Pentax K-1 II vs K-S1
The Pentax K-1 II and the Pentax K-S1 are two digital cameras that were revealed to the public, respectively, in February 2018 and August 2014. Both are DSLR (Digital Single Lens Reflex) cameras that are based on a full frame (K-1 II) and an APS-C (K-S1) sensor. The K-1 II has a resolution of 36.2 megapixels, whereas the K-S1 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 Pentax K-1 II 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.
The side-by-side display below illustrates the physical size and weight of the Pentax K-1 II and the Pentax K-S1. 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.
The K-1 II 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 (25 percent) than the Pentax K-1 II. Moreover, the K-S1 is substantially lighter (45 percent) than the K-1 II. It is worth mentioning in this context that the K-1 II 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.
The adjacent table lists the principal physical characteristics of the two cameras alongside a wider set of alternatives. 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.||Pentax K-1 II||137 mm||110 mm||86 mm||1010 g||670||Y||Feb 2018||1,999|
|2.||Pentax K-S1||121 mm||93 mm||70 mm||558 g||410||n||Aug 2014||749|
|3.||Canon R||139 mm||98 mm||84 mm||660 g||370||Y||Sep 2018||2,299|
|4.||Nikon Z6||134 mm||101 mm||67 mm||675 g||310||Y||Aug 2018||1,999|
|5.||Nikon D5300||125 mm||98 mm||76 mm||480 g||600||n||Oct 2013||799|
|6.||Panasonic S1||149 mm||110 mm||97 mm||1017 g||400||Y||Feb 2019||2,499|
|7.||Panasonic S1R||149 mm||110 mm||97 mm||1016 g||380||Y||Feb 2019||3,699|
|8.||Panasonic S1H||151 mm||114 mm||110 mm||1052 g||400||Y||May 2019||3,999|
|9.||Pentax K-1||137 mm||110 mm||86 mm||1010 g||760||Y||Feb 2016||1,799|
|10.||Pentax K-S2||123 mm||91 mm||73 mm||678 g||410||Y||Feb 2015||749|
|11.||Pentax K-500||130 mm||97 mm||71 mm||646 g||710||n||Jun 2013||549|
|12.||Pentax K-3||131 mm||100 mm||77 mm||800 g||560||Y||Oct 2013||1,299|
|13.||Sony A7 III||127 mm||96 mm||74 mm||650 g||610||Y||Feb 2018||1,999|
|14.||Sony A7R III||127 mm||96 mm||74 mm||650 g||650||Y||Oct 2017||3,199|
|15.||Sony A99 II||143 mm||104 mm||76 mm||849 g||490||Y||Sep 2016||3,199|
|16.||Sony A68||143 mm||104 mm||81 mm||610 g||540||n||Nov 2015||699|
|17.||Sony A850||156 mm||117 mm||82 mm||895 g||880||Y||Aug 2009||1,999|
|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 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 63 percent) than the K-1 II, which puts it into a different market segment. Normally, street prices remain initially close to the MSRP, but after a couple of months, the first discounts appear. 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 size of the sensor inside a digital camera is one of the key determinants 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. 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 tend to be associated with larger, more expensive camera bodies and lenses.
Of the two cameras under consideration, the Pentax K-1 II features a full frame sensor and the Pentax K-S1 an APS-C sensor. The sensor area in the K-S1 is 57 percent smaller. As a result of these sensor size differences, the cameras have a format factor of, respectively, 1.0 and 1.5. Both cameras have a native aspect ratio (sensor width to sensor height) of 3:2.
In terms of chip-set technology, the K-1 II uses a more advanced image processing engine (PRIME IV) than the K-S1 (PRIME MII), with benefits for noise reduction, color accuracy, and processing speed.
