Fujifilm X-T3 vs Pentax K-S1
The Fujifilm X-T3 and the Pentax K-S1 are two digital cameras that were revealed to the public, respectively, in September 2018 and August 2014. The X-T3 is a mirrorless interchangeable lens camera, while the K-S1 is a DSLR. Both cameras are equipped with an APS-C sensor. The Fujifilm has a resolution of 26 megapixels, whereas the Pentax provides 20 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 X-T3 and the Pentax K-S1? 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 X-T3 and the Pentax K-S1 is provided in the side-by-side display below. The two cameras are presented according to their relative size. Three consecutive perspectives from the front, the top, and the back are available. All width, height and depth measures are rounded to the nearest millimeter.
The X-T3 can be obtained in two different colors (black, silver), while the K-S1 is available in four color-versions (black, grey, orange, white).
If the front view area (width x height) of the cameras is taken as an aggregate measure of their size, the Pentax K-S1 is notably smaller (9 percent) than the Fujifilm X-T3. However, the K-S1 is slightly heavier (4 percent) than the X-T3. It is worth mentioning in this context that the X-T3 is splash and dust resistant, while the K-S1 does not feature any corresponding weather-sealing.
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 X-T3 gets 390 shots out of its NP-W126S battery, while the K-S1 can take 410 images on a single charge of its D-LI109 power pack. The power pack in the X-T3 can be charged via the USB port, so that it is not always necessary to take the battery charger along when travelling.
The adjacent table lists the principal physical characteristics of the two cameras alongside a wider set of alternatives. If you would like to visualize and compare a different camera combination, you can navigate to the CAM-parator app and make your selection from a broad list of cameras there.
|1.||Fujifilm X-T3||133 mm||93 mm||59 mm||539 g||390||Y||Sep 2018||1,499|
|2.||Pentax K-S1||121 mm||93 mm||70 mm||558 g||410||n||Aug 2014||749|
|3.||Canon G1 X Mark III||115 mm||78 mm||51 mm||399 g||200||Y||Oct 2017||1,299|
|4.||Fujifilm X100V||128 mm||75 mm||53 mm||478 g||420||Y||Feb 2020||1,399|
|5.||Fujifilm X-T4||135 mm||93 mm||64 mm||607 g||500||Y||Feb 2020||1,699|
|6.||Fujifilm X-Pro3||141 mm||83 mm||46 mm||497 g||440||Y||Oct 2019||1,799|
|7.||Fujifilm X-T100||121 mm||83 mm||47 mm||448 g||430||n||May 2018||599|
|8.||Fujifilm X100F||127 mm||75 mm||52 mm||469 g||390||n||Jan 2017||1,299|
|9.||Fujifilm X-T20||118 mm||83 mm||41 mm||383 g||350||n||Jan 2017||899|
|10.||Fujifilm X-Pro2||141 mm||83 mm||46 mm||495 g||350||Y||Jan 2016||1,699|
|11.||Fujifilm X-T2||133 mm||92 mm||49 mm||507 g||340||Y||Jul 2016||1,599|
|12.||Fujifilm X-T1||129 mm||90 mm||47 mm||440 g||350||Y||Jan 2014||1,299|
|13.||Nikon D5300||125 mm||98 mm||76 mm||480 g||600||n||Oct 2013||799|
|14.||Pentax K-S2||123 mm||91 mm||73 mm||678 g||410||Y||Feb 2015||749|
|15.||Pentax K-500||130 mm||97 mm||71 mm||646 g||710||n||Jun 2013||549|
|16.||Pentax K-3||131 mm||100 mm||77 mm||800 g||560||Y||Oct 2013||1,299|
|17.||Sony A68||143 mm||104 mm||81 mm||610 g||540||n||Nov 2015||699|
|Notes: Measurements and pricing do not include easily detachable parts, such as add-on or interchangeable lenses or optional viewfinders.|
Any camera decision will obviously take relative prices into account. The listed launch prices provide an indication of the market segment that the manufacturer of the cameras have been targeting. The K-S1 was launched at a markedly lower price (by 50 percent) than the X-T3, 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. Then, after the new model is out, very good deals can frequently be found on the pre-owned market.
