Pentax K-70 vs Sony A7S
The Pentax K-70 and the Sony Alpha A7S are two digital cameras that were officially introduced, respectively, in June 2016 and April 2014. The K-70 is a DSLR, while the A7S is a mirrorless interchangeable lens camera. The cameras are based on an APS-C (K-70) and a full frame (A7S) sensor. The Pentax has a resolution of 24 megapixels, whereas the Sony provides 12 MP.
Below is an overview of the main specs of the two cameras as a starting point for the comparison.
|Pentax K-70||Sony A7S|
|Digital single lens reflex||Mirrorless system camera|
|Pentax K mount lenses||Sony E mount lenses|
|24 MP, APS-C Sensor||12 MP, Full Frame Sensor|
|1080/60i Video||1080/60p Video|
|ISO 100-102,400||ISO 100-102,400 (50 - 409,600)|
|Optical viewfinder||Electronic viewfinder (2400k dots)|
|3.0 LCD, 921k dots||3.0 LCD, 921k dots|
|Swivel screen (not touch-sensitive)||Tilting screen (not touch-sensitive)|
|6 shutter flaps per second||5 shutter flaps per second|
|In-body stabilization||Lens stabilization only|
|Weathersealed body||Weathersealed body|
|410 shots per battery charge||380 shots per battery charge|
|126 x 93 x 74 mm, 688 g||127 x 94 x 48 mm, 489 g|
Going beyond this snapshot of core features and characteristics, what are the differences between the Pentax K-70 and the Sony Alpha A7S? 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-70 and the Sony A7S 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 width, height and depth measures are rounded to the nearest millimeter.
The K-70 can be obtained in two different colors (black, silver), while the A7S 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 A7S is somewhat larger (2 percent) than the Pentax K-70. However, the A7S is markedly lighter (29 percent) than the K-70. 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-70 gets 410 shots out of its D-LI109 battery, while the A7S can take 380 images on a single charge of its NP-FW50 power pack. The power pack in the A7S 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, just use the right or left arrows in the table to switch to the respective camera. Alternatively, you can also navigate to the CAM-parator app and make your selection from the full list of cameras there.
|Pentax K-70||5.0 in||3.7 in||2.9 in||24.3 oz||410||Y||Jun 2016||649|
|Sony A7S||5.0 in||3.7 in||1.9 in||17.2 oz||380||Y||Apr 2014||2,499|
|Nikon Df||5.7 in||4.3 in||2.6 in||26.8 oz||1400||Y||Nov 2013||2,749|
|Olympus E-M1 II||5.3 in||3.6 in||2.6 in||20.2 oz||440||Y||Sep 2016||1,999|
|Panasonic G9||5.4 in||3.8 in||3.6 in||23.2 oz||400||Y||Nov 2017||1,699|
|Panasonic GH5||5.5 in||3.9 in||3.4 in||25.6 oz||410||Y||Jan 2017||1,999|
|Pentax KP||5.2 in||4.0 in||3.0 in||24.8 oz||390||Y||Jan 2017||1,099|
|Pentax K-3 II||5.2 in||3.9 in||3.0 in||28.2 oz||720||Y||Apr 2015||1,099|
|Pentax K-3||5.2 in||3.9 in||3.0 in||28.2 oz||560||Y||Oct 2013||1,299|
|Pentax K-5||5.2 in||3.8 in||2.9 in||26.8 oz||740||Y||Sep 2010||1,099|
|Sony A9||5.0 in||3.8 in||2.5 in||23.7 oz||650||Y||Apr 2017||4,499|
|Sony A6500||4.7 in||2.6 in||2.1 in||16.0 oz||350||Y||Oct 2016||1,399|
|Sony A7S II||5.0 in||3.8 in||2.4 in||22.1 oz||370||Y||Sep 2015||2,999|
|Sony A68||5.6 in||4.1 in||3.2 in||21.5 oz||540||n||Nov 2015||699|
|Sony A7 II||5.0 in||3.8 in||2.4 in||21.1 oz||350||Y||Nov 2014||1,999|
|Sony A7||5.0 in||3.7 in||1.9 in||16.7 oz||340||Y||Oct 2013||1,699|
|Sony A7R||5.0 in||3.7 in||1.9 in||16.4 oz||340||Y||Oct 2013||2,299|
Notes: Measurements and pricing do not include easily detachable parts, such as add-on or interchangeable lenses or optional viewfinders.
(1) Number of images that can be taken on a full battery charge according to the CIPA-standard; (2) Official announcement.
