Fujifilm GFX 100S vs Pentax 645D
The Fujifilm GFX 100S and the Pentax 645D are two professional cameras that were officially introduced, respectively, in January 2021 and March 2010. The GFX 100S is a mirrorless interchangeable lens camera, while the 645D is a DSLR. Both cameras are equipped with a medium format sensor. The Fujifilm has a resolution of 101.8 megapixels, whereas the Pentax provides 39.5 MP.
Below is an overview of the main specs of the two cameras as a starting point for the comparison.
Going beyond this snapshot of core features and characteristics, what are the differences between the Fujifilm GFX 100S and the Pentax 645D? 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.
An illustration of the physical size and weight of the Fujifilm GFX 100S and the Pentax 645D 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 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 645D is notably larger (17 percent) than the Fujifilm GFX 100S. Moreover, the 645D is substantially heavier (64 percent) than the GFX 100S. 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 GFX 100S gets 460 shots out of its NP-W235 battery, while the 645D can take 800 images on a single charge of its D-LI90 power pack. The power pack in the GFX 100S can be charged via the USB port, so that it is not always necessary to take the battery charger along when travelling.
The table below summarizes the key physical specs of the two cameras alongside a broader set of comparators. If you want to switch the focus of the display and review another camera pair, you can move across to the CAM-parator tool and choose from the broad selection of possible camera comparisons there.
|1.||Fujifilm GFX 100S||150 mm||104 mm||87 mm||900 g||460||Y||Jan 2021||5,999|
|2.||Pentax 645D||156 mm||117 mm||119 mm||1480 g||800||Y||Mar 2010||9,995|
|3.||Canon R5||138 mm||98 mm||88 mm||738 g||320||Y||Jul 2020||3,899|
|4.||Canon 1D X||158 mm||168 mm||83 mm||1551 g||1120||Y||Oct 2011||6,799|
|5.||Canon 1D Mark IV||156 mm||157 mm||80 mm||1230 g||1500||Y||Oct 2009||4,999|
|6.||Fujifilm X-T4||135 mm||93 mm||64 mm||607 g||500||Y||Feb 2020||1,699|
|7.||Fujifilm GFX 100||156 mm||144 mm||75 mm||1320 g||800||Y||May 2019||9,999|
|8.||Fujifilm GFX 50R||161 mm||97 mm||66 mm||775 g||400||Y||Sep 2018||4,499|
|9.||Fujifilm XP130||110 mm||71 mm||28 mm||207 g||240||n||Jan 2018||229|
|10.||Fujifilm GFX 50S||148 mm||94 mm||91 mm||740 g||400||Y||Sep 2016||6,499|
|11.||Leica SL2-S||146 mm||107 mm||83 mm||931 g||510||Y||Dec 2020||4,895|
|12.||Leica SL2||146 mm||107 mm||42 mm||953 g||370||Y||Nov 2019||5,999|
|13.||Leica S Typ 006||160 mm||120 mm||80 mm||1260 g||..||Y||Sep 2012||21,950|
|14.||Nikon D3S||160 mm||157 mm||88 mm||1240 g||4200||Y||Oct 2009||5,199|
|15.||Pentax K-3 III||135 mm||104 mm||74 mm||820 g||800||Y||Mar 2021||1,999|
|16.||Pentax 645Z||156 mm||117 mm||123 mm||1550 g||650||Y||Apr 2014||8,499|
|17.||Sony A1||129 mm||97 mm||81 mm||737 g||530||Y||Jan 2021||6,499|
|Notes: Measurements and pricing do not include easily detachable parts, such as add-on or interchangeable lenses or optional viewfinders.|
The price is, of course, an important factor in any camera decision. The retail prices at the time of the camera’s release place the model in the market relative to other models in the producer’s line-up and the competition. The GFX 100S was launched at a markedly lower price (by 40 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.
The imaging sensor is at the core of digital cameras and its size is one of the main determining factors 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. 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 more expensive and 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 645D 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.
Despite having a slightly smaller sensor, the Fujifilm GFX 100S offers a higher resolution of 101.8 megapixels, compared with 39.5 MP of the Pentax 645D. 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 3.76μm versus 6.06μm for the 645D). However, it should be noted that the GFX 100S is much more recent (by 10 years and 10 months) than the 645D, 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 Fujifilm GFX 100S implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the GFX 100S for good quality output (200 dots per inch) amounts to 58.2 x 43.7 inches or 147.9 x 110.9 cm, for very good quality (250 dpi) 46.6 x 34.9 inches or 118.3 x 88.8 cm, and for excellent quality (300 dpi) 38.8 x 29.1 inches or 98.6 x 74 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 GFX 100S has on-sensor phase detect pixels, which results in fast and reliable autofocus acquisition even during live view operation.
