Pentax K-3 III vs Sony A9 III
The Pentax K-3 III and the Sony Alpha A9 III are two digital cameras that were revealed to the public, respectively, in March 2021 and November 2023. The K-3 III is a DSLR, while the A9 III is a mirrorless interchangeable lens camera. The cameras are based on an APS-C (K-3 III) and a full frame (A9 III) 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.
Going beyond this snapshot of core features and characteristics, what are the differences between the Pentax K-3 III and the Sony Alpha A9 III? 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.
Body comparison
An illustration of the physical size and weight of the Pentax K-3 III and the Sony A9 III 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-3 III can be obtained in two different colors (black, silver), while the A9 III 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 A9 III is notably smaller (6 percent) than the Pentax K-3 III. Moreover, the A9 III is markedly lighter (14 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 III can take 530 images on a single charge of its Sony NP-FZ100 power pack. The power pack in the A9 III 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 would like to visualize and compare a different camera combination, you can navigate to the CAM-parator app and make your selection from a broad list of cameras there.
Camera Model |
Camera Width |
Camera Height |
Camera Depth |
Camera Weight |
Battery Life |
Weather Sealing |
Camera Launch |
Launch Price |
Street Price |
||
---|---|---|---|---|---|---|---|---|---|---|---|
1. | Pentax K-3 III | 135 mm | 104 mm | 74 mm | 820 g | 800 | Y | Mar 2021 | US$ 1 999 | amazon.com | |
2. | Sony A9 III | 136 mm | 97 mm | 83 mm | 702 g | 530 | Y | Nov 2023 | US$ 5 999 | amazon.com | |
3. | Fujifilm X-H1 | 140 mm | 97 mm | 86 mm | 673 g | 310 | Y | Feb 2018 | US$ 1 899 | ebay.com | |
4. | Fujifilm X-T4 | 135 mm | 93 mm | 64 mm | 607 g | 500 | Y | Feb 2020 | US$ 1 699 | ebay.com | |
5. | Nikon Z6 II | 134 mm | 101 mm | 70 mm | 705 g | 410 | Y | Oct 2020 | US$ 1 999 | amazon.com | |
6. | Panasonic S5 | 133 mm | 98 mm | 82 mm | 714 g | 440 | Y | Sep 2020 | US$ 1 999 | amazon.com | |
7. | Pentax K-3 | 131 mm | 100 mm | 77 mm | 800 g | 560 | Y | Oct 2013 | US$ 1 299 | ebay.com | |
8. | Pentax K-3 II | 131 mm | 100 mm | 77 mm | 800 g | 720 | Y | Apr 2015 | US$ 1 099 | ebay.com | |
9. | Pentax K-5 II | 131 mm | 97 mm | 73 mm | 760 g | 740 | Y | Sep 2012 | US$ 1 099 | ebay.com | |
10. | Pentax K-70 | 126 mm | 93 mm | 74 mm | 688 g | 410 | Y | Jun 2016 | US$ 649 | ebay.com | |
11. | Pentax KP | 132 mm | 101 mm | 76 mm | 703 g | 390 | Y | Jan 2017 | US$ 1 099 | ebay.com | |
12. | Pentax K-S2 | 123 mm | 91 mm | 73 mm | 678 g | 410 | Y | Feb 2015 | US$ 749 | ebay.com | |
13. | Sony A1 | 129 mm | 97 mm | 81 mm | 737 g | 530 | Y | Jan 2021 | US$ 6 499 | amazon.com | |
14. | Sony A7 II | 127 mm | 96 mm | 60 mm | 599 g | 350 | Y | Nov 2014 | US$ 1 999 | ebay.com | |
15. | Sony A7 III | 127 mm | 96 mm | 74 mm | 650 g | 610 | Y | Feb 2018 | US$ 1 999 | amazon.com | |
16. | Sony A9 | 127 mm | 96 mm | 63 mm | 673 g | 650 | Y | Apr 2017 | US$ 4 499 | ebay.com | |
17. | Sony A9 II | 129 mm | 96 mm | 76 mm | 678 g | 690 | Y | Oct 2019 | US$ 4 499 | amazon.com | |
Note: Measurements and pricing do not include easily detachable parts, such as add-on or interchangeable lenses or optional viewfinders. | |||||||||||
Any camera decision will naturally be influenced heavily by the price. The listed launch prices provide an indication of the market segment that the manufacturer of the cameras have been targeting. The K-3 III was launched at a markedly lower price (by 67 percent) than the A9 III, 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.
