Leica M10-R vs Pentax K-3 III

The Leica M10-R and the Pentax K-3 III are two enthusiast cameras that were revealed to the public, respectively, in July 2020 and March 2021. The M10-R is a rangefinder-focusing mirrorless camera, while the K-3 III is a DSLR. The cameras are based on a full frame (M10-R) and an APS-C (K-3 III) sensor. The Leica has a resolution of 40.9 megapixels, whereas the Pentax provides 25.6 MP.

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

Headline Specifications

Leica M10-R		Pentax K-3 III
Rangefinder camera		Digital single lens reflex
Leica M mount lenses		Pentax K mount lenses
40.9 MP – Full Frame sensor		25.6 MP – APS-C sensor
no Video		4K/30p Video
ISO 100-50,000		ISO 100-160,000
Optical viewfinder		Optical viewfinder
3.0" LCD – 1037k dots		3.2" LCD – 1620k dots
Fixed touchscreen		Fixed touchscreen
4.5 shutter flaps per second		12 shutter flaps per second
no shake reduction		In-body stabilization
Weathersealed body		Weathersealed body
210 shots per battery charge		800 shots per battery charge
139 x 80 x 39 mm, 660 g		135 x 104 x 74 mm, 820 g

Check M10-R offers at
ebay.com
Check K-3 III price at
amazon.com

Going beyond this snapshot of core features and characteristics, what are the differences between the Leica M10-R and the Pentax K-3 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 Leica M10-R and the Pentax K-3 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 size dimensions are rounded to the nearest millimeter.

Both cameras are available in two different colors (black, silver).

If the front view area (width x height) of the cameras is taken as an aggregate measure of their size, the Pentax K-3 III is notably larger (26 percent) than the Leica M10-R. Moreover, the K-3 III is markedly heavier (24 percent) than the M10-R. 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.

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.

Concerning battery life, the M10-R gets 210 shots out of its Leica BP-SCL5 battery, while the K-3 III can take 800 images on a single charge of its Pentax D-LI90 power pack.

The adjacent table lists the principal physical characteristics of the two cameras alongside a wider set of alternatives. 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.		Leica M10-R	139 mm	80 mm	39 mm	660 g	210	Y	Jul 2020	8,295	ebay.com
2.		Pentax K-3 III	135 mm	104 mm	74 mm	820 g	800	Y	Mar 2021	1,999	amazon.com
3.		Fujifilm X-H1	140 mm	97 mm	86 mm	673 g	310	Y	Feb 2018	1,899	ebay.com
4.		Leica M11	139 mm	80 mm	39 mm	640 g	700	Y	Jan 2022	8,995	amazon.com
5.		Leica SL2	146 mm	107 mm	42 mm	953 g	370	Y	Nov 2019	5,999	amazon.com
6.		Leica Q2	130 mm	80 mm	92 mm	718 g	370	Y	Mar 2019	4,995	amazon.com
7.		Leica M-E Typ 240	139 mm	80 mm	42 mm	680 g	500	Y	Jun 2019	3,999	ebay.com
8.		Leica M10-P	139 mm	80 mm	39 mm	660 g	210	Y	Aug 2018	7,995	ebay.com
9.		Leica M10	139 mm	80 mm	39 mm	660 g	210	Y	Jan 2017	6,595	ebay.com
10.		Leica M Typ 262	139 mm	80 mm	42 mm	680 g	400	Y	Nov 2015	5,195	ebay.com
11.		Leica SL	147 mm	104 mm	39 mm	847 g	400	Y	Oct 2015	7,450	ebay.com
12.		Leica M Typ 240	139 mm	80 mm	42 mm	680 g	500	Y	Sep 2012	6,950	ebay.com
13.		Leica M9	139 mm	80 mm	37 mm	585 g	550	n	Sep 2009	7,999	ebay.com
14.		Pentax KP	132 mm	101 mm	76 mm	703 g	390	Y	Jan 2017	1,099	ebay.com
15.		Pentax K-70	126 mm	93 mm	74 mm	688 g	410	Y	Jun 2016	649	ebay.com
16.		Pentax K-3 II	131 mm	100 mm	77 mm	800 g	720	Y	Apr 2015	1,099	ebay.com
17.		Pentax K-3	131 mm	100 mm	77 mm	800 g	560	Y	Oct 2013	1,299	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

The price is, of course, an important factor in any camera decision. 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 K-3 III was launched at a markedly lower price (by 76 percent) than the M10-R, which puts it into a different market segment. 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. 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.

