Pentax 645D vs Zeiss ZX1

The Pentax 645D and the Zeiss ZX1 are two digital cameras that were revealed to the public, respectively, in March 2010 and September 2018. The 645D is a DSLR, while the ZX1 is a fixed lens compact. The cameras are based on a medium format (645D) and a full frame (ZX1) sensor. The Pentax has a resolution of 39.5 megapixels, whereas the Zeiss provides 37.4 MP.

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

Headline Specifications

Pentax 645D		Zeiss ZX1
Digital single lens reflex		Fixed lens compact camera
Pentax 645 mount lenses		35mm f/2.8
39.5 MP – Medium Format sensor		37.4 MP – Full Frame sensor
no Video		4K/30p Video
ISO 100-1,600		ISO 80-51,200
Optical viewfinder		Electronic viewfinder (6221k dots)
3.0" LCD – 921k dots		4.3" LCD – 2765k dots
Fixed screen (not touch-sensitive)		Fixed touchscreen
1.1 shutter flaps per second		3 shutter flaps per second
Weathersealed body		not weather sealed
800 shots per battery charge		250 shots per battery charge
156 x 117 x 119 mm, 1480 g		142 x 93 x 46 mm, 800 g

Check 645D offers at
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Check ZX1 offers at
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Going beyond this snapshot of core features and characteristics, what are the differences between the Pentax 645D and the Zeiss ZX1? 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 645D and the Zeiss ZX1 is provided 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 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 Zeiss ZX1 is notably smaller (28 percent) than the Pentax 645D. It is worth mentioning in this context that the 645D is splash and dust resistant, while the ZX1 does not feature any corresponding weather-sealing.

The above size and weight comparisons are to some extent incomplete and possibly misleading, as the ZX1 has a lens built in, whereas the 645D 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 645D gets 800 shots out of its Pentax D-LI90 battery, while the ZX1 can take 250 images on a single charge of its Zeiss DD-PS1A power pack.

The following table provides a synthesis of the main physical specifications of the two cameras and other similar ones. 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 645D	156 mm	117 mm	119 mm	1480 g	800	Y	Mar 2010	9,995	ebay.com
2.		Zeiss ZX1	142 mm	93 mm	46 mm	800 g	250	n	Sep 2018	5,999	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 1D X	158 mm	168 mm	83 mm	1551 g	1120	Y	Oct 2011	6,799	ebay.com
5.		Canon 1D Mark IV	156 mm	157 mm	80 mm	1230 g	1500	Y	Oct 2009	4,999	ebay.com
6.		Leica Q2	130 mm	80 mm	92 mm	718 g	370	Y	Mar 2019	4,995	amazon.com
7.		Leica M10	139 mm	80 mm	39 mm	660 g	210	Y	Jan 2017	6,595	ebay.com
8.		Leica Q Typ 116	130 mm	80 mm	93 mm	640 g	300	n	Jun 2015	4,249	ebay.com
9.		Leica S Typ 006	160 mm	120 mm	80 mm	1260 g	..	Y	Sep 2012	21,950	ebay.com
10.		Nikon D850	146 mm	124 mm	79 mm	1005 g	1840	Y	Jul 2017	3,299	amazon.com
11.		Nikon D5	160 mm	159 mm	92 mm	1415 g	3780	Y	Jan 2016	6,499	ebay.com
12.		Nikon D810	146 mm	123 mm	82 mm	980 g	1200	Y	Jun 2014	3,299	ebay.com
13.		Nikon D3S	160 mm	157 mm	88 mm	1240 g	4200	Y	Oct 2009	5,199	ebay.com
14.		Panasonic FZ1000	137 mm	99 mm	131 mm	831 g	360	n	Jun 2014	899	ebay.com
15.		Pentax 645Z	156 mm	117 mm	123 mm	1550 g	650	Y	Apr 2014	8,499	ebay.com
16.		Sony RX1R II	113 mm	65 mm	72 mm	507 g	220	n	Oct 2015	3,299	ebay.com
17.		Sony A7R	127 mm	94 mm	48 mm	465 g	340	Y	Oct 2013	2,299	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

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 ZX1 was launched at a lower price than the 645D, 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 imaging sensor is at the core of digital cameras and its size is one of the main determining factors 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. Furthermore, a large sensor camera will give the photographer more possibilities to use shallow depth-of-field in order to isolate a subject from the background. On the downside, larger sensors tend to be associated with larger, more expensive camera bodies and lenses.

