Pentax K-S2 vs Sony A7R IV
The Pentax K-S2 and the Sony Alpha A7R IV are two digital cameras that were officially introduced, respectively, in February 2015 and July 2019. The K-S2 is a DSLR, while the A7R IV is a mirrorless interchangeable lens camera. The cameras are based on an APS-C (K-S2) and a full frame (A7R IV) sensor. The Pentax has a resolution of 20 megapixels, whereas the Sony provides 60.2 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-S2 and the Sony Alpha A7R IV? 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-S2 and the Sony A7R IV. The two cameras are presented according to their relative size. Three consecutive perspectives from the front, the top, and the back are available. All size dimensions are rounded to the nearest millimeter.
The K-S2 can be obtained in six different colors (black, grey, pink, orange, green, white), while the A7R IV is only available in black.
If the front view area (width x height) of the cameras is taken as an aggregate measure of their size, the Sony A7R IV is notably larger (11 percent) than the Pentax K-S2. However, the A7R IV is slightly lighter (2 percent) than the K-S2. 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 K-S2 gets 410 shots out of its D-LI109 battery, while the A7R IV can take 670 images on a single charge of its NP-FZ100 power pack. The power pack in the A7R IV 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-S2||123 mm||91 mm||73 mm||678 g||410||Y||Feb 2015||749|
|2.||Sony A7R IV||129 mm||96 mm||78 mm||665 g||670||Y||Jul 2019||3,499|
|3.||Olympus E-M1 II||134 mm||91 mm||67 mm||574 g||440||Y||Sep 2016||1,999|
|4.||Pentax KP||132 mm||101 mm||76 mm||703 g||390||Y||Jan 2017||1,099|
|5.||Pentax K-70||126 mm||93 mm||74 mm||688 g||410||Y||Jun 2016||649|
|6.||Pentax K-3 II||131 mm||100 mm||77 mm||800 g||720||Y||Apr 2015||1,099|
|7.||Pentax K-S1||121 mm||93 mm||70 mm||558 g||410||n||Aug 2014||749|
|8.||Pentax K-3||131 mm||100 mm||77 mm||800 g||560||Y||Oct 2013||1,299|
|9.||Pentax K-30||130 mm||97 mm||71 mm||650 g||410||Y||May 2012||849|
|10.||Pentax K-5||131 mm||97 mm||73 mm||760 g||740||Y||Sep 2010||1,099|
|11.||Sony A7S III||127 mm||97 mm||81 mm||699 g||600||Y||Jul 2020||3,499|
|12.||Sony A7R III||127 mm||96 mm||74 mm||650 g||650||Y||Oct 2017||3,199|
|13.||Sony A9||127 mm||96 mm||63 mm||673 g||650||Y||Apr 2017||4,499|
|14.||Sony A7R II||127 mm||96 mm||60 mm||625 g||290||Y||Jun 2015||3,199|
|15.||Sony A7S II||127 mm||96 mm||60 mm||627 g||370||Y||Sep 2015||2,999|
|16.||Sony A7 II||127 mm||96 mm||60 mm||599 g||350||Y||Nov 2014||1,999|
|17.||Sony A77 II||143 mm||104 mm||81 mm||647 g||480||Y||May 2014||1,199|
|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-S2 was launched at a markedly lower price (by 79 percent) than the A7R IV, 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. 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-S2 features an APS-C sensor and the Sony A7R IV a full frame sensor. The sensor area in the A7R IV is 132 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 60.2MP, the A7R IV offers a higher resolution than the K-S2 (20MP), but the A7R IV has smaller individual pixels (pixel pitch of 3.76μm versus 4.28μm for the K-S2). Yet, the A7R IV is a much more recent model (by 4 years and 5 months) than the K-S2, and its sensor will have benefitted from technological advances during this time that enhance the light gathering capacity of its pixel-units. 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 Sony A7R IV implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the A7R IV for good quality output (200 dots per inch) amounts to 47.5 x 31.7 inches or 120.7 x 80.5 cm, for very good quality (250 dpi) 38 x 25.3 inches or 96.6 x 64.4 cm, and for excellent quality (300 dpi) 31.7 x 21.1 inches or 80.5 x 53.6 cm. The corresponding values for the Pentax K-S2 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 A7R IV has on-sensor phase detect pixels, which results in fast and reliable autofocus acquisition even during live view operation.