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 associated with larger, more expensive camera bodies and lenses.
Of the two cameras under consideration, the Pentax K-3 III features an APS-C sensor and the Sony A9 III a full frame sensor. The sensor area in the A9 III 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.
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 III. 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 III). Moreover, it should be noted that the A9 III is much more recent (by 2 years and 7 months) than the K-3 III, and its sensor will have benefitted from technological advances during this time that further enhance the light gathering capacity of its pixel-units. 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 III has on-sensor phase detect pixels, which results in fast and reliable autofocus acquisition even during live view operation.
Unlike the A9 III, 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 III are ISO 250 to ISO 25600, with the possibility to increase the ISO range to 125-51200.
In terms of underlying technology, the K-3 III is build around a CMOS sensor, while the A9 III uses a Stacked 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.
For many cameras, data on sensor performance has been reported by DXO Mark. 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 following table provides an overview of the physical sensor characteristics, as well as the sensor quality measurements for a selection of comparators.
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 | 4128 | 4K/30p | 24.2 | 13.7 | 2083 | 85 | |
2. | Sony A9 III | Full Frame | 24.0 | 6000 | 4000 | 4K/120p | 25.4 | 14.7 | 3243 | 96 | |
3. | Fujifilm X-H1 | APS-C | 24.0 | 6000 | 4000 | 4K/30p | 24.0 | 13.3 | 1806 | 82 | |
4. | Fujifilm X-T4 | APS-C | 26.0 | 6240 | 4160 | 4K/60p | 24.1 | 13.6 | 1995 | 84 | |
5. | Nikon Z6 II | Full Frame | 24.3 | 6048 | 4024 | 4K/60p | 25.0 | 14.4 | 3303 | 94 | |
6. | Panasonic S5 | Full Frame | 24.0 | 6000 | 4000 | 4K/60p | 25.1 | 14.5 | 2697 | 94 | |
7. | Pentax K-3 | APS-C | 24.1 | 6016 | 4000 | 1080/60i | 23.7 | 13.4 | 1216 | 80 | |
8. | Pentax K-3 II | APS-C | 24.1 | 6016 | 4000 | 1080/60i | 23.6 | 13.6 | 1106 | 80 | |
9. | Pentax K-5 II | APS-C | 16.1 | 4928 | 3264 | 1080/25p | 23.8 | 14.1 | 1235 | 82 | |
10. | Pentax K-70 | APS-C | 24.0 | 6000 | 4000 | 1080/60i | 23.8 | 13.1 | 1639 | 80 | |
11. | Pentax KP | APS-C | 24.1 | 6016 | 4000 | 1080/60i | 23.9 | 13.2 | 1699 | 81 | |
12. | Pentax K-S2 | APS-C | 20.0 | 5472 | 3648 | 1080/30p | 23.6 | 12.9 | 1514 | 79 | |
13. | Sony A1 | Full Frame | 49.8 | 8640 | 5760 | 8k/30p | 25.9 | 14.5 | 3163 | 98 | |
14. | Sony A7 II | Full Frame | 24.0 | 6000 | 4000 | 1080/60p | 24.9 | 13.6 | 2449 | 90 | |
15. | Sony A7 III | Full Frame | 24.0 | 6000 | 4000 | 4K/30p | 25.0 | 14.7 | 3730 | 96 | |
16. | Sony A9 | Full Frame | 24.0 | 6000 | 4000 | 4K/30p | 24.9 | 13.3 | 3517 | 92 | |
17. | Sony A9 II | Full Frame | 24.0 | 6000 | 4000 | 4K/30p | 25.0 | 14.0 | 3434 | 93 | |
Note: DXO values in italics represent estimates based on sensor size and age. |
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, but the A9 III provides a faster frame rate than the K-3 III. It can shoot movie footage at 4K/120p, while the Pentax is limited to 4K/30p.
