Pentax K-3 vs Sony A7R III
The Pentax K-3 and the Sony Alpha A7R III are two enthusiast cameras that were revealed to the public, respectively, in October 2013 and October 2017. The K-3 is a DSLR, while the A7R III is a mirrorless interchangeable lens camera. The cameras are based on an APS-C (K-3) and a full frame (A7R III) sensor. The Pentax has a resolution of 24.1 megapixels, whereas the Sony provides 42.2 MP.
Below is an overview of the main specs of the two cameras as a starting point for the comparison.
|Pentax K-3||Sony A7R III|
|Digital single lens reflex||Mirrorless system camera|
|Pentax K mount lenses||Sony E mount lenses|
|24.1 MP, APS-C Sensor||42.2 MP, Full Frame Sensor|
|1080/60i Video||4K/30p Video|
|ISO 100-51200||ISO 100-32000 (50-102400)|
|Optical viewfinder||Electronic viewfinder (3686k dots)|
|3.2" LCD, 1037k dots||3.0" LCD, 1440k dots|
|Fixed screen (not touch-sensitive)||Tilting touchscreen|
|8.3 shutter flaps per second||10 shutter flaps per second|
|In-body stabilization||In-body stabilization|
|Weathersealed body||Weathersealed body|
|560 shots per battery charge||650 shots per battery charge|
|131 x 100 x 77 mm, 800 g||127 x 96 x 74 mm, 650 g|
Going beyond this snapshot of core features and characteristics, what are the differences between the Pentax K-3 and the Sony Alpha A7R III? 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-3 and the Sony A7R III are illustrated in the side-by-side display below. The two cameras are presented according to their relative size. Three consecutive perspectives from the front, the top, and the back are available. All width, height and depth measures are rounded to the nearest millimeter.
The K-3 can be obtained in two different colors (black, silver), while the A7R III 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 III is notably smaller (7 percent) than the Pentax K-3. Moreover, the A7R III is markedly lighter (19 percent) than the K-3. 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-3 gets 560 shots out of its D-LI90 battery, while the A7R III can take 650 images on a single charge of its NP-FZ100 power pack. The power pack in the A7R III 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-3»||5.2 in||3.9 in||3.0 in||28.2 oz||560||Y||Oct 2013||1,299||-||Pentax K-3|
|Sony A7R III«||5.0 in||3.8 in||2.9 in||22.9 oz||650||Y||Oct 2017||3,199||-||Sony A7R III|
|Canon 70D« »||5.5 in||4.1 in||3.1 in||26.6 oz||920||Y||Jul 2013||1,199||-||Canon 70D|
|Nikon Z7« »||5.3 in||4.0 in||2.6 in||23.8 oz||330||Y||Aug 2018||3,399||Nikon Z7|
|Nikon D7200« »||5.4 in||4.2 in||3.0 in||27.0 oz||1110||Y||Mar 2015||1,199||-||Nikon D7200|
|Nikon D7100« »||5.4 in||4.2 in||3.0 in||27.0 oz||950||Y||Feb 2013||1,199||-||Nikon D7100|
|Pentax KP« »||5.2 in||4.0 in||3.0 in||24.8 oz||390||Y||Jan 2017||1,099||Pentax KP|
|Pentax K-70« »||5.0 in||3.7 in||2.9 in||24.3 oz||410||Y||Jun 2016||649||Pentax K-70|
|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 II|
|Pentax K-5« »||5.2 in||3.8 in||2.9 in||26.8 oz||740||Y||Sep 2010||1,099||-||Pentax K-5|
|Sony A9« »||5.0 in||3.8 in||2.5 in||23.7 oz||650||Y||Apr 2017||4,499||Sony A9|
|Sony A99 II« »||5.6 in||4.1 in||3.0 in||29.9 oz||490||Y||Sep 2016||3,199||Sony A99 II|
|Sony A6500« »||4.7 in||2.6 in||2.1 in||16.0 oz||350||Y||Oct 2016||1,399||-||Sony A6500|
|Sony A7R II« »||5.0 in||3.8 in||2.4 in||22.0 oz||290||Y||Jun 2015||3,199||-||Sony A7R II|
|Sony A7S II« »||5.0 in||3.8 in||2.4 in||22.1 oz||370||Y||Sep 2015||2,999||Sony A7S II|
|Sony A99« »||5.8 in||4.4 in||3.1 in||28.6 oz||500||Y||Sep 2012||2,799||-||Sony A99|
|Sony A77« »||5.6 in||4.1 in||3.2 in||25.8 oz||470||Y||Aug 2011||1,399||-||Sony A77|
|Note: Measurements and pricing do not include easily detachable parts, such as 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 K-3 was launched at a markedly lower price (by 59 percent) than the A7R III, 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 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-3 features an APS-C sensor and the Sony A7R III a full frame sensor. The sensor area in the A7R III is 135 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 42.2MP, the A7R III offers a higher resolution than the K-3 (24.1MP), but the A7R III nevertheless has larger individual pixels (pixel pitch of 4.52μm versus 3.90μm for the K-3) due to its larger sensor. Moreover, the A7R III is a much more recent model (by 4 years) than the K-3, 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 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 III implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the A7R III for good quality output (200 dots per inch) amounts to 39.8 x 26.5 inch or 101 x 67.4 cm, for very good quality (250 dpi) 31.8 x 21.2 inch or 80.8 x 53.9 cm, and for excellent quality (300 dpi) 26.5 x 17.7 inch or 67.3 x 44.9 cm. The corresponding values for the Pentax K-3 are 30.1 x 20 inch or 76.4 x 50.8 cm for good quality, 24.1 x 16 inch or 61.1 x 40.6 cm for very good quality, and 20.1 x 13.3 inch or 50.9 x 33.9 cm for excellent quality prints.