Of the two cameras under consideration, the Leica M10-R features a full frame sensor and the Pentax K-3 III an APS-C sensor. The sensor area in the K-3 III is 58 percent smaller. As a result of these sensor size differences, the cameras have a format factor of, respectively, 1.0 and 1.5. Both cameras have a native aspect ratio (sensor width to sensor height) of 3:2.

With 40.9MP, the M10-R offers a higher resolution than the K-3 III (25.6MP), but the M10-R nevertheless has larger individual pixels (pixel pitch of 4.57μm versus 3.76μm for the K-3 III) due to its larger sensor. However, the K-3 III is a somewhat more recent model (by 8 months) than the M10-R, 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 Leica M10-R implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the M10-R for good quality output (200 dots per inch) amounts to 39.3 x 26 inches or 99.9 x 66 cm, for very good quality (250 dpi) 31.5 x 20.8 inches or 79.9 x 52.8 cm, and for excellent quality (300 dpi) 26.2 x 17.3 inches or 66.6 x 44 cm. The corresponding values for the Pentax K-3 III are 31 x 20.6 inches or 78.6 x 52.4 cm for good quality, 24.8 x 16.5 inches or 62.9 x 41.9 cm for very good quality, and 20.6 x 13.8 inches or 52.4 x 35 cm for excellent quality prints.

Unlike the M10-R, the K-3 III has the capacity to capture high quality composite images (YESMP) 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 Leica M10-R has a native sensitivity range from ISO 100 to ISO 50000. The corresponding ISO settings for the Pentax K-3 III are ISO 100 to ISO 160000 (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.

For many cameras, data on sensor performance has been reported by DXO Mark. 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 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.		Leica M10-R	Full Frame	40.9	7864	5200	none	25.3	14.3	2924	95
2.		Pentax K-3 III	APS-C	25.6	6192	4128	4K/30p	24.2	13.7	2083	85
3.		Fujifilm X-H1	APS-C	24.0	6000	4000	4K/30p	24.0	13.3	1806	82
4.		Leica M11	Full Frame	60.3	9528	6328	none	26.3	14.8	3376	100
5.		Leica SL2	Full Frame	46.7	8368	5584	4K/60p	25.3	14.3	2866	95
6.		Leica Q2	Full Frame	46.7	8368	5584	4K/30p	26.4	13.5	2491	96
7.		Leica M-E Typ 240	Full Frame	23.7	5952	3976	1080/25p	25.2	14.2	2821	94
8.		Leica M10-P	Full Frame	23.8	5952	3992	none	25.1	14.1	2739	93
9.		Leica M10	Full Frame	23.8	5952	3992	none	24.4	13.2	2133	86
10.		Leica M Typ 262	Full Frame	23.7	5952	3976	none	24.8	13.7	2478	90
11.		Leica SL	Full Frame	24.0	6000	4000	4K/30p	25.0	13.4	1821	88
12.		Leica M Typ 240	Full Frame	23.7	5952	3976	1080/25p	24.0	13.3	1860	84
13.		Leica M9	Full Frame	18.1	5212	3472	none	22.5	11.7	884	69
14.		Pentax KP	APS-C	24.1	6016	4000	1080/60i	23.9	13.2	1699	81
15.		Pentax K-70	APS-C	24.0	6000	4000	1080/60i	23.8	13.1	1639	80
16.		Pentax K-3 II	APS-C	24.1	6016	4000	1080/60i	23.6	13.6	1106	80
17.		Pentax K-3	APS-C	24.1	6016	4000	1080/60i	23.7	13.4	1216	80
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 K-3 III indeed provides for movie recording, while the M10-R does not. The highest resolution format that the K-3 III can use is 4K/30p.