Of the two cameras under consideration, the Pentax 645D features a medium format sensor and the Zeiss ZX1 a full frame sensor. The sensor area in the ZX1 is 40 percent smaller. As a result of these sensor size differences, the cameras have a format factor of, respectively, 0.79 and 1.0. The sensor in the 645D has a native 4:3 aspect ratio, while the one in the ZX1 offers a 3:2 aspect.

With 39.5MP, the 645D offers a slightly higher resolution than the ZX1 (37.4MP), but the 645D nevertheless has larger individual pixels (pixel pitch of 6.06μm versus 4.81μm for the ZX1) due to its larger sensor. However, the ZX1 is a much more recent model (by 8 years and 6 months) than the 645D, 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 the 645D has no anti-alias filter installed, so that it can capture all the detail its sensor resolves.

The Pentax 645D has a native sensitivity range from ISO 100 to ISO 1600. The corresponding ISO settings for the Zeiss ZX1 are ISO 80 to ISO 51200 (no boost).

In terms of underlying technology, the 645D is build around a CCD sensor, while the ZX1 uses a 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.

For many cameras, data on sensor performance has been reported by DXO Mark. This service assesses and scores the color depth ("DXO Portrait"), dynamic range ("DXO Landscape"), and low-light sensitivity ("DXO Sports") of camera sensors, and also publishes an overall camera score. The table below summarizes the physical sensor characteristics and sensor quality findings and compares them across a set of similar 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 645D	Medium Format	39.5	7264	5440	none	24.6	12.6	1262	82
2.		Zeiss ZX1	Full Frame	37.4	7488	4992	4K/30p	25.2	14.1	2759	94
3.		Canon 1D X Mark II	Full Frame	20.0	5472	3648	4K/60p	24.1	13.5	3207	88
4.		Canon 1D X	Full Frame	17.9	5184	3456	1080/30p	23.8	11.8	2786	82
5.		Canon 1D Mark IV	APS-H	16.0	4896	3264	1080/30p	22.8	12.0	1320	74
6.		Leica Q2	Full Frame	46.7	8368	5584	4K/30p	26.4	13.5	2491	96
7.		Leica M10	Full Frame	23.8	5952	3992	none	24.4	13.2	2133	86
8.		Leica Q Typ 116	Full Frame	24.0	6000	4000	1080/60p	24.3	12.7	2221	85
9.		Leica S Typ 006	Medium Format	37.5	7500	5000	none	23.9	12.2	824	76
10.		Nikon D850	Full Frame	45.4	8256	5504	4K/30p	26.4	14.8	2660	100
11.		Nikon D5	Full Frame	20.7	5588	3712	4K/30p	25.1	12.3	2343	88
12.		Nikon D810	Full Frame	36.2	7360	4912	1080/60p	25.7	14.8	2853	97
13.		Nikon D3S	Full Frame	12.1	4256	2832	720/24p	23.5	12.0	3253	82
14.		Panasonic FZ1000	1-inch	20.0	5472	3648	4K/30p	22.1	11.7	517	64
15.		Pentax 645Z	Medium Format	51.1	8256	6192	1080/60i	26.0	14.7	4505	101
16.		Sony RX1R II	Full Frame	42.2	7952	5304	1080/60p	25.8	13.9	3204	97
17.		Sony A7R	Full Frame	36.2	7360	4912	1080/60p	25.6	14.1	2746	95
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 ZX1 indeed provides for movie recording, while the 645D does not. The highest resolution format that the ZX1 can use is 4K/30p.

