A potelyt.com – Photography & Imaging Resources
ad

When you use links on apotelyt.com to buy products,
the site may earn a commission.

PW

Pentax K-3 III vs Sony A9

The Pentax K-3 III and the Sony Alpha A9 are two digital cameras that were revealed to the public, respectively, in March 2021 and April 2017. The K-3 III is a DSLR, while the A9 is a mirrorless interchangeable lens camera. The cameras are based on an APS-C (K-3 III) and a full frame (A9) sensor. The Pentax has a resolution of 25.6 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.

Headline Specifications
Pentax K-3 III
versus
Sony A9
Pentax K-3 III   Sony A9
Digital single lens reflex Mirrorless system camera
Pentax K mount lenses Sony E mount lenses
25.6 MP – APS-C sensor 24 MP – Full Frame sensor
4K/30p Video 4K/30p Video
ISO 100-160,000 ISO 100-51,200 (50 - 204,800)
Optical viewfinder Electronic viewfinder (3686k dots)
3.2" LCD – 1620k dots 3.0" LCD – 1440k dots
Fixed touchscreen Tilting touchscreen
12 shutter flaps per second 20 shutter flaps per second
In-body stabilizationIn-body stabilization
Weathersealed bodyWeathersealed body
800 shots per battery charge650 shots per battery charge
135 x 104 x 74 mm, 820 g 127 x 96 x 63 mm, 673 g
logo
Check K-3 III price at
amazon.com
logo
Check A9 offers at
ebay.com

Going beyond this snapshot of core features and characteristics, what are the differences between the Pentax K-3 III and the Sony Alpha A9? 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.

ad

Body comparison

The side-by-side display below illustrates the physical size and weight of the Pentax K-3 III and the Sony A9. 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 size dimensions are rounded to the nearest millimeter.

The K-3 III can be obtained in two different colors (black, silver), while the A9 is only available in black.

Size Pentax K-3 III vs Sony A9
Compare K-3 III versus A9 top
Comparison K-3 III or A9 rear

If the front view area (width x height) of the cameras is taken as an aggregate measure of their size, the Sony A9 is notably smaller (13 percent) than the Pentax K-3 III. Moreover, the A9 is markedly lighter (18 percent) than the K-3 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 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 III gets 800 shots out of its Pentax D-LI90 battery, while the A9 can take 650 images on a single charge of its Sony NP-FZ100 power pack. The power pack in the A9 can be charged via the USB port, which can be very convenient when travelling.

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, you can move across to the CAM-parator tool and choose from the broad selection of possible camera comparisons there.

scroll hint
Body Specifications
# image Camera
Model
Camera
Width
Camera
Height
Camera
Depth
Camera
Weight
Battery
Life
Weather
Sealing
Camera
Launch
Launch
Price (USD)
Street
Price
1.
 
Pentax K-3 III 135 mm 104 mm 74 mm 820 g 800 Y Mar 2021 1,999 amazon.com
2.
 
Sony A9 127 mm 96 mm 63 mm 673 g 650 Y Apr 2017 4,499ebay.com
3.
 
Fujifilm X-T4 135 mm 93 mm 64 mm 607 g 500 Y Feb 2020 1,699ebay.com
4.
 
Fujifilm X-H1 140 mm 97 mm 86 mm 673 g 310 Y Feb 2018 1,899ebay.com
5.
 
Nikon Z6 II 134 mm 101 mm 70 mm 705 g 410 Y Oct 2020 1,999 amazon.com
6.
 
Panasonic S5 133 mm 98 mm 82 mm 714 g 440 Y Sep 2020 1,999 amazon.com
7.
 
Pentax KP 132 mm 101 mm 76 mm 703 g 390 Y Jan 2017 1,099ebay.com
8.
 
Pentax K-70 126 mm 93 mm 74 mm 688 g 410 Y Jun 2016 649ebay.com
9.
 
Pentax K-S2 123 mm 91 mm 73 mm 678 g 410 Y Feb 2015 749ebay.com
10.
 