The A7R III has on-sensor phase detect pixels, which results in fast and reliable autofocus acquisition even during live view operation.
Unlike the K-3, the A7R III 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-3 has a native sensitivity range from ISO 100 to ISO 51200. The corresponding ISO settings for the Sony Alpha A7R III 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 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. Of the two cameras under consideration, the A7R III offers substantially better image quality than the K-3 (overall score 20 points higher). The advantage is based on 2.3 bits higher color depth, 1.3 EV in additional dynamic range, and 1.5 stops in additional low light sensitivity. The following table provides an overview of the physical sensor characteristics, as well as the sensor quality measurements for a selection of comparators.
|Pentax K-3»||APS-C||24.1||6016||4000||1080/60i||23.7||13.4||1216||80||Pentax K-3|
|Sony A7R III«||Full Frame||42.2||7952||5304||4K/30p||26.0||14.7||3523||100||Sony A7R III|
|Canon 70D« »||APS-C||20.0||5472||3648||1080/30p||22.5||11.6||926||68||Canon 70D|
|Nikon Z7« »||Full Frame||45.4||8256||5504||4K/30p||26.3||14.6||2668||99||Nikon Z7|
|Nikon D7200« »||APS-C||24.0||6000||4000||1080/60p||24.5||14.6||1333||87||Nikon D7200|
|Nikon D7100« »||APS-C||24.0||6000||4000||1080/60p||24.2||13.7||1256||83||Nikon D7100|
|Pentax KP« »||APS-C||24.1||6016||4000||1080/60i||-||-||-||-||Pentax KP|
|Pentax K-70« »||APS-C||24.0||6000||4000||1080/60i||-||-||-||-||Pentax K-70|
|Pentax K-3 II« »||APS-C||24.1||6016||4000||1080/60i||23.6||13.6||1106||80||Pentax K-3 II|
|Pentax K-5« »||APS-C||16.1||4928||3264||1080/25p||23.7||14.1||1162||82||Pentax K-5|
|Sony A9« »||Full Frame||24.0||6000||4000||4K/30p||24.9||13.3||3517||92||Sony A9|
|Sony A99 II« »||Full Frame||42.2||7952||5304||4K/30p||25.4||13.4||2317||92||Sony A99 II|
|Sony A6500« »||APS-C||24.0||6000||4000||4K/30p||24.5||13.7||1405||85||Sony A6500|
|Sony A7R II« »||Full Frame||42.2||7952||5304||4K/30p||26.0||13.9||3434||98||Sony A7R II|
|Sony A7S II« »||Full Frame||12.0||4240||2832||4K/30p||23.6||13.3||2993||85||Sony A7S II|
|Sony A99« »||Full Frame||24.0||6000||4000||1080/60p||25.0||14.0||1555||89||Sony A99|
|Sony A77« »||APS-C||24.0||6000||4000||1080/60p||24.0||13.2||801||78||Sony A77|
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 A7R III provides a better video resolution than the K-3. It can shoot movie footage at 4K/30p, while the Pentax is limited to 1080/60i.
