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Sony A7R III versus Pentax K-1

The Sony Alpha A7R III and the Pentax K-1 are two enthusiast cameras that were officially introduced, respectively, in October 2017 and February 2016. The A7R III is a mirrorless interchangeable lens camera, while the K-1 is a DSLR. Both cameras are equipped with a full frame sensor. The Sony has a resolution of 42.2 megapixel, whereas the Pentax provides 36.2 MP. Read on to find out how these two cameras compare with respect to their size, their sensors, their features, and their reception by expert reviewers.

Body comparison: Sony A7R III vs Pentax K-1

An illustration of the physical size and weight of the Sony A7R III and the Pentax K-1 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 width, height and depth dimensions are rounded to the nearest millimeter. You can also use the toggle button to switch to a percentage comparison if you prefer that the measures are being expressed in relative terms (in this case, the camera on the left – the A7R III – represents the basis or 100 percent across all the size and weight measures).

Compare Sony A7R III vs Pentax K-1
Compare A7R III versus K-1 top
Compare A7R III and K-1 rear

If the front view area (width x height) of the cameras is taken as an aggregate measure of their size, the Pentax K-1 is notably larger (24 percent) than the Sony A7R III. Moreover, the K-1 is substantially heavier (55 percent) than the A7R III. 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 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 A7R III gets 650 shots out of its NP-FZ100 battery, while the K-1 can take 760 images on a single charge of its D-LI90 power pack.

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, 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.

Camera Body Specifications
  Camera
Model
Camera
Width
Camera
Height
Camera
Depth
Camera
Weight
Battery
Life
(CIPA)
Weather
Sealing
(yes/no)
Camera
Launch
(announced)
Launch
Price
(USD)
Street
Price
(USD)
Used
Price
(USD)
Camera
Model
Sony A7R III» 5.0 in 3.8 in 2.9 in 22.9 oz 650 Y Oct 2017 3,199 i i Sony A7R III
Pentax K-1« 5.4 in 4.3 in 3.4 in 35.6 oz 760 Y Feb 2016 1,799- i Pentax K-1
Canon 5D Mark IV« » 5.9 in 4.6 in 3.0 in 31.4 oz 900 Y Aug 2016 3,499 i i Canon 5D Mark IV
Nikon Z7« » 5.3 in 4.0 in 2.6 in 23.8 oz 330 Y Aug 2018 3,399 i i Nikon Z7
Nikon D500« » 5.8 in 4.5 in 3.2 in 30.3 oz 1240 Y Jan 2016 1,999 i i Nikon D500
Olympus E-M1 II« » 5.3 in 3.6 in 2.6 in 20.2 oz 440 Y Sep 2016 1,999 i i Olympus E-M1 II
Pentax K-1 II« » 5.4 in 4.3 in 3.4 in 35.6 oz 670 Y Feb 2018 1,999 i i Pentax K-1 II
Sony A7 III« » 5.0 in 3.8 in 2.9 in 22.9 oz 610 Y Feb 2018 1,999 i i Sony A7 III
Sony A9« » 5.0 in 3.8 in 2.5 in 23.7 oz 650 Y Apr 2017 4,499 i i Sony A9
Sony A99 II« » 5.6 in 4.1 in 3.0 in 29.9 oz 490 Y Sep 2016 3,199 i i Sony A99 II
Sony A7R II« » 5.0 in 3.8 in 2.4 in 22.0 oz 290 Y Jun 2015 3,199- i Sony A7R II
Sony A7S II« » 5.0 in 3.8 in 2.4 in 22.1 oz 370 Y Sep 2015 2,999 i i Sony A7S II
Sony A7 II« » 5.0 in 3.8 in 2.4 in 21.1 oz 350 Y Nov 2014 1,999- i Sony A7 II
Sony A7R« » 5.0 in 3.7 in 1.9 in 16.4 oz 340 Y Oct 2013 2,299- i Sony A7R
Sony A99« » 5.8 in 4.4 in 3.1 in 28.6 oz 500 Y Sep 2012 2,799- i Sony A99

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 K-1 was launched at a markedly lower price (by 44 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.

 

Sensor comparison: Sony A7R III vs Pentax K-1

The size of the sensor inside a digital camera is one of the key determinants 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 tend to be more expensive and lead to bigger and heavier cameras and lenses.

Both cameras under consideration feature a full frame sensor and have a format factor (sometimes also referred to as "crop factor") of 1.0. Within the spectrum of camera sensors, this places the review cameras among the large-sensor cameras that aim for top notch image quality. Both cameras have a native aspect ratio (sensor width to sensor height) of 3:2.

