Pentax 645D vs Fujifilm GFX 50S

The Pentax 645D and the Fujifilm GFX 50S are two professional cameras that were officially introduced, respectively, in March 2010 and September 2016. The 645D is a DSLR, while the GFX 50S is a mirrorless interchangeable lens camera. Both cameras are equipped with a medium format sensor. The Pentax has a resolution of 39.5 megapixels, whereas the Fujifilm 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

Pentax 645D		Fujifilm GFX 50S
Digital single lens reflex		Mirrorless system camera
Pentax 645 mount lenses		Fujifilm G mount lenses
39.5 MP – Medium Format sensor		51.1 MP – Medium Format sensor
no Video		1080/30p Video
ISO 100-1,600		ISO 100-12,800 (50 - 102,400)
Optical viewfinder		Viewfinder optional
3.0" LCD – 921k dots		3.2" LCD – 2360k dots
Fixed screen (not touch-sensitive)		Fully flexible touchscreen
1.1 shutter flaps per second		3 shutter flaps per second
Weathersealed body		Weathersealed body
800 shots per battery charge		400 shots per battery charge
156 x 117 x 119 mm, 1480 g		148 x 94 x 91 mm, 740 g

Check 645D 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 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 645D 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 measures 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 645D. Moreover, the GFX 50S is substantially lighter (50 percent) than the 645D. 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 645D gets 800 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 645D	156 mm	117 mm	119 mm	1480 g	800	Y	Mar 2010	9,995	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 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.		Fujifilm GFX 50S II	150 mm	104 mm	87 mm	900 g	440	Y	Sep 2021	3,999	amazon.com
7.		Fujifilm GFX 50R	161 mm	97 mm	66 mm	775 g	400	Y	Sep 2018	4,499	ebay.com
8.		Hasselblad X1D II	148 mm	97 mm	70 mm	766 g	..	Y	Jun 2019	5,750	ebay.com
9.		Leica M10	139 mm	80 mm	39 mm	660 g	210	Y	Jan 2017	6,595	ebay.com
10.		Leica SL	147 mm	104 mm	39 mm	847 g	400	Y	Oct 2015	7,450	ebay.com
11.		Leica S Typ 006	160 mm	120 mm	80 mm	1260 g	..	Y	Sep 2012	21,950	ebay.com
12.		Nikon D850	146 mm	124 mm	79 mm	1005 g	1840	Y	Jul 2017	3,299	amazon.com
13.		Nikon D5	160 mm	159 mm	92 mm	1415 g	3780	Y	Jan 2016	6,499	ebay.com
14.		Nikon D810	146 mm	123 mm	82 mm	980 g	1200	Y	Jun 2014	3,299	ebay.com
15.		Nikon D3S	160 mm	157 mm	88 mm	1240 g	4200	Y	Oct 2009	5,199	ebay.com
16.		Pentax 645Z	156 mm	117 mm	123 mm	1550 g	650	Y	Apr 2014	8,499	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 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 GFX 50S was launched at a markedly lower price (by 35 percent) than the 645D, 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 imaging sensor is a crucial determinant 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 more expensive and lead to bigger and heavier cameras and lenses.

Both cameras under consideration feature a medium format sensor and have a format factor (sometimes also referred to as "crop factor") of 0.79. Within the spectrum of camera sensors, this places the review cameras among the large-sensor cameras that aim for top notch image quality. Both cameras feature a native aspect ratio (sensor width to sensor height) of 4:3.

While the two cameras under review share the same sensor size, the GFX 50S offers a higher resolution of 51.1 megapixels, compared with 39.5 MP of the 645D. This megapixels advantage translates into a 14 percent gain in linear resolution. On the other hand, these sensor specs imply that the GFX 50S has a higher pixel density and a smaller size of the individual pixel (with a pixel pitch of 5.33μm versus 6.06μm for the 645D). However, it should be noted that the GFX 50S is much more recent (by 6 years and 6 months) than the 645D, and its sensor will have benefitted from technological advances during this time that compensate for the smaller pixel size. 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 Fujifilm GFX 50S implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the GFX 50S for good quality output (200 dots per inch) amounts to 41.3 x 31 inches or 104.9 x 78.6 cm, for very good quality (250 dpi) 33 x 24.8 inches or 83.9 x 62.9 cm, and for excellent quality (300 dpi) 27.5 x 20.6 inches or 69.9 x 52.4 cm. The corresponding values for the Pentax 645D are 36.3 x 27.2 inches or 92.3 x 69.1 cm for good quality, 29.1 x 21.8 inches or 73.8 x 55.3 cm for very good quality, and 24.2 x 18.1 inches or 61.5 x 46.1 cm for excellent quality prints.