Unlike the K-S2, the A7R IV has the capacity to capture high quality composite images (241MP) 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-S2 has a native sensitivity range from ISO 100 to ISO 51200. The corresponding ISO settings for the Sony Alpha A7R IV are ISO 100 to ISO 32000, with the possibility to increase the ISO range to 50-102400.
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 |
|2.||Sony A7R IV||Full Frame||60.2||9504||6336||4K/30p||26.0||14.8||3344||99|
|3.||Olympus E-M1 II||Four Thirds||20.2||5184||3888||4K/30p||23.7||12.8||1312||80|
|6.||Pentax K-3 II||APS-C||24.1||6016||4000||1080/60i||23.6||13.6||1106||80|
|11.||Sony A7S III||Full Frame||12.0||4240||2832||4K/120p||23.7||13.9||2520||86|
|12.||Sony A7R III||Full Frame||42.2||7952||5304||4K/30p||26.0||14.7||3523||100|
|13.||Sony A9||Full Frame||24.0||6000||4000||4K/30p||24.9||13.3||3517||92|
|14.||Sony A7R II||Full Frame||42.2||7952||5304||4K/30p||26.0||13.9||3434||98|
|15.||Sony A7S II||Full Frame||12.0||4240||2832||4K/30p||23.6||13.3||2993||85|
|16.||Sony A7 II||Full Frame||24.0||6000||4000||1080/60p||24.9||13.6||2449||90|
|17.||Sony A77 II||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 A7R IV provides a better video resolution than the K-S2. 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 A7R IV has an electronic viewfinder (5760k dots), while the K-S2 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 A7R IV has a higher magnification than the one of the K-S2 (0.78x vs 0.63x), so that the size of the image transmitted appears closer to the size seen with the naked human eye. The table below summarizes some of the other core capabilities of the Pentax K-S2 and Sony A7R IV in connection with corresponding information for a sample of similar cameras.
|2.||Sony A7R IV||5760||n||3.0||1440||tilting||Y||1/8000s||10.0||n||Y|
|3.||Olympus E-M1 II||2360||n||3.0||1037||swivel||Y||1/8000s||18.0||n||Y|
|6.||Pentax K-3 II||optical||Y||3.2||1037||fixed||n||1/8000s||8.3||n||Y|
|11.||Sony A7S III||9440||n||3.0||1440||swivel||Y||1/8000s||10.0||n||Y|
|12.||Sony A7R III||3686||n||3.0||1440||tilting||Y||1/8000s||10.0||n||Y|
|14.||Sony A7R II||2400||n||3.0||1229||tilting||n||1/8000s||5.0||n||Y|
|15.||Sony A7S II||2400||n||3.0||1229||tilting||n||1/8000s||5.0||n||Y|
|16.||Sony A7 II||2400||n||3.0||1230||tilting||n||1/8000s||5.0||n||Y|
|17.||Sony A77 II||2359||Y||3.0||1229||full-flex||n||1/8000s||12.0||Y||Y|
One difference between the cameras concerns the presence of an on-board flash. The K-S2 has one, while the A7R IV does not. While the built-in flash of the K-S2 is not very powerful, it can at times be useful as a fill-in light.The K-S2 has an articulated LCD that can be turned to be front-facing. This characteristic will be appreciated by vloggers and photographers who are interested in snapping selfies. In contrast, the A7R IV 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 A7R IV 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 Pentax K-S2 and the Sony A7R IV 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 K-S2 and the A7R IV write their files to SDXC cards. The A7R IV features dual card slots, which can be very useful in case a memory card fails. In contrast, the K-S2 only has one slot. The A7R IV supports UHS-II cards (on both slots), while the K-S2 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 Pentax K-S2 and Sony Alpha A7R IV and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.
| WiFi |
| NFC |
|2.||Sony A7R IV||Y||stereo||mono||Y||Y||micro||3.1||Y||Y||Y|
|3.||Olympus E-M1 II||Y||stereo||mono||Y||Y||micro||3.0||Y||-||-|
|6.||Pentax K-3 II||Y||mono||mono||Y||Y||mini||3.0||-||-||-|
|11.||Sony A7S III||Y||stereo||mono||Y||Y||full||3.2||Y||-||Y|
|12.||Sony A7R III||Y||stereo||mono||Y||Y||micro||3.1||Y||Y||Y|
|14.||Sony A7R II||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||-|
|15.||Sony A7S II||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||-|
|16.||Sony A7 II||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||-|
|17.||Sony A77 II||Y||stereo||mono||Y||-||mini||2.0||Y||Y||-|
It is notable that the A7R IV has a headphone jack, which makes it possible to attach external headphones and monitor the quality of sound during the recording process. The K-S2 lacks such a headphone port.
