PW

Pentax K-1 versus Pentax 645Z

The Pentax K-1 and the Pentax 645Z are two digital cameras that were announced, respectively, in February 2016 and April 2014. Both are DSLR (Digital Single Lens Reflex) cameras that are based on a full frame (K-1) and a medium format sensor. The K-1 has a resolution of 36.2 megapixel, whereas the 645Z provides 51.1 MP.

Body comparison

An illustration of the physical size and weight of the Pentax K-1 and the Pentax 645Z is provided in the side-by-side display below. 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. If you prefer, you can also use the toggle button to switch to a comparison in percentage terms (in this case, the camera on the left – the K-1 – represents 100 percent across all the size and weight measures).

Pentax K-1 vs Pentax 645Z front
K-1 versus 645Z top view
K-1 and 645Z rear side
Body view (K-1 on the left)

If the front view area (width x height) of the cameras is taken as an aggregate measure of their size, the Pentax 645Z is notably larger (21 percent) than the Pentax K-1. Moreover, the 645Z is substantially heavier (53 percent) than the K-1. 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.

The table below summarizes the key physical specs of the two cameras alongside a broader set of comparators. If you want to switch the focus of the display and review another camera pair, just select a new right or left comparator from among the camera models in the table. Alternatively, you can also move across to the CAM-parator tool and choose from the broad selection of possible comparisons there.

Camera Body Specifications
Camera Camera
Width
Camera
Height
Camera
Depth
Camera
Weight
Battery
Life
(CIPA)
Weather
Sealing
(y/n)
Camera
Launch
(year)
Launch
Price
(USD)
Street
Price
(amazon)
Used
Price
(ebay)
Pentax K-1 (⇒ rgt) 137 mm 110 mm 86 mm 1010 g 760 YES 2016 1,799 latest check
Pentax 645Z (⇒ lft) 156 mm 117 mm 123 mm 1550 g 650 YES 2014 8,499 latest check
Canon 6D Mark II (⇒ lft | rgt) 144 mm 111 mm 75 mm 765 g 1200 YES 2017 1,999 latest check
Canon 5D Mark IV (⇒ lft | rgt) 151 mm 116 mm 76 mm 890 g 900 YES 2016 3,499 latest check
Canon 5DS R (⇒ lft | rgt) 152 mm 116 mm 76 mm 930 g 700 YES 2015 3,699 latest check
Canon 5DS (⇒ lft | rgt) 152 mm 116 mm 76 mm 930 g 700 YES 2015 3,699 latest check
Leica SL (⇒ lft | rgt) 147 mm 104 mm 39 mm 847 g 400 YES 2015 7,450 latest check
Nikon D500 (⇒ lft | rgt) 147 mm 115 mm 81 mm 860 g 1240 YES 2016 1,999 latest check
Nikon D750 (⇒ lft | rgt) 141 mm 113 mm 78 mm 750 g 1230 YES 2014 2,299 latest check
Olympus E-M1 II (⇒ lft | rgt) 134 mm 91 mm 67 mm 574 g 440 YES 2016 1,999 latest check
Panasonic GH5 (⇒ lft | rgt) 139 mm 98 mm 87 mm 725 g 410 YES 2017 1,999 latest check
Pentax K-3 II (⇒ lft | rgt) 131 mm 100 mm 77 mm 800 g 720 YES 2015 1,099 latest check
Pentax 645D (⇒ lft | rgt) 156 mm 117 mm 119 mm 1480 g .. YES 2010 9,995discont. check
Sony A7R III (⇒ lft | rgt) 127 mm 96 mm 74 mm 650 g 650 YES 2017 3,199 latest check
Sony A99 II (⇒ lft | rgt) 143 mm 104 mm 76 mm 849 g 490 YES 2016 3,199 latest check
Sony A7R II (⇒ lft | rgt) 127 mm 96 mm 60 mm 625 g 290 YES 2015 3,199discont. check
Sony A850 (⇒ lft | rgt) 156 mm 117 mm 82 mm 895 g 880 YES 2009 1,999discont. check

The listed prices provide an indication of the market segment that the manufacturer of the cameras have been targeting. The K-1 was launched at a markedly lower price (by 79 percent) than the 645Z, 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

The imaging sensor is at the core of digital cameras and its size is one of the main determining factors 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 features a full frame sensor and the Pentax 645Z a medium format sensor. The sensor area in the 645Z is 67 percent bigger. As a result of these sensor size differences, the cameras have a format factor of, respectively, 1.0 and 0.79. The sensor in the K-1 has a native 3:2 aspect ratio, while the one in the 645Z offers a 4:3 aspect.