With 36.2MP, the K-1 II offers a higher resolution than the K-S1 (20MP), but the K-1 II nevertheless has larger individual pixels (pixel pitch of 4.88μm versus 4.28μm for the K-S1) due to its larger sensor. Moreover, the K-1 II is a much more recent model (by 3 years and 5 months) than the K-S1, 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 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 Pentax K-1 II implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the K-1 II for good quality output (200 dots per inch) amounts to 36.8 x 24.6 inches or 93.5 x 62.4 cm, for very good quality (250 dpi) 29.4 x 19.6 inches or 74.8 x 49.9 cm, and for excellent quality (300 dpi) 24.5 x 16.4 inches or 62.3 x 41.6 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.
Unlike the K-S1, the K-1 II has the capacity to capture high quality composite images 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 Pentax K-1 II has a native sensitivity range from ISO 100 to ISO 819200. 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 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 following table provides an overview of the physical sensor characteristics, as well as the sensor quality measurements for a selection of comparators.
| DXO |
|1.||Pentax K-1 II||Full Frame||36.2||7360||4912||1080/60i||..||..||..||..|
|3.||Canon R||Full Frame||30.1||6720||4480||4K/30p||24.5||13.5||2742||89|
|4.||Nikon Z6||Full Frame||24.3||6048||4024||4K/30p||25.3||14.3||3299||95|
|6.||Panasonic S1||Full Frame||24.0||6000||4000||4K/60p||25.2||14.5||3333||95|
|7.||Panasonic S1R||Full Frame||46.7||8368||5584||4K/60p||26.4||14.1||3525||100|
|8.||Panasonic S1H||Full Frame||24.0||6000||4000||6K/30p||..||..||..||..|
|9.||Pentax K-1||Full Frame||36.2||7360||4912||1080/60i||25.4||14.6||3280||96|
|13.||Sony A7 III||Full Frame||24.0||6000||4000||4K/30p||25.0||14.7||3730||96|
|14.||Sony A7R III||Full Frame||42.2||7952||5304||4K/30p||26.0||14.7||3523||100|
|15.||Sony A99 II||Full Frame||42.2||7952||5304||4K/30p||25.4||13.4||2317||92|
|17.||Sony A850||Full Frame||24.4||6048||4032||none||23.8||12.2||1415||79|
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 K-1 II provides a higher frame rate than the K-S1. It can shoot video footage at 1080/60i, while the K-S1 is limited to 1080/30p.
Apart from body and sensor, cameras can and do differ across a range of features. The K-1 II and the K-S1 are similar in the sense that both have an optical viewfinder. The latter is useful for getting a clear image for framing even in brightly lit environments. The viewfinders of both cameras offer the same field of view (100%), but the viewfinder of the K-1 II has a higher magnification than the one of the K-S1 (0.70x 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 Pentax K-1 II, the Pentax K-S1, and comparable cameras.
|1.||Pentax K-1 II||optical||Y||3.2||1037||full-flex||n||1/8000s||4.4||n||Y|
|13.||Sony A7 III||2359||n||3.0||922||tilting||Y||1/8000s||10.0||n||Y|
|14.||Sony A7R III||3686||n||3.0||1440||tilting||Y||1/8000s||10.0||n||Y|
|15.||Sony A99 II||2400||Y||3.0||1229||full-flex||n||1/8000s||12.0||n||Y|
One feature that is present on the K-1 II, but is missing on the K-S1 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 Pentax K-1 II 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 K-1 II and the K-S1 write their files to SDXC cards. The K-1 II features dual card slots, which can be very useful in case a memory card fails. In contrast, the K-S1 only has one slot. Both cameras can use UHS-I cards, which provide for Ultra High Speed data transfer of up to 104 MB/s.
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 K-1 II and Pentax K-S1 and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.
| WiFi |
| NFC |
|1.||Pentax K-1 II||Y||stereo||mono||Y||Y||micro||2.0||Y||-||-|
|13.||Sony A7 III||Y||stereo||mono||Y||Y||micro||3.1||Y||Y||Y|
|14.||Sony A7R III||Y||stereo||mono||Y||Y||micro||3.1||Y||Y||Y|
|15.||Sony A99 II||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||Y|
It is notable that the K-1 II 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 Pentax K-1 II (unlike the K-S1) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.
Travel and landscape photographers will find it useful that the K-1 II has an internal geolocalization sensor and can record GPS coordinates in its EXIF data.