Studio photographers will appreciate that the Sony A7R IV (unlike the K-S2) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.
Both the K-S2 and the A7R IV are recent models that are part of the current product line-up. The K-S2 replaced the earlier Pentax K-S1, while the A7R IV followed on from the Sony A7R III. 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-S2 and the Sony A7R IV? Which camera is better? A synthesis of the relative strong points of each of the models is listed below.
Reasons to prefer the Pentax K-S2:
- Brighter framing: Features an optical viewfinder for clear, lag-free composition.
- More flexible LCD: Has a swivel screen for odd-angle shots in portrait or landscape orientation.
- More selfie-friendly: Has an articulated screen that can be turned to be front-facing.
- Easier fill-in: Is equipped with a small onboard flash to brighten deep shadow areas.
- More affordable: Was introduced into a lower priced category (79 percent cheaper at launch).
- More heavily discounted: Has been available for much longer (launched in February 2015).
Advantages of the Sony Alpha A7R IV:
- More detail: Has more megapixels (60.2 vs 20MP), which boosts linear resolution by 74%.
- High quality composites: Can combine several shots after pixel-shifting its sensor.
- Better image quality: Is equipped with a larger and more technologically advanced 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 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 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 (0.78x vs 0.63x).
- More detailed LCD: Has a higher resolution rear screen (1440k vs 921k dots).
- Fewer buttons to press: Has a touchscreen to facilitate handling and shooting adjustments.
- Faster shutter: Has higher mechanical shutter speed (1/8000s vs 1/6000s) to freeze action.
- 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.
- Longer lasting: Gets more shots (670 versus 410) out of a single battery charge.
- Easier travel charging: Can be conveniently charged via its USB port.
- More legacy lens friendly: Can use many non-native lenses via adapters.
- Faster data transfer: Supports a more advanced USB protocol (3.1 vs 2.0).
- 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 and 5 months of technical progress since the K-S2 launch.
If the number of relative strengths (bullet points above) is taken as a guide, the A7R IV is the clear winner of the contest (25 : 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 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 Pentax K-S2 and the Sony A7R IV 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 remains incomplete and does no justice, for example, to the way the K-S2 or the A7R IV perform in practice. 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 where reviews by experts come in. 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-S2||4.5/5||..||..||5/5||4.5/5||Feb 2015||749|
|2.||Sony A7R IV||5/5||+||91/100||4.5/5||5/5||Jul 2019||3,499|
|3.||Olympus E-M1 II||5/5||+ +||85/100||4.5/5||4.5/5||Sep 2016||1,999|
|4.||Pentax KP||4/5||..||82/100||5/5||4.5/5||Jan 2017||1,099|
|5.||Pentax K-70||4.5/5||..||79/100||4.5/5||4.5/5||Jun 2016||649|
|6.||Pentax K-3 II||4.5/5||..||..||5/5||5/5||Apr 2015||1,099|
|7.||Pentax K-S1||4/5||..||..||4.5/5||4/5||Aug 2014||749|
|8.||Pentax K-3||4/5||..||83/100||5/5||5/5||Oct 2013||1,299|
|9.||Pentax K-30||4/5||..||78/100||4.5/5||4.5/5||May 2012||849|
|10.||Pentax K-5||4/5||..||83/100||5/5||4.5/5||Sep 2010||1,099|
|11.||Sony A7S III||..||+ +||91/100||4.5/5||5/5||Jul 2020||3,499|
