Pentax K-1 II vs Sony A6400
The Pentax K-1 II and the Sony Alpha A6400 are two enthusiast cameras that were announced, respectively, in February 2018 and January 2019. The K-1 II is a DSLR, while the A6400 is a mirrorless interchangeable lens camera. The cameras are based on a full frame (K-1 II) and an APS-C (A6400) sensor. The Pentax has a resolution of 36.2 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-1 II and the Sony Alpha A6400? 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.
An illustration of the physical size and weight of the Pentax K-1 II and the Sony A6400 is provided 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-1 II can be obtained in two different colors (black, silver), while the A6400 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 A6400 is considerably smaller (47 percent) than the Pentax K-1 II. Moreover, the A6400 is substantially lighter (60 percent) than the K-1 II. It is worth mentioning in this context that the K-1 II is splash and dust resistant, while the A6400 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-1 II gets 670 shots out of its D-LI90 battery, while the A6400 can take 410 images on a single charge of its NP-FW50 power pack. The power pack in the A6400 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. 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.
|Pentax K-1 II||5.4 in||4.3 in||3.4 in||35.6 oz||670||Y||Feb 2018||1,999|
|Sony A6400||4.7 in||2.6 in||2.0 in||14.2 oz||410||n||Jan 2019||899|
|Canon R||5.5 in||3.9 in||3.3 in||23.3 oz||370||Y||Sep 2018||2,299|
|Nikon Z6||5.3 in||4.0 in||2.6 in||23.8 oz||310||Y||Aug 2018||1,999|
|Nikon D5300||4.9 in||3.9 in||3.0 in||16.9 oz||600||n||Oct 2013||799|
|Panasonic S1||5.9 in||4.3 in||3.8 in||35.9 oz||400||Y||Feb 2019||2,499|
|Panasonic S1R||5.9 in||4.3 in||3.8 in||35.8 oz||380||Y||Feb 2019||3,699|
|Panasonic S1H||5.9 in||4.5 in||4.3 in||37.1 oz||400||Y||May 2019||3,999|
|Pentax K-1||5.4 in||4.3 in||3.4 in||35.6 oz||760||Y||Feb 2016||1,799|
|Sony A6100||4.7 in||2.6 in||2.3 in||14.0 oz||420||n||Aug 2019||749|
|Sony A7 III||5.0 in||3.8 in||2.9 in||22.9 oz||610||Y||Feb 2018||1,999|
|Sony A7R III||5.0 in||3.8 in||2.9 in||22.9 oz||650||Y||Oct 2017||3,199|
|Sony A99 II||5.6 in||4.1 in||3.0 in||29.9 oz||490||Y||Sep 2016||3,199|
|Sony A6300||4.7 in||2.6 in||1.9 in||14.3 oz||400||Y||Feb 2016||999|
|Sony A5100||4.3 in||2.5 in||1.4 in||10.0 oz||400||n||Aug 2014||549|
|Sony A6000||4.7 in||2.6 in||1.8 in||12.1 oz||360||n||Feb 2014||599|
|Sony A850||6.1 in||4.6 in||3.2 in||31.6 oz||880||Y||Aug 2009||1,999|
|Notes: Measurements and pricing do not include easily detachable parts, such as add-on or interchangeable lenses or optional viewfinders.|
The price is, of course, an important factor in any camera decision. 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 A6400 was launched at a markedly lower price (by 55 percent) than the K-1 II, 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 imaging sensor is a crucial determinant of image quality. All other things equal, a large sensor will have larger individual pixel-units that offer better low-light sensitivity, wider dynamic range, and richer color-depth than smaller pixels 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-1 II features a full frame sensor and the Sony A6400 an APS-C sensor. The sensor area in the A6400 is 57 percent smaller. As a result of these sensor size differences, the cameras have a format factor of, respectively, 1.0 and 1.5. Both cameras have a native aspect ratio (sensor width to sensor height) of 3:2.
In terms of underlying technology, both cameras are build around CMOS sensors.
With 36.2MP, the K-1 II offers a higher resolution than the A6400 (24MP), but the K-1 II nevertheless has larger individual pixels (pixel pitch of 4.88μm versus 3.91μm for the A6400) due to its larger sensor. However, the A6400 is a somewhat more recent model (by 10 months) than the K-1 II, and its sensor might have benefitted from technological advances during this time that enhance the light gathering capacity of its pixels. Coming back to sensor resolution, it should be mentioned that the K-1 II has no anti-alias filter installed, so that it can capture all the detail its sensor resolves.
