Pentax K-S1 vs Sony A6100
The Pentax K-S1 and the Sony Alpha A6100 are two digital cameras that were announced, respectively, in August 2014 and August 2019. The K-S1 is a DSLR, while the A6100 is a mirrorless interchangeable lens camera. Both cameras are equipped with an APS-C sensor. The Pentax has a resolution of 20 megapixels, whereas the Sony provides 24 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-S1 and the Sony Alpha A6100? 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 physical size and weight of the Pentax K-S1 and the Sony A6100 are illustrated in the side-by-side display below. The two cameras are presented according to their relative size. Three consecutive views from the front, the top, and the rear side are shown. All size dimensions are rounded to the nearest millimeter.
The K-S1 can be obtained in four different colors (black, grey, orange, white), while the A6100 is available in three color-versions (black, silver, white).
If the front view area (width x height) of the cameras is taken as an aggregate measure of their size, the Sony A6100 is notably smaller (29 percent) than the Pentax K-S1. Moreover, the A6100 is markedly lighter (29 percent) than the K-S1. In this context, it is worth noting that neither the K-S1 nor the A6100 are weather-sealed.
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 K-S1 gets 410 shots out of its D-LI109 battery, while the A6100 can take 420 images on a single charge of its NP-FW50 power pack. The power pack in the A6100 can be charged via the USB port, which can be very convenient when travelling.
The following table provides a synthesis of the main physical specifications of the two cameras and other similar ones. 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.||Pentax K-S1||121 mm||93 mm||70 mm||558 g||410||n||Aug 2014||749|
|2.||Sony A6100||120 mm||67 mm||59 mm||396 g||420||n||Aug 2019||749|
|3.||Canon M50||116 mm||88 mm||59 mm||390 g||235||n||Feb 2018||779|
|4.||Canon 750D||132 mm||101 mm||78 mm||555 g||440||n||Feb 2015||749|
|5.||Canon 760D||132 mm||101 mm||78 mm||565 g||440||n||Feb 2015||649|
|6.||Nikon D5300||125 mm||98 mm||76 mm||480 g||600||n||Oct 2013||799|
|7.||Pentax K-S2||123 mm||91 mm||73 mm||678 g||410||Y||Feb 2015||749|
|8.||Pentax K-3 II||131 mm||100 mm||77 mm||800 g||720||Y||Apr 2015||1,099|
|9.||Pentax K-50||130 mm||97 mm||71 mm||650 g||410||Y||Jun 2013||599|
|10.||Pentax K-500||130 mm||97 mm||71 mm||646 g||710||n||Jun 2013||549|
|11.||Pentax K-3||131 mm||100 mm||77 mm||800 g||560||Y||Oct 2013||1,299|
|12.||Sony A6400||120 mm||67 mm||50 mm||403 g||410||Y||Jan 2019||899|
|13.||Sony A68||143 mm||104 mm||81 mm||610 g||540||n||Nov 2015||699|
|14.||Sony A6000||120 mm||67 mm||45 mm||344 g||360||n||Feb 2014||599|
|15.||Sony A58||129 mm||95 mm||78 mm||492 g||690||n||Feb 2013||599|
|16.||Sony A3000||128 mm||91 mm||85 mm||411 g||470||n||Aug 2013||329|
|17.||Sony NEX-7||120 mm||67 mm||43 mm||400 g||430||n||Aug 2011||1,349|
|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 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 two cameras under review were launched at the same price and fall into the same 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 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. 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 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.
In terms of underlying technology, both cameras are build around CMOS sensors.
While the two cameras under review share the same sensor size, the A6100 offers a higher resolution of 24 megapixels, compared with 20 MP of the K-S1. This megapixels advantage translates into a 10 percent gain in linear resolution. On the other hand, these sensor specs imply that the A6100 has a higher pixel density and a smaller size of the individual pixel (with a pixel pitch of 3.91μm versus 4.28μm for the K-S1). However, it should be noted that the A6100 is much more recent (by 5 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 the K-S1 has no anti-alias filter installed, so that it can capture all the detail its sensor resolves.
The resolution advantage of the Sony A6100 implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the A6100 for good quality output (200 dots per inch) amounts to 30 x 20 inches or 76.2 x 50.8 cm, for very good quality (250 dpi) 24 x 16 inches or 61 x 40.6 cm, and for excellent quality (300 dpi) 20 x 13.3 inches or 50.8 x 33.9 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 A6100 has on-sensor phase detect pixels, which results in fast and reliable autofocus acquisition even during live view operation.
