be very useful when shooting in bright sunlight. In contrast, the GR III relies on live view and the rear LCD for framing. That said, the GR III can be equipped with an optional viewfinder – the GV-1. The table below summarizes some of the other core capabilities of the Pentax K-3 II and Ricoh GR III 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 K-3 II	optical	Y	3.2 / 1037	fixed	n	1/8000s	8.3/s	n	Y
2.		Ricoh GR III	optional	n	3.0 / 1037	fixed	Y	1/4000s	4.0/s	n	Y
3.		Fujifilm XF10	none	n	3.0 / 1040	fixed	Y	1/4000s	6.0/s	Y	n
4.		Nikon D7200	optical	Y	3.2 / 1229	fixed	n	1/8000s	6.0/s	Y	n
5.		Panasonic ZS200	2330	n	3.0 / 1240	fixed	Y	1/2000s	10.0/s	Y	Y
6.		Pentax K-3	optical	Y	3.2 / 1037	fixed	n	1/8000s	8.3/s	Y	Y
7.		Pentax K-3 III	optical	Y	3.2 / 1620	fixed	Y	1/8000s	12.0/s	n	Y
8.		Pentax K-5	optical	Y	3.0 / 921	fixed	n	1/8000s	7.0/s	Y	Y
9.		Pentax K-5 II	optical	Y	3.0 / 921	fixed	n	1/8000s	7.0/s	Y	Y
10.		Pentax K-70	optical	n	3.0 / 921	swivel	n	1/6000s	6.0/s	Y	Y
11.		Pentax KP	optical	n	3.0 / 921	tilting	n	1/6000s	7.0/s	Y	Y
12.		Pentax K-S1	optical	n	3.0 / 921	fixed	n	1/6000s	5.4/s	Y	Y
13.		Pentax K-S2	optical	n	3.0 / 921	swivel	n	1/6000s	5.4/s	Y	Y
14.		Ricoh GR	optional	n	3.0 / 1230	fixed	n	1/4000s	4.0/s	Y	n
15.		Ricoh GR II	optional	n	3.0 / 1230	fixed	n	1/4000s	4.0/s	Y	n
16.		Ricoh GR IIIx	optional	n	3.0 / 1037	fixed	Y	1/4000s	4.0/s	n	Y
17.		Sony A77 II	2359	Y	3.0 / 1229	full-flex	n	1/8000s	12.0/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 K-3 II, but is missing on the GR III 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 K-3 II and the Ricoh GR III 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 K-3 II and the GR III write their files to SDXC cards. The K-3 II features dual card slots, which can be very useful in case a memory card fails. In contrast, the GR III 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 K-3 II and Ricoh GR III 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 K-3 II	Y	mono / mono	Y	Y	mini	3.0	-	-	-
2.		Ricoh GR III	Y	stereo / mono	-	-	-	3.0	Y	-	Y
3.		Fujifilm XF10	-	stereo / mono	Y	-	micro	2.0	Y	-	Y
4.		Nikon D7200	Y	stereo / mono	Y	Y	mini	2.0	Y	Y	-
5.		Panasonic ZS200	-	stereo / mono	-	-	micro	2.0	Y	-	Y
6.		Pentax K-3	Y	mono / mono	Y	Y	mini	3.0	-	-	-
7.		Pentax K-3 III	Y	stereo / mono	Y	Y	micro	3.2	Y	-	Y
8.		Pentax K-5	Y	stereo / mono	Y	-	mini	2.0	-	-	-
9.		Pentax K-5 II	Y	stereo / mono	Y	-	mini	2.0	-	-	-
10.		Pentax K-70	Y	stereo / mono	Y	-	mini	2.0	Y	-	-
11.		Pentax KP	Y	stereo / mono	Y	-	-	2.0	Y	-	-
12.		Pentax K-S1	Y	stereo / mono	-	-	micro	2.0	-	-	-
13.		Pentax K-S2	Y	mono / mono	Y	-	micro	2.0	Y	Y	-
14.		Ricoh GR	Y	mono / mono	-	-	micro	2.0	-	-	-
15.		Ricoh GR II	Y	stereo / mono	-	-	micro	2.0	Y	Y	-
16.		Ricoh GR IIIx	Y	stereo / mono	-	-	-	3.0	Y	-	Y
17.		Sony A77 II	Y	stereo / mono	Y	-	mini	2.0	Y	Y	-

It is notable that the K-3 II has a microphone port, which is missing on the GR III. 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 K-3 II (unlike the GR III) 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 K-3 II has an internal geolocalization sensor and can record GPS coordinates in its EXIF data.

