Pentax K-S1 vs Sony A7C
The Pentax K-S1 and the Sony Alpha A7C are two digital cameras that were announced, respectively, in August 2014 and September 2020. The K-S1 is a DSLR, while the A7C is a mirrorless interchangeable lens camera. The cameras are based on an APS-C (K-S1) and a full frame (A7C) 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 A7C? 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-S1 and the Sony A7C. 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-S1 can be obtained in four different colors (black, grey, orange, white), while the A7C is available in two color-versions (black, silver).
If the front view area (width x height) of the cameras is taken as an aggregate measure of their size, the Sony A7C is notably smaller (22 percent) than the Pentax K-S1. Moreover, the A7C is markedly lighter (9 percent) than the K-S1. It is noteworthy in this context that the A7C is splash and dust-proof, 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 K-S1 gets 410 shots out of its D-LI109 battery, while the A7C can take 740 images on a single charge of its NP-FZ100 power pack. The power pack in the A7C can be charged via the USB port, which can be very convenient when travelling.
The adjacent table lists the principal physical characteristics of the two cameras alongside a wider set of alternatives. 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.
|1.||Pentax K-S1||121 mm||93 mm||70 mm||558 g||410||n||Aug 2014||749|
|2.||Sony A7C||124 mm||71 mm||60 mm||509 g||740||Y||Sep 2020||1,799|
|3.||Canon 750D||132 mm||101 mm||78 mm||555 g||440||n||Feb 2015||749|
|4.||Canon 760D||132 mm||101 mm||78 mm||565 g||440||n||Feb 2015||649|
|5.||Nikon D5300||125 mm||98 mm||76 mm||480 g||600||n||Oct 2013||799|
|6.||Olympus E-M1 II||134 mm||91 mm||67 mm||574 g||440||Y||Sep 2016||1,999|
|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 A9||127 mm||96 mm||63 mm||673 g||650||Y||Apr 2017||4,499|
|13.||Sony A6500||120 mm||67 mm||53 mm||453 g||350||Y||Oct 2016||1,399|
|14.||Sony A68||143 mm||104 mm||81 mm||610 g||540||n||Nov 2015||699|
|15.||Sony A7 II||127 mm||96 mm||60 mm||599 g||350||Y||Nov 2014||1,999|
|16.||Sony A7||127 mm||94 mm||48 mm||474 g||340||Y||Oct 2013||1,699|
|17.||Sony A58||129 mm||95 mm||78 mm||492 g||690||n||Feb 2013||599|
|Notes: Measurements and pricing do not include easily detachable parts, such as add-on or interchangeable lenses or optional viewfinders.|
Any camera decision will naturally be influenced heavily by the price. 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 58 percent) than the A7C, 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 size of the sensor inside a digital camera is one of the key determinants 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.
Of the two cameras under consideration, the Pentax K-S1 features an APS-C sensor and the Sony A7C a full frame sensor. The sensor area in the A7C is 131 percent bigger. As a result of these sensor size differences, the cameras have a format factor of, respectively, 1.5 and 1.0. Both cameras have a native aspect ratio (sensor width to sensor height) of 3:2.
With 24MP, the A7C offers a higher resolution than the K-S1 (20MP), but the A7C nevertheless has larger individual pixels (pixel pitch of 5.94μm versus 4.28μm for the K-S1) due to its larger sensor. Moreover, the A7C is a much more recent model (by 6 years) 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 pixel-units. 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 A7C implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the A7C 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 A7C 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 A7C are ISO 100 to ISO 51200, with the possibility to increase the ISO range to 50-204800.
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"). Of the two cameras under consideration, the A7C offers substantially better image quality than the K-S1 (overall score 17 points higher). The advantage is based on 1.5 bits higher color depth, 1.7 EV in additional dynamic range, and 1.7 stops in additional low light sensitivity. 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 |
|2.||Sony A7C||Full Frame||24.0||6000||4000||4K/30p||25.0||14.7||3407||95|
|6.||Olympus E-M1 II||Four Thirds||20.2||5184||3888||4K/30p||23.7||12.8||1312||80|
|8.||Pentax K-3 II||APS-C||24.1||6016||4000||1080/60i||23.6||13.6||1106||80|
|12.||Sony A9||Full Frame||24.0||6000||4000||4K/30p||24.9||13.3||3517||92|
|15.||Sony A7 II||Full Frame||24.0||6000||4000||1080/60p||24.9||13.6||2449||90|
|16.||Sony A7||Full Frame||24.0||6000||4000||1080/60p||24.8||14.2||2248||90|
Many modern cameras are not only capable of taking still images, but also of capturing video footage. Both cameras under consideration have a sensor with sufficiently fast read-out times for moving pictures, but the A7C 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.