Beyond body and sensor, cameras can and do differ across a range of features. For example, the A7R III has an electronic viewfinder (3686k dots), while the K-3 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 III has a higher magnification than the one of the K-3 (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 following table reports on some other key feature differences and similarities of the Pentax K-3, the Sony A7R III, and comparable cameras.
|Pentax K-3»||optical||Y||3.2||1037||fixed||n||1/8000s||8.3||Y||Y||Pentax K-3|
|Sony A7R III«||3686||n||3.0||1440||tilting||Y||1/8000s||10.0||n||Y||Sony A7R III|
|Canon 70D« »||optical||Y||3.0||1040||swivel||Y||1/8000s||7.0||Y||n||Canon 70D|
|Nikon Z7« »||3690||Y||3.2||2100||tilting||Y||1/8000s||9.0||n||Y||Nikon Z7|
|Nikon D7200« »||optical||Y||3.2||1229||fixed||n||1/8000s||6.0||Y||n||Nikon D7200|
|Nikon D7100« »||optical||Y||3.2||1229||fixed||n||1/8000s||6.0||Y||n||Nikon D7100|
|Pentax KP« »||optical||n||3.0||921||tilting||n||1/6000s||7.0||Y||Y||Pentax KP|
|Pentax K-70« »||optical||n||3.0||921||swivel||n||1/6000s||6.0||Y||Y||Pentax K-70|
|Pentax K-3 II« »||optical||Y||3.2||1037||fixed||n||1/8000s||8.3||n||Y||Pentax K-3 II|
|Pentax K-5« »||optical||Y||3.0||921||fixed||n||1/8000s||7.0||Y||Y||Pentax K-5|
|Sony A9« »||3686||n||3.0||1440||tilting||Y||1/8000s||20.0||n||Y||Sony A9|
|Sony A99 II« »||2400||Y||3.0||1229||full-flex||n||1/8000s||12.0||n||Y||Sony A99 II|
|Sony A6500« »||2359||n||3.0||922||tilting||Y||1/4000s||11.0||Y||Y||Sony A6500|
|Sony A7R II« »||2400||n||3.0||1229||tilting||n||1/8000s||5.0||n||Y||Sony A7R II|
|Sony A7S II« »||2400||n||3.0||1229||tilting||n||1/8000s||5.0||n||Y||Sony A7S II|
|Sony A99« »||2359||Y||3.0||1229||full-flex||n||1/8000s||6.0||n||Y||Sony A99|
|Sony A77« »||2359||Y||3.0||921||full-flex||n||1/8000s||12.0||Y||Y||Sony A77|
One difference between the cameras concerns the presence of an on-board flash. The K-3 has one, while the A7R III does not. While the built-in flash of the K-3 is not very powerful, it can at times be useful as a fill-in light.
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 III 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-3 and the Sony A7R III 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.
The K-3 writes its imaging data to SDXC cards, while the A7R III uses SDXC or Memory Stick PRO Duo cards. Both cameras feature dual card slots, which can be very useful in case a memory card fails. The A7R III supports UHS-II cards (on its first slot), while the K-3 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-3 and Sony Alpha A7R III and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.
|Pentax K-3»||Y||mono||mono||Y||Y||mini||3.0||-||-||-||Pentax K-3|
|Sony A7R III«||Y||stereo||mono||Y||Y||micro||3.1||Y||Y||Y||Sony A7R III|
|Canon 70D« »||Y||stereo||mono||Y||-||mini||2.0||Y||-||-||Canon 70D|
|Nikon Z7« »||Y||stereo||mono||Y||Y||micro||3.1||Y||-||Y||Nikon Z7|
|Nikon D7200« »||Y||stereo||mono||Y||Y||mini||2.0||Y||Y||-||Nikon D7200|
|Nikon D7100« »||Y||stereo||mono||Y||Y||mini||2.0||-||-||-||Nikon D7100|
|Pentax KP« »||Y||stereo||mono||Y||-||-||2.0||Y||-||-||Pentax KP|
|Pentax K-70« »||Y||stereo||mono||Y||-||mini||2.0||Y||-||-||Pentax K-70|
|Pentax K-3 II« »||Y||mono||mono||Y||Y||mini||3.0||-||-||-||Pentax K-3 II|
|Pentax K-5« »||Y||stereo||mono||Y||-||mini||2.0||-||-||-||Pentax K-5|
|Sony A9« »||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||Y||Sony A9|
|Sony A99 II« »||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||Y||Sony A99 II|
|Sony A6500« »||Y||stereo||mono||Y||-||micro||2.0||Y||Y||-||Sony A6500|
|Sony A7R II« »||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||-||Sony A7R II|
|Sony A7S II« »||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||-||Sony A7S II|
|Sony A99« »||Y||stereo||mono||Y||Y||mini||2.0||-||-||-||Sony A99|
|Sony A77« »||Y||stereo||mono||Y||-||mini||2.0||-||-||-||Sony A77|
It is notable that the A7R III offers wifi support, which can be a very convenient means to transfer image data to an off-camera location. In contrast, the K-3 does not offer wifi capability.