Pentax K-3 II 131 mm 100 mm 77 mm 800 g 720 Y Apr 2015 1,099ebay.com
11.
 
Pentax K-3 131 mm 100 mm 77 mm 800 g 560 Y Oct 2013 1,299ebay.com
12.
 
Pentax K-5 II 131 mm 97 mm 73 mm 760 g 740 Y Sep 2012 1,099ebay.com
13.
 
Sony A7R V 131 mm 97 mm 82 mm 723 g 530 Y Oct 2022 3,899 amazon.com
14.
 
Sony A7R IIIA 127 mm 96 mm 74 mm 650 g 650 Y Apr 2021 3,199 amazon.com
15.
 
Sony A9 II 129 mm 96 mm 76 mm 678 g 690 Y Oct 2019 4,499 amazon.com
16.
 
Sony A7 III 127 mm 96 mm 74 mm 650 g 610 Y Feb 2018 1,999 amazon.com
17.
 
Sony A7 II 127 mm 96 mm 60 mm 599 g 350 Y Nov 2014 1,999ebay.com
Note: Measurements and pricing do not include easily detachable parts, such as add-on or interchangeable lenses or optional viewfinders.
padding

Any camera decision will naturally be influenced heavily by the price. 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 III was launched at a markedly lower price (by 56 percent) than the A9, which puts it into a different market segment. Normally, street prices remain initially close to the MSRP, but after a couple of months, the first discounts appear. 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 size of the imaging sensor is a crucial determinant 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. 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 are more costly to manufacture and tend to lead to bigger and heavier cameras and lenses.

Of the two cameras under consideration, the Pentax K-3 III features an APS-C sensor and the Sony A9 a full frame sensor. The sensor area in the A9 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.

Pentax K-3 III and Sony A9 sensor measures

Despite having a smaller sensor, the Pentax K-3 III offers a higher resolution of 25.6 megapixels, compared with 24 MP of the Sony A9. This megapixels advantage comes at the cost of a higher pixel density and a smaller size of the individual pixel (with a pixel pitch of 3.76μm versus 5.94μm for the A9). However, it should be noted that the K-3 III is much more recent (by 3 years and 11 months) than the A9, and its sensor will have benefitted from technological advances during this time that make it possible to gather light more efficiently. Coming back to sensor resolution, it should be mentioned that the K-3 III has no anti-alias filter installed, so that it can capture all the detail its sensor resolves.

The A9 has on-sensor phase detect pixels, which results in fast and reliable autofocus acquisition even during live view operation.

Unlike the A9, the K-3 III has the capacity to capture high quality composite images (YESMP) 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 III has a native sensitivity range from ISO 100 to ISO 160000. The corresponding ISO settings for the Sony Alpha A9 are ISO 100 to ISO 51200, with the possibility to increase the ISO range to 50-204800.

In terms of underlying technology, the K-3 III is build around a CMOS sensor, while the A9 uses a Stacked BSI-CMOS imager. Both cameras use a Bayer filter for capturing RGB colors on a square grid of photosensors. This arrangement is found in most digital cameras.

K-3 III versus A9 MP

Consistent information on actual sensor performance is available from DXO Mark for many cameras. 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"). The adjacent table reports on the physical sensor characteristics and the outcomes of the DXO sensor quality tests for a sample of comparator-cameras.

scroll hint
Sensor Characteristics
# image Camera
Model
Sensor
Class
Resolution
(MP)
Horiz.
Pixels
Vert.
Pixels
Video
Format
DXO
Portrait
DXO
Landscape
DXO
Sports
DXO
Overall
1.
 
Pentax K-3 III APS-C 25.6 6192 41284K/30p24.213.7208385
2.
 
Sony A9 Full Frame 24.0 6000 40004K/30p24.913.3351792
3.
 
Fujifilm X-T4 APS-C 26.0 6240 41604K/60p24.113.6199584
4.
 
Fujifilm X-H1 APS-C 24.0 6000 40004K/30p24.013.3180682
5.
 
Nikon Z6 II Full Frame 24.3 6048 40244K/60p25.014.4330394
6.
 