Apart from body and sensor, cameras can and do differ across a variety of features. For example, the A7C has an electronic viewfinder (2360k 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 K-S1 has a higher magnification than the one of the A7C (0.63x vs 0.59x), 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 A7C along with similar information for a selection of comparators.
|6.||Olympus E-M1 II||2360||n||3.0||1037||swivel||Y||1/8000s||18.0||n||Y|
|8.||Pentax K-3 II||optical||Y||3.2||1037||fixed||n||1/8000s||8.3||n||Y|
|15.||Sony A7 II||2400||n||3.0||1230||tilting||n||1/8000s||5.0||n||Y|
One difference between the cameras concerns the presence of an on-board flash. The K-S1 has one, while the A7C does not. While the built-in flash of the K-S1 is not very powerful, it can at times be useful as a fill-in light.The A7C 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 A7C 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 A7C 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 A7C uses SDXC or Memory Stick PRO Duo cards. The A7C supports UHS-II cards (Ultra High Speed data transfer of up to 312 MB/s), while the K-S1 can use UHS-I cards (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 A7C and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.
| WiFi |
| NFC |
|6.||Olympus E-M1 II||Y||stereo||mono||Y||Y||micro||3.0||Y||-||-|
|8.||Pentax K-3 II||Y||mono||mono||Y||Y||mini||3.0||-||-||-|
|15.||Sony A7 II||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||-|
It is notable that the A7C 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 A7C 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 how do things add up? Is there a clear favorite between the Pentax K-S1 and the Sony A7C? Which camera is better? Below is a summary of the relative strengths of each of the two contestants.
Advantages 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.
- Larger viewfinder image: Features a viewfinder with a higher magnification (0.63x vs 0.59x).
- Faster shutter: Has higher mechanical shutter speed (1/6000s vs 1/4000s) to freeze action.
- Easier fill-in: Is equipped with a small onboard flash to brighten deep shadow areas.
- More affordable: Was introduced into a lower priced category (58 percent cheaper at launch).
- More heavily discounted: Has been available for much longer (launched in August 2014).
Arguments in favor of the Sony Alpha A7C:
- 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 image quality: Scores substantially higher (17 points) in the DXO overall evaluation.
- Richer colors: Generates noticeably more natural colors (1.5 bits more color depth).
- More dynamic range: Captures a broader range of light and dark details (1.7 EV of extra DR).
- Better low-light sensitivity: Can shoot in dim conditions (1.7 stops ISO advantage).
- 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.
- Better sound control: Has a headphone port that enables audio monitoring while recording.
- More framing info: Has an electronic viewfinder that displays shooting data.
- More flexible LCD: Has a swivel screen for odd-angle shots in portrait or 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 (10 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 (124x71mm vs 121x93mm) and will fit more readily into a bag.
- Longer lasting: Gets more shots (740 versus 410) out of a single battery charge.
- Easier travel charging: Can be conveniently charged via its USB port.
- Better sealing: Is splash and dust sealed for shooting in inclement weather conditions.
- More legacy lens friendly: Can use many 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 device pairing: Supports NFC for fast wireless image transfer over short distances.
- Easier wireless transfer: Supports Bluetooth for image sharing without cables.
- Faster buffer clearing: Supports a more advanced SD data transfer standard (UHS-II vs UHS-I).
- More modern: Reflects 6 years of technical progress since the K-S1 launch.