The Pentax K-S1 has a native sensitivity range from ISO 100 to ISO 51200. The corresponding ISO settings for the Sony Alpha A6100 are ISO 100 to ISO 32000, with the possibility to increase the ISO range to 100-51200.
For many cameras, data on sensor performance has been reported by DXO Mark. 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 |
|8.||Pentax K-3 II||APS-C||24.1||6016||4000||1080/60i||23.6||13.6||1106||80|
Many modern cameras are not only capable of taking still images, but can also record movies. The two cameras under consideration both have sensors whose read-out speed is fast enough to capture moving pictures, but the A6100 provides a better video resolution than the K-S1. It can shoot movie footage at 4K/30p, while the Pentax is limited to 1080/30p.
Beyond body and sensor, cameras can and do differ across a range of features. For example, the A6100 has an electronic viewfinder (1440k 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 A6100 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 adjacent table lists some of the other core features of the Pentax K-S1 and Sony A6100 along with similar information for a selection of comparators.
|8.||Pentax K-3 II||optical||Y||3.2||1037||fixed||n||1/8000s||8.3||n||Y|
One feature that differentiates the K-S1 and the A6100 is in-body image stabilization (IBIS). The K-S1 reduces the risk of handshake-induced blur with all attached lenses, while the A6100 offers no blur reduction with lenses that themselves do not provide optical image stabilization.The A6100 has an articulated screen that can be turned to be front-facing. This characteristic will be appreciated by vloggers and photographers who are interested in taking selfies. In contrast, the K-S1 does not have a selfie-screen.
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 A6100 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 Sony A6100 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.
The K-S1 writes its imaging data to SDXC cards, while the A6100 uses SDXC or Memory Stick PRO Duo cards. 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-S1 and Sony Alpha A6100 and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.
| WiFi |
| NFC |
|8.||Pentax K-3 II||Y||mono||mono||Y||Y||mini||3.0||-||-||-|
It is notable that the A6100 offers wifi support, which can be a very convenient means to transfer image data to an off-camera location. In contrast, the K-S1 does not provide wifi capability.
The A6100 is a recent model that features in the current product line-up of Sony. 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 and Sony websites.
So what conclusions can be drawn? Is the Pentax K-S1 better than the Sony A6100 or vice versa? The listing below highlights the relative strengths of the two models.
Arguments in favor of the Pentax K-S1:
- Maximized detail: Lacks an anti-alias filter to exploit the sensor's full resolution potential.
- Brighter framing: Features an optical viewfinder for clear, lag-free composition.
- Faster shutter: Has higher mechanical shutter speed (1/6000s vs 1/4000s) to freeze action.
- Sharper images: Has hand-shake reducing image stabilization built-in.
- More heavily discounted: Has been available for much longer (launched in August 2014).
Advantages of the Sony Alpha A6100:
- More detail: Has more megapixels (24 vs 20MP), which boosts linear resolution by 10%.
- Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
- Better video: Provides higher definition movie capture (4K/30p 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.
- More framing info: Has an electronic viewfinder that displays shooting data.
- Larger viewfinder image: Features a viewfinder with a higher magnification (0.70x vs 0.63x).
- More flexible LCD: Has a tilting screen for odd-angle shots in landscape orientation.
- Fewer buttons to press: Has a touchscreen to facilitate handling and shooting adjustments.
- More selfie-friendly: Has an articulated screen that can be turned to be front-facing.
- 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.
- More compact: Is smaller (120x67mm vs 121x93mm) and will fit more readily into a bag.
- Less heavy: Has a lower weight (by 162g or 29 percent) and is thus easier to take along.
- Easier travel charging: Can be conveniently charged via its USB port.
- 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.
- Easier device pairing: Supports NFC for fast wireless image transfer over short distances.
- Easier wireless transfer: Supports Bluetooth for image sharing without cables.
- More modern: Reflects 5 years of technical progress since the K-S1 launch.
