Pentax 645Z vs Fujifilm GFX 50S

The Pentax 645Z and the Fujifilm GFX 50S are two professional cameras that were officially introduced, respectively, in April 2014 and September 2016. The 645Z is a DSLR, while the GFX 50S is a mirrorless interchangeable lens camera. Both cameras are equipped with a medium format sensor. Both cameras offer a resolution of 51.1 megapixels.

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

Headline Specifications

Pentax 645Z		Fujifilm GFX 50S
Digital single lens reflex		Mirrorless system camera
Pentax 645 mount lenses		Fujifilm G mount lenses
51.1 MP – Medium Format sensor		51.1 MP – Medium Format sensor
1080/60i Video		1080/30p Video
ISO 100-204,800		ISO 100-12,800 (50 - 102,400)
Optical viewfinder		Viewfinder optional
3.2" LCD – 1037k dots		3.2" LCD – 2360k dots
Tilting screen (no touchscreen)		Fully flexible touchscreen
3 shutter flaps per second		3 shutter flaps per second
Weathersealed body		Weathersealed body
650 shots per battery charge		400 shots per battery charge
156 x 117 x 123 mm, 1550 g		148 x 94 x 91 mm, 740 g

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Going beyond this snapshot of core features and characteristics, what are the differences between the Pentax 645Z and the Fujifilm GFX 50S? 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 Fujifilm GFX 50S 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 Fujifilm GFX 50S is notably smaller (24 percent) than the Pentax 645Z. Moreover, the GFX 50S is substantially lighter (52 percent) than the 645Z. 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 645Z gets 650 shots out of its Pentax D-LI90 battery, while the GFX 50S can take 400 images on a single charge of its Fujifilm NP-T125 power pack.

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 645Z	156 mm	117 mm	123 mm	1550 g	650	Y	Apr 2014	8,499	ebay.com
2.		Fujifilm GFX 50S	148 mm	94 mm	91 mm	740 g	400	Y	Sep 2016	6,499	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.		Fujifilm GFX 50R	161 mm	97 mm	66 mm	775 g	400	Y	Sep 2018	4,499	ebay.com
7.		Fujifilm GFX 50S II	150 mm	104 mm	87 mm	900 g	440	Y	Sep 2021	3,999	amazon.com
8.		Hasselblad X1D	150 mm	98 mm	71 mm	725 g	..	Y	Jun 2016	8,995	ebay.com
9.		Hasselblad X1D II	148 mm	97 mm	70 mm	766 g	..	Y	Jun 2019	5,750	ebay.com
10.		Leica M10	139 mm	80 mm	39 mm	660 g	210	Y	Jan 2017	6,595	ebay.com
11.		Leica M11	139 mm	80 mm	39 mm	640 g	700	Y	Jan 2022	8,995	amazon.com
12.		Leica SL	147 mm	104 mm	39 mm	847 g	400	Y	Oct 2015	7,450	ebay.com
13.		Nikon D4S	160 mm	157 mm	91 mm	1350 g	3020	Y	Feb 2014	6,499	ebay.com
14.		Nikon D5	160 mm	159 mm	92 mm	1415 g	3780	Y	Jan 2016	6,499	ebay.com
15.		Nikon D7200	136 mm	107 mm	76 mm	765 g	1110	Y	Mar 2015	1,199	ebay.com
16.		Pentax 645D	156 mm	117 mm	119 mm	1480 g	800	Y	Mar 2010	9,995	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 manufacturer’s suggested retail prices give an idea on the placement of the camera in the maker’s lineup and the broader market. The GFX 50S was launched at a somewhat lower price (by 24 percent) than the 645Z, which makes it more attractive for photographers on a tight budget. 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. 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.

Both cameras under consideration feature a medium format sensor, but their sensors differ slightly in size. The sensor area in the GFX 50S is 1 percent bigger. They nevertheless have the same format factor of 0.79. Both cameras feature a native aspect ratio (sensor width to sensor height) of 4:3.

Even though the GFX 50S has a slightly larger sensor, both cameras offer the same resolution of 51.1 megapixels. This implies that the GFX 50S has a lower pixel density and marginally larger individual pixels (with a pixel pitch of 5.33μm versus 5.30μm for the 645Z), which gives it a potential advantage in terms of light gathering capacity. In addition, the GFX 50S is much more recent (by 2 years and 5 months) than the 645Z, and its sensor will have benefitted from technological advances during this time. 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 Pentax 645Z has a native sensitivity range from ISO 100 to ISO 204800. The corresponding ISO settings for the Fujifilm GFX 50S are ISO 100 to ISO 12800, with the possibility to increase the ISO range to 50-102400.