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 K-70 was launched at a markedly lower price (by 74 percent) than the A7S, 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 imaging sensor is at the core of digital cameras and its size is one of the main determining factors of image quality. A large sensor will generally have larger individual pixels that offer better low-light sensitivity, provide wider dynamic range, and have richer color-depth than smaller pixels 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 are more costly to manufacture and tend to lead to bigger and heavier cameras and lenses.
Of the two cameras under consideration, the Pentax K-70 features an APS-C sensor and the Sony A7S a full frame sensor. The sensor area in the A7S is 133 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.
Despite having a smaller sensor, the Pentax K-70 offers a higher resolution of 24 megapixels, compared with 12 MP of the Sony A7S. This megapixels advantage comes at the cost of a higher pixel density and a smaller size of the individual pixel (with a pixel pitch of 3.91μm versus 8.45μm for the A7S). However, it should be noted that the K-70 is much more recent (by 2 years and 2 months) than the A7S, and its sensor will have benefitted from technological advances during this time that make it possible to gather light more efficiently. Coming back to sensor resolution, it should be mentioned that the K-70 has no anti-alias filter installed, so that it can capture all the detail its sensor resolves.
The resolution advantage of the Pentax K-70 implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the K-70 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 Sony A7S are 21.2 x 14.2 inches or 53.8 x 36 cm for good quality, 17 x 11.3 inches or 43.1 x 28.8 cm for very good quality, and 14.1 x 9.4 inches or 35.9 x 24 cm for excellent quality prints.
The K-70 has on-sensor phase detect pixels, which results in fast and reliable autofocus acquisition even during live view operation.
Unlike the A7S, the K-70 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-70 has a native sensitivity range from ISO 100 to ISO 102400. The corresponding ISO settings for the Sony Alpha A7S are ISO 100 to ISO 102400, with the possibility to increase the ISO range to 50-409600.
Since 2007, DXO Mark has published sensor performance measurements that have been derived using a consistent methodology. This service determines an overall sensor rating, as well as sub-scores for low-light sensitivity ("DXO Sports"), dynamic range ("DXO Landscape"), and color depth ("DXO Portrait"). The adjacent table reports on the physical sensor characteristics and the outcomes of the DXO sensor quality tests for a sample of comparator-cameras.
|Sony A7S||Full Frame||12.0||4240||2832||1080/60p||23.9||13.2||3702||87|
|Nikon Df||Full Frame||16.2||4928||3280||none||24.6||13.1||3279||89|
|Olympus E-M1 II||Four Thirds||20.2||5184||3888||4K/30p||23.7||12.8||1312||80|
|Panasonic G9||Four Thirds||20.2||5184||3888||4K/60p||..||..||..||..|
|Panasonic GH5||Four Thirds||20.2||5184||3888||4K/60p||23.9||13.0||807||77|
|Pentax K-3 II||APS-C||24.1||6016||4000||1080/60i||23.6||13.6||1106||80|
|Sony A9||Full Frame||24.0||6000||4000||4K/30p||24.9||13.3||3517||92|
|Sony A7S II||Full Frame||12.0||4240||2832||4K/30p||23.6||13.3||2993||85|
|Sony A7 II||Full Frame||24.0||6000||4000||1080/60p||24.9||13.6||2449||90|
|Sony A7||Full Frame||24.0||6000||4000||1080/60p||24.8||14.2||2248||90|
|Sony A7R||Full Frame||36.2||7360||4912||1080/60p||25.6||14.1||2746||95|
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 A7S provides a faster frame rate than the K-70. It can shoot movie footage at 1080/60p, while the Pentax is limited to 1080/60i.
Apart from body and sensor, cameras can and do differ across a variety of features. For example, the A7S has an electronic viewfinder (2400k dots), while the K-70 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 A7S has a higher magnification than the one of the K-70 (0.71x 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-70 and Sony A7S in connection with corresponding information for a sample of similar cameras.
|Olympus E-M1 II||2360||n||3.0||1037||swivel||Y||1/8000s||18.0||n||Y|
|Pentax K-3 II||optical||Y||3.2||1037||fixed||n||1/8000s||8.3||n||Y|
|Sony A7S II||2400||n||3.0||1229||tilting||n||1/8000s||5.0||n||Y|
|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-70 has one, while the A7S does not. While the built-in flash of the K-70 is not very powerful, it can at times be useful as a fill-in light.The K-70 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 A7S 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 A7S 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-70 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-70 writes its imaging data to SDXC cards, while the A7S 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-70 and Sony Alpha A7S and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.
| WiFi |
|Olympus E-M1 II||Y||stereo||mono||Y||Y||micro||3.0||Y||-||-|
|Pentax K-3 II||Y||mono||mono||Y||Y||mini||3.0||-||-||-|
|Sony A7S II||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||-|
|Sony A7 II||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||-|
It is notable that the A7S has a headphone jack, which makes it possible to attach external headphones and monitor the quality of sound during the recording process. The K-70 lacks such a headphone port.