Feature comparison

Beyond body and sensor, cameras can and do differ across a range of features. For example, the ZX1 has an electronic viewfinder (6221k dots), while the 645D has an optical one. Both systems have their advantages, with the electronic viewfinder making it possible to project supplementary shooting information into the framing view, whereas the optical viewfinder offers lag-free viewing and a very clear framing image. The viewfinder in the ZX1 offers a wider field of view (100%) than the one in the 645D (98%), so that a larger proportion of the captured image is visible in the finder. On the other hand, the viewfinder of the 645D has a higher magnification (0.78x vs 0.74x), 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 Pentax 645D and Zeiss ZX1 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.		Pentax 645D	optical	Y	3.0 / 921	fixed	n	1/4000s	1.1/s	n	n
2.		Zeiss ZX1	6221	n	4.3 / 2765	fixed	Y	1/1000s	3.0/s	n	n
3.		Canon 1D X Mark II	optical	Y	3.2 / 1620	fixed	Y	1/8000s	16.0/s	n	n
4.		Canon 1D X	optical	Y	3.2 / 1040	fixed	n	1/8000s	14.0/s	n	n
5.		Canon 1D Mark IV	optical	Y	3.0 / 920	fixed	n	1/8000s	10.0/s	n	n
6.		Leica Q2	3680	n	3.0 / 1040	fixed	Y	1/2000s	10.0/s	n	Y
7.		Leica M10	optical	n	3.0 / 1037	fixed	n	1/4000s	5.0/s	n	n
8.		Leica Q Typ 116	3680	n	3.0 / 1040	fixed	Y	1/2000s	10.0/s	n	Y
9.		Leica S Typ 006	optical	Y	3.0 / 922	fixed	n	1/4000s	1.5/s	n	n
10.		Nikon D850	optical	Y	3.2 / 2359	tilting	Y	1/8000s	9.0/s	n	n
11.		Nikon D5	optical	Y	3.2 / 2359	fixed	Y	1/8000s	14.0/s	n	n
12.		Nikon D810	optical	Y	3.2 / 1229	fixed	n	1/8000s	5.0/s	Y	n
13.		Nikon D3S	optical	Y	3.0 / 921	fixed	n	1/8000s	11.0/s	n	n
14.		Panasonic FZ1000	2359	n	3.0 / 921	swivel	n	1/4000s	12.0/s	Y	Y
15.		Pentax 645Z	optical	Y	3.2 / 1037	tilting	n	1/4000s	3.0/s	n	n
16.		Sony RX1R II	2360	n	3.0 / 1229	tilting	n	1/4000s	5.0/s	n	n
17.		Sony A7R	2400	n	3.0 / 1230	tilting	n	1/8000s	4.0/s	n	n
Note: *) Information refers to the mechanical shutter, unless the camera only has an electronic one.

One feature that is present on the 645D, but is missing on the ZX1 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 reported shutter speed information refers to the use of the mechanical shutter. Yet, some cameras only have an electronic shutter, while others have an electronic shutter in addition to a mechanical one. In fact, the ZX1 is one of those camera that have an additional electronic shutter, which makes completely silent shooting possible. However, this mode is less suitable for photographing moving objects (risk of rolling shutter) or shooting under artificial light sources (risk of flickering).

The Pentax 645D 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 645D writes its imaging data to SDXC cards, while the ZX1 uses an internal SSD.

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 645D and Zeiss ZX1 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 645D	Y	stereo / -	-	-	-	2.0	-	-	-
2.		Zeiss ZX1	Y	stereo / mono	-	-	-	3.1	Y	Y	Y
3.		Canon 1D X Mark II	Y	mono / mono	Y	Y	mini	3.0	-	-	-
4.		Canon 1D X	Y	mono / -	Y	-	mini	2.0	-	-	-
5.		Canon 1D Mark IV	Y	stereo / -	Y	-	mini	2.0	-	-	-
6.		Leica Q2	Y	stereo / mono	-	-	-	-	Y	-	Y
7.		Leica M10	Y	- / -	-	-	-	-	Y	-	-
8.		Leica Q Typ 116	Y	stereo / mono	-	-	micro	2.0	Y	Y	-
9.		Leica S Typ 006	Y	- / -	-	-	mini	2.0	-	-	-
10.		Nikon D850	Y	stereo / mono	Y	Y	mini	3.0	Y	Y	Y
11.		Nikon D5	Y	stereo / mono	Y	Y	mini	3.0	-	-	-
12.		Nikon D810	Y	stereo / mono	Y	Y	mini	3.0	Y	-	-
13.		Nikon D3S	Y	stereo / -	-	-	mini	2.0	-	-	-
14.		Panasonic FZ1000	Y	stereo / mono	Y	-	micro	2.0	Y	Y	-
15.		Pentax 645Z	Y	stereo / mono	Y	-	mini	3.0	-	-	-
16.		Sony RX1R II	Y	stereo / mono	Y	-	micro	2.0	Y	Y	-
17.		Sony A7R	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-

It is notable that the ZX1 offers wifi support, which can be a very convenient means to transfer image data to an off-camera location. In contrast, the 645D does not provide wifi capability.

Studio photographers will appreciate that the Pentax 645D (unlike the ZX1) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.

Both the 645D and the ZX1 have been discontinued, but can regularly be found used on ebay. The 645D was replaced by the Pentax 645Z, while the ZX1 does not have a direct successor. Further information on the features and operation of the 645D and ZX1 can be found, respectively, in the Pentax 645D Manual (free pdf) or the online Zeiss ZX1 Manual.

Review summary

So what is the bottom line? Is the Pentax 645D better than the Zeiss ZX1 or vice versa? A synthesis of the relative strong points of each of the models is listed below.