Unlike the 645D, the GFX 100S 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 Fujifilm GFX 100S has a native sensitivity range from ISO 100 to ISO 12800, which can be extended to ISO 50-102400. The corresponding ISO settings for the Pentax 645D are ISO 100 to ISO 1600 (no boost).
Consistent information on actual sensor performance is available from DXO Mark for many cameras. 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.
| DXO |
|1.||Fujifilm GFX 100S||Medium Format||101.8||11648||8736||4K/30p||..||..||..||..|
|2.||Pentax 645D||Medium Format||39.5||7264||5440||none||24.6||12.6||1262||82|
|3.||Canon R5||Full Frame||44.8||8192||5464||8k/30p||25.3||14.6||3042||95|
|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|
|7.||Fujifilm GFX 100||Medium Format||101.8||11648||8736||4K/30p||..||..||..||..|
|8.||Fujifilm GFX 50R||Medium Format||51.1||8256||6192||1080/30p||..||..||..||..|
|10.||Fujifilm GFX 50S||Medium Format||51.1||8256||6192||1080/30p||..||..||..||..|
|11.||Leica SL2-S||Full Frame||24.0||6000||4000||4K/60p||25.2||14.1||3504||95|
|12.||Leica SL2||Full Frame||46.7||8368||5584||4K/60p||..||..||..||..|
|13.||Leica S Typ 006||Medium Format||37.5||7500||5000||none||23.9||12.2||824||76|
|14.||Nikon D3S||Full Frame||12.1||4256||2832||720/24p||23.5||12.0||3253||82|
|15.||Pentax K-3 III||APS-C||25.6||6192||4128||4K/30p||..||..||..||..|
|16.||Pentax 645Z||Medium Format||51.1||8256||6192||1080/60i||26.0||14.7||4505||101|
|17.||Sony A1||Full Frame||49.8||8640||5760||8k/30p||..||..||..||..|
Many modern cameras are not only capable of taking still images, but also of capturing video footage. The GFX 100S indeed provides movie recording capabilities, while the 645D does not. The highest resolution format that the GFX 100S can use is 4K/30p.
Beyond body and sensor, cameras can and do differ across a range of features. For example, the GFX 100S has an electronic viewfinder (3690k 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 GFX 100S 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 0.77x), 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 Fujifilm GFX 100S and Pentax 645D along with similar information for a selection of comparators.
|1.||Fujifilm GFX 100S||3690||Y||3.2||2360||full-flex||Y||1/4000s||5.0||n||Y|
|4.||Canon 1D X||optical||Y||3.2||1040||fixed||n||1/8000s||14.0||n||n|
|5.||Canon 1D Mark IV||optical||Y||3.0||920||fixed||n||1/8000s||10.0||n||n|
|7.||Fujifilm GFX 100||optional||Y||3.2||2360||tilting||Y||1/4000s||5.0||n||Y|
|8.||Fujifilm GFX 50R||3690||n||3.2||2360||tilting||Y||1/4000s||3.0||n||n|
|10.||Fujifilm GFX 50S||optional||Y||3.2||2360||full-flex||Y||1/4000s||3.0||n||n|
|13.||Leica S Typ 006||optical||Y||3.0||922||fixed||n||1/4000s||1.5||n||n|
|15.||Pentax K-3 III||optical||Y||3.2||1620||fixed||Y||1/8000s||12.0||n||Y|
One feature that differentiates the GFX 100S and the 645D is in-body image stabilization (IBIS). The GFX 100S reduces the risk of handshake-induced blur with all attached lenses, while the 645D offers no blur reduction with lenses that themselves do not provide optical image stabilization.
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 100S 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 Fujifilm GFX 100S and the Pentax 645D 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 GFX 100S and the 645D 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 100S supports UHS-II cards (on both slots), while the 645D cannot take advantage of Ultra High Speed SD cards.
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 Fujifilm GFX 100S and Pentax 645D and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.
| WiFi |
| NFC |
|1.||Fujifilm GFX 100S||Y||stereo||mono||Y||Y||micro||3.2||Y||-||Y|
|4.||Canon 1D X||Y||mono||-||Y||-||mini||2.0||-||-||-|
|5.||Canon 1D Mark IV||Y||stereo||-||Y||-||mini||2.0||-||-||-|
|7.||Fujifilm GFX 100||Y||stereo||mono||Y||Y||micro||3.1||Y||-||Y|
|8.||Fujifilm GFX 50R||Y||stereo||mono||Y||Y||micro||3.0||Y||-||Y|
|10.||Fujifilm GFX 50S||Y||stereo||mono||Y||Y||micro||3.0||Y||-||-|
|13.||Leica S Typ 006||Y||-||-||-||-||mini||2.0||-||-||-|
|15.||Pentax K-3 III||Y||stereo||mono||Y||Y||micro||3.2||Y||-||Y|
It is notable that the GFX 100S offers wifi support, while the 645D does not. Wifi can be a very convenient means to transfer image data to an off-camera location.