Feature comparison
Apart from body and sensor, cameras can and do differ across a range of features. For example, the A9 III has an electronic viewfinder (9440k 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 III has a higher magnification than the one of the K-3 III (0.9x vs 0.70x), so that the size of the image transmitted appears closer to the size seen with the naked human eye. The table below summarizes some of the other core capabilities of the Pentax K-3 III and Sony A9 III in connection with corresponding information for a sample of similar cameras.
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 III | optical | Y | 3.2 / 1620 | fixed | Y | 1/8000s | 12.0/s | n | Y | |
2. | Sony A9 III | 9440 | n | 3.2 / 2100 | full-flex | Y | 1/80000s | 120.0/s | n | Y | |
3. | Fujifilm X-H1 | 3690 | Y | 3.0 / 1040 | full-flex | Y | 1/8000s | 14.0/s | n | Y | |
4. | Fujifilm X-T4 | 3690 | n | 3.0 / 1620 | swivel | Y | 1/8000s | 15.0/s | n | Y | |
5. | Nikon Z6 II | 3690 | Y | 3.2 / 2100 | tilting | Y | 1/8000s | 14.0/s | n | Y | |
6. | Panasonic S5 | 2360 | n | 3.0 / 1840 | swivel | Y | 1/8000s | 7.0/s | n | Y | |
7. | Pentax K-3 | optical | Y | 3.2 / 1037 | fixed | n | 1/8000s | 8.3/s | Y | Y | |
8. | Pentax K-3 II | optical | Y | 3.2 / 1037 | fixed | n | 1/8000s | 8.3/s | n | Y | |
9. | Pentax K-5 II | optical | Y | 3.0 / 921 | fixed | n | 1/8000s | 7.0/s | Y | Y | |
10. | Pentax K-70 | optical | n | 3.0 / 921 | swivel | n | 1/6000s | 6.0/s | Y | Y | |
11. | Pentax KP | optical | n | 3.0 / 921 | tilting | n | 1/6000s | 7.0/s | Y | Y | |
12. | Pentax K-S2 | optical | n | 3.0 / 921 | swivel | n | 1/6000s | 5.4/s | Y | Y | |
13. | Sony A1 | 9437 | n | 3.0 / 1440 | tilting | Y | 1/8000s | 10.0/s | n | Y | |
14. | Sony A7 II | 2400 | n | 3.0 / 1230 | tilting | n | 1/8000s | 5.0/s | n | Y | |
15. | Sony A7 III | 2359 | n | 3.0 / 922 | tilting | Y | 1/8000s | 10.0/s | n | Y | |
16. | Sony A9 | 3686 | n | 3.0 / 1440 | tilting | Y | 1/8000s | 20.0/s | n | Y | |
17. | Sony A9 II | 3686 | n | 3.0 / 1440 | tilting | Y | 1/8000s | 20.0/s | n | Y | |
Note: *) Information refers to the mechanical shutter, unless the camera only has an electronic one. |
One feature that is present on the K-3 III, but is missing on the A9 III 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 A9 III 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-3 III 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 A9 III 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 and the Sony A9 III both have 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 III uses CFexpress (type A) or SDXC cards. Both cameras feature dual card slots, which can be very useful in case a memory card fails. Both cameras support UHS-II cards, which provide for Ultra High Speed data transfer of up to 312 MB/s (the second slot of the K-3 III supports only UHS-I, though).
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 III and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.