Arguments in favor of the Pentax 645D:

• Maximized detail: Lacks an anti-alias filter to exploit the sensor's full resolution potential.
• Brighter framing: Features an optical viewfinder for clear, lag-free composition.
• Larger viewfinder image: Features a viewfinder with a higher magnification (0.78x vs 0.74x).
• Easier setting verification: Features an LCD display on top to control shooting parameters.
• Faster shutter: Has higher mechanical shutter speed (1/4000s vs 1/1000s) to freeze action.
• Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
• More flexible: Can take a variety of interchangeable lenses, including specialty optics.
• Longer lasting: Can take more shots (800 versus 250) on a single battery charge.
• Better sealing: Is weather sealed to enable shooting in dusty or wet environments.
• Better studio light control: Has a PC Sync socket to connect to professional strobe lights.
• More heavily discounted: Has been available for much longer (launched in March 2010).

Advantages of the Zeiss ZX1:

• Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
• Broader imaging potential: Can capture not only stills but also 4K/30p video.
• More framing info: Has an electronic viewfinder that displays shooting data.
• More complete view: Has a viewfinder with a larger field of view (100% vs 98%).
• Larger screen: Has a bigger rear LCD (4.3" vs 3.0") for image review and settings control.
• More detailed LCD: Has a higher resolution rear screen (2765k vs 921k dots).
• Fewer buttons to press: Has a touchscreen to facilitate handling and shooting adjustments.
• Faster burst: Shoots at higher frequency (3 vs 1.1 flaps/sec) to capture the decisive moment.
• Less disturbing: Has an electronic shutter option for completely silent shooting.
• Ready to shoot: Comes with an integrated lens, while the 645D requires a separate lens.
• More compact: Is smaller (142x93mm 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 645D).
• Faster data transfer: Supports a more advanced USB protocol (3.1 vs 2.0).
• 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.
• Easier wireless transfer: Supports Bluetooth for image sharing without cables.
• More prestigious: Has the Zeiss luxury appeal, which ensures a high resale value.
• More affordable: Was introduced at a lower price, despite coming with a built-in lens.
• More modern: Reflects 8 years and 6 months of technical progress since the 645D launch.

If the count of relative strengths (bullet points above) is taken as a measure, the ZX1 is the clear winner of the contest (19 : 11 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.

How about other alternatives? Do the specifications of the Pentax 645D and the Zeiss ZX1 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 645D or the ZX1 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 hands-on reviews by experts 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.		Pentax 645D	5/5	..	..	..	..	..	Mar 2010	9,995	ebay.com
2.		Zeiss ZX1	3/5	..	..	83/100	4/5	4/5	Sep 2018	5,999	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 1D X	5/5	..	..	..	4.5/5	4.5/5	Oct 2011	6,799	ebay.com
5.		Canon 1D Mark IV	5/5	..	..	89/100	..	..	Oct 2009	4,999	ebay.com
6.		Leica Q2	..	..	4.5/5	84/100	4.5/5	4/5	Mar 2019	4,995	amazon.com
7.		Leica M10	4.5/5	..	..	..	4/5	4.5/5	Jan 2017	6,595	ebay.com
8.		Leica Q Typ 116	5/5	..	..	80/100	4.5/5	4.5/5	Jun 2015	4,249	ebay.com
9.		Leica S Typ 006	..	..	..	..	..	..	Sep 2012	21,950	ebay.com
10.		Nikon D850	4.5/5	+ +	5/5	89/100	4.5/5	5/5	Jul 2017	3,299	amazon.com
11.		Nikon D5	..	..	4/5	89/100	4.5/5	5/5	Jan 2016	6,499	ebay.com
12.		Nikon D810	5/5	..	5/5	86/100	5/5	4.5/5	Jun 2014	3,299	ebay.com
13.		Nikon D3S	5/5	..	..	89/100	4.5/5	5/5	Oct 2009	5,199	ebay.com
14.		Panasonic FZ1000	4/5	+ +	..	82/100	4.5/5	4.5/5	Jun 2014	899	ebay.com
15.		Pentax 645Z	5/5	..	3.5/5	..	4.5/5	5/5	Apr 2014	8,499	ebay.com
16.		Sony RX1R II	5/5	..	..	82/100	..	4.5/5	Oct 2015	3,299	ebay.com
17.		Sony A7R	5/5	+ +	..	82/100	4.5/5	5/5	Oct 2013	2,299	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. 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

Did this review help to inform your camera decision process? In case you are interested in seeing how other cameras pair up, just make your choice using the following search menu. Alternatively, you can follow any of the listed hyperlinks for comparisons that others found interesting.

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