Sony A7R III and Pentax K-1 sensor measures

While the two cameras under review share the same sensor size, the A7R III offers a higher resolution of 42.2 megapixel, compared with 36.2 MP of the K-1. This megapixel advantage translates into a 8 percent gain in linear resolution. On the other hand, these sensor specs imply that the A7R III has a higher pixel density and a smaller size of the individual pixel (with a pixel pitch of 4.52μm versus 4.88μm for the K-1). In this context, it should be noted, however, that the A7R III is a somewhat more recent model (by 1 year and 8 months) than the K-1, and its sensor might have benefitted from technological advances during this time that at least partly compensate for the smaller pixel size. 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 A7R III has on-sensor phase detect pixels, which results in relatively fast and reliable autofocus acquisition during video recording.

Both cameras have the capacity to capture high quality composite images by combining multiple shots after shifting the sensor by miniscule distances. This multi-shot, pixel-shift mode is most suitable for photography of stationary objects (landscapes, studio scenes).

A7R III versus K-1 MP

Since 2007, DXO Mark has published sensor performance measurements that have been derived using a consistent methodology. This service is based on lab testing and assigns an overall score to each camera sensor, as well as ratings for dynamic range ("DXO Landscape"), color depth ("DXO Portrait"), and low-light sensitivity ("DXO Sports"). Of the two cameras under review, the A7R III has a notably higher overall DXO score than the K-1 (overall score 4 points higher), which gives it an advantage in terms of imaging quality. This advantage is based on 0.6 bits higher color depth, 0.1 EV in additional dynamic range, and 0.1 stops in additional low light sensitivity. The table below summarizes the physical sensor characteristics and sensor quality findings and compares them across a set of similar cameras.

Sensor Characteristics
  Camera
Model
Sensor
Class
Resolution
(MP)
Horiz.
Pixels
Vert.
Pixels
Video
Format
DXO
Portrait
DXO
Landscape
DXO
Sports
DXO
Overall
Camera
Model
Sony A7R III» Full Frame 42.2 7952 53044K/30p26.014.73523100Sony A7R III
Pentax K-1« Full Frame 36.2 7360 49121080/60i25.414.6328096Pentax K-1
Canon 5D Mark IV« » Full Frame 30.1 6720 44804K/30p24.813.6299591Canon 5D Mark IV
Nikon Z7« » Full Frame 45.4 8256 55044K/30p----Nikon Z7
Nikon D500« » APS-C 20.7 5568 37124K/30p24.014.0132483Nikon D500
Olympus E-M1 II« » Four Thirds 20.2 5184 38884K/30p23.712.8131280Olympus E-M1 II
Pentax K-1 II« » Full Frame 36.2 7360 49121080/60i----Pentax K-1 II
Sony A7 III« » Full Frame 24.0 6000 40004K/30p25.014.7373096Sony A7 III
Sony A9« » Full Frame 24.0 6000 40004K/30p24.913.3351792Sony A9
Sony A99 II« » Full Frame 42.2 7952 53044K/30p25.413.4231792Sony A99 II
Sony A7R II« » Full Frame 42.2 7952 53044K/30p26.013.9343498Sony A7R II
Sony A7S II« » Full Frame 12.0 4240 28324K/30p23.613.3299385Sony A7S II
Sony A7 II« » Full Frame 24.0 6000 40001080/60p24.913.6244990Sony A7 II
Sony A7R« » Full Frame 36.2 7360 49121080/60p25.614.1274695Sony A7R
Sony A99« » Full Frame 24.0 6000 40001080/60p25.014.0155589Sony A99

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 A7R III provides a higher video resolution than the K-1. It can shoot video footage at 4K/30p, while the Pentax is limited to 1080/60i.

 

Feature comparison: Sony A7R III vs Pentax K-1

Apart from 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-1 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 adjacent table lists some of the other core features of the Sony A7R III and Pentax K-1 along with similar information for a selection of comparators. If needed, the dpreview camera hub, for example, contains further detail on the cameras' specs.