If the count of relative strengths (bullet points above) is taken as a measure, the A6100 is the clear winner of the contest (21 : 5 points). However, the pertinence of the various camera strengths will differ across photographers, so that you might want to weigh individual camera traits according to their importance for your own imaging needs before making a camera decision. 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-S1 and the Sony A6100 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 K-S1 or the A6100. 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 why expert reviews 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], 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-S1||4/5||..||..||4.5/5||4/5||Aug 2014||749|
|2.||Sony A6100||..||..||82/100||4/5||5/5||Aug 2019||749|
|3.||Canon M50||..||+||79/100||..||3.5/5||Feb 2018||779|
|4.||Canon 750D||5/5||..||75/100||4.5/5||4.5/5||Feb 2015||749|
|5.||Canon 760D||5/5||+||77/100||4.5/5||4.5/5||Feb 2015||649|
|6.||Nikon D5300||4/5||+ +||79/100||4.5/5||4.5/5||Oct 2013||799|
|7.||Pentax K-S2||4.5/5||..||..||5/5||4.5/5||Feb 2015||749|
|8.||Pentax K-3 II||4.5/5||..||..||5/5||5/5||Apr 2015||1,099|
|9.||Pentax K-50||5/5||..||..||5/5||4.5/5||Jun 2013||599|
|10.||Pentax K-500||..||..||..||4.5/5||4.5/5||Jun 2013||549|
|11.||Pentax K-3||4/5||..||83/100||5/5||5/5||Oct 2013||1,299|
|12.||Sony A6400||4/5||+||85/100||4.5/5||4/5||Jan 2019||899|
|13.||Sony A68||3/5||..||..||4/5||4/5||Nov 2015||699|
|14.||Sony A6000||5/5||+||80/100||4.5/5||5/5||Feb 2014||599|
|15.||Sony A58||3/5||..||..||4.5/5||4.5/5||Feb 2013||599|
|16.||Sony A3000||3/5||+||..||4/5||4/5||Aug 2013||329|
|17.||Sony NEX-7||5/5||+ +||81/100||4.5/5||5/5||Aug 2011||1,349|
|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. Thus, a score needs to be put into the context of the launch date and the launch price 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 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-S1 vs Sony A6100
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-S1||Sony A6100|
|Camera Type||Digital single lens reflex||Mirrorless system camera|
|Camera Lens||Pentax K mount lenses||Sony E mount lenses|
|Launch Date||August 2014||August 2019|
|Launch Price||USD 749||USD 749|
|Sensor Specs||Pentax K-S1||Sony A6100|
|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||20 Megapixels||24 Megapixels|
|Image Resolution||5472 x 3648 pixels||6000 x 4000 pixels|
|Pixel Pitch||4.28 μm||3.91 μm|
|Pixel Density||5.45 MP/cm2||6.55 MP/cm2|
|Moiré control||no AA filter||Anti-Alias filter|
|Movie Capability||1080/30p Video||4K/30p Video|
|ISO Setting||100 - 51,200 ISO||100 - 32,000 ISO|
|ISO Boost||no Enhancement||100 - 51,200 ISO|
|Image Processor||PRIME MII||BIONZ X|
|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-S1||Sony A6100|
|Viewfinder Type||Optical viewfinder||Electronic viewfinder|
|Viewfinder Field of View||100%||100%|
|Viewfinder Resolution||1440k dots|
|LCD Framing||Live View||Live View|
|Rear LCD Size||3.0inch||3.0inch|
|LCD Resolution||921k dots||922k dots|
|LCD Attachment||Fixed screen||Tilting screen|
|Touch Input||no Touchscreen||Touchscreen|
|Shooting Specs||Pentax K-S1||Sony A6100|
|Focus System||Phase-detect AF||On-Sensor Phase-detect|
|Manual Focusing Aid||Focus Peaking||Focus Peaking|
|Max Shutter Speed (mechanical)||1/6000s||1/4000s|
|Continuous Shooting||5.4 shutter flaps/s||11 shutter flaps/s|
|Electronic Shutter||no E-Shutter||YES|
|Time-Lapse Photography||no Intervalometer||Intervalometer built-in|
|Image Stabilization||In-body stabilization||Lens stabilization only|
|Fill Flash||Build-in Flash||Build-in Flash|
|Storage Medium||SDXC cards||MS or SDXC cards|
|Second Storage Option||Single card slot||Single card slot|
|UHS card support||UHS-I||UHS-I|
|Connectivity Specs||Pentax K-S1||Sony A6100|
|USB Connector||USB 2.0||USB 2.0|
|HDMI Port||micro HDMI||micro HDMI|
|Microphone Port||no MIC socket||External MIC port|
|Wifi Support||no Wifi||Wifi built-in|
|Near-Field Communication||no NFC||NFC built-in|
|Bluetooth Support||no Bluetooth||Bluetooth built-in|
|Body Specs||Pentax K-S1||Sony A6100|
|Battery Life (CIPA)||410 shots per charge||420 shots per charge|
|In-Camera Charging||no USB charging||USB charging|
121 x 93 x 70 mm
(4.8 x 3.7 x 2.8 in)
120 x 67 x 59 mm
(4.7 x 2.6 x 2.3 in)
|Camera Weight||558 g (19.7 oz)||396 g (14.0 oz)|
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