The K-1 II is a recent model that features in the current product line-up of Pentax. In contrast, the K-S1 has been discontinued (but can be found pre-owned on eBay). As a replacement in the same line of cameras, the K-S1 was succeeded by the Pentax K-S2. Further information on the two cameras (e.g. user guides, manuals), as well as related accessories, can be found on the official Pentax website.
So what is the bottom line? Is there a clear favorite between the Pentax K-1 II and the Pentax K-S1? Which camera is better? The listing below highlights the relative strengths of the two models.
Arguments in favor of the Pentax K-1 II:
- More detail: Offers more megapixels (36.2 vs 20MP) with a 35% higher linear resolution.
- High quality composites: Can combine several shots after pixel-shifting its sensor.
- Better image quality: Features a larger and more technologically advanced imaging sensor.
- Richer colors: The sensor size advantage translates into images with better, more accurate colors.
- More dynamic range: Larger sensor captures a wider spectrum of light and dark details.
- Better low-light sensitivity: Larger sensor produces good images even in poorly lit environments.
- Better jpgs: Has a more modern image processing engine (PRIME IV vs PRIME MII).
- Better video: Provides higher movie framerates (1080/60i versus 1080/30p).
- 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.
- Larger viewfinder image: Features a viewfinder with a higher magnification (0.70x vs 0.63x).
- Easier setting verification: Features an LCD display on top to control shooting parameters.
- 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 (1037k vs 921k dots).
- More flexible LCD: Has a full-flex screen for odd-angle shots in portrait or landscape orientation.
- Faster shutter: Has higher mechanical shutter speed (1/8000s vs 1/6000s) to freeze action.
- Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
- Longer lasting: Can take more shots (670 versus 410) on a single battery charge.
- Better sealing: Is weather sealed to enable shooting in dusty or wet environments.
- Easier geotagging: Features an internal GPS sensor to log localization data.
- Easier file upload: Has wifi built in for automatic backup or image transfer to the web.
- 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.
- More modern: Reflects 3 years and 5 months of technical progress since the K-S1 launch.
Reasons to prefer the Pentax K-S1:
- Faster burst: Shoots at higher frequency (5.4 vs 4.4 flaps/sec) to capture the decisive moment.
- More compact: Is smaller (121x93mm vs 137x110mm) and will fit more readily into a bag.
- Less heavy: Has a lower weight (by 452g or 45 percent) and is thus easier to take along.
- Easier fill-in: Has a small integrated flash to brighten shadows of backlit subjects.
- More affordable: Was introduced into a lower priced category (63 percent cheaper at launch).
- More heavily discounted: Has been around for much longer (launched in August 2014).
If the count of individual advantages (bullet points above) is taken as a guide, the K-1 II is the clear winner of the match-up (24 : 6 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 K-1 II and the Pentax K-S1 place the cameras among the top in their class? Find out in the latest Best DSLR Camera listing 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 incomplete and does no justice, for example, to the way the K-1 II or the K-S1 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.