Both cameras feature a PC Sync terminal to control professional strobe lights, which will be appreciated by studio photographers.
The GFX 100S is a recent model that features in the current product line-up of Fujifilm. In contrast, the 645D has been discontinued (but can be found pre-owned on eBay). As a replacement in the same line of cameras, the 645D was succeeded by the Pentax 645Z. Further information on the two cameras (e.g. user guides, manuals), as well as related accessories, can be found on the official Fujifilm and Pentax websites.
So what is the bottom line? Is the Fujifilm GFX 100S better than the Pentax 645D or vice versa? Below is a summary of the relative strengths of each of the two contestants.
Advantages of the Fujifilm GFX 100S:
- More detail: Offers more megapixels (101.8 vs 39.5MP) with a 60% higher linear resolution.
- High quality composites: Can combine several shots after pixel-shifting its sensor.
- Broader imaging potential: Can record not only still images but also 4K/30p movies.
- Better live-view autofocus: Features on-sensor phase-detection for more confident autofocus.
- 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 (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: Is equipped with a touch-sensitive rear screen to facilitate handling.
- Faster burst: Shoots at higher frequency (5 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 (150x104mm vs 156x117mm) and thus needs less room in the bag.
- Less heavy: Is lighter (by 580g or 39 percent) and hence easier to carry around.
- Easier travel charging: Can be conveniently charged via its USB port.
- Sharper images: Has hand-shake reducing image stabilization built-in.
- More legacy lens friendly: Can take a broad range of non-native lenses via adapters.
- Faster data transfer: Supports a more advanced USB protocol (3.2 vs 2.0).
- Easier file upload: Has wifi built in for automatic backup or image transfer to the web.
- Easier wireless transfer: Supports Bluetooth for image sharing without cables.
- Faster buffer clearing: Supports Ultra High Speed (UHS-II) SDXC cards on both slots.
- More affordable: Was introduced into a lower priced category (40 percent cheaper at launch).
- More modern: Reflects 10 years and 10 months of technical progress since the 645D launch.
Arguments in favor of the Pentax 645D:
- Brighter framing: Features an optical viewfinder for clear, lag-free composition.
- Larger viewfinder image: Features a viewfinder with a higher magnification (0.78x vs 0.77x).
- Longer lasting: Gets more shots (800 versus 460) out of a single battery charge.
- More heavily discounted: Has been around for much longer (launched in March 2010).
If the count of individual advantages (bullet points above) is taken as a guide, the GFX 100S is the clear winner of the match-up (23 : 4 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 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 Fujifilm GFX 100S and the Pentax 645D place the cameras among the top in their class? Find out in the latest Best Mirrorless Interchangeable Lens Camera and Best DSLR 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 says little about, for example, the shooting experience and imaging performance of the GFX 100S and the 645D in practical situations. 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.
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], 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.
|1.||Fujifilm GFX 100S||5/5||..||90/100||..||5/5||Jan 2021||5,999|
|2.||Pentax 645D||5/5||..||..||..||..||Mar 2010||9,995|
|3.||Canon R5||4.5/5||..||91/100||4.5/5||4.5/5||Jul 2020||3,899|
|4.||Canon 1D X||5/5||..||..||4.5/5||4.5/5||Oct 2011||6,799|
|5.||Canon 1D Mark IV||5/5||..||89/100||..||..||Oct 2009||4,999|
|6.||Fujifilm X-T4||5/5||+ +||..||5/5||5/5||Feb 2020||1,699|
|7.||Fujifilm GFX 100||4.5/5||+ +||90/100||5/5||4.5/5||May 2019||9,999|
|8.||Fujifilm GFX 50R||5/5||..||84/100||4.5/5||4.5/5||Sep 2018||4,499|
|9.||Fujifilm XP130||..||o||..||3.5/5||4/5||Jan 2018||229|
|10.||Fujifilm GFX 50S||..||..||85/100||5/5||4.5/5||Sep 2016||6,499|
|11.||Leica SL2-S||4/5||..||..||4.5/5||4.5/5||Dec 2020||4,895|
|12.||Leica SL2||4/5||..||..||4.5/5||4/5||Nov 2019||5,999|
|13.||Leica S Typ 006||..||..||..||..||..||Sep 2012||21,950|
|14.||Nikon D3S||5/5||..||89/100||4.5/5||5/5||Oct 2009||5,199|
|15.||Pentax K-3 III||..||..||..||..||..||Mar 2021||1,999|
|16.||Pentax 645Z||5/5||..||..||4.5/5||5/5||Apr 2014||8,499|
|17.||Sony A1||5/5||o||93/100||4.5/5||5/5||Jan 2021||6,499|
|Notes: (+ +) 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. 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.