The GR III is a recent model that features in the current product line-up of Ricoh. In contrast, the K-3 II has been discontinued (but can be found pre-owned on ebay). As a replacement in the same line of cameras, the K-3 II was succeeded by the Pentax K-3 III. Further information on the features and operation of the K-3 II and GR III can be found, respectively, in the Pentax K-3 II Manual (free pdf) or the online Ricoh GR III Manual.

Review summary

So what conclusions can be drawn? Which of the two cameras – the Pentax K-3 II or the Ricoh GR III – has the upper hand? Is one clearly better than the other? Below is a summary of the relative strengths of each of the two contestants.

Advantages of the Pentax K-3 II:

• High quality composites: Can combine several shots after pixel-shifting its sensor.
• Better sound: Can connect to an external microphone for higher quality sound recording.
• Better sound control: Has a headphone port that enables audio monitoring while 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.
• Faster shutter: Has higher mechanical shutter speed (1/8000s vs 1/4000s) to freeze action.
• Faster burst: Shoots at higher frequency (8.3 vs 4 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 (720 versus 200) on a single battery charge.
• Better sealing: Is weather sealed to enable shooting in dusty or wet environments.
• Easier geotagging: Features an internal GPS sensor to log localization data.
• 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 April 2015).

Reasons to prefer the Ricoh GR III:

• Better video: Provides higher movie framerates (1080/60p versus 1080/60i).
• Better live-view autofocus: Features on-sensor phase-detection for more confident autofocus.
• Fewer buttons to press: Has a touchscreen to facilitate handling and shooting adjustments.
• Ready to shoot: Comes with an integrated lens, while the K-3 II requires a separate lens.
• More compact: Is smaller (109x62mm vs 131x100mm) and will fit more readily into a bag.
• Less heavy: Has a lower weight even though it has a lens built in (unlike the K-3 II).
• Easier travel charging: Can be conveniently charged via its USB port.
• Easier file upload: Has wifi built in for automatic backup or image transfer to the web.
• Easier wireless transfer: Supports Bluetooth for image sharing without cables.
• More affordable: Was introduced at a lower price, despite coming with a built-in lens.
• More modern: Reflects 3 years and 10 months of technical progress since the K-3 II launch.

If the count of individual advantages (bullet points above) is taken as a guide, the K-3 II is the clear winner of the match-up (15 : 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 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 K-3 II and the Ricoh GR III 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 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 K-3 II and the GR III 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 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 K-3 II	4.5/5	..	..	..	5/5	5/5	Apr 2015	1,099	ebay.com
2.		Ricoh GR III	4/5	..	3.5/5	81/100	4/5	..	Feb 2019	899	amazon.com
3.		Fujifilm XF10	..	..	4/5	75/100	4/5	4.5/5	Jul 2018	499	ebay.com
4.		Nikon D7200	4/5	+ +	..	84/100	4.5/5	4.5/5	Mar 2015	1,199	ebay.com
5.		Panasonic ZS200	..	+ +	4.5/5	81/100	4.5/5	4.5/5	Feb 2018	799	amazon.com
6.		Pentax K-3	4/5	..	..	83/100	5/5	5/5	Oct 2013	1,299	ebay.com
7.		Pentax K-3 III	4/5	..	3/5	..	4.5/5	..	Mar 2021	1,999	amazon.com
8.		Pentax K-5	4/5	..	..	83/100	5/5	4.5/5	Sep 2010	1,099	ebay.com
9.		Pentax K-5 II	5/5	..	..	80/100	5/5	4.5/5	Sep 2012	1,099	ebay.com
10.		Pentax K-70	4.5/5	..	4/5	79/100	4.5/5	4.5/5	Jun 2016	649	ebay.com
11.		Pentax KP	4/5	..	3/5	82/100	5/5	4.5/5	Jan 2017	1,099	ebay.com
12.		Pentax K-S1	4/5	..	..	..	4.5/5	4/5	Aug 2014	749	ebay.com
13.		Pentax K-S2	4.5/5	..	..	..	5/5	4.5/5	Feb 2015	749	ebay.com
14.		Ricoh GR	5/5	..	..	79/100	4.5/5	4.5/5	Apr 2013	799	ebay.com
15.		Ricoh GR II	..	..	..	..	4.5/5	4.5/5	Jun 2015	699	ebay.com
16.		Ricoh GR IIIx	..	..	4.5/5	..	..	..	Sep 2021	999	amazon.com
17.		Sony A77 II	4/5	..	..	80/100	4.5/5	5/5	May 2014	1,199	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 comparing ratings of very distinct cameras or ones that are far apart in terms of their release date 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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