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.||Pentax K-1 II||..||..||79/100||4.5/5||4.5/5||Feb 2018||1,999|
|2.||Pentax K-S1||4/5||..||..||4.5/5||4/5||Aug 2014||749|
|3.||Canon R||4/5||o||79/100||4.5/5||4/5||Sep 2018||2,299|
|4.||Nikon Z6||5/5||..||..||4.5/5||5/5||Aug 2018||1,999|
|5.||Nikon D5300||4/5||+ +||79/100||4.5/5||4.5/5||Oct 2013||799|
|6.||Panasonic S1||4.5/5||+ +||88/100||4.5/5||4/5||Feb 2019||2,499|
|7.||Panasonic S1R||4.5/5||..||89/100||4.5/5||4.5/5||Feb 2019||3,699|
|8.||Panasonic S1H||..||..||90/100||..||..||May 2019||3,999|
|9.||Pentax K-1||5/5||..||84/100||5/5||5/5||Feb 2016||1,799|
|10.||Pentax K-S2||4.5/5||..||..||5/5||4.5/5||Feb 2015||749|
|11.||Pentax K-500||..||..||..||4.5/5||4.5/5||Jun 2013||549|
|12.||Pentax K-3||4/5||..||83/100||5/5||5/5||Oct 2013||1,299|
|13.||Sony A7 III||..||+ +||89/100||5/5||5/5||Feb 2018||1,999|
|14.||Sony A7R III||..||+ +||90/100||4.5/5||5/5||Oct 2017||3,199|
|15.||Sony A99 II||..||..||85/100||4.5/5||4.5/5||Sep 2016||3,199|
|16.||Sony A68||3/5||..||..||4/5||4/5||Nov 2015||699|
|17.||Sony A850||3/5||..||75/100||..||4.5/5||Aug 2009||1,999|
|Notes: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.|
The review scores listed above should be treated with care, 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 rating-comparisons among cameras that span long time periods or concern very differently equipped models make little sense. 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 are interested in seeing how other cameras pair up, just make a corresponding selection in the search boxes below. There is also a set of direct links to comparison reviews that other users of the CAM-parator app explored.
Specifications: Pentax K-1 II 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||Pentax K-1 II||Pentax K-S1|
|Camera Type||Digital single lens reflex||Digital single lens reflex|
|Camera Lens||Pentax K mount lenses||Pentax K mount lenses|
|Launch Date||February 2018||August 2014|
|Launch Price||USD 1,999||USD 749|
|Sensor Specs||Pentax K-1 II||Pentax K-S1|
|Sensor Format||Full Frame Sensor||APS-C Sensor|
|Sensor Size||35.9 x 24.0 mm||23.5 x 15.6 mm|
|Sensor Area||861.6 mm2||366.6 mm2|
|Sensor Diagonal||43.2 mm||28.2 mm|
|Sensor Resolution||36.2 Megapixels||20 Megapixels|
|Image Resolution||7360 x 4912 pixels||5472 x 3648 pixels|
|Pixel Pitch||4.88 μm||4.28 μm|
|Pixel Density||4.20 MP/cm2||5.45 MP/cm2|
|Moiré control||no AA filter||no AA filter|
|Movie Capability||1080/60i Video||1080/30p Video|
|ISO Setting||100 - 819,200 ISO||100 - 51,200 ISO|
|Image Processor||PRIME IV||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||Pentax K-1 II||Pentax K-S1|
|Viewfinder Type||Optical viewfinder||Optical viewfinder|
|Viewfinder Field of View||100%||100%|
|Top-Level Screen||Control Panel||no Top Display|
|LCD Framing||Live View||Live View|
|Rear LCD Size||3.2inch||3.0inch|
|LCD Resolution||1037k dots||921k dots|
|LCD Attachment||Fully flexible screen||Fixed screen|
|Shooting Specs||Pentax K-1 II||Pentax K-S1|
|Focus System||Phase-detect AF||Phase-detect AF|
|Manual Focusing Aid||Focus Peaking||Focus Peaking|
|Max Shutter Speed (mechanical)||1/8000s||1/6000s|
|Continuous Shooting||4.4 shutter flaps/s||5.4 shutter flaps/s|
|Time-Lapse Photography||Intervalometer built-in||no Intervalometer|
|Image Stabilization||In-body stabilization||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||UHS-I||UHS-I|
|Connectivity Specs||Pentax K-1 II||Pentax K-S1|
|Studio Flash||PC Sync socket||no PC Sync|
|USB Connector||USB 2.0||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|
|Geotagging||GPS built-in||no internal GPS|
|Body Specs||Pentax K-1 II||Pentax K-S1|
|Environmental Sealing||Weathersealed body||not weather sealed|
|Battery Life (CIPA)||670 shots per charge||410 shots per charge|
137 x 110 x 86 mm
(5.4 x 4.3 x 3.4 in)
121 x 93 x 70 mm
(4.8 x 3.7 x 2.8 in)
|Camera Weight||1010 g (35.6 oz)||558 g (19.7 oz)|
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