Pentax K-1 and Pentax 645Z sensor measures
Sensor size

With 51.1MP, the 645Z offers a higher resolution than the K-1 (36.2MP), but the 645Z nevertheless has larger individual pixels (pixel pitch of 5.30μm versus 4.88μm for the K-1) due to its larger sensor. However, the K-1 is a somewhat more recent model (by 1 year and 10 months) than the 645Z, and its sensor might have benefitted from technological advances during this time that 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.

Unlike the 645Z, the K-1 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).

K-1 versus 645Z MP
Sensor resolution

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 consideration, the 645Z has a markedly higher DXO score than the K-1 (overall score 5 points higher), which will translate into better image quality. The advantage is based on 0.6 bits higher color depth, 0.1 EV in additional dynamic range, and 0.5 stops in additional low light sensitivity. The adjacent table reports on the physical sensor characteristics and the outcomes of the DXO sensor quality tests for a sample of comparator-cameras.

Sensor Characteristics
Camera Sensor
Class
Resolution
(Megapixel)
Horiz.
Pixels
Vert.
Pixels
Video
Format
DXO
Portrait
DXO
Landscape
DXO
Sports
DXO
Overall
Pentax K-1 (⇒ rgt) Full Frame 36.2 7360 4912 1080/60i 25.4 14.6 3280 96
Pentax 645Z (⇒ lft) Medium Format 51.1 8256 6192 1080/60i 26.0 14.7 4505 101
Canon 6D Mark II (⇒ lft | rgt) Full Frame 26.0 6240 4160 1080/60p 24.4 11.9 2862 85
Canon 5D Mark IV (⇒ lft | rgt) Full Frame 30.1 6720 4480 4K/30p 24.8 13.6 2995 91
Canon 5DS R (⇒ lft | rgt) Full Frame 50.3 8688 5792 1080/60p 24.6 12.4 2308 86
Canon 5DS (⇒ lft | rgt) Full Frame 50.3 8688 5792 1080/60p 24.7 12.4 2381 87
Leica SL (⇒ lft | rgt) Full Frame 24.0 6000 4000 4K/30p 25.0 13.4 1821 88
Nikon D500 (⇒ lft | rgt) APS-C 20.7 5568 3712 4K/30p 24.0 14.0 1324 83
Nikon D750 (⇒ lft | rgt) Full Frame 24.2 6016 4016 1080/60p 24.8 14.5 2956 93
Olympus E-M1 II (⇒ lft | rgt) Four Thirds 20.2 5184 3888 4K/30p 23.7 12.8 1312 80
Panasonic GH5 (⇒ lft | rgt) Four Thirds 20.2 5184 3888 4K/60p 23.9 13.0 807 77
Pentax K-3 II (⇒ lft | rgt) APS-C 24.1 6016 4000 1080/60i 23.6 13.6 1106 80
Pentax 645D (⇒ lft | rgt) Medium Format 39.5 7264 5440 no 24.6 12.6 1262 82
Sony A7R III (⇒ lft | rgt) Full Frame 42.2 7952 5304 4K/30p 26.0 14.7 3523 100
Sony A99 II (⇒ lft | rgt) Full Frame 42.2 7952 5304 4K/30p 25.4 13.4 2317 92
Sony A7R II (⇒ lft | rgt) Full Frame 42.2 7952 5304 4K/30p 26.0 13.9 3434 98
Sony A850 (⇒ lft | rgt) Full Frame 24.4 6048 4032 no 23.8 12.2 1415 79

Many modern cameras are not only capable of taking still images, but can also record movies. Both cameras under consideration have a sensor with sufficiently fast read-out times for moving pictures, and both provide the same movie specifications (1080/60i).