The Pentax 645D has a native sensitivity range from ISO 100 to ISO 1600. 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.

In terms of underlying technology, the 645D is build around a CCD sensor, while the GFX 50S 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 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 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.		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 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.		Fujifilm GFX 50S II	Medium Format	51.1	8256	6192	1080/30p	25.9	14.8	3456	100
7.		Fujifilm GFX 50R	Medium Format	51.1	8256	6192	1080/30p	25.7	14.4	3169	98
8.		Hasselblad X1D II	Medium Format	51.3	8272	6200	1080/25p	25.7	14.5	3234	99
9.		Leica M10	Full Frame	23.8	5952	3992	none	24.4	13.2	2133	86
10.		Leica SL	Full Frame	24.0	6000	4000	4K/30p	25.0	13.4	1821	88
11.		Leica S Typ 006	Medium Format	37.5	7500	5000	none	23.9	12.2	824	76
12.		Nikon D850	Full Frame	45.4	8256	5504	4K/30p	26.4	14.8	2660	100
13.		Nikon D5	Full Frame	20.7	5588	3712	4K/30p	25.1	12.3	2343	88
14.		Nikon D810	Full Frame	36.2	7360	4912	1080/60p	25.7	14.8	2853	97
15.		Nikon D3S	Full Frame	12.1	4256	2832	720/24p	23.5	12.0	3253	82
16.		Pentax 645Z	Medium Format	51.1	8256	6192	1080/60i	26.0	14.7	4505	101
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 can also record movies. The GFX 50S indeed provides for movie recording, while the 645D does not. The highest resolution format that the GFX 50S can use is 1080/30p.

Feature comparison

Beyond body and sensor, cameras can and do differ across a range of features. For example, the 645D 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 table below summarizes some of the other core capabilities of the Pentax 645D and Fujifilm GFX 50S 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 645D	optical	Y	3.0 / 921	fixed	n	1/4000s	1.1/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 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.		Fujifilm GFX 50S II	3690	Y	3.2 / 2360	full-flex	Y	1/4000s	3.0/s	n	Y
7.		Fujifilm GFX 50R	3690	n	3.2 / 2360	tilting	Y	1/4000s	3.0/s	n	n
8.		Hasselblad X1D II	3690	n	3.6 / 2360	fixed	Y	1/2000s	2.7/s	n	n
9.		Leica M10	optical	n	3.0 / 1037	fixed	n	1/4000s	5.0/s	n	n
10.		Leica SL	4400	Y	3.0 / 1040	fixed	Y	1/8000s	11.0/s	n	n
11.		Leica S Typ 006	optical	Y	3.0 / 922	fixed	n	1/4000s	1.5/s	n	n
12.		Nikon D850	optical	Y	3.2 / 2359	tilting	Y	1/8000s	9.0/s	n	n
13.		Nikon D5	optical	Y	3.2 / 2359	fixed	Y	1/8000s	14.0/s	n	n
14.		Nikon D810	optical	Y	3.2 / 1229	fixed	n	1/8000s	5.0/s	Y	n
15.		Nikon D3S	optical	Y	3.0 / 921	fixed	n	1/8000s	11.0/s	n	n
16.		Pentax 645Z	optical	Y	3.2 / 1037	tilting	n	1/4000s	3.0/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 differentiating feature between the two cameras concerns the touch sensitivity of the rear screen. The GFX 50S has a touchscreen, while the 645D 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 645D 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 645D 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 645D cannot take advantage of Ultra High Speed SD 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 645D 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 645D	Y	stereo / -	-	-	-	2.0	-	-	-
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 1D X	Y	mono / -	Y	-	mini	2.0	-	-	-
5.		Canon 1D Mark IV	Y	stereo / -	Y	-	mini	2.0	-	-	-
6.		Fujifilm GFX 50S II	Y	stereo / mono	Y	Y	micro	3.2	Y	-	-
7.		Fujifilm GFX 50R	Y	stereo / mono	Y	Y	micro	3.0	Y	-	Y
8.		Hasselblad X1D II	Y	stereo / mono	Y	Y	-	3.0	Y	-	-
9.		Leica M10	Y	- / -	-	-	-	-	Y	-	-
10.		Leica SL	Y	stereo / mono	Y	Y	full	3.0	Y	-	-
11.		Leica S Typ 006	Y	- / -	-	-	mini	2.0	-	-	-
12.		Nikon D850	Y	stereo / mono	Y	Y	mini	3.0	Y	Y	Y
13.		Nikon D5	Y	stereo / mono	Y	Y	mini	3.0	-	-	-
14.		Nikon D810	Y	stereo / mono	Y	Y	mini	3.0	Y	-	-
15.		Nikon D3S	Y	stereo / -	-	-	mini	2.0	-	-	-
16.		Pentax 645Z	Y	stereo / mono	Y	-	mini	3.0	-	-	-
17.		Sony A7R	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-