Panasonic S5 Full Frame 24.0 6000 40004K/60p25.114.5269794
7.
 
Pentax KP APS-C 24.1 6016 40001080/60i23.913.2169981
8.
 
Pentax K-70 APS-C 24.0 6000 40001080/60i23.813.1163980
9.
 
Pentax K-S2 APS-C 20.0 5472 36481080/30p23.612.9151479
10.
 
Pentax K-3 II APS-C 24.1 6016 40001080/60i23.613.6110680
11.
 
Pentax K-3 APS-C 24.1 6016 40001080/60i23.713.4121680
12.
 
Pentax K-5 II APS-C 16.1 4928 32641080/25p23.814.1123582
13.
 
Sony A7R V Full Frame 60.2 9504 63368k/24p26.514.83187100
14.
 
Sony A7R IIIA Full Frame 42.2 7952 53044K/30p26.014.73523100
15.
 
Sony A9 II Full Frame 24.0 6000 40004K/30p25.014.0343493
16.
 
Sony A7 III Full Frame 24.0 6000 40004K/30p25.014.7373096
17.
 
Sony A7 II Full Frame 24.0 6000 40001080/60p24.913.6244990
Note: DXO values in italics represent estimates based on sensor size and age.
padding

Many modern cameras are not only capable of taking still images, but also of capturing video footage. The two cameras under consideration both have sensors whose read-out speed is fast enough to capture moving pictures, and both provide the same movie specifications (4K/30p).

ad

Feature comparison

Apart from body and sensor, cameras can and do differ across a range of features. For example, the A9 has an electronic viewfinder (3686k dots), while the K-3 III 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 A9 has a higher magnification than the one of the K-3 III (0.78x vs 0.70x), so that the size of the image transmitted appears closer to the size seen with the naked human eye. The adjacent table lists some of the other core features of the Pentax K-3 III and Sony A9 along with similar information for a selection of comparators.

scroll hint
Core Features
# image Camera
Model
Viewfinder
(Type or
000 dots)
Control
Panel
(yes/no)
LCD
Specifications
(inch/000 dots)
LCD
Attach-
ment
Touch
Screen
(yes/no)
Max
Shutter
Speed *
Max
Shutter
Flaps *
Built-in
Flash
(yes/no)
Built-in
Image
Stab
1.
 
Pentax K-3 IIIoptical Y3.2 / 1620 fixed Y 1/8000s 12.0/s n Y
2.
 
Sony A93686 n3.0 / 1440 tilting Y 1/8000s 20.0/s n Y
3.
 
Fujifilm X-T43690 n3.0 / 1620 swivel Y 1/8000s 15.0/s n Y
4.
 
Fujifilm X-H13690 Y3.0 / 1040 full-flex Y 1/8000s 14.0/s n Y
5.
 
Nikon Z6 II3690 Y3.2 / 2100 tilting Y 1/8000s 14.0/s n Y
6.
 
Panasonic S52360 n3.0 / 1840 swivel Y 1/8000s 7.0/s n Y
7.
 
Pentax KPoptical n3.0 / 921 tilting n 1/6000s 7.0/s Y Y
8.
 
Pentax K-70optical n3.0 / 921 swivel n 1/6000s 6.0/s Y Y
9.
 
Pentax K-S2optical n3.0 / 921 swivel n 1/6000s 5.4/s Y Y
10.
 
Pentax K-3 IIoptical Y3.2 / 1037 fixed n 1/8000s 8.3/s n Y
11.
 
Pentax K-3optical Y3.2 / 1037 fixed n 1/8000s 8.3/s Y Y
12.
 
Pentax K-5 IIoptical Y3.0 / 921 fixed n 1/8000s 7.0/s Y Y
13.
 
Sony A7R V9440 n3.2 / 2100 full-flex Y 1/8000s 10.0/s n Y
14.
 
Sony A7R IIIA3686 n3.0 / 2340 tilting Y 1/8000s 10.0/s n Y
15.
 
Sony A9 II3686 n3.0 / 1440 tilting Y 1/8000s 20.0/s n Y
16.
 