Both cameras feature a PC Sync terminal to control professional strobe lights, which will be appreciated by studio photographers.
Both the K-3 and the A7R III have been discontinued, but can regularly be found used on eBay. The K-3 was replaced by the Pentax K-3 II, while the A7R III was followed by the Sony A7R IV. 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? Which of the two cameras – the Pentax K-3 or the Sony A7R III – has the upper hand? Is one clearly better than the other? Below is a summary of the relative strengths of each of the two contestants.
Reasons to prefer the Pentax K-3:
- Brighter framing: Features an optical viewfinder for clear, lag-free composition.
- 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.
- Easier fill-in: Is equipped with a small onboard flash to brighten deep shadow areas.
- More affordable: Was introduced into a lower priced category (59 percent cheaper at launch).
- More heavily discounted: Has been available for much longer (launched in October 2013).
Arguments in favor of the Sony Alpha A7R III:
- More detail: Has more megapixels (42.2 vs 24.1MP), which boosts linear resolution by 32%.
- High quality composites: Can combine several shots after pixel-shifting its sensor.
- Better image quality: Scores substantially higher (20 points) in the DXO overall evaluation.
- Richer colors: Generates noticeably more natural colors (2.3 bits more color depth).
- More dynamic range: Captures a broader range of light and dark details (1.3 EV of extra DR).
- Better low-light sensitivity: Can shoot in dim conditions (1.5 stops ISO advantage).
- Better video: Provides higher definition movie capture (4K/30p vs 1080/60i).
- Better live-view autofocus: Features on-sensor phase-detection for more confident autofocus.
- 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 1037k dots).
- 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.
- Faster burst: Shoots at higher frequency (10 vs 8.3 flaps/sec) to capture the decisive moment.
- Less disturbing: Has an electronic shutter option for completely silent shooting.
- Less heavy: Has a lower weight (by 150g or 19 percent) and is thus easier to take along.
- Longer lasting: Gets more shots (650 versus 560) 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.
- 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 4 years of technical progress since the K-3 launch.
If the number of relative strengths (bullet points above) is taken as a guide, the A7R III is the clear winner of the contest (23 : 6 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-3 and the Sony A7R III 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 specs-based evaluation of cameras can be instructive in revealing their potential as photographic tools, it remains partial and cannot reveal, for example, the shooting experience and imaging performance when actually working with the K-3 or the A7R III. 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 (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-3»||-||83/100||5/5||4.5/5||5/5||Oct 2013||1,299||-||Pentax K-3|
|Sony A7R III«||+ +||90/100||4.5/5||5/5||5/5||Oct 2017||3,199||-||Sony A7R III|
|Canon 70D« »||+ +||83/100||4.5/5||4.5/5||5/5||Jul 2013||1,199||-||Canon 70D|
|Nikon Z7« »||+||89/100||4.5/5||4.5/5||5/5||Aug 2018||3,399||Nikon Z7|
|Nikon D7200« »||+ +||84/100||4.5/5||4/5||4.5/5||Mar 2015||1,199||-||Nikon D7200|
|Nikon D7100« »||+ +||85/100||4.5/5||5/5||4.5/5||Feb 2013||1,199||-||Nikon D7100|
|Pentax KP« »||-||82/100||5/5||-||4.5/5||Jan 2017||1,099||Pentax KP|
|Pentax K-70« »||-||79/100||4.5/5||4/5||4.5/5||Jun 2016||649||Pentax K-70|
|Pentax K-3 II« »||-||-||5/5||4.5/5||5/5||Apr 2015||1,099||Pentax K-3 II|