The resolution advantage of the Pentax K-1 II implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the K-1 II for good quality output (200 dots per inch) amounts to 36.8 x 24.6 inches or 93.5 x 62.4 cm, for very good quality (250 dpi) 29.4 x 19.6 inches or 74.8 x 49.9 cm, and for excellent quality (300 dpi) 24.5 x 16.4 inches or 62.3 x 41.6 cm. The corresponding values for the Sony A6400 are 30 x 20 inches or 76.2 x 50.8 cm for good quality, 24 x 16 inches or 61 x 40.6 cm for very good quality, and 20 x 13.3 inches or 50.8 x 33.9 cm for excellent quality prints.
The A6400 has on-sensor phase detect pixels, which results in fast and reliable autofocus acquisition even during live view operation.
Unlike the A6400, the K-1 II 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-1 II has a native sensitivity range from ISO 100 to ISO 819200. The corresponding ISO settings for the Sony Alpha A6400 are ISO 100 to ISO 32000, with the possibility to increase the ISO range to 100-102400.
Consistent information on actual sensor performance is available from DXO Mark for many cameras. 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.
| DXO |
|Pentax K-1 II||Full Frame||36.2||7360||4912||1080/60i||..||..||..||..|
|Canon R||Full Frame||30.1||6720||4480||4K/30p||24.5||13.5||2742||89|
|Nikon Z6||Full Frame||24.3||6048||4024||4K/30p||25.3||14.3||3299||95|
|Panasonic S1||Full Frame||24.0||6000||4000||4K/60p||25.2||14.5||3333||95|
|Panasonic S1R||Full Frame||46.7||8368||5584||4K/60p||26.4||14.1||3525||100|
|Panasonic S1H||Full Frame||24.0||6000||4000||6K/30p||..||..||..||..|
|Pentax K-1||Full Frame||36.2||7360||4912||1080/60i||25.4||14.6||3280||96|
|Sony A7 III||Full Frame||24.0||6000||4000||4K/30p||25.0||14.7||3730||96|
|Sony A7R III||Full Frame||42.2||7952||5304||4K/30p||26.0||14.7||3523||100|
|Sony A99 II||Full Frame||42.2||7952||5304||4K/30p||25.4||13.4||2317||92|
|Sony A850||Full Frame||24.4||6048||4032||none||23.8||12.2||1415||79|
Many modern cameras cannot only take still pictures, but also record videos. The two cameras under consideration both have sensors whose read-out speed is fast enough to capture moving pictures, but the A6400 provides a better video resolution than the K-1 II. It can shoot movie footage at 4K/30p, while the Pentax is limited to 1080/60i.
Apart from body and sensor, cameras can and do differ across a range of features. For example, the A6400 has an electronic viewfinder (2359k dots), while the K-1 II 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%), as well as the same magnification (0.70x). The table below summarizes some of the other core capabilities of the Pentax K-1 II and Sony A6400 in connection with corresponding information for a sample of similar cameras.
|Pentax K-1 II||optical||Y||3.2||1037||full-flex||n||1/8000s||4.4||n||Y|
|Sony A7 III||2359||n||3.0||922||tilting||Y||1/8000s||10.0||n||Y|
|Sony A7R III||3686||n||3.0||1440||tilting||Y||1/8000s||10.0||n||Y|
|Sony A99 II||2400||Y||3.0||1229||full-flex||n||1/8000s||12.0||n||Y|
One feature that is present on the K-1 II, but is missing on the A6400 is a top-level LCD. While being, of course, smaller than the rear screen, the control panel conveys some of the essential shooting information and can be convenient for quick and easy settings verification.The A6400 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-1 II 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 A6400 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-1 II 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-1 II writes its imaging data to SDXC cards, while the A6400 uses SDXC or Memory Stick PRO Duo cards. The K-1 II features dual card slots, which can be very useful in case a memory card fails. In contrast, the A6400 only has one slot. 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-1 II and Sony Alpha A6400 and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.
| WiFi |
| NFC |
|Pentax K-1 II||Y||stereo||mono||Y||Y||micro||2.0||Y||-||-|
|Sony A7 III||Y||stereo||mono||Y||Y||micro||3.1||Y||Y||Y|
|Sony A7R III||Y||stereo||mono||Y||Y||micro||3.1||Y||Y||Y|
|Sony A99 II||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||Y|
It is notable that the K-1 II has a headphone jack, which is not present on the A6400 This port makes it possible to attach external headphones and monitor the quality of sound during the recording process.