Sony A7 III2359 n3.0 / 922 tilting Y 1/8000s 10.0/s n Y
17.
 
Sony A7 II2400 n3.0 / 1230 tilting n 1/8000s 5.0/s n Y
Note: *) Information refers to the mechanical shutter, unless the camera only has an electronic one.
padding

One feature that is present on the K-3 III, but is missing on the A9 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 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 A9 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 III 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-3 III writes its imaging data to SDXC cards, while the A9 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. Both the K-3 III and the A9 support UHS-II cards (Ultra High Speed data transfer of up to 312 MB/s) on the first slot and UHS-I cards (104 MB/s) on the second one.

ad

Connectivity comparison

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 III and Sony Alpha A9 and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.

scroll hint
Input-Output Connections
# image Camera
Model
Hotshoe
Port
Internal
Mic / Speaker
Microphone
Port
Headphone
Port
HDMI
Port
USB
Port
WiFi
Support
NFC
Support
Bluetooth
Support
1.
 
Pentax K-3 IIIYstereo / monoYYmicro3.2Y-Y
2.
 
Sony A9Ystereo / monoYYmicro2.0YYY
3.
 
Fujifilm X-T4Ystereo / monoY-micro3.1Y-Y
4.
 
Fujifilm X-H1Ystereo / monoY-micro3.0Y--
5.
 
Nikon Z6 IIYstereo / monoYYmicro3.2Y-Y
6.
 
Panasonic S5Ystereo / monoYYmicro3.2Y-Y
7.
 
Pentax KPYstereo / monoY--2.0Y--
8.
 
Pentax K-70Ystereo / monoY-mini2.0Y--
9.
 
Pentax K-S2Ymono / monoY-micro2.0YY-
10.
 
Pentax K-3 IIYmono / monoYYmini3.0---
11.
 
Pentax K-3Ymono / monoYYmini3.0---
12.
 
Pentax K-5 IIYstereo / monoY-mini2.0---
13.
 
Sony A7R VYstereo / monoYYfull3.2Y-Y
14.
 
Sony A7R IIIAYstereo / monoYYmicro3.2YYY
15.
 
Sony A9 IIYstereo / monoYYmicro3.1YYY
16.
 
Sony A7 IIIYstereo / monoYYmicro3.1YYY
17.
 
Sony A7 IIYstereo / monoYYmicro2.0YY-
padding

Both cameras feature a PC Sync terminal to control professional strobe lights, which will be appreciated by studio photographers.

Travel and landscape photographers will find it useful that the K-3 III has an internal geolocalization sensor and can record GPS coordinates in its EXIF data.

The K-3 III is a recent model that features in the current product line-up of Pentax. In contrast, the A9 has been discontinued (but can be found pre-owned on ebay). As a replacement in the same line of cameras, the A9 was succeeded by the Sony A9 II. Further information on the features and operation of the K-3 III and A9 can be found, respectively, in the Pentax K-3 III Manual (free pdf) or the online Sony A9 Manual.

ad

Review summary

So what conclusions can be drawn? Is there a clear favorite between the Pentax K-3 III and the Sony A9? Which camera is better? A synthesis of the relative strong points of each of the models is listed below.

ilogo

Advantages of the Pentax K-3 III:

  • 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.
  • 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 (1620k vs 1440k dots).
  • Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
  • Longer lasting: Can take more shots (800 versus 650) on a single battery charge.
  • Easier geotagging: Features an internal GPS sensor to log localization data.
  • Faster data transfer: Supports a more advanced USB protocol (3.2 vs 2.0).
  • More affordable: Was introduced into a lower priced category (56 percent cheaper at launch).
  • More modern: Reflects 3 years and 11 months of technical progress since the A9 launch.

ilogo

Arguments in favor of the Sony Alpha A9:

  • Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
  • 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 0.70x).
  • More flexible LCD: Has a tilting screen for odd-angle shots in landscape orientation.
  • Faster burst: Shoots at higher frequency (20 vs 12 flaps/sec) to capture the decisive moment.
  • Less disturbing: Has an electronic shutter option for completely silent shooting.
  • More compact: Is smaller (127x96mm vs 135x104mm) and will fit more readily into a bag.
  • Less heavy: Has a lower weight (by 147g or 18 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 device pairing: Supports NFC for fast wireless image transfer over short distances.
  • More heavily discounted: Has been around for much longer (launched in April 2017).