Feature comparison

Beyond body and sensor, cameras can and do differ across a range of features. The K-1 and the 645Z are similar in the sense that both have an optical viewfinder. The latter is useful for getting a clear image for framing even in brightly lit environments. The following table reports on some other key feature differences and similarities of the Pentax K-1, the Pentax 645Z, and comparable cameras. The full specs-sheets can be found in the camera manual or, for example, in the dpreview camera hub.

Core Features
Camera Viewfinder
(Type or
'000 dots)
Control
Panel
(Y/n)
LCD
Size
(inch)
LCD
Resolution
('000 dots)
LCD
Attach-
ment
Touch
Screen
(Y/n)
Shutter
speed
(1/sec)
Shutter
flaps
(1/sec))
Build-in
Flash
(GN)
Build-in
Image
Stab
Pentax K-1 (⇒ rgt) optical YES 3.2 1037 full-flex no 8000 4.4 no YES
Pentax 645Z (⇒ lft) optical YES 3.2 1037 tilting no 4000 3.0 no no
Canon 6D Mark II (⇒ lft | rgt) optical YES 3.0 1040 swivel YES 4000 6.5 no no
Canon 5D Mark IV (⇒ lft | rgt) optical YES 3.2 1620 fixed YES 8000 7.0 no no
Canon 5DS R (⇒ lft | rgt) optical YES 3.2 1040 fixed no 8000 5.0 no no
Canon 5DS (⇒ lft | rgt) optical YES 3.2 1040 fixed no 8000 5.0 no no
Leica SL (⇒ lft | rgt) 4400 YES 3.0 1040 fixed YES 8000 11.0 no no
Nikon D500 (⇒ lft | rgt) optical YES 3.2 2359 tilting YES 8000 10.0 no no
Nikon D750 (⇒ lft | rgt) optical YES 3.2 1229 tilting no 4000 6.0 12 no
Olympus E-M1 II (⇒ lft | rgt) 2360 no 3.0 1037 swivel YES 8000 18.0 no YES
Panasonic GH5 (⇒ lft | rgt) 3680 no 3.2 1620 swivel YES 8000 12.0 no YES
Pentax K-3 II (⇒ lft | rgt) optical YES 3.2 1037 fixed no 8000 8.3 no YES
Pentax 645D (⇒ lft | rgt) optical YES 3.0 921 fixed no 4000 1.1 no no
Sony A7R III (⇒ lft | rgt) 3686 no 3.0 1440 tilting YES 8000 10.0 no YES
Sony A99 II (⇒ lft | rgt) 2400 YES 3.0 1229 tilting no 8000 12.0 no YES
Sony A7R II (⇒ lft | rgt) 2400 no 3.0 1229 tilting no 8000 5.0 no YES
Sony A850 (⇒ lft | rgt) optical YES 3.0 922 fixed no 8000 3.0 no YES

Both the K-1 and the 645Z are current models that good online retailers will have in stock. You can check the latest prices, for example, at amazon. The 645Z replaced the earlier Pentax 645D, while the K-1 does not have a direct predecessor.

Summary

So how do things add up? Which of the two cameras – the Pentax K-1 or the Pentax 645Z – has the upper hand? A synthesis of the relative strong points of each of the models is listed below.


Arguments in favor of the Pentax K-1:

  • High quality composites: Can combine several shots after pixel-shifting its sensor.
  • More flexible LCD: Has full-flex screen for odd-angle shots in portrait or landscape orientation.
  • Faster shutter: Has higher mechanical shutter speed (8000/sec vs 4000/sec) to freeze action.
  • Faster burst: Shoots at higher frequency (4.4 vs 3 flaps/sec) to capture the decisive moment.
  • More compact: Is smaller (137x110mm vs 156x117mm) and thus needs less room in the bag.
  • Less heavy: Is lighter (by 540g or 35 percent) and hence easier to carry around.
  • Longer lasting: Can take more shots (760 versus 650) on a single battery charge.
  • Sharper images: Has hand-shake reducing image stabilization build-in.
  • More affordable: Was introduced into a lower priced category (79 percent cheaper at launch).
  • More modern: Is somewhat more recent (announced 1 year and 10 months after the 645Z).

