Leica S3 vs Pentax 645Z

The Leica S3 and the Pentax 645Z are two professional cameras that were revealed to the public, respectively, in September 2018 and April 2014. Both are DSLR (Digital Single Lens Reflex) cameras that are equipped with a medium format sensor. The Leica has a resolution of 64 megapixels, whereas the Pentax provides 51.1 MP.

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

Headline Specifications

Leica S3		Pentax 645Z
Digital single lens reflex		Digital single lens reflex
Leica S mount lenses		Pentax 645 mount lenses
64 MP – Medium Format sensor		51.1 MP – Medium Format sensor
4K/24p Video		1080/60i Video
ISO 100-50,000		ISO 100-204,800
Optical viewfinder		Optical viewfinder
3.0" LCD – 922k dots		3.2" LCD – 1037k dots
Fixed screen (not touch-sensitive)		Tilting screen (no touchscreen)
3 shutter flaps per second		3 shutter flaps per second
Weathersealed body		Weathersealed body
160 x 120 x 80 mm, 1260 g		156 x 117 x 123 mm, 1550 g

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Going beyond this snapshot of core features and characteristics, what are the differences between the Leica S3 and the Pentax 645Z? 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 Leica S3 and the Pentax 645Z are illustrated in the side-by-side display below. The two cameras are presented according to their relative size. Three successive views from the front, the top, and the rear are shown. All width, height and depth 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 Pentax 645Z is notably smaller (5 percent) than the Leica S3. However, the 645Z is markedly heavier (23 percent) than the S3. 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 S3 gets .. shots out of its Leica BP-PRO1 battery, while the 645Z can take 650 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. 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	Street Price
1.		Leica S3	160 mm	120 mm	80 mm	1260 g	..	Y	Sep 2018	US$ 18 999	ebay.com
2.		Pentax 645Z	156 mm	117 mm	123 mm	1550 g	650	Y	Apr 2014	US$ 8 499	ebay.com
3.		Canon 5DS	152 mm	116 mm	76 mm	930 g	700	Y	Feb 2015	US$ 3 699	ebay.com
4.		Canon 5DS R	152 mm	116 mm	76 mm	930 g	700	Y	Feb 2015	US$ 3 699	ebay.com
5.		Hasselblad X1D	150 mm	98 mm	71 mm	725 g	..	Y	Jun 2016	US$ 8 995	ebay.com
6.		Leica M-E Typ 240	139 mm	80 mm	42 mm	680 g	500	Y	Jun 2019	US$ 3 999	ebay.com
7.		Leica M10	139 mm	80 mm	39 mm	660 g	210	Y	Jan 2017	US$ 6 599	ebay.com
8.		Leica M10-P	139 mm	80 mm	39 mm	660 g	210	Y	Aug 2018	US$ 7 999	ebay.com
9.		Leica Q2	130 mm	80 mm	92 mm	718 g	370	Y	Mar 2019	US$ 4 999	amazon.com
10.		Leica S2	160 mm	120 mm	80 mm	1410 g	..	Y	Sep 2008	US$ 22 999	ebay.com
11.		Leica S Typ 006	160 mm	120 mm	80 mm	1260 g	..	Y	Sep 2012	US$ 21 949	ebay.com
12.		Leica S-E Typ 006	160 mm	120 mm	80 mm	1260 g	..	Y	Sep 2014	US$ 16 599	ebay.com
13.		Leica S Typ 007	160 mm	120 mm	80 mm	1260 g	..	Y	Sep 2014	US$ 24 499	ebay.com
14.		Leica SL	147 mm	104 mm	39 mm	847 g	400	Y	Oct 2015	US$ 7 449	ebay.com
15.		Nikon D6	160 mm	163 mm	92 mm	1270 g	3580	Y	Feb 2020	US$ 6 499	amazon.com
16.		Pentax 645D	156 mm	117 mm	119 mm	1480 g	800	Y	Mar 2010	US$ 9 995	ebay.com
17.		Sony RX10 IV	133 mm	94 mm	145 mm	1095 g	400	Y	Sep 2017	US$ 1 699	amazon.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 645Z was launched at a markedly lower price (by 55 percent) than the S3, 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.

Sensor comparison

The size of the sensor inside a digital camera is one of the key determinants of image quality. All other things equal, a large sensor will have larger individual pixel-units that offer better low-light sensitivity, wider dynamic range, and 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 associated with larger, more expensive camera bodies and lenses.