If the count of individual advantages (bullet points above) is taken as a guide, the A9 comes out slightly ahead of the K-3 III (13 : 12 points). However, the pertinence of the various camera strengths will differ across photographers, so that you might want to weigh individual camera traits according to their importance for your own imaging needs before making a camera decision. 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.

K-3 III 12:13 A9

How about other alternatives? Do the specifications of the Pentax K-3 III and the Sony A9 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-3 III or the A9 perform in practice. User reviews, such as those found at amazon, can sometimes inform about these issues, but such feedback is often incomplete, inconsistent, and biased.

Expert reviews

This is why expert reviews are important. The following table reports the overall ratings of the cameras as published by some of the major camera review sites (amateurphotographer [AP], cameralabs [CL], digitalcameraworld [DCW], dpreview [DPR], ephotozine [EPZ], photographyblog [PB]). 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.

scroll hint
Expert Camera Reviews
# image  Camera 
 Model 
 AP 
 score 
 CL 
 score 
 DCW 
 score 
 DPR 
 score 
 EPZ 
 score 
 PB 
 score 
Camera
Launch
Launch
Price (USD)
Street
Price
1.
 
Pentax K-3 III4/5..3/5..4.5/5.. Mar 2021 1,999 amazon.com
2.
 
Sony A95/5+ +4.8/589/1005/55/5 Apr 2017 4,499ebay.com
3.
 
Fujifilm X-T45/5+ +5/588/1005/55/5 Feb 2020 1,699ebay.com
4.
 
Fujifilm X-H1..+5/586/1004.5/54.5/5 Feb 2018 1,899ebay.com
5.
 
Nikon Z6 II4.5/5..4/589/1004.5/54.5/5 Oct 2020 1,999 amazon.com
6.
 
Panasonic S54.5/5+ +4.5/588/1004.5/54.5/5 Sep 2020 1,999 amazon.com
7.
 
Pentax KP4/5..3/582/1005/54.5/5 Jan 2017 1,099ebay.com
8.
 
Pentax K-704.5/5..4/579/1004.5/54.5/5 Jun 2016 649ebay.com
9.
 
Pentax K-S24.5/5......5/54.5/5 Feb 2015 749ebay.com
10.
 
Pentax K-3 II4.5/5......5/55/5 Apr 2015 1,099ebay.com
11.
 
Pentax K-34/5....83/1005/55/5 Oct 2013 1,299ebay.com
12.
 
Pentax K-5 II5/5....80/1005/54.5/5 Sep 2012 1,099ebay.com
13.
 
Sony A7R V5/5+ +4.5/592/100.... Oct 2022 3,899 amazon.com
14.
 
Sony A7R IIIA..+ +4/590/1004.5/55/5 Apr 2021 3,199 amazon.com
15.
 
Sony A9 II....5/590/1005/55/5 Oct 2019 4,499 amazon.com
16.
 
Sony A7 III..+ +4.5/589/1005/55/5 Feb 2018 1,999 amazon.com
17.
 
Sony A7 II5/5+4/582/1004.5/55/5 Nov 2014 1,999ebay.com
Note: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.
padding

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. Hence, a score should always be seen in the context of the camera's market launch date and its price, 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.

logo
Check K-3 III price at
amazon.com
logo
Check A9 offers at
ebay.com

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. Alternatively, you can follow any of the listed hyperlinks for comparisons that others found interesting.