The K-70 is a recent model that features in the current product line-up of Pentax. In contrast, the A7S has been discontinued (but can be found pre-owned on eBay). As a replacement in the same line of cameras, the A7S was succeeded by the Sony A7S II. 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-70 and the Sony A7S? Which camera is better? The listing below highlights the relative strengths of the two models.
Advantages of the Pentax K-70:
- More detail: Offers more megapixels (24 vs 12MP) with a 41% higher linear resolution.
- Maximized detail: Lacks an anti-alias filter to exploit the sensor's full resolution potential.
- High quality composites: Can combine several shots after pixel-shifting its sensor.
- Better live-view autofocus: Features on-sensor phase-detection for more confident autofocus.
- 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.
- Faster burst: Shoots at higher frequency (6 vs 5 flaps/sec) to capture the decisive moment.
- Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
- Sharper images: Has hand-shake reducing image stabilization built-in.
- Easier fill-in: Is equipped with a small onboard flash to brighten deep shadow areas.
- More affordable: Was introduced into a lower priced category (74 percent cheaper at launch).
- More modern: Reflects 2 years and 2 months of technical progress since the A7S launch.
Reasons to prefer the Sony Alpha A7S:
- Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
- Better image quality: Features bigger pixels on a larger sensor for higher quality imaging.
- Richer colors: The pixel size advantage translates into images with better, more accurate colors.
- More dynamic range: Larger pixels capture a wider spectrum of light and dark details.
- Better low-light sensitivity: Larger pixels means good image quality even under poor lighting.
- Better video: Provides higher movie framerates (1080/60p versus 1080/60i).
- 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 (0.71x vs 0.63x).
- Faster shutter: Has higher mechanical shutter speed (1/8000s vs 1/6000s) to freeze action.
- Less disturbing: Has an electronic shutter option for completely silent shooting.
- Less heavy: Has a lower weight (by 199g 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 device pairing: Supports NFC for fast wireless image transfer over short distances.
- More heavily discounted: Has been around for much longer (launched in April 2014).
If the count of individual advantages (bullet points above) is taken as a guide, the A7S emerges as the winner of the match-up (15 : 13 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 Pentax K-70 and the Sony A7S 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-70 or the A7S perform in practice. 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 hands-on reviews by experts are important. The adjacent summary-table relays the overall verdicts of several of the most popular camera review sites (cameralabs, dpreview, ephotozine, imaging-resource, and photographyblog). 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.
|Pentax K-70||..||79/100||4.5/5||4/5||4.5/5||Jun 2016||649|
|Sony A7S||..||86/100||4.5/5||4.5/5||5/5||Apr 2014||2,499|
|Nikon Df||..||81/100||4/5||4/5||4/5||Nov 2013||2,749|
|Olympus E-M1 II||+ +||85/100||4.5/5||5/5||4.5/5||Sep 2016||1,999|
|Panasonic G9||+ +||85/100||5/5||5/5||5/5||Nov 2017||1,699|
|Panasonic GH5||+ +||85/100||4.5/5||5/5||5/5||Jan 2017||1,999|
|Pentax KP||..||82/100||5/5||..||4.5/5||Jan 2017||1,099|
|Pentax K-3 II||..||..||5/5||4.5/5||5/5||Apr 2015||1,099|
|Pentax K-3||..||83/100||5/5||4.5/5||5/5||Oct 2013||1,299|
|Pentax K-5||..||83/100||5/5||4.5/5||4.5/5||Sep 2010||1,099|
|Sony A9||+ +||89/100||5/5||5/5||5/5||Apr 2017||4,499|
|Sony A6500||+ +||85/100||4.5/5||5/5||4.5/5||Oct 2016||1,399|
|Sony A7S II||+||..||4.5/5||5/5||5/5||Sep 2015||2,999|
|Sony A68||..||..||4/5||..||4/5||Nov 2015||699|
|Sony A7 II||+||82/100||4.5/5||5/5||5/5||Nov 2014||1,999|
|Sony A7||+ +||80/100||5/5||4.5/5||5/5||Oct 2013||1,699|
|Sony A7R||+ +||82/100||4.5/5||5/5||5/5||Oct 2013||2,299|
|Notes: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.|
Care should be taken when interpreting the review scores above, though. The ratings were established in reference to similarly priced cameras that were available in the market at the time of the review. Hence, a score should always be seen in the context of the camera's market launch date and its price, and comparisons of ratings among very different cameras or across long time periods 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. Alternatively, you can follow any of the listed hyperlinks for comparisons that others found interesting.