Feature comparison

Apart from body and sensor, cameras can and do differ across a range of features. The M10-R and the K-3 III are similar in the sense that both have an optical viewfinder. The latter is useful for getting a clear image for framing even in brightly lit environments. The viewfinders of both cameras offer the same field of view (100%), but the viewfinder of the M10-R has a higher magnification than the one of the K-3 III (0.73x vs 0.70x), so that the size of the image transmitted appears closer to the size seen with the naked human eye. The adjacent table lists some of the other core features of the Leica M10-R and Pentax K-3 III 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.		Leica M10-R	optical	n	3.0 / 1037	fixed	Y	1/4000s	4.5/s	n	n
2.		Pentax K-3 III	optical	Y	3.2 / 1620	fixed	Y	1/8000s	12.0/s	n	Y
3.		Fujifilm X-H1	3690	Y	3.0 / 1040	full-flex	Y	1/8000s	14.0/s	n	Y
4.		Leica M11	optical	n	3.0 / 2333	fixed	Y	1/4000s	4.5/s	n	n
5.		Leica SL2	5760	Y	3.2 / 2100	fixed	Y	1/8000s	10.0/s	n	Y
6.		Leica Q2	3680	n	3.0 / 1040	fixed	Y	1/2000s	10.0/s	n	Y
7.		Leica M-E Typ 240	optical	n	3.0 / 920	fixed	n	1/4000s	3.0/s	n	n
8.		Leica M10-P	optical	n	3.0 / 1037	fixed	Y	1/4000s	5.0/s	n	n
9.		Leica M10	optical	n	3.0 / 1037	fixed	n	1/4000s	5.0/s	n	n
10.		Leica M Typ 262	optical	n	3.0 / 921	fixed	n	1/4000s	3.0/s	n	n
11.		Leica SL	4400	Y	3.0 / 1040	fixed	Y	1/8000s	11.0/s	n	n
12.		Leica M Typ 240	optical	n	3.0 / 920	fixed	n	1/4000s	3.0/s	n	n
13.		Leica M9	optical	n	2.5 / 230	fixed	n	1/4000s	2.0/s	n	n
14.		Pentax KP	optical	n	3.0 / 921	tilting	n	1/6000s	7.0/s	Y	Y
15.		Pentax K-70	optical	n	3.0 / 921	swivel	n	1/6000s	6.0/s	Y	Y
16.		Pentax K-3 II	optical	Y	3.2 / 1037	fixed	n	1/8000s	8.3/s	n	Y
17.		Pentax K-3	optical	Y	3.2 / 1037	fixed	n	1/8000s	8.3/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 III, but is missing on the M10-R 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 Leica M10-R and the Pentax K-3 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 M10-R and the K-3 III write their files to SDXC cards. The K-3 III features dual card slots, which can be very useful in case a memory card fails. In contrast, the M10-R only has one slot. The K-3 III supports UHS-II cards (on its first slot), while the M10-R can use UHS-I 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 Leica M10-R and Pentax K-3 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.		Leica M10-R	Y	- / -	-	-	-	-	Y	-	-
2.		Pentax K-3 III	Y	stereo / mono	Y	Y	micro	3.2	Y	-	Y
3.		Fujifilm X-H1	Y	stereo / mono	Y	-	micro	3.0	Y	-	-
4.		Leica M11	Y	- / -	-	-	-	3.2	Y	-	Y
5.		Leica SL2	Y	stereo / mono	Y	Y	full	3.1	Y	-	Y
6.		Leica Q2	Y	stereo / mono	-	-	-	-	Y	-	Y
7.		Leica M-E Typ 240	Y	mono / -	-	-	-	2.0	-	-	-
8.		Leica M10-P	Y	- / -	-	-	-	-	Y	-	-
9.		Leica M10	Y	- / -	-	-	-	-	Y	-	-
10.		Leica M Typ 262	Y	- / -	-	-	-	2.0	-	-	-
11.		Leica SL	Y	stereo / mono	Y	Y	full	3.0	Y	-	-
12.		Leica M Typ 240	Y	stereo / mono	-	-	-	2.0	-	-	-
13.		Leica M9	Y	- / -	-	-	-	2.0	-	-	-
14.		Pentax KP	Y	stereo / mono	Y	-	-	2.0	Y	-	-
15.		Pentax K-70	Y	stereo / mono	Y	-	mini	2.0	Y	-	-
16.		Pentax K-3 II	Y	mono / mono	Y	Y	mini	3.0	-	-	-
17.		Pentax K-3	Y	mono / mono	Y	Y	mini	3.0	-	-	-

Studio photographers will appreciate that the Pentax K-3 III (unlike the M10-R) 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 III has an internal geolocalization sensor and can record GPS coordinates in its EXIF data.

The K-3 III is a recent model that features in the current product line-up of Pentax. In contrast, the M10-R has been discontinued (but can be found pre-owned on ebay). There has not been a direct replacement model for the M10-R from Leica. Further information on the features and operation of the M10-R and K-3 III can be found, respectively, in the Leica M10-R Manual (free pdf) or the online Pentax K-3 III Manual.

Review summary

So how do things add up? Which of the two cameras – the Leica M10-R or the Pentax K-3 III – has the upper hand? Is one clearly better than the other? The listing below highlights the relative strengths of the two models.