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 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 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 645Z	Medium Format	51.1	8256	6192	1080/60i	26.0	14.7	4505	101
2.		Fujifilm GFX 50S	Medium Format	51.1	8256	6192	1080/30p	25.4	14.1	2977	96
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.		Fujifilm GFX 50R	Medium Format	51.1	8256	6192	1080/30p	25.7	14.4	3169	98
7.		Fujifilm GFX 50S II	Medium Format	51.1	8256	6192	1080/30p	25.9	14.8	3456	100
8.		Hasselblad X1D	Medium Format	51.3	8272	6200	1080/25p	26.2	14.8	4489	102
9.		Hasselblad X1D II	Medium Format	51.3	8272	6200	1080/25p	25.7	14.5	3234	99
10.		Leica M10	Full Frame	23.8	5952	3992	none	24.4	13.2	2133	86
11.		Leica M11	Full Frame	60.3	9528	6328	none	26.3	14.8	3376	100
12.		Leica SL	Full Frame	24.0	6000	4000	4K/30p	25.0	13.4	1821	88
13.		Nikon D4S	Full Frame	16.2	4928	3280	1080/60p	24.4	13.3	3074	89
14.		Nikon D5	Full Frame	20.7	5588	3712	4K/30p	25.1	12.3	2343	88
15.		Nikon D7200	APS-C	24.0	6000	4000	1080/60p	24.5	14.6	1333	87
16.		Pentax 645D	Medium Format	39.5	7264	5440	none	24.6	12.6	1262	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 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 645Z provides a higher frame rate than the GFX 50S. It can shoot video footage at 1080/60i, while the Fujifilm 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 GFX 50S relies on live view and the rear LCD for framing. That said, the GFX 50S can be equipped with an optional viewfinder – the EVF-TL1. The following table reports on some other key feature differences and similarities of the Pentax 645Z, the Fujifilm GFX 50S, and comparable 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.		Fujifilm GFX 50S	optional	Y	3.2 / 2360	full-flex	Y	1/4000s	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 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.		Fujifilm GFX 50R	3690	n	3.2 / 2360	tilting	Y	1/4000s	3.0/s	n	n
7.		Fujifilm GFX 50S II	3690	Y	3.2 / 2360	full-flex	Y	1/4000s	3.0/s	n	Y
8.		Hasselblad X1D	2360	n	3.0 / 920	fixed	Y	1/2000s	2.3/s	n	n
9.		Hasselblad X1D II	3690	n	3.6 / 2360	fixed	Y	1/2000s	2.7/s	n	n
10.		Leica M10	optical	n	3.0 / 1037	fixed	n	1/4000s	5.0/s	n	n
11.		Leica M11	optical	n	3.0 / 2333	fixed	Y	1/4000s	4.5/s	n	n
12.		Leica SL	4400	Y	3.0 / 1040	fixed	Y	1/8000s	11.0/s	n	n
13.		Nikon D4S	optical	Y	3.2 / 921	fixed	n	1/8000s	11.0/s	n	n
14.		Nikon D5	optical	Y	3.2 / 2359	fixed	Y	1/8000s	14.0/s	n	n
15.		Nikon D7200	optical	Y	3.2 / 1229	fixed	n	1/8000s	6.0/s	Y	n
16.		Pentax 645D	optical	Y	3.0 / 921	fixed	n	1/4000s	1.1/s	n	n
Note: *) Information refers to the mechanical shutter, unless the camera only has an electronic one.

One differentiating feature between the two cameras concerns the touch sensitivity of the rear screen. The GFX 50S has a touchscreen, while the 645Z has a conventional panel. Touch control can be particularly helpful, for example, for setting the focus point.

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 GFX 50S 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 645Z and the Fujifilm GFX 50S 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 GFX 50S write their files to SDXC cards. Both cameras feature dual card slots, which can be very useful in case a memory card fails. The GFX 50S supports UHS-II cards (on both slots), while the 645Z 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 Pentax 645Z and Fujifilm GFX 50S 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.		Fujifilm GFX 50S	Y	stereo / mono	Y	Y	micro	3.0	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.		Fujifilm GFX 50R	Y	stereo / mono	Y	Y	micro	3.0	Y	-	Y
7.		Fujifilm GFX 50S II	Y	stereo / mono	Y	Y	micro	3.2	Y	-	-
8.		Hasselblad X1D	Y	stereo / mono	Y	Y	mini	3.0	Y	-	-
9.		Hasselblad X1D II	Y	stereo / mono	Y	Y	-	3.0	Y	-	-
10.		Leica M10	Y	- / -	-	-	-	-	Y	-	-
11.		Leica M11	Y	- / -	-	-	-	3.2	Y	-	Y
12.		Leica SL	Y	stereo / mono	Y	Y	full	3.0	Y	-	-
13.		Nikon D4S	Y	mono / mono	Y	Y	mini	2.0	-	-	-
14.		Nikon D5	Y	stereo / mono	Y	Y	mini	3.0	-	-	-
15.		Nikon D7200	Y	stereo / mono	Y	Y	mini	2.0	Y	Y	-
16.		Pentax 645D	Y	stereo / -	-	-	-	2.0	-	-	-

It is notable that the GFX 50S offers wifi support, which can be a very convenient means to transfer image data to an off-camera location. In contrast, the 645Z does not provide wifi capability.