Both cameras under consideration feature a medium format sensor, but their sensors differ slightly in size. The sensor area in the 645Z is 6 percent bigger. As a result of these sensor size differences, the cameras have format factors, respectively, of 0.8 (S3) and 0.79. The sensor in the S3 has a native 3:2 aspect ratio, while the one in the 645Z offers a 4:3 aspect.

Despite having a smaller sensor, the Leica S3 offers a higher resolution of 64 megapixels, compared with 51.1 MP of the Pentax 645Z. This megapixels advantage comes at the cost of a higher pixel density and a smaller size of the individual pixel (with a pixel pitch of 4.59μm versus 5.30μm for the 645Z). However, it should be noted that the S3 is much more recent (by 4 years and 5 months) than the 645Z, and its sensor will have benefitted from technological advances during this time that make it possible to gather light more efficiently. 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 S3 implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the S3 for good quality output (200 dots per inch) amounts to 49 x 32.7 inches or 124.5 x 83 cm, for very good quality (250 dpi) 39.2 x 26.1 inches or 99.6 x 66.4 cm, and for excellent quality (300 dpi) 32.7 x 21.8 inches or 83 x 55.3 cm. The corresponding values for the Pentax 645Z are 41.3 x 31 inches or 104.9 x 78.6 cm for good quality, 33 x 24.8 inches or 83.9 x 62.9 cm for very good quality, and 27.5 x 20.6 inches or 69.9 x 52.4 cm for excellent quality prints.

The Leica S3 has a native sensitivity range from ISO 100 to ISO 50000. The corresponding ISO settings for the Pentax 645Z are ISO 100 to ISO 204800 (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 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 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.		Leica S3	Medium Format	64.0	9800	6533	4K/24p	25.6	14.4	3143	98
2.		Pentax 645Z	Medium Format	51.1	8256	6192	1080/60i	26.0	14.7	4505	101
3.		Canon 5DS	Full Frame	50.3	8688	5792	1080/30p	24.7	12.4	2381	87
4.		Canon 5DS R	Full Frame	50.3	8688	5792	1080/30p	24.6	12.4	2308	86
5.		Hasselblad X1D	Medium Format	51.3	8272	6200	1080/25p	26.2	14.8	4489	102
6.		Leica M-E Typ 240	Full Frame	23.7	5952	3976	1080/25p	25.2	14.2	2821	94
7.		Leica M10	Full Frame	23.8	5952	3992	none	24.4	13.2	2133	86
8.		Leica M10-P	Full Frame	23.8	5952	3992	none	25.1	14.1	2739	93
9.		Leica Q2	Full Frame	46.7	8368	5584	4K/30p	26.4	13.5	2491	96
10.		Leica S2	Medium Format	37.5	7500	5000	none	23.9	12.5	2224	82
11.		Leica S Typ 006	Medium Format	37.5	7500	5000	none	23.9	12.2	824	76
12.		Leica S-E Typ 006	Medium Format	37.5	7500	5000	none	25.1	13.7	2763	93
13.		Leica S Typ 007	Medium Format	37.5	7500	5000	4K/24p	25.1	13.7	2763	93
14.		Leica SL	Full Frame	24.0	6000	4000	4K/30p	25.0	13.4	1821	88
15.		Nikon D6	Full Frame	20.7	5568	3712	4K/30p	25.3	14.3	2886	95
16.		Pentax 645D	Medium Format	39.5	7264	5440	none	24.6	12.6	1262	82
17.		Sony RX10 IV	1-inch	20.0	5472	3648	4K/30p	22.0	12.2	408	63
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 can also record movies. Both cameras under consideration are equipped with sensors that have a sufficiently high read-out speed for moving images, but the S3 provides a higher video resolution than the 645Z. It can shoot video footage at 4K/24p, while the Pentax is limited to 1080/60i.