Advantages of the Leica M10-R:

• More detail: Offers more megapixels (40.9 vs 25.6MP) with a 27% 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.
• Larger viewfinder image: Features a viewfinder with a higher magnification (0.73x vs 0.70x).
• More compact: Is smaller (139x80mm vs 135x104mm) and thus needs less room in the bag.
• Less heavy: Is lighter (by 160g or 20 percent) and hence easier to carry around.
• More prestigious: Has the Leica luxury appeal, which ensures a high resale price.
• More heavily discounted: Has been on the market for longer (launched in July 2020).

Arguments in favor of the Pentax K-3 III:

• High quality composites: Can combine several shots after pixel-shifting its sensor.
• Broader imaging potential: Can capture not only stills but also 4K/30p video.
• Easier setting verification: Features a control panel on top to check shooting parameters.
• Larger screen: Has a bigger rear LCD (3.2" vs 3.0") for image review and settings control.
• More detailed LCD: Has a higher resolution rear screen (1620k vs 1037k dots).
• Faster shutter: Has higher mechanical shutter speed (1/8000s vs 1/4000s) to freeze action.
• Faster burst: Shoots at higher frequency (12 vs 4.5 flaps/sec) to capture the decisive moment.
• Longer lasting: Gets more shots (800 versus 210) out of a single battery charge.
• Sharper images: Has stabilization technology built-in to reduce the impact of hand-shake.
• Easier geotagging: Features an internal GPS sensor to log localization data.
• Easier wireless transfer: Supports Bluetooth for image sharing without cables.
• 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: Supports a more advanced SD data transfer standard (UHS-II vs UHS-I).
• More affordable: Was introduced into a lower priced category (76 percent cheaper at launch).
• More modern: Was introduced somewhat (8 months) more recently.

If the count of relative strengths (bullet points above) is taken as a measure, the K-3 III is the clear winner of the contest (16 : 10 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 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.

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 M10-R or the K-3 III 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 why expert reviews are important. 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.		Leica M10-R	4.5/5	..	4/5	..	..	4/5	Jul 2020	8,295	ebay.com
2.		Pentax K-3 III	4/5	..	3/5	..	4.5/5	..	Mar 2021	1,999	amazon.com
3.		Fujifilm X-H1	..	+	5/5	86/100	4.5/5	4.5/5	Feb 2018	1,899	ebay.com
4.		Leica M11	4.5/5	..	4.5/5	..	4.5/5	4.5/5	Jan 2022	8,995	amazon.com
5.		Leica SL2	4/5	..	4.5/5	..	4.5/5	4/5	Nov 2019	5,999	amazon.com
6.		Leica Q2	..	..	4.5/5	84/100	4.5/5	4/5	Mar 2019	4,995	amazon.com
7.		Leica M-E Typ 240	..	..	..	..	..	..	Jun 2019	3,999	ebay.com
8.		Leica M10-P	..	..	3/5	..	..	4/5	Aug 2018	7,995	ebay.com
9.		Leica M10	4.5/5	..	..	..	4/5	4.5/5	Jan 2017	6,595	ebay.com
10.		Leica M Typ 262	..	..	..	..	..	..	Nov 2015	5,195	ebay.com
11.		Leica SL	4/5	..	4/5	84/100	4.5/5	4/5	Oct 2015	7,450	ebay.com
12.		Leica M Typ 240	4/5	..	..	..	4/5	..	Sep 2012	6,950	ebay.com
13.		Leica M9	..	..	..	..	4.5/5	..	Sep 2009	7,999	ebay.com
14.		Pentax KP	4/5	..	3/5	82/100	5/5	4.5/5	Jan 2017	1,099	ebay.com
15.		Pentax K-70	4.5/5	..	4/5	79/100	4.5/5	4.5/5	Jun 2016	649	ebay.com
16.		Pentax K-3 II	4.5/5	..	..	..	5/5	5/5	Apr 2015	1,099	ebay.com
17.		Pentax K-3	4/5	..	..	83/100	5/5	5/5	Oct 2013	1,299	ebay.com
Note: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.

The above review scores should be interpreted with care, 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 rating-comparisons among cameras that span long time periods or concern very differently equipped models make little sense. It should also be noted that some of the review sites have over time altered the way they render their verdicts.

Check M10-R offers at
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Check K-3 III price at
amazon.com

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 make a corresponding selection in the search boxes below. As an alternative, you can also directly jump to any one of the listed comparisons that were previously generated by the CAM-parator tool.

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