Studio photographers will appreciate that the Pentax K-1 II (unlike the A6400) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.
Travel and landscape photographers will find it useful that the K-1 II has an internal geolocalization sensor and can record GPS coordinates in its EXIF data.
Both the K-1 II and the A6400 are recent models that are part of the current product line-up. The K-1 II replaced the earlier Pentax K-1, while the A6400 followed on from the Sony A6300. 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-1 II and the Sony A6400? Which camera is better? Below is a summary of the relative strengths of each of the two contestants.
Reasons to prefer the Pentax K-1 II:
- More detail: Offers more megapixels (36.2 vs 24MP) with a 23% 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 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 sound control: Has a headphone port that enables audio monitoring while recording.
- 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.
- More detailed LCD: Has a higher resolution rear screen (1037k vs 922k dots).
- More flexible LCD: Has a full-flex screen for odd-angle shots in portrait or landscape orientation.
- Faster shutter: Has higher mechanical shutter speed (1/8000s vs 1/4000s) to freeze action.
- Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
- Longer lasting: Can take more shots (670 versus 410) on a single battery charge.
- Better sealing: Is weather sealed to enable shooting in dusty or wet environments.
- Sharper images: Has hand-shake reducing image stabilization built-in.
- Easier geotagging: Features an internal GPS sensor to log localization data.
- 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.
- More heavily discounted: Has been on the market for longer (launched in February 2018).
Advantages of the Sony Alpha A6400:
- Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
- Better video: Provides higher definition movie capture (4K/30p vs 1080/60i).
- Better live-view autofocus: Features on-sensor phase-detection for more confident autofocus.
- More framing info: Has an electronic viewfinder that displays shooting data.
- Fewer buttons to press: Has a touchscreen to facilitate handling and shooting adjustments.
- More selfie-friendly: Has an articulated screen that can be turned to be front-facing.
- Faster burst: Shoots at higher frequency (11 vs 4.4 flaps/sec) to capture the decisive moment.
- Less disturbing: Has an electronic shutter option for completely silent shooting.
- More compact: Is smaller (120x67mm vs 137x110mm) and will fit more readily into a bag.
- Less heavy: Has a lower weight (by 607g or 60 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 fill-in: Has a small integrated flash to brighten shadows of backlit subjects.
- Easier device pairing: Supports NFC for fast wireless image transfer over short distances.
- Easier wireless transfer: Supports Bluetooth for image sharing without cables.
- More affordable: Was introduced into a lower priced category (55 percent cheaper at launch).
- More modern: Was introduced somewhat (10 months) more recently.
If the count of individual advantages (bullet points above) is taken as a guide, the K-1 II is the clear winner of the match-up (22 : 17 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 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-1 II and the Sony A6400 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-1 II or the A6400. 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 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 (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-1 II||..||79/100||4.5/5||4.5/5||4.5/5||Feb 2018||1,999|
|Sony A6400||+||85/100||4.5/5||..||4/5||Jan 2019||899|
|Canon R||o||79/100||4.5/5||4/5||4/5||Sep 2018||2,299|
|Nikon Z6||..||..||4.5/5||4.5/5||5/5||Aug 2018||1,999|
|Nikon D5300||+ +||79/100||4.5/5||4.5/5||4.5/5||Oct 2013||799|
|Panasonic S1||+ +||88/100||4.5/5||..||4/5||Feb 2019||2,499|
|Panasonic S1R||..||89/100||4.5/5||5/5||4.5/5||Feb 2019||3,699|
|Panasonic S1H||..||90/100||..||..||..||May 2019||3,999|
|Pentax K-1||..||84/100||5/5||4.5/5||5/5||Feb 2016||1,799|
|Sony A6100||..||82/100||4/5||..||5/5||Aug 2019||749|
|Sony A7 III||+ +||89/100||5/5||5/5||5/5||Feb 2018||1,999|
|Sony A7R III||+ +||90/100||4.5/5||5/5||5/5||Oct 2017||3,199|
|Sony A99 II||..||85/100||4.5/5||4.5/5||4.5/5||Sep 2016||3,199|
|Sony A6300||+||85/100||5/5||5/5||5/5||Feb 2016||999|
|Sony A5100||+||..||4.5/5||4.5/5||5/5||Aug 2014||549|
|Sony A6000||+||80/100||4.5/5||5/5||5/5||Feb 2014||599|
|Sony A850||..||75/100||..||4/5||4.5/5||Aug 2009||1,999|
|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. Thus, a score needs to be put into the context of the launch date and the launch price of the camera, and rating-comparisons among cameras that span long time periods or concern very differently equipped models make little sense. Also, please note that some of the review sites have changed their methodology and reporting over time.