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 use the search menu 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.
Specifications: Fujifilm GFX 100S vs Pentax 645D
Below is a side-by-side comparison of the specs of the two cameras to facilitate a quick review of their differences and common features.
|Camera Model||Fujifilm GFX 100S||Pentax 645D|
|Camera Type||Mirrorless system camera||Digital single lens reflex|
|Camera Lens||Fujifilm G mount lenses||Pentax 645 mount lenses|
|Launch Date||January 2021||March 2010|
|Launch Price||USD 5,999||USD 9,995|
|Sensor Specs||Fujifilm GFX 100S||Pentax 645D|
|Sensor Format||Medium Format Sensor||Medium Format Sensor|
|Sensor Size||43.8 x 32.9 mm||44.0 x 33.0 mm|
|Sensor Area||1441.02 mm2||1452 mm2|
|Sensor Diagonal||54.8 mm||55 mm|
|Sensor Resolution||101.8 Megapixels||39.5 Megapixels|
|Image Resolution||11648 x 8736 pixels||7264 x 5440 pixels|
|Pixel Pitch||3.76 μm||6.06 μm|
|Pixel Density||7.06 MP/cm2||2.72 MP/cm2|
|Moiré control||no AA filter||no AA filter|
|Movie Capability||4K/30p Video||no Video|
|ISO Setting||100 - 12,800 ISO||100 - 1,600 ISO|
|ISO Boost||50 - 102,400 ISO||no Enhancement|
|Image Processor||X-Processor 4||PRIME II|
|DXO Sensor Quality (score)||..||82|
|DXO Color Depth (bits)||..||24.6|
|DXO Dynamic Range (EV)||..||12.6|
|DXO Low Light (ISO)||..||1262|
|Screen Specs||Fujifilm GFX 100S||Pentax 645D|
|Viewfinder Type||Electronic viewfinder||Optical viewfinder|
|Viewfinder Field of View||100%||98%|
|Viewfinder Resolution||3690k dots|
|Top-Level Screen||Control Panel||Control Panel|
|LCD Framing||Live View|
|Rear LCD Size||3.2inch||3.0inch|
|LCD Resolution||2360k dots||921k dots|
|LCD Attachment||Fully flexible screen||Fixed screen|
|Touch Input||Touchscreen||no Touchscreen|
|Shooting Specs||Fujifilm GFX 100S||Pentax 645D|
|Focus System||On-Sensor Phase-detect||Phase-detect AF|
|Manual Focusing Aid||Focus Peaking||no Peaking Feature|
|Continuous Shooting||5 shutter flaps/s||1.1 shutter flaps/s|
|Electronic Shutter||up to 1/16000s||no E-Shutter|
|Time-Lapse Photography||Intervalometer built-in||Intervalometer built-in|
|Image Stabilization||In-body stabilization||Lens stabilization only|
|Fill Flash||no On-Board Flash||no On-Board Flash|
|Storage Medium||SDXC cards||SDXC cards|
|Second Storage Option||Dual card slots||Dual card slots|
|UHS card support||Dual UHS-II||no|
|Connectivity Specs||Fujifilm GFX 100S||Pentax 645D|
|Studio Flash||PC Sync socket||PC Sync socket|
|USB Connector||USB 3.2||USB 2.0|
|HDMI Port||micro HDMI||no HDMI|
|Microphone Port||External MIC port||no MIC socket|
|Headphone Socket||Headphone port||no Headphone port|
|Wifi Support||Wifi built-in||no Wifi|
|Bluetooth Support||Bluetooth built-in||no Bluetooth|
|Body Specs||Fujifilm GFX 100S||Pentax 645D|
|Environmental Sealing||Weathersealed body||Weathersealed body|
|Battery Life (CIPA)||460 shots per charge||800 shots per charge|
|In-Camera Charging||USB charging||no USB charging|
150 x 104 x 87 mm
(5.9 x 4.1 x 3.4 in)
156 x 117 x 119 mm
(6.1 x 4.6 x 4.7 in)
|Camera Weight||900 g (31.7 oz)||1480 g (52.2 oz)|
Did you notice an error on this page? If so, please get in touch, so that we can correct the information.