Feature comparison

Beyond body and sensor, cameras can and do differ across a range of features. The S3 and the 645Z 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 (98%), but the viewfinder of the S3 has a higher magnification than the one of the 645Z (0.87x vs 0.78x), 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 S3 and Pentax 645Z 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 S3	optical	Y	3.0 / 922	fixed	n	1/4000s	3.0/s	n	n
2.		Pentax 645Z	optical	Y	3.2 / 1037	tilting	n	1/4000s	3.0/s	n	n
3.		Canon 5DS	optical	Y	3.2 / 1040	fixed	n	1/8000s	5.0/s	n	n
4.		Canon 5DS R	optical	Y	3.2 / 1040	fixed	n	1/8000s	5.0/s	n	n
5.		Hasselblad X1D	2360	n	3.0 / 920	fixed	Y	1/2000s	2.3/s	n	n
6.		Leica M-E Typ 240	optical	n	3.0 / 920	fixed	n	1/4000s	3.0/s	n	n
7.		Leica M10	optical	n	3.0 / 1037	fixed	n	1/4000s	5.0/s	n	n
8.		Leica M10-P	optical	n	3.0 / 1037	fixed	Y	1/4000s	5.0/s	n	n
9.		Leica Q2	3680	n	3.0 / 1040	fixed	Y	1/2000s	10.0/s	n	Y
10.		Leica S2	optical	Y	3.0 / 460	fixed	n	1/4000s	1.5/s	n	n
11.		Leica S Typ 006	optical	Y	3.0 / 922	fixed	n	1/4000s	1.5/s	n	n
12.		Leica S-E Typ 006	optical	Y	3.0 / 922	fixed	n	1/4000s	1.5/s	n	n
13.		Leica S Typ 007	optical	Y	3.0 / 922	fixed	n	1/4000s	3.5/s	n	n
14.		Leica SL	4400	Y	3.0 / 1040	fixed	Y	1/8000s	11.0/s	n	n
15.		Nikon D6	optical	Y	3.2 / 2359	fixed	Y	1/8000s	14.0/s	n	n
16.		Pentax 645D	optical	Y	3.0 / 921	fixed	n	1/4000s	1.1/s	n	n
17.		Sony RX10 IV	2359	Y	3.0 / 1440	tilting	Y	1/2000s	24.0/s	Y	Y
Note: *) Information refers to the mechanical shutter, unless the camera only has an electronic one.

The Pentax 645Z has 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.

The S3 writes its imaging data to Compact Flash or SDXC cards, while the 645Z uses SDXC cards. Both cameras feature dual card slots, which can be very useful in case a memory card fails. The S3 supports UHS-II cards (Ultra High Speed data transfer of up to 312 MB/s), while the 645Z can use UHS-I cards (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 Leica S3 and Pentax 645Z 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 S3	Y	stereo / mono	Y	Y	mini	3.0	Y	-	-
2.		Pentax 645Z	Y	stereo / mono	Y	-	mini	3.0	-	-	-
3.		Canon 5DS	Y	mono / mono	Y	-	mini	3.0	-	-	-
4.		Canon 5DS R	Y	mono / mono	Y	-	mini	3.0	-	-	-
5.		Hasselblad X1D	Y	stereo / mono	Y	Y	mini	3.0	Y	-	-
6.		Leica M-E Typ 240	Y	mono / -	-	-	-	2.0	-	-	-
7.		Leica M10	Y	- / -	-	-	-	-	Y	-	-
8.		Leica M10-P	Y	- / -	-	-	-	-	Y	-	-
9.		Leica Q2	Y	stereo / mono	-	-	-	-	Y	-	Y
10.		Leica S2	Y	- / -	-	-	mini	2.0	-	-	-
11.		Leica S Typ 006	Y	- / -	-	-	mini	2.0	-	-	-
12.		Leica S-E Typ 006	Y	- / -	-	-	mini	2.0	-	-	-
13.		Leica S Typ 007	Y	stereo / mono	Y	Y	mini	3.0	Y	-	-
14.		Leica SL	Y	stereo / mono	Y	Y	full	3.0	Y	-	-
15.		Nikon D6	Y	stereo / mono	Y	Y	mini	3.1	Y	-	Y
16.		Pentax 645D	Y	stereo / -	-	-	-	2.0	-	-	-
17.		Sony RX10 IV	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-

It is notable that the S3 has a headphone jack, which is not present on the 645Z This port makes it possible to attach external headphones and monitor the quality of sound during the recording process.

Both cameras feature a PC Sync terminal to control professional strobe lights, which will be appreciated by studio photographers.

Travel and landscape photographers will find it useful that the S3 has an internal geolocalization sensor and can record GPS coordinates in its EXIF data.

