Pentax K-1 II vs Sony A5100
The Pentax K-1 II and the Sony Alpha A5100 are two digital cameras that were officially introduced, respectively, in February 2018 and August 2014. The K-1 II is a DSLR, while the A5100 is a mirrorless interchangeable lens camera. The cameras are based on a full frame (K-1 II) and an APS-C (A5100) 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.
|Pentax K-1 II||Sony A5100|
|Digital single lens reflex||Mirrorless system camera|
|Pentax K mount lenses||Sony E mount lenses|
|36.2 MP, Full Frame Sensor||24 MP, APS-C Sensor|
|1080/60i Video||1080/60p Video|
|ISO 100-819,200||ISO 100-25,600|
|Optical viewfinder||No viewfinder, LCD framing|
|3.2 LCD, 1037k dots||3.0 LCD, 922k dots|
|Fully flexible screen (no touchscreen)||Tilting touchscreen|
|4.4 shutter flaps per second||6 shutter flaps per second|
|In-body stabilization||Lens stabilization only|
|Weathersealed body||not weather sealed|
|670 shots per battery charge||400 shots per battery charge|
|137 x 110 x 86 mm, 1010 g||110 x 63 x 36 mm, 283 g|
Going beyond this snapshot of core features and characteristics, what are the differences between the Pentax K-1 II and the Sony Alpha A5100? 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 A5100 is provided 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 size dimensions are rounded to the nearest millimeter.
The K-1 II can be obtained in two different colors (black, silver), while the A5100 is also available in two color-versions, but different ones (black, white).
If the front view area (width x height) of the cameras is taken as an aggregate measure of their size, the Sony A5100 is considerably smaller (54 percent) than the Pentax K-1 II. Moreover, the A5100 is substantially lighter (72 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 A5100 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 A5100 can take 400 images on a single charge of its NP-FW50 power pack. The power pack in the A5100 can be charged via the USB port, which can be very convenient when travelling.
The adjacent table lists the principal physical characteristics of the two cameras alongside a wider set of alternatives. In case you want to display and compare another camera duo, just click on the right or left arrow next to the camera that you would like to inspect. Alternatively, you can also use the CAM-parator to select your camera combination among a larger 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 A5100||4.3 in||2.5 in||1.4 in||10.0 oz||400||n||Aug 2014||549|
|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|
|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 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 A5000||4.3 in||2.5 in||1.4 in||9.5 oz||420||n||Jan 2014||449|
|Sony A6000||4.7 in||2.6 in||1.8 in||12.1 oz||360||n||Feb 2014||599|
|Sony A3000||5.0 in||3.6 in||3.3 in||14.5 oz||470||n||Aug 2013||329|
|Sony NEX-3N||4.3 in||2.4 in||1.4 in||9.5 oz||480||n||Feb 2013||499|
|Sony NEX-3||4.6 in||2.4 in||1.3 in||10.5 oz||330||n||May 2010||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.
(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 listed launch prices provide an indication of the market segment that the manufacturer of the cameras have been targeting. The A5100 was launched at a markedly lower price (by 73 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. 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. 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. Moreover, a large sensor camera will give the photographer more control over depth-of-field in the image and, thus, the ability to better isolate a subject from the 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-1 II features a full frame sensor and the Sony A5100 an APS-C sensor. The sensor area in the A5100 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.
With 36.2MP, the K-1 II offers a higher resolution than the A5100 (24MP), but the K-1 II nevertheless has larger individual pixels (pixel pitch of 4.88μm versus 3.91μm for the A5100) due to its larger sensor. Moreover, the K-1 II is a much more recent model (by 3 years and 6 months) than the A5100, and its sensor will have benefitted from technological advances during this time that further 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 A5100 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 A5100 has on-sensor phase detect pixels, which results in fast and reliable autofocus acquisition even during live view operation.
Unlike the A5100, 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 A5100 are ISO 100 to ISO 25600 (no boost).
Since 2007, DXO Mark has published sensor performance measurements that have been derived using a consistent methodology. 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. The table below summarizes the physical sensor characteristics and sensor quality findings and compares them across a set of similar cameras.
|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. Both cameras under consideration have a sensor with sufficiently fast read-out times for moving pictures, but the A5100 provides a faster frame rate than the K-1 II. It can shoot movie footage at 1080/60p, 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 K-1 II has an optical viewfinder, which can be very useful when shooting in bright sunlight. In contrast, the A5100 relies on live view and the rear LCD for framing. The table below summarizes some of the other core capabilities of the Pentax K-1 II and Sony A5100 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 A5100 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 A5100 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 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 A5100 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 A5100 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 A5100 and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.
| WiFi |
|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 hotshoe, while the A5100 does not. This socket makes it possible to easily attach optional accessories, such as an external flash gun.