The size of the imaging sensor is a crucial determinant of image quality. A large sensor will tend to have larger individual pixels that provide better low-light sensitivity, wider dynamic range, and richer color-depth than smaller pixel-units 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 an APS-C sensor and have a format factor (sometimes also referred to as "crop factor") of 1.5. Within the spectrum of camera sensors, this places the review cameras among the medium-sized sensor cameras that aim to strike a balance between image quality and portability. Both cameras have a native aspect ratio (sensor width to sensor height) of 3:2.
While the two cameras under review share the same sensor size, the X-T3 offers a higher resolution of 26 megapixels, compared with 20 MP of the K-S1. This megapixels advantage translates into a 14 percent gain in linear resolution. On the other hand, these sensor specs imply that the X-T3 has a higher pixel density and a smaller size of the individual pixel (with a pixel pitch of 3.76μm versus 4.28μm for the K-S1). In this context, it should be noted, however, that the X-T3 is much more recent (by 4 years) than the K-S1, 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 X-T3 implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the X-T3 for good quality output (200 dots per inch) amounts to 31.2 x 20.8 inches or 79.2 x 52.8 cm, for very good quality (250 dpi) 25 x 16.6 inches or 63.4 x 42.3 cm, and for excellent quality (300 dpi) 20.8 x 13.9 inches or 52.8 x 35.2 cm. The corresponding values for the Pentax K-S1 are 27.4 x 18.2 inches or 69.5 x 46.3 cm for good quality, 21.9 x 14.6 inches or 55.6 x 37.1 cm for very good quality, and 18.2 x 12.2 inches or 46.3 x 30.9 cm for excellent quality prints.
The X-T3 has on-sensor phase detect pixels, which results in fast and reliable autofocus acquisition even during live view operation.
The Fujifilm X-T3 has a native sensitivity range from ISO 160 to ISO 12800, which can be extended to ISO 80-51200. The corresponding ISO settings for the Pentax K-S1 are ISO 100 to ISO 51200 (no boost).
Consistent information on actual sensor performance is available from DXO Mark for many cameras. 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 adjacent table reports on the physical sensor characteristics and the outcomes of the DXO sensor quality tests for a sample of comparator-cameras.
| DXO |
|3.||Canon G1 X Mark III||APS-C||24.0||6000||4000||1080/60p||..||..||..||..|
Many modern cameras cannot only take still pictures, but also record videos. Both cameras under consideration are equipped with sensors that have a sufficiently high read-out speed for moving images, but the X-T3 provides a higher video resolution than the K-S1. It can shoot video footage at 4K/60p, while the Pentax is limited to 1080/30p.
Apart from body and sensor, cameras can and do differ across a range of features. For example, the X-T3 has an electronic viewfinder (3690k dots), while the K-S1 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 viewfinders of both cameras offer the same field of view (100%), but the viewfinder of the X-T3 has a higher magnification than the one of the K-S1 (0.75x vs 0.63x), so that the size of the image transmitted appears closer to the size seen with the naked human eye. The following table reports on some other key feature differences and similarities of the Fujifilm X-T3, the Pentax K-S1, and comparable cameras.
|3.||Canon G1 X Mark III||2360||n||3.0||1040||swivel||Y||1/2000s||9.0||Y||Y|
One differentiating feature between the two cameras concerns the touch sensitivity of the rear screen. The X-T3 has a touchscreen, while the K-S1 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 X-T3 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 X-T3 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.
Concerning the storage of imaging data, both the X-T3 and the K-S1 write their files to SDXC cards. The X-T3 features dual card slots, which can be very useful in case a memory card fails. In contrast, the K-S1 only has one slot. The X-T3 supports UHS-II cards (on both slots), while the K-S1 can use UHS-I 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 X-T3 and Pentax K-S1 and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.
| WiFi |
| NFC |
|3.||Canon G1 X Mark III||Y||stereo||mono||-||-||micro||2.0||Y||Y||Y|
It is notable that the X-T3 has a microphone port, which is missing on the K-S1. Such an external microphone input can help to substantially improve the quality of audio recordings when a good external microphone is used.
Studio photographers will appreciate that the Fujifilm X-T3 (unlike the K-S1) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.
Both the X-T3 and the K-S1 have been discontinued, but can regularly be found used on eBay. The K-S1 was replaced by the Pentax K-S2, while the X-T3 was followed by the Fujifilm X-T4. 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 how do things add up? Which of the two cameras – the Fujifilm X-T3 or the Pentax K-S1 – has the upper hand? Is one clearly better than the other? Below is a summary of the relative strengths of each of the two contestants.