Reasons to prefer the Pentax 645Z:

  • More detail: Has more megapixels (51.1 vs 36.2MP), which boosts linear resolution by 17%.
  • Better image quality: Scores markedly higher (5 points) in the DXO overall evaluation.
  • Better low-light sensitivity: Can shoot in dim conditions (0.5 stops ISO advantage).
  • More heavily discounted: Has been on the market for longer (launched in April 2014).

If the count of individual advantages (bullet points above) is taken as a guide, the K-1 is the clear winner of the match-up (10 : 4 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.

K-1 10:04 645Z

In any case, while the specs-based evaluation of cameras is instructive in revealing their potential as photographic tools, it remains partial and cannot reveal, for example, the handling experience and imaging performance when actually working with the K-1 or the 645Z. User reviews that are available, for instance, at amazon can sometimes shed light on these issues, but such feedback is all too often partial, inconsistent, and inaccurate. This is where reviews by experts come in. The adjacent table relays the overall verdicts of several of the most popular camera review sites. You can find the full text of the reviews, respectively, at cameralabs.com, dpreview.com, ephotozine.com, imaging-resource.com, and photographyblog.com.

Review scores
Camera camera
labs
dp
review
ephoto
zine
imaging
resource
photography
blog
Camera
Launch
(year)
Launch
Price
(USD)
Street
Price
(amazon)
Used
Price
(ebay)
Pentax K-1 (⇒ rgt) - 84/100 Silver 5/5 4.5/5 5/5 2016 1,799 latest check
Pentax 645Z (⇒ lft) - - 4.5/5 5/5 5/5 2014 8,499 latest check
Canon 6D Mark II (⇒ lft | rgt) Rec 80/100 4.5/5 4/5 4/5 2017 1,999 latest check
Canon 5D Mark IV (⇒ lft | rgt) HiRec 87/100 Gold 4.5/5 5/5 4.5/5 2016 3,499 latest check
Canon 5DS R (⇒ lft | rgt) Rec 83/100 Silver 5/5 5/5 4.5/5 2015 3,699 latest check
Canon 5DS (⇒ lft | rgt) Rec 83/100 Silver 4.5/5 5/5 4.5/5 2015 3,699 latest check
Leica SL (⇒ lft | rgt) - 84/100 4.5/5 4/5 4/5 2015 7,450 latest check
Nikon D500 (⇒ lft | rgt) HiRec 91/100 Gold 4.5/5 5/5 5/5 2016 1,999 latest check
Nikon D750 (⇒ lft | rgt) HiRec 90/100 Gold 4.5/5 5/5 4.5/5 2014 2,299 latest check
Olympus E-M1 II (⇒ lft | rgt) HiRec 85/100 Gold 4.5/5 5/5 4.5/5 2016 1,999 latest check
Panasonic GH5 (⇒ lft | rgt) HiRec 85/100 Gold 4.5/5 5/5 5/5 2017 1,999 latest check
Pentax K-3 II (⇒ lft | rgt) - - 5/5 4.5/5 5/5 2015 1,099 latest check
Pentax 645D (⇒ lft | rgt) - - - 4.5/5 - 2010 9,995discont. check
Sony A7R III (⇒ lft | rgt) HiRec 90/100 Gold .. .. .. 2017 3,199 latest check
Sony A99 II (⇒ lft | rgt) - 85/100 Silver 4.5/5 4.5/5 4.5/5 2016 3,199 latest check
Sony A7R II (⇒ lft | rgt) HiRec 90/100 Gold 5/5 4.5/5 5/5 2015 3,199discont. check
Sony A850 (⇒ lft | rgt) - 75/100 - 4/5 4.5/5 2009 1,999discont. check

The review scores listed above should be treated 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, kindly note that some of the listed sites have over time developped their review approaches and their reporting style.

Other comparisons

In case you are interested in seeing how other cameras pair up, just make your choice using the following search menu. An an alternative, you can also directly jump to any one of the listed comparisons that were previously generated by the CAM-parator tool. If you cannot find the camera you are interested in, please contact me, and I will try to locate and add the respective data to the application.

vs