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 645D 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 645D and the GFX 50S have been discontinued, but can regularly be found used on ebay. The 645D was replaced by the Pentax 645Z, while the GFX 50S was followed by the Fujifilm GFX 50S II. Further information on the features and operation of the 645D and GFX 50S can be found, respectively, in the Pentax 645D Manual (free pdf) or the online Fujifilm GFX 50S Manual.

Review summary

So what is the bottom line? Which of the two cameras – the Pentax 645D or the Fujifilm GFX 50S – has the upper hand? Is one clearly better than the other? The listing below highlights the relative strengths of the two models.

Reasons to prefer the Pentax 645D:

• Easier framing: Has an optical viewfinder for image composition and settings control.
• Longer lasting: Can take more shots (800 versus 400) on a single battery charge.
• More heavily discounted: Has been available for much longer (launched in March 2010).

Advantages of the Fujifilm GFX 50S:

• More detail: Has more megapixels (51.1 vs 39.5MP), which boosts linear resolution by 14%.
• Broader imaging potential: Can capture not only stills but also 1080/30p video.
• 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 (2360k vs 921k 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.
• 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.
• More compact: Is smaller (148x94mm vs 156x117mm) and will fit more readily into a bag.
• Less heavy: Has a lower weight (by 740g or 50 percent) and is thus easier to take along.
• More legacy lens friendly: Can use many non-native lenses via adapters.
• Faster data transfer: Supports a more advanced USB protocol (3.0 vs 2.0).
• Easier file upload: Has wifi built in for automatic backup or image transfer to the web.
• Faster buffer clearing: Supports Ultra High Speed (UHS-II) SDXC cards on both slots.
• More affordable: Was introduced into a lower priced category (35 percent cheaper at launch).
• More modern: Reflects 6 years and 6 months of technical progress since the 645D launch.

If the number of relative strengths (bullet points above) is taken as a guide, the GFX 50S is the clear winner of the contest (16 : 3 points). However, the relative importance of the various individual camera aspects will vary according to personal preferences and needs, so that you might like to apply corresponding weights to the particular features before making a decision 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 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 specs-based evaluation of cameras can be instructive in revealing their potential as photographic tools, it remains incomplete and does no justice, for example, to the way the 645D or the GFX 50S perform in practice. 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 expert reviews are important. The following table reports the overall ratings of the cameras as published by some of the major 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.		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 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.		Fujifilm GFX 50S II	5/5	..	5/5	87/100	..	5/5	Sep 2021	3,999	amazon.com
7.		Fujifilm GFX 50R	5/5	..	5/5	84/100	4.5/5	4.5/5	Sep 2018	4,499	ebay.com
8.		Hasselblad X1D II	..	..	4/5	..	4/5	4/5	Jun 2019	5,750	ebay.com
9.		Leica M10	4.5/5	..	..	..	4/5	4.5/5	Jan 2017	6,595	ebay.com
10.		Leica SL	4/5	..	4/5	84/100	4.5/5	4/5	Oct 2015	7,450	ebay.com
11.		Leica S Typ 006	..	..	..	..	..	..	Sep 2012	21,950	ebay.com
12.		Nikon D850	4.5/5	+ +	5/5	89/100	4.5/5	5/5	Jul 2017	3,299	amazon.com
13.		Nikon D5	..	..	4/5	89/100	4.5/5	5/5	Jan 2016	6,499	ebay.com
14.		Nikon D810	5/5	..	5/5	86/100	5/5	4.5/5	Jun 2014	3,299	ebay.com
15.		Nikon D3S	5/5	..	..	89/100	4.5/5	5/5	Oct 2009	5,199	ebay.com
16.		Pentax 645Z	5/5	..	3.5/5	..	4.5/5	5/5	Apr 2014	8,499	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 ratings are only valid when referring to cameras in the same category and of the same age. 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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