Arguments in favor of the Fujifilm X-T3:
- More detail: Offers more megapixels (26 vs 20MP) with a 14% higher linear resolution.
- Better video: Provides higher definition movie capture (4K/60p vs 1080/30p).
- Better live-view autofocus: Features on-sensor phase-detection for more confident autofocus.
- Better sound: Can connect to an external microphone for higher quality sound recording.
- Better sound control: Has a headphone port that enables audio monitoring while recording.
- More framing info: Has an electronic viewfinder that displays shooting data.
- Larger viewfinder image: Features a viewfinder with a higher magnification (0.75x vs 0.63x).
- More detailed LCD: Has a higher resolution rear screen (1040k vs 921k dots).
- More flexible LCD: Has a tilting screen for odd-angle shots in landscape orientation.
- Fewer buttons to press: Is equipped with a touch-sensitive rear screen to facilitate handling.
- Faster shutter: Has higher mechanical shutter speed (1/8000s vs 1/6000s) to freeze action.
- Faster burst: Shoots at higher frequency (11 vs 5.4 flaps/sec) to capture the decisive moment.
- Less disturbing: Has an electronic shutter option for completely silent shooting.
- Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
- Easier travel charging: Can be conveniently charged via its USB port.
- Better sealing: Is weather sealed to enable shooting in dusty or wet environments.
- More legacy lens friendly: Can take a broad range of non-native lenses via adapters.
- Faster data transfer: Supports a more advanced USB protocol (3.1 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.
- Better studio light control: Has a PC Sync socket to connect to professional strobe lights.
- Greater peace of mind: Features a second card slot as a backup in case of memory card failure.
- Faster buffer clearing: Supports a more advanced SD data transfer standard (UHS-II vs UHS-I).
- More modern: Reflects 4 years of technical progress since the K-S1 launch.
Reasons to prefer the Pentax K-S1:
- Brighter framing: Features an optical viewfinder for clear, lag-free composition.
- Sharper images: Has stabilization technology built-in to reduce the impact of hand-shake.
- Easier fill-in: Has a small integrated flash to brighten shadows of backlit subjects.
- More affordable: Was introduced into a lower priced category (50 percent cheaper at launch).
- More heavily discounted: Has been around for much longer (launched in August 2014).
If the number of relative strengths (bullet points above) is taken as a guide, the X-T3 is the clear winner of the match-up (24 : 5 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 Fujifilm X-T3 and the Pentax K-S1 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 comparison of technical specifications can provide a useful overview of the capabilities of different cameras, it says little about, for example, the shooting experience and imaging performance of the X-T3 and the K-S1 in practical situations. 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.
This is where reviews by experts come in. The table below provides a synthesis of the camera assessments of some of the best known photo-gear 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 X-T3||5/5||+ +||88/100||5/5||5/5||Sep 2018||1,499|
|2.||Pentax K-S1||4/5||..||..||4.5/5||4/5||Aug 2014||749|
|3.||Canon G1 X Mark III||5/5||+||79/100||4.5/5||4.5/5||Oct 2017||1,299|
|4.||Fujifilm X100V||5/5||+ +||86/100||5/5||4.5/5||Feb 2020||1,399|
|5.||Fujifilm X-T4||5/5||+ +||..||5/5||5/5||Feb 2020||1,699|
|6.||Fujifilm X-Pro3||4/5||+||85/100||4/5||..||Oct 2019||1,799|
|7.||Fujifilm X-T100||4/5||+||79/100||4/5||4.5/5||May 2018||599|
|8.||Fujifilm X100F||5/5||+||83/100||4.5/5||4.5/5||Jan 2017||1,299|
|9.||Fujifilm X-T20||5/5||+ +||82/100||5/5||4.5/5||Jan 2017||899|
|10.||Fujifilm X-Pro2||..||+||83/100||4.5/5||4.5/5||Jan 2016||1,699|
|11.||Fujifilm X-T2||5/5||+ +||86/100||4.5/5||5/5||Jul 2016||1,599|
|12.||Fujifilm X-T1||5/5||+ +||84/100||5/5||5/5||Jan 2014||1,299|
|13.||Nikon D5300||4/5||+ +||79/100||4.5/5||4.5/5||Oct 2013||799|
|14.||Pentax K-S2||4.5/5||..||..||5/5||4.5/5||Feb 2015||749|
|15.||Pentax K-500||..||..||..||4.5/5||4.5/5||Jun 2013||549|
|16.||Pentax K-3||4/5||..||83/100||5/5||5/5||Oct 2013||1,299|
|17.||Sony A68||3/5||..||..||4/5||4/5||Nov 2015||699|
|Notes: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.|
The above review scores should be interpreted 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. 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. Also, please note that some of the review sites have changed their methodology and reporting over time.