|12.||Sony A7R III||..||+ +||90/100||4.5/5||5/5||Oct 2017||3,199|
|13.||Sony A9||5/5||+ +||89/100||5/5||5/5||Apr 2017||4,499|
|14.||Sony A7R II||5/5||+ +||90/100||5/5||5/5||Jun 2015||3,199|
|15.||Sony A7S II||5/5||+||..||4.5/5||5/5||Sep 2015||2,999|
|16.||Sony A7 II||5/5||+||82/100||4.5/5||5/5||Nov 2014||1,999|
|17.||Sony A77 II||4/5||..||80/100||4.5/5||5/5||May 2014||1,199|
|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 rating-comparisons among cameras that span long time periods or concern very differently equipped models make little sense. 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 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: Pentax K-S2 vs Sony A7R IV
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-S2||Sony A7R IV|
|Camera Type||Digital single lens reflex||Mirrorless system camera|
|Camera Lens||Pentax K mount lenses||Sony E mount lenses|
|Launch Date||February 2015||July 2019|
|Launch Price||USD 749||USD 3,499|
|Sensor Specs||Pentax K-S2||Sony A7R IV|
|Sensor Format||APS-C Sensor||Full Frame Sensor|
|Sensor Size||23.5 x 15.6 mm||35.7 x 23.8 mm|
|Sensor Area||366.6 mm2||849.66 mm2|
|Sensor Diagonal||28.2 mm||42.9 mm|
|Sensor Resolution||20 Megapixels||60.2 Megapixels|
|Image Resolution||5472 x 3648 pixels||9504 x 6336 pixels|
|Pixel Pitch||4.28 μm||3.76 μm|
|Pixel Density||5.45 MP/cm2||7.09 MP/cm2|
|Moiré control||no AA filter||no AA filter|
|Movie Capability||1080/30p Video||4K/30p Video|
|ISO Setting||100 - 51,200 ISO||100 - 32,000 ISO|
|ISO Boost||no Enhancement||50 - 102,400 ISO|
|Image Processor||PRIME MII||BIONZ X|
|DXO Sensor Quality (score)||..||99|
|DXO Color Depth (bits)||..||26.0|
|DXO Dynamic Range (EV)||..||14.8|
|DXO Low Light (ISO)||..||3344|
|Screen Specs||Pentax K-S2||Sony A7R IV|
|Viewfinder Type||Optical viewfinder||Electronic viewfinder|
|Viewfinder Field of View||100%||100%|
|Viewfinder Resolution||5760k dots|
|LCD Framing||Live View||Live View|
|Rear LCD Size||3.0inch||3.0inch|
|LCD Resolution||921k dots||1440k dots|
|LCD Attachment||Swivel screen||Tilting screen|
|Touch Input||no Touchscreen||Touchscreen|
|Shooting Specs||Pentax K-S2||Sony A7R IV|
|Focus System||Phase-detect AF||On-Sensor Phase-detect|
|Manual Focusing Aid||Focus Peaking||Focus Peaking|
|Max Shutter Speed (mechanical)||1/6000s||1/8000s|
|Continuous Shooting||5.4 shutter flaps/s||10 shutter flaps/s|
|Electronic Shutter||no E-Shutter||YES|
|Time-Lapse Photography||Intervalometer built-in||Intervalometer built-in|
|Image Stabilization||In-body stabilization||In-body stabilization|
|Fill Flash||Build-in Flash||no On-Board Flash|
|Storage Medium||SDXC cards||SDXC cards|
|Second Storage Option||Single card slot||Dual card slots|
|UHS card support||UHS-I||Dual UHS-II|
|Connectivity Specs||Pentax K-S2||Sony A7R IV|
|Studio Flash||no PC Sync||PC Sync socket|
|USB Connector||USB 2.0||USB 3.1|
|HDMI Port||micro HDMI||micro HDMI|
|Microphone Port||External MIC port||External MIC port|
|Headphone Socket||no Headphone port||Headphone port|
|Wifi Support||Wifi built-in||Wifi built-in|
|Near-Field Communication||NFC built-in||NFC built-in|
|Bluetooth Support||no Bluetooth||Bluetooth built-in|
|Body Specs||Pentax K-S2||Sony A7R IV|
|Environmental Sealing||Weathersealed body||Weathersealed body|
|Battery Life (CIPA)||410 shots per charge||670 shots per charge|
|In-Camera Charging||no USB charging||USB charging|
123 x 91 x 73 mm
(4.8 x 3.6 x 2.9 in)
129 x 96 x 78 mm
(5.1 x 3.8 x 3.1 in)
|Camera Weight||678 g (23.9 oz)||665 g (23.5 oz)|
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