If the number of relative strengths (bullet points above) is taken as a guide, the A7C is the clear winner of the contest (28 : 7 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-S1 and the Sony A7C 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 the spec-sheets of cameras can offer a general idea of their imaging potential, it says little about, for example, the shooting experience and imaging performance of the K-S1 and the A7C in practical situations. 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 why hands-on reviews by experts 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], 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 A7C||3.5/5||..||86/100||4/5||4/5||Sep 2020||1,799|
|3.||Canon 750D||5/5||..||75/100||4.5/5||4.5/5||Feb 2015||749|
|4.||Canon 760D||5/5||+||77/100||4.5/5||4.5/5||Feb 2015||649|
|5.||Nikon D5300||4/5||+ +||79/100||4.5/5||4.5/5||Oct 2013||799|
|6.||Olympus E-M1 II||5/5||+ +||85/100||4.5/5||4.5/5||Sep 2016||1,999|
|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 A9||5/5||+ +||89/100||5/5||5/5||Apr 2017||4,499|
|13.||Sony A6500||5/5||+ +||85/100||4.5/5||4.5/5||Oct 2016||1,399|
|14.||Sony A68||3/5||..||..||4/5||4/5||Nov 2015||699|
|15.||Sony A7 II||5/5||+||82/100||4.5/5||5/5||Nov 2014||1,999|
|16.||Sony A7||5/5||+ +||80/100||5/5||5/5||Oct 2013||1,699|
|17.||Sony A58||3/5||..||..||4.5/5||4.5/5||Feb 2013||599|
|Notes: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.|
The above review scores should be interpreted with care, though. The ratings are only valid when referring to cameras in the same category and of the same age. 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. Also, kindly note that some of the listed sites have over time developped their review approaches and their reporting style.
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. Alternatively, you can follow any of the listed hyperlinks for comparisons that others found interesting.
Specifications: Pentax K-S1 vs Sony A7C
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 A7C|
|Camera Type||Digital single lens reflex||Mirrorless system camera|
|Camera Lens||Pentax K mount lenses||Sony E mount lenses|
|Launch Date||August 2014||September 2020|
|Launch Price||USD 749||USD 1,799|
|Sensor Specs||Pentax K-S1||Sony A7C|
|Sensor Format||APS-C Sensor||Full Frame Sensor|
|Sensor Size||23.5 x 15.6 mm||35.6 x 23.8 mm|
|Sensor Area||366.6 mm2||847.28 mm2|
|Sensor Diagonal||28.2 mm||42.8 mm|
|Sensor Resolution||20 Megapixels||24 Megapixels|
|Image Resolution||5472 x 3648 pixels||6000 x 4000 pixels|
|Pixel Pitch||4.28 μm||5.94 μm|
|Pixel Density||5.45 MP/cm2||2.83 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 - 51,200 ISO|
|ISO Boost||no Enhancement||50 - 204,800 ISO|
|Image Processor||PRIME MII||BIONZ X|
|DXO Sensor Quality (score)||78||95|
|DXO Color Depth (bits)||23.5||25.0|
|DXO Dynamic Range (EV)||13.0||14.7|
|DXO Low Light (ISO)||1061||3407|
|Screen Specs||Pentax K-S1||Sony A7C|
|Viewfinder Type||Optical viewfinder||Electronic viewfinder|
|Viewfinder Field of View||100%||100%|
|Viewfinder Resolution||2360k dots|
|LCD Framing||Live View||Live View|
|Rear LCD Size||3.0inch||3.0inch|
|LCD Resolution||921k dots||922k dots|
|LCD Attachment||Fixed screen||Swivel screen|
|Touch Input||no Touchscreen||Touchscreen|
|Shooting Specs||Pentax K-S1||Sony A7C|
|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||10 shutter flaps/s|
|Electronic Shutter||no E-Shutter||up to 1/8000s|
|Time-Lapse Photography||no Intervalometer||Intervalometer built-in|
|Image Stabilization||In-body stabilization||In-body stabilization|
|Fill Flash||Build-in Flash||no On-Board Flash|
|Storage Medium||SDXC cards||MS or SDXC cards|
|Second Storage Option||Single card slot||Single card slot|
|UHS card support||UHS-I||UHS-II|
|Connectivity Specs||Pentax K-S1||Sony A7C|
|USB Connector||USB 2.0||USB 3.2|
|HDMI Port||micro HDMI||micro HDMI|
|Microphone Port||no MIC socket||External MIC port|
|Headphone Socket||no Headphone port||Headphone 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 A7C|
|Environmental Sealing||not weather sealed||Weathersealed body|
|Battery Life (CIPA)||410 shots per charge||740 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)
124 x 71 x 60 mm
(4.9 x 2.8 x 2.4 in)
|Camera Weight||558 g (19.7 oz)||509 g (18.0 oz)|
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