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.
Specifications: Fujifilm X-T3 vs Pentax K-S1
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 X-T3||Pentax K-S1|
|Camera Type||Mirrorless system camera||Digital single lens reflex|
|Camera Lens||Fujifilm X mount lenses||Pentax K mount lenses|
|Launch Date||September 2018||August 2014|
|Launch Price||USD 1,499||USD 749|
|Sensor Specs||Fujifilm X-T3||Pentax K-S1|
|Sensor Format||APS-C Sensor||APS-C Sensor|
|Sensor Size||23.5 x 15.6 mm||23.5 x 15.6 mm|
|Sensor Area||366.6 mm2||366.6 mm2|
|Sensor Diagonal||28.2 mm||28.2 mm|
|Sensor Resolution||26 Megapixels||20 Megapixels|
|Image Resolution||6240 x 4160 pixels||5472 x 3648 pixels|
|Pixel Pitch||3.76 μm||4.28 μm|
|Pixel Density||7.08 MP/cm2||5.45 MP/cm2|
|Moiré control||no AA filter||no AA filter|
|Movie Capability||4K/60p Video||1080/30p Video|
|ISO Setting||160 - 12,800 ISO||100 - 51,200 ISO|
|ISO Boost||80 - 51,200 ISO||no Enhancement|
|Image Processor||X-Processor 4||PRIME MII|
|DXO Sensor Quality (score)||..||78|
|DXO Color Depth (bits)||..||23.5|
|DXO Dynamic Range (EV)||..||13.0|
|DXO Low Light (ISO)||..||1061|
|Screen Specs||Fujifilm X-T3||Pentax K-S1|
|Viewfinder Type||Electronic viewfinder||Optical viewfinder|
|Viewfinder Field of View||100%||100%|
|Viewfinder Resolution||3690k dots|
|LCD Framing||Live View||Live View|
|Rear LCD Size||3.0inch||3.0inch|
|LCD Resolution||1040k dots||921k dots|
|LCD Attachment||Tilting screen||Fixed screen|
|Touch Input||Touchscreen||no Touchscreen|
|Shooting Specs||Fujifilm X-T3||Pentax K-S1|
|Focus System||On-Sensor Phase-detect||Phase-detect AF|
|Manual Focusing Aid||Focus Peaking||Focus Peaking|
|Max Shutter Speed (mechanical)||1/8000s||1/6000s|
|Continuous Shooting||11 shutter flaps/s||5.4 shutter flaps/s|
|Electronic Shutter||up to 1/32000s||no E-Shutter|
|Time-Lapse Photography||Intervalometer built-in||no Intervalometer|
|Image Stabilization||Lens stabilization only||In-body stabilization|
|Fill Flash||no On-Board Flash||Build-in Flash|
|Storage Medium||SDXC cards||SDXC cards|
|Second Storage Option||Dual card slots||Single card slot|
|UHS card support||Dual UHS-II||UHS-I|
|Connectivity Specs||Fujifilm X-T3||Pentax K-S1|
|Studio Flash||PC Sync socket||no PC Sync|
|USB Connector||USB 3.1||USB 2.0|
|HDMI Port||micro HDMI||micro 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 X-T3||Pentax K-S1|
|Environmental Sealing||Weathersealed body||not weather sealed|
|Battery Life (CIPA)||390 shots per charge||410 shots per charge|
|In-Camera Charging||USB charging||no USB charging|
133 x 93 x 59 mm
(5.2 x 3.7 x 2.3 in)
121 x 93 x 70 mm
(4.8 x 3.7 x 2.8 in)
|Camera Weight||539 g (19.0 oz)||558 g (19.7 oz)|
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