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

Both the 645Z and the GFX 50S have been discontinued, but can regularly be found used on ebay. The GFX 50S was replaced by the Fujifilm GFX 50S II, while the 645Z does not have a direct successor. Further information on the features and operation of the 645Z and GFX 50S can be found, respectively, in the Pentax 645Z Manual (free pdf) or the online Fujifilm GFX 50S Manual.

Review summary

So how do things add up? Is the Pentax 645Z better than the Fujifilm GFX 50S or vice versa? Below is a summary of the relative strengths of each of the two contestants.

Arguments in favor of the Pentax 645Z:

• Better video: Provides higher movie framerates (1080/60i versus 1080/30p).
• Easier framing: Has an optical viewfinder for image composition and settings control.
• Longer lasting: Can take more shots (650 versus 400) on a single battery charge.
• More heavily discounted: Has been available for much longer (launched in April 2014).

Reasons to prefer the Fujifilm GFX 50S:

• Better sound control: Has a headphone port that enables audio monitoring while recording.
• More detailed LCD: Has a higher resolution rear screen (2360k vs 1037k dots).
• More flexible LCD: Has a full-flex screen for odd-angle shots in portrait or landscape orientation.
• Fewer buttons to press: Has a touchscreen to facilitate handling and shooting adjustments.
• Less disturbing: Has an electronic shutter option for completely silent shooting.
• More compact: Is smaller (148x94mm vs 156x117mm) and will fit more readily into a bag.
• Less heavy: Has a lower weight (by 810g or 52 percent) and is thus easier to take along.
• More legacy lens friendly: Can use many non-native lenses via adapters.
• 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 affordable: Was released into a lower priced segment (24 percent cheaper at launch).
• More modern: Reflects 2 years and 5 months of technical progress since the 645Z launch.

If the count of relative strengths (bullet points above) is taken as a measure, the GFX 50S is the clear winner of the contest (12 : 4 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 645Z and the Fujifilm GFX 50S place the cameras among the top in their class? Find out in the latest Best DSLR Camera and Best Mirrorless Interchangeable Lens Camera listings whether the two cameras rank among the cream of the crop.

In any case, while the comparison of technical specifications can provide a useful overview of the capabilities of different cameras, it remains partial and cannot reveal, for example, the shooting experience and imaging performance when actually working with the 645Z or the GFX 50S. 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 why hands-on reviews by experts are important. 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 645Z	5/5	..	3.5/5	..	4.5/5	5/5	Apr 2014	8,499	ebay.com
2.		Fujifilm GFX 50S	..	..	4.5/5	85/100	5/5	4.5/5	Sep 2016	6,499	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.		Fujifilm GFX 50R	5/5	..	5/5	84/100	4.5/5	4.5/5	Sep 2018	4,499	ebay.com
7.		Fujifilm GFX 50S II	5/5	..	5/5	87/100	..	5/5	Sep 2021	3,999	amazon.com
8.		Hasselblad X1D	..	o	..	81/100	..	4/5	Jun 2016	8,995	ebay.com
9.		Hasselblad X1D II	..	..	4/5	..	4/5	4/5	Jun 2019	5,750	ebay.com
10.		Leica M10	4.5/5	..	..	..	4/5	4.5/5	Jan 2017	6,595	ebay.com
11.		Leica M11	4.5/5	..	4.5/5	..	4.5/5	4.5/5	Jan 2022	8,995	amazon.com
12.		Leica SL	4/5	..	4/5	84/100	4.5/5	4/5	Oct 2015	7,450	ebay.com
13.		Nikon D4S	5/5	..	..	..	4.5/5	4.5/5	Feb 2014	6,499	ebay.com
14.		Nikon D5	..	..	4/5	89/100	4.5/5	5/5	Jan 2016	6,499	ebay.com
15.		Nikon D7200	4/5	+ +	..	84/100	4.5/5	4.5/5	Mar 2015	1,199	ebay.com
16.		Pentax 645D	5/5	..	..	..	..	..	Mar 2010	9,995	ebay.com
Note: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.

The review scores listed above should be treated with care, though. The ratings were established in reference to similarly priced cameras that were available in the market at the time of the review. 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.

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Other camera comparisons

Did this review help to inform your camera decision process? In case you would like to check on the differences and similarities of other camera models, just make your choice using the following search menu. There is also a set of direct links to comparison reviews that other users of the CAM-parator app explored.

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