Core Features
  Camera
Model
Viewfinder
(Type or
'000 dots)
Control
Panel
(yes/no)
LCD
Size
(inch)
LCD
Resolution
('000 dots)
LCD
Attach-
ment
Touch
Screen
(yes/no)
Shutter
speed
(1/sec)
Shutter
flaps
(1/sec)
Build-in
Flash
(yes/no)
Build-in
Image
Stab
Camera
Model
Sony A7R III»3686 n 3.0 1440 tilting Y 8000 10.0 n Y Sony A7R III
Pentax K-1«optical Y 3.2 1037 full-flex n 8000 4.4 n Y Pentax K-1
Canon 5D Mark IV« »optical Y 3.2 1620 fixed Y 8000 7.0 n n Canon 5D Mark IV
Nikon Z7« »3690 Y 3.2 2100 tilting Y 8000 9.0 n Y Nikon Z7
Nikon D500« »optical Y 3.2 2359 tilting Y 8000 10.0 n n Nikon D500
Olympus E-M1 II« »2360 n 3.0 1037 swivel Y 8000 18.0 n Y Olympus E-M1 II
Pentax K-1 II« »optical Y 3.2 1037 full-flex n 8000 4.4 n Y Pentax K-1 II
Sony A7 III« »2359 n 3.0 922 tilting Y 8000 10.0 n Y Sony A7 III
Sony A9« »3686 n 3.0 1440 tilting Y 8000 20.0 n Y Sony A9
Sony A99 II« »2400 Y 3.0 1229 full-flex n 8000 12.0 n Y Sony A99 II
Sony A7R II« »2400 n 3.0 1229 tilting n 8000 5.0 n Y Sony A7R II
Sony A7S II« »2400 n 3.0 1229 tilting n 8000 5.0 n Y Sony A7S II
Sony A7 II« »2400 n 3.0 1230 tilting n 8000 5.0 n Y Sony A7 II
Sony A7R« »2400 n 3.0 1230 tilting n 8000 4.0 n n Sony A7R
Sony A99« »2359 Y 3.0 1229 full-flex n 8000 6.0 n Y Sony A99

One differentiating feature between the two cameras concerns the touch sensitivity of the rear screen. The A7R III has a touchscreen, while the K-1 has a conventional panel. Touch control can be particularly helpful, for example, for setting the focus point.

The reported shutter speed and shutter burst refer to the use of the mechanical shutter. In addition, the A7R III features an electronic shutter, which makes completely silent shooting possible. However, this mode is less suitable for photographing moving objects (rolling shutter) or shooting under artificial light sources (flickering).

The A7R III writes its imaging data to SDXC or Memory Stick PRO Duo cards, while the K-1 uses SDXC cards. Both cameras feature dual card slots, which can be very useful in case a memory card fails.

Input-Output Connections
  Camera
Model
Hotshoe
Port
Internal
Microphone
Internal
Speaker
Microphone
Port
Headphone
Port
HDMI
Port
USB
Type
WiFi
Support
NFC
Support
Bluetooth
Support
Camera
Model
Sony A7R III»YstereomonoYYmicro3.1YYYSony A7R III
Pentax K-1«YstereomonoYYmicro2.0Y--Pentax K-1
Canon 5D Mark IV« »YmonomonoYYmini3.0YY-Canon 5D Mark IV
Nikon Z7« »YstereomonoYYmicro3.1Y-YNikon Z7
Nikon D500« »YstereomonoYYmini3.0YYYNikon D500
Olympus E-M1 II« »YstereomonoYYmicro3.0Y--Olympus E-M1 II
Pentax K-1 II« »YstereomonoYYmicro2.0Y--Pentax K-1 II
Sony A7 III« »YstereomonoYYmicro3.1YYYSony A7 III
Sony A9« »YstereomonoYYmicro2.0YYYSony A9
Sony A99 II« »YstereomonoYYmicro2.0YYYSony A99 II
Sony A7R II« »YstereomonoYYmicro2.0YY-Sony A7R II
Sony A7S II« »YstereomonoYYmicro2.0YY-Sony A7S II
Sony A7 II« »YstereomonoYYmicro2.0YY-Sony A7 II
Sony A7R« »YstereomonoYYmicro2.0YY-Sony A7R
Sony A99« »YstereomonoYYmini2.0---Sony A99

The A7R III is a recent model that features in the current product line-up of Sony. In contrast, the K-1 has been discontinued (but it can be found pre-owned on eBay). As a replacement in the same line of cameras, the K-1 was succeeded by the Pentax K-1 II.

Review summary: Sony A7R III vs Pentax K-1

So what is the bottom line? Which of the two cameras – the Sony A7R III or the Pentax K-1 – has the upper hand? The listing below highlights the relative strengths of the two models.