Both the S3 and the 645Z have been discontinued, but can regularly be found used on ebay. Neither of the two has a direct successor, so they represent the end of the respective camera lines from Leica and Pentax. Further information on the features and operation of the S3 and 645Z can be found, respectively, in the Leica S3 Manual (free pdf) or the online Pentax 645Z Manual.

Review summary

So what conclusions can be drawn? Is the Leica S3 better than the Pentax 645Z or vice versa? A synthesis of the relative strong points of each of the models is listed below.

Advantages of the Leica S3:

• More detail: Offers more megapixels (64 vs 51.1MP) with a 14% higher linear resolution.
• Better video: Provides higher definition movie capture (4K/24p vs 1080/60i).
• Better sound control: Has a headphone port that enables audio monitoring while recording.
• Larger viewfinder image: Features a viewfinder with a higher magnification (0.87x vs 0.78x).
• Less heavy: Is lighter (by 290g or 19 percent) and hence easier to carry around.
• Easier geotagging: Features an internal GPS sensor to log localization data.
• Easier file upload: Has wifi built in for automatic backup or image transfer to the web.
• Faster buffer clearing: Supports a more advanced SD data transfer standard (UHS-II vs UHS-I).
• More prestigious: Has the Leica luxury appeal, which ensures a high resale price.
• More modern: Reflects 4 years and 5 months of technical progress since the 645Z launch.

Arguments in favor of the Pentax 645Z:

• 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 (1037k vs 922k dots).
• More flexible LCD: Has a tilting screen for odd-angle shots in landscape orientation.
• Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
• More affordable: Was introduced into a lower priced category (55 percent cheaper at launch).
• More heavily discounted: Has been around for much longer (launched in April 2014).

If the count of relative strengths (bullet points above) is taken as a measure, the S3 is the clear winner of the match-up (10 : 6 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 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 Leica S3 and the Pentax 645Z place the cameras among the top in their class? Find out in the latest Best DSLR Camera listing 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 S3 or the 645Z 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 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	Street Price
1.		Leica S3	..	..	..	..	..	..	Sep 2018	US$ 18 999	ebay.com
2.		Pentax 645Z	5/5	..	3.5/5	..	4.5/5	5/5	Apr 2014	US$ 8 499	ebay.com
3.		Canon 5DS	..	+	..	83/100	4.5/5	4.5/5	Feb 2015	US$ 3 699	ebay.com
4.		Canon 5DS R	5/5	+	..	83/100	5/5	4.5/5	Feb 2015	US$ 3 699	ebay.com
5.		Hasselblad X1D	..	o	..	81/100	..	4/5	Jun 2016	US$ 8 995	ebay.com
6.		Leica M-E Typ 240	..	..	..	..	..	..	Jun 2019	US$ 3 999	ebay.com
7.		Leica M10	4.5/5	..	..	..	4/5	4.5/5	Jan 2017	US$ 6 599	ebay.com
8.		Leica M10-P	..	..	3/5	..	..	4/5	Aug 2018	US$ 7 999	ebay.com
9.		Leica Q2	..	..	4.5/5	84/100	4.5/5	4/5	Mar 2019	US$ 4 999	amazon.com
10.		Leica S2	..	..	..	..	..	..	Sep 2008	US$ 22 999	ebay.com
11.		Leica S Typ 006	..	..	..	..	..	..	Sep 2012	US$ 21 949	ebay.com
12.		Leica S-E Typ 006	..	..	..	..	..	..	Sep 2014	US$ 16 599	ebay.com
13.		Leica S Typ 007	4/5	..	..	..	..	..	Sep 2014	US$ 24 499	ebay.com
14.		Leica SL	4/5	..	4/5	84/100	4.5/5	4/5	Oct 2015	US$ 7 449	ebay.com
15.		Nikon D6	..	..	4/5	..	4.5/5	4.5/5	Feb 2020	US$ 6 499	amazon.com
16.		Pentax 645D	5/5	..	..	..	..	..	Mar 2010	US$ 9 995	ebay.com
17.		Sony RX10 IV	5/5	+	3.5/5	84/100	4.5/5	5/5	Sep 2017	US$ 1 699	amazon.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. A score, therefore, has to be seen in close connection to the price and market introduction time 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. It should also be noted that some of the review sites have over time altered the way they render their verdicts.

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Other camera comparisons

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