Studio photographers will appreciate that the Pentax K-1 II (unlike the A5100) 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 A5100 are recent models that are part of the current product line-up. The A5100 replaced the earlier Sony A5000, while the K-1 II followed on from the Pentax K-1. 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 is the bottom line? Which of the two cameras – the Pentax K-1 II or the Sony A5100 – has the upper hand? Is one clearly better than the other? The listing below highlights the relative strengths of the two models.
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 a larger and more technologically advanced imaging 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 sound: Can connect to an external microphone for higher quality sound recording.
- Better sound control: Has a headphone port that enables audio monitoring while recording.
- Easier framing: Has an optical viewfinder for image composition and settings control.
- 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 400) 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.
- Better lighting: Features a hotshoe and can thus hold and trigger an external flash gun.
- 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 modern: Reflects 3 years and 6 months of technical progress since the A5100 launch.
Advantages of the Sony Alpha A5100:
- Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
- Better video: Provides higher movie framerates (1080/60p versus 1080/60i).
- Better live-view autofocus: Features on-sensor phase-detection for more confident autofocus.
- 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 (6 vs 4.4 flaps/sec) to capture the decisive moment.
- More compact: Is smaller (110x63mm vs 137x110mm) and will fit more readily into a bag.
- Less heavy: Has a lower weight (by 727g or 72 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.
- More affordable: Was introduced into a lower priced category (73 percent cheaper at launch).
- More heavily discounted: Has been around for much longer (launched in August 2014).
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 (24 : 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-1 II and the Sony A5100 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 incomplete and does no justice, for example, to the way the K-1 II or the A5100 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 expert reviews 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-1 II||..||79/100||4.5/5||4.5/5||4.5/5||Feb 2018||1,999|
|Sony A5100||+||..||4.5/5||4.5/5||5/5||Aug 2014||549|
|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|
|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 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 A5000||+||..||4.5/5||o||4.5/5||Jan 2014||449|
|Sony A6000||+||80/100||4.5/5||5/5||5/5||Feb 2014||599|
|Sony A3000||+||..||4/5||4.5/5||4/5||Aug 2013||329|
|Sony NEX-3N||..||..||4.5/5||4/5||4.5/5||Feb 2013||499|
|Sony NEX-3||..||70/100||4.5/5||5/5||4/5||May 2010||599|
|Sony A850||..||75/100||..||4/5||4.5/5||Aug 2009||1,999|
|Notes: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.|
The review scores listed above should be treated with care, though. The ratings were established in reference to similarly priced cameras that were available in the market at the time of the review. 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. 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 would like to check on the differences and similarities of other camera models, just make your choice using the following search menu. There is also a set of direct links to comparison reviews that other users of the CAM-parator app explored.
- Canon 1Ds vs Sony A5100
- Canon SX610 vs Sony A5100
- Canon T3i vs Pentax K-1 II
- Contax N Digital vs Pentax K-1 II
- Fujifilm X100 vs Sony A5100
- Fujifilm X100T vs Pentax K-1 II
- Leica S Typ 007 vs Sony A5100
- Leica T vs Sony A5100
- Nikon D3S vs Pentax K-1 II
- Olympus E-510 vs Sony A5100
- Panasonic GM5 vs Pentax K-1 II
- Panasonic GX850 vs Pentax K-1 II
Specifications: Pentax K-1 II vs Sony A5100
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 A5100|
|Camera Type||Digital single lens reflex||Mirrorless system camera|
|Camera Lens||Pentax K mount lenses||Sony E mount lenses|
|Launch Date||February 2018||August 2014|
|Launch Price||USD 1,999||USD 549|
|Sensor Specs||Pentax K-1 II||Sony A5100|
|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||1080/60p Video|
|ISO Setting||100 - 819,200 ISO||100 - 25,600 ISO|
|Image Processor||PRIME IV||BIONZ X|
|DXO Sensor Quality (score)||..||80|
|DXO Color Depth (bits)||..||23.8|
|DXO Dynamic Range (EV)||..||12.7|
|DXO Low Light (ISO)||..||1347|
|Screen Specs||Pentax K-1 II||Sony A5100|
|Viewfinder Type||Optical viewfinder||no viewfinder|
|Viewfinder Field of View||100%|
|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 A5100|
|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||6 shutter flaps/s|
|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 A5100|
|External Flash||Hotshoe||no Hotshoe|
|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||no MIC socket|
|Headphone Socket||Headphone port||no Headphone port|
|Wifi Support||Wifi built-in||Wifi built-in|
|Near-Field Communication||no NFC||NFC built-in|
|Geotagging||GPS built-in||no internal GPS|
|Body Specs||Pentax K-1 II||Sony A5100|
|Environmental Sealing||Weathersealed body||not weather sealed|
|Battery Life (CIPA)||670 shots per charge||400 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)
110 x 63 x 36 mm
(4.3 x 2.5 x 1.4 in)
|Camera Weight||1010 g (35.6 oz)||283 g (10.0 oz)|
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