Other camera comparisons
Did this review help to inform your camera decision process? If you would like to see a different side-by-side camera review, just use the search menu below. There is also a set of direct links to comparison reviews that other users of the CAM-parator app explored.
Specifications: Pentax K-1 II vs Sony A6400
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-1 II||Sony A6400|
|Camera Type||Digital single lens reflex||Mirrorless system camera|
|Camera Lens||Pentax K mount lenses||Sony E mount lenses|
|Launch Date||February 2018||January 2019|
|Launch Price||USD 1,999||USD 899|
|Sensor Specs||Pentax K-1 II||Sony A6400|
|Sensor Format||Full Frame Sensor||APS-C Sensor|
|Sensor Size||35.9 x 24.0 mm||23.5 x 15.6 mm|
|Sensor Area||861.6 mm2||366.6 mm2|
|Sensor Diagonal||43.2 mm||28.2 mm|
|Sensor Resolution||36.2 Megapixels||24 Megapixels|
|Image Resolution||7360 x 4912 pixels||6000 x 4000 pixels|
|Pixel Pitch||4.88 μm||3.91 μm|
|Pixel Density||4.20 MP/cm2||6.55 MP/cm2|
|Moiré control||no AA filter||Anti-Alias filter|
|Movie Capability||1080/60i Video||4K/30p Video|
|ISO Setting||100 - 819,200 ISO||100 - 32,000 ISO|
|ISO Boost||no Enhancement||100 - 102,400 ISO|
|Image Processor||PRIME IV||BIONZ X|
|DXO Sensor Quality (score)||..||83|
|DXO Color Depth (bits)||..||24|
|DXO Dynamic Range (EV)||..||13.6|
|DXO Low Light (ISO)||..||1431|
|Screen Specs||Pentax K-1 II||Sony A6400|
|Viewfinder Type||Optical viewfinder||Electronic viewfinder|
|Viewfinder Field of View||100%||100%|
|Viewfinder Resolution||2359k dots|
|Top-Level Screen||Control Panel||no Top Display|
|LCD Framing||Live View||Live View|
|Rear LCD Size||3.2inch||3.0inch|
|LCD Resolution||1037k dots||922k dots|
|LCD Attachment||Fully flexible screen||Tilting screen|
|Touch Input||no Touchscreen||Touchscreen|
|Shooting Specs||Pentax K-1 II||Sony A6400|
|Focus System||Phase-detect AF||On-Sensor Phase-detect|
|Manual Focusing Aid||Focus Peaking||Focus Peaking|
|Max Shutter Speed (mechanical)||1/8000s||1/4000s|
|Continuous Shooting||4.4 shutter flaps/s||11 shutter flaps/s|
|Shutter Life Expectancy||300 000 actuations||200 000 actuations|
|Electronic Shutter||no E-Shutter||YES|
|Time-Lapse Photography||Intervalometer built-in||no Intervalometer|
|Image Stabilization||In-body stabilization||Lens stabilization only|
|Fill Flash||no On-Board Flash||Build-in Flash|
|Storage Medium||SDXC cards||MS or SDXC cards|
|Second Storage Option||Dual card slots||Single card slot|
|UHS card support||UHS-I||UHS-I|
|Connectivity Specs||Pentax K-1 II||Sony A6400|
|Studio Flash||PC Sync socket||no PC Sync|
|USB Connector||USB 2.0||USB 2.0|
|HDMI Port||micro HDMI||micro HDMI|
|Microphone Port||External MIC port||External MIC port|
|Headphone Socket||Headphone port||no Headphone port|
|Wifi Support||Wifi built-in||Wifi built-in|
|Near-Field Communication||no NFC||NFC built-in|
|Bluetooth Support||no Bluetooth||Bluetooth built-in|
|Geotagging||GPS built-in||no internal GPS|
|Body Specs||Pentax K-1 II||Sony A6400|
|Environmental Sealing||Weathersealed body||not weather sealed|
|Battery Life (CIPA)||670 shots per charge||410 shots per charge|
|In-Camera Charging||no USB charging||USB charging|
137 x 110 x 86 mm
(5.4 x 4.3 x 3.4 in)
120 x 67 x 50 mm
(4.7 x 2.6 x 2.0 in)
|Camera Weight||1010 g (35.6 oz)||403 g (14.2 oz)|
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