~
    loader
    ad

    Specifications: Pentax K-3 III vs Sony A9

    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 Specifications
    Camera Model Pentax K-3 III Sony A9
    Camera Type Digital single lens reflex Mirrorless system camera
    Camera Lens Pentax K mount lenses Sony E mount lenses
    Launch Date March 2021 April 2017
    Launch Price USD 1,999 USD 4,499
    Sensor Specs Pentax K-3 III Sony A9
    Sensor Technology CMOS Stacked BSI-CMOS
    Sensor Format APS-C Sensor Full Frame Sensor
    Sensor Size 23.3 x 15.5 mm 35.6 x 23.8 mm
    Sensor Area 361.15 mm2 847.28 mm2
    Sensor Diagonal 28 mm 42.8 mm
    Crop Factor 1.5x 1.0x
    Sensor Resolution 25.6 Megapixels 24 Megapixels
    Image Resolution 6192 x 4128 pixels 6000 x 4000 pixels
    Pixel Pitch 3.76 μm 5.94 μm
    Pixel Density 7.08 MP/cm2 2.83 MP/cm2
    Moiré control no AA filter Anti-Alias filter
    Movie Capability 4K/30p Video 4K/30p Video
    ISO Setting 100 - 160,000 ISO 100 - 51,200 ISO
    ISO Boost no Enhancement 50 - 204,800 ISO
    Image Processor PRIME V BIONZ X
    DXO Sensor Quality (score) .. 92
    DXO Color Depth (bits) .. 24.9
    DXO Dynamic Range (EV) .. 13.3
    DXO Low Light (ISO) .. 3517
    Screen Specs Pentax K-3 III Sony A9
    Viewfinder Type Optical viewfinder Electronic viewfinder
    Viewfinder Field of View 100% 100%
    Viewfinder Magnification 0.70x 0.78x
    Viewfinder Resolution 3686k dots
    Top-Level Screen Control Panel no Top Display
    LCD Framing Live View Live View
    Rear LCD Size 3.2inch 3.0inch
    LCD Resolution 1620k dots 1440k dots
    LCD Attachment Fixed screen Tilting screen
    Touch Input Touchscreen Touchscreen
    Shooting Specs Pentax K-3 III Sony A9
    Focus System Phase-detect AF On-Sensor Phase-detect
    Manual Focusing AidFocus PeakingFocus Peaking
    Max Shutter Speed (mechanical) 1/8000s 1/8000s
    Continuous Shooting 12 shutter flaps/s 20 shutter flaps/s
    Shutter Life Expectancy200 000 actuations500 000 actuations
    Electronic Shutterno E-Shutterup to 1/32000s
    Time-Lapse PhotographyIntervalometer built-inno Intervalometer
    Image StabilizationIn-body stabilizationIn-body stabilization
    Fill Flash no On-Board Flash no On-Board Flash
    Storage Medium SDXC cards MS or SDXC cards
    Single or Dual Card Slots Dual card slots Dual card slots
    UHS card support Single UHS-II Single UHS-II
    Connectivity Specs Pentax K-3 III Sony A9
    External Flash Hotshoe Hotshoe
    Studio Flash PC Sync socket PC Sync socket
    USB Connector USB 3.2 USB 2.0
    HDMI Port micro HDMI micro HDMI
    Microphone Port External MIC port External MIC port
    Headphone Socket Headphone port Headphone port
    Wifi Support Wifi built-in Wifi built-in
    Near-Field Communication no NFC NFC built-in
    Bluetooth Support Bluetooth built-in Bluetooth built-in
    Geotagging GPS built-in no internal GPS
    Body Specs Pentax K-3 III Sony A9
    Environmental SealingWeathersealed bodyWeathersealed body
    Battery Type Pentax D-LI90 Sony NP-FZ100
    Battery Life (CIPA)800 shots per charge650 shots per charge
    In-Camera Charging no USB charging USB charging
    Body Dimensions 135 x 104 x 74 mm
    (5.3 x 4.1 x 2.9 in)
    127 x 96 x 63 mm
    (5.0 x 3.8 x 2.5 in)
    Camera Weight 820 g (28.9 oz) 673 g (23.7 oz)
    logo
    Check K-3 III price at
    amazon.com
    logo
    Check A9 offers at
    ebay.com

    Did you notice an error on this page? If so, please get in touch, so that we can correct the information.

    You are here Home  »  CAM-parator  »  Pentax K-3 III vs Sony A9