- Canon 1D Mark II vs Sony A7S
- Canon 5D Mark III vs Sony A7S III
- Canon 750D vs Pentax K-70
- Fujifilm GFX 50S vs Sony A7S
- Leica D-LUX 7 vs Pentax K-70
- Nikon W150 vs Sony A7S III
- Olympus E-M1 II vs Pentax K-70
- Panasonic FT7 vs Sony A7S III
- Panasonic G9 vs Sony A7S
- Panasonic GH4 vs Pentax K-70
- Sony A7S II vs Sony HX400V
- Sony A7S vs Sony HX99
Specifications: Pentax K-70 vs Sony A7S
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-70||Sony A7S|
|Camera Type||Digital single lens reflex||Mirrorless system camera|
|Camera Lens||Pentax K mount lenses||Sony E mount lenses|
|Launch Date||June 2016||April 2014|
|Launch Price||USD 649||USD 2,499|
|Sensor Specs||Pentax K-70||Sony A7S|
|Sensor Format||APS-C Sensor||Full Frame Sensor|
|Sensor Size||23.5 x 15.6 mm||35.8 x 23.9 mm|
|Sensor Area||366.6 mm2||855.62 mm2|
|Sensor Diagonal||28.2 mm||43 mm|
|Sensor Resolution||24 Megapixels||12 Megapixels|
|Image Resolution||6000 x 4000 pixels||4240 x 2832 pixels|
|Pixel Pitch||3.91 μm||8.45 μm|
|Pixel Density||6.55 MP/cm2||1.40 MP/cm2|
|Moiré control||no AA filter||Anti-Alias filter|
|Movie Capability||1080/60i Video||1080/60p Video|
|ISO Setting||100 - 102,400 ISO||100 - 102,400 ISO|
|ISO Boost||no Enhancement||50 - 409,600 ISO|
|Image Processor||PRIME MII||BIONZ X|
|DXO Sensor Quality (score)||..||87|
|DXO Color Depth (bits)||..||23.9|
|DXO Dynamic Range (EV)||..||13.2|
|DXO Low Light (ISO)||..||3702|
|Screen Specs||Pentax K-70||Sony A7S|
|Viewfinder Type||Optical viewfinder||Electronic viewfinder|
|Viewfinder Field of View||100%||100%|
|Viewfinder Resolution||2400k dots|
|LCD Framing||Live View||Live View|
|Rear LCD Size||3.0inch||3.0inch|
|LCD Resolution||921k dots||921k dots|
|LCD Attachment||Swivel screen||Tilting screen|
|Shooting Specs||Pentax K-70||Sony A7S|
|Focus System||Phase-detect AF||Contrast-detect AF|
|Manual Focusing Aid||Focus Peaking||Focus Peaking|
|Max Shutter Speed (mechanical)||1/6000s||1/8000s|
|Continuous Shooting||6 shutter flaps/s||5 shutter flaps/s|
|Electronic Shutter||no E-Shutter||YES|
|Time-Lapse Photography||Intervalometer built-in||no Intervalometer|
|Image Stabilization||In-body stabilization||Lens stabilization only|
|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-I|
|Connectivity Specs||Pentax K-70||Sony A7S|
|USB Connector||USB 2.0||USB 2.0|
|HDMI Port||mini 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||no NFC||NFC built-in|
|Body Specs||Pentax K-70||Sony A7S|
|Environmental Sealing||Weathersealed body||Weathersealed body|
|Battery Life (CIPA)||410 shots per charge||380 shots per charge|
|In-Camera Charging||no USB charging||USB charging|
126 x 93 x 74 mm
(5.0 x 3.7 x 2.9 in)
127 x 94 x 48 mm
(5.0 x 3.7 x 1.9 in)
|Camera Weight||688 g (24.3 oz)||489 g (17.2 oz)|
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