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Advantages of the Sony Alpha A7R III:

  • More detail: Offers more megapixels (42.2 vs 36.2MP) with a 8% higher linear resolution.
  • Better image quality: Scores markedly higher (4 points) in the DXO overall assessment.
  • Better video: Provides higher definition movie capture (4K/30p vs 1080/60i).
  • Better video autofocus: Features on-sensor phase-detection for more confident movie autofocus.
  • More framing info: Has an electronic viewfinder that displays shooting data.
  • More detailed LCD: Has a higher resolution rear screen (1440k vs 1037k dots).
  • Fewer buttons to press: Is equipped with a touch-sensitive rear screen to facilitate handling.
  • Faster burst: Shoots at higher frequency (10 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 (127x96mm vs 137x110mm) and thus needs less room in the bag.
  • Less heavy: Is lighter (by 360g or 36 percent) and hence easier to carry around.
  • More legacy lens friendly: Can take a broad range of non-native lenses via adapters.
  • Faster data transfer: Supports a more advanced USB protocol (3.1 vs 2.0).
  • Easier device pairing: Supports NFC for fast wireless image transfer over short distances.
  • Easier wireless transfer: Supports Bluetooth for image sharing without cables.
  • More modern: Is somewhat more recent (announced 1 year and 8 months after the K-1).

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Arguments in favor of the Pentax K-1:

  • Brighter framing: Features an optical viewfinder for clear, lag-free composition.
  • Easier setting verification: Features a control panel on top to check shooting parameters.
  • Larger screen: Has a bigger rear LCD (3.2" vs 3.0") for image review and settings control.
  • More flexible LCD: Has full-flex screen for odd-angle shots in portrait or landscape orientation.
  • Longer lasting: Gets more shots (760 versus 650) out of a single battery charge.
  • More affordable: Was introduced into a lower priced category (44 percent cheaper at launch).
  • More heavily discounted: Has been on the market for longer (launched in February 2016).

If the count of relative strengths (bullet points above) is taken as a measure, the A7R III is the clear winner of the match-up (16 : 7 points). However, the relevance of individual strengths will vary across photographers, so that you might want to apply your own weighing scheme to the summary points when reflecting and deciding on a new camera.

A7R III 16:07 K-1

In any case, while the comparison of the spec-sheets of cameras can offer a general idea of their imaging potential, it remains partial and cannot reveal, for example, the handling experience and imaging performance when actually working with the A7R III or the K-1. 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 rankings of the cameras as published by some of the major camera review sites (cameralabs, dpreview, ephotozine, imaging-resource, photographyblog). The full reviews are available by clicking on the site logo in the table header.

Review Scores
  Camera
Model
cameralabs dpreview ephotozine imaging-resource photographyblog Camera
Launch
(announced)
Launch
Price
(USD)
Street
Price
(USD)
Used
Price
(USD)
Camera
Model
Sony A7R III»HiRec90/1004.5/55/55/5 Oct 2017 3,199 i i Sony A7R III
Pentax K-1«-84/1005/54.5/55/5 Feb 2016 1,799- i Pentax K-1
Canon 5D Mark IV« »HiRec87/1004.5/55/54.5/5 Aug 2016 3,499 i i Canon 5D Mark IV
Nikon Z7« »-89/1004.5/5-5/5 Aug 2018 3,399 i i Nikon Z7
Nikon D500« »HiRec91/1004.5/55/55/5 Jan 2016 1,999 i i Nikon D500
Olympus E-M1 II« »HiRec85/1004.5/55/54.5/5 Sep 2016 1,999 i i Olympus E-M1 II
Pentax K-1 II« »-79/1004.5/5-4.5/5 Feb 2018 1,999 i i Pentax K-1 II
Sony A7 III« »HiRec89/1005/55/55/5 Feb 2018 1,999 i i Sony A7 III
Sony A9« »HiRec89/1005/55/55/5 Apr 2017 4,499 i i Sony A9
Sony A99 II« »-85/1004.5/54.5/54.5/5 Sep 2016 3,199 i i Sony A99 II
Sony A7R II« »HiRec90/1005/54.5/55/5 Jun 2015 3,199- i Sony A7R II
Sony A7S II« »Rec-4.5/55/55/5 Sep 2015 2,999 i i Sony A7S II
Sony A7 II« »Rec82/1004.5/55/55/5 Nov 2014 1,999- i Sony A7 II
Sony A7R« »HiRec82/1004.5/55/55/5 Oct 2013 2,299- i Sony A7R
Sony A99« »-84/1004.5/5rev4.5/5 Sep 2012 2,799- i Sony A99

The above review scores should be interpreted with care, 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 comparing ratings of very distinct cameras or ones that are far apart in terms of their release date have little meaning. 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. Alternatively, you can follow any of the listed hyperlinks for comparisons that others found interesting. If the camera you are interested in is not available, please contact me, and I will try to locate and add the respective data to the application.

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