|Pentax K-5« »||-||83/100||5/5||4.5/5||4.5/5||Sep 2010||1,099||-||Pentax K-5|
|Sony A9« »||+ +||89/100||5/5||5/5||5/5||Apr 2017||4,499||Sony A9|
|Sony A99 II« »||-||85/100||4.5/5||4.5/5||4.5/5||Sep 2016||3,199||Sony A99 II|
|Sony A6500« »||+ +||85/100||4.5/5||5/5||4.5/5||Oct 2016||1,399||-||Sony A6500|
|Sony A7R II« »||+ +||90/100||5/5||4.5/5||5/5||Jun 2015||3,199||-||Sony A7R II|
|Sony A7S II« »||+||-||4.5/5||5/5||5/5||Sep 2015||2,999||Sony A7S II|
|Sony A99« »||-||84/100||4.5/5||o||4.5/5||Sep 2012||2,799||-||Sony A99|
|Sony A77« »||91/100||81/100||-||4.5/5||5/5||Aug 2011||1,399||-||Sony A77|
|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. 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 N vs Pentax K-3
- Canon M3 vs Pentax K-3 II
- Fujifilm GFX 50S vs Pentax K-3 II
- Fujifilm X-T1 vs Sony A7R III
- Leica V-LUX 1 vs Sony A7R III
- Leica V-LUX Typ 114 vs Sony A7R III
- Nikon B500 vs Pentax K-3 II
- Panasonic G3 vs Pentax K-3 II
- Panasonic GX9 vs Pentax K-3 II
- Pentax K-3 II vs Pentax KP
- Pentax K-3 II vs Sony H300
- Ricoh WG-6 vs Sony A7R III
Specifications: Pentax K-3 vs Sony A7R III
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-3||Sony A7R III|
|Camera Type||Digital single lens reflex||Mirrorless system camera|
|Camera Lens||Pentax K mount lenses||Sony E mount lenses|
|Launch Date||October 2013||October 2017|
|Launch Price||USD 1299||USD 3199|
|Sensor Specs||Pentax K-3||Sony A7R III|
|Sensor Format||APS-C Sensor||Full Frame Sensor|
|Sensor Size||23.5 x 15.6 mm||35.9 x 24.0 mm|
|Sensor Area||366.6 mm2||861.6 mm2|
|Sensor Diagonal||28.2 mm||43.2 mm|
|Sensor Resolution||24.1 Megapixels||42.2 Megapixels|
|Image Resolution||6016 x 4000 pixels||7952 x 5304 pixels|
|Pixel Pitch||3.90 μm||4.52 μm|
|Pixel Density||6.56 MP/cm2||4.90 MP/cm2|
|Moiré control||no AA filter||no AA filter|
|Movie Capability||1080/60i Video||4K/30p Video|
|ISO Setting||100-51200 ISO||100-32000 ISO|
|ISO Boost||no Enhancement||50-102400 ISO|
|Image Processor||PRIME III||BIONZ X|
|DXO Sensor Quality (score)||80||100|
|DXO Color Depth (bits)||23.7||26.0|
|DXO Dynamic Range (EV)||13.4||14.7|
|DXO Low Light (ISO)||1216||3523|
|Screen Specs||Pentax K-3||Sony A7R III|
|Viewfinder Type||Optical viewfinder||Electronic viewfinder|
|Viewfinder Field of View||100%||100%|
|Viewfinder Resolution||3686k dots|
|Top-Level Screen||Control Panel||no Top Display|
|LCD Framing||Live View||Live View|
|Rear LCD Size||3.2 inch||3.0 inch|
|LCD Resolution||1037k dots||1440k dots|
|LCD Attachment||Fixed screen||Tilting screen|
|Touch Input||no Touchscreen||Touchscreen|
|Shooting Specs||Pentax K-3||Sony A7R III|
|Autofocus System||Phase-detect AF||On-Sensor Phase-detect|
|Manual Focusing Aid||Focus Peaking||Focus Peaking|
|Max Shutter Speed (mechanical)||1/8000/s||1/8000/s|
|Continuous Shooting||8.3 shutter flaps/s||10 shutter flaps/s|
|Shutter Life Expectancy||200 000 actuations||500 000 actuations|
|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||MS or SDXC cards|
|Second Storage Option||Dual card slots||Dual card slots|
|UHS card support||UHS-I||Single UHS-II|
|Connectivity Specs||Pentax K-3||Sony A7R III|
|Studio Flash||PC Sync socket||PC Sync socket|
|USB Connector||USB 3.0||USB 3.1|
|HDMI Port||mini HDMI||micro HDMI|
|Microphone Port||External MIC port||External MIC port|
|Headphone Socket||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-3||Sony A7R III|
|Environmental Sealing||Weathersealed body||Weathersealed body|
|Battery Life (CIPA)||560 shots per charge||650 shots per charge|
|In-Camera Charging||no USB charging||USB charging|
131 x 100 x 77 mm
(5.2 x 3.9 x 3.0 in)
127 x 96 x 74 mm
(5.0 x 3.8 x 2.9 in)
|Camera Weight||800 g (28.2 oz)||650 g (22.9 oz)|
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