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 III | Y | stereo / mono | Y | Y | micro | 3.2 | Y | - | Y | |
2. | Sony A9 III | Y | stereo / mono | Y | Y | full | 3.2 | Y | - | Y | |
3. | Fujifilm X-H1 | Y | stereo / mono | Y | - | micro | 3.0 | Y | - | - | |
4. | Fujifilm X-T4 | Y | stereo / mono | Y | - | micro | 3.1 | Y | - | Y | |
5. | Nikon Z6 II | Y | stereo / mono | Y | Y | micro | 3.2 | Y | - | Y | |
6. | Panasonic S5 | Y | stereo / mono | Y | Y | micro | 3.2 | Y | - | Y | |
7. | Pentax K-3 | Y | mono / mono | Y | Y | mini | 3.0 | - | - | - | |
8. | Pentax K-3 II | Y | mono / mono | Y | Y | mini | 3.0 | - | - | - | |
9. | Pentax K-5 II | Y | stereo / mono | Y | - | mini | 2.0 | - | - | - | |
10. | Pentax K-70 | Y | stereo / mono | Y | - | mini | 2.0 | Y | - | - | |
11. | Pentax KP | Y | stereo / mono | Y | - | - | 2.0 | Y | - | - | |
12. | Pentax K-S2 | Y | mono / mono | Y | - | micro | 2.0 | Y | Y | - | |
13. | Sony A1 | Y | stereo / mono | Y | Y | full | 3.2 | Y | - | Y | |
14. | Sony A7 II | Y | stereo / mono | Y | Y | micro | 2.0 | Y | Y | - | |
15. | Sony A7 III | Y | stereo / mono | Y | Y | micro | 3.1 | Y | Y | Y | |
16. | Sony A9 | Y | stereo / mono | Y | Y | micro | 2.0 | Y | Y | Y | |
17. | Sony A9 II | Y | stereo / mono | Y | Y | micro | 3.1 | Y | Y | Y |
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.
Both the K-3 III and the A9 III are recent models that are part of the current product line-up. The K-3 III replaced the earlier Pentax K-3 II, while the A9 III followed on from the Sony A9 II. Further information on the features and operation of the K-3 III and A9 III can be found, respectively, in the Pentax K-3 III Manual (free pdf) or the online Sony A9 III Manual.
Review summary
So what is the bottom line? Which of the two cameras – the Pentax K-3 III or the Sony A9 III – has the upper hand? Is one clearly better than the other? Below is a summary of the relative strengths of each of the two contestants.
Reasons to prefer 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.
- Longer lasting: Can take more shots (800 versus 530) on a single battery charge.
- Easier geotagging: Features an internal GPS sensor to log localization data.
- More affordable: Was introduced into a lower priced category (67 percent cheaper at launch).
- More heavily discounted: Has been available for much longer (launched in March 2021).
Advantages of the Sony Alpha A9 III:
- Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
- Better image quality: Is equipped with a larger and more technologically advanced 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 video: Provides higher movie framerates (4K/120p versus 4K/30p).
- 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 (0.9x vs 0.70x).
- More detailed LCD: Has a higher resolution rear screen (2100k vs 1620k dots).
- More flexible LCD: Has a full-flex screen for odd-angle shots in portrait or landscape orientation.
- More selfie-friendly: Has an articulated screen that can be turned to be front-facing.
- Faster shutter: Has higher mechanical shutter speed (1/80000s vs 1/8000s) to freeze action.
- Faster burst: Shoots at higher frequency (120 vs 12 flaps/sec) to capture the decisive moment.
- Less disturbing: Has an electronic shutter option for completely silent shooting.
- Less heavy: Has a lower weight (by 118g or 14 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.
- More solid recording: Has a full-sized HDMI port for a sturdy connection to an external recorder.
- More modern: Reflects 2 years and 7 months of technical progress since the K-3 III launch.
If the count of relative strengths (bullet points above) is taken as a measure, the A9 III is the clear winner of the contest (20 : 8 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. 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-3 III and the Sony A9 III 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 comparison of the spec-sheets of cameras can offer a general idea of their imaging potential, it says little about, for example, the shooting experience and imaging performance of the K-3 III and the A9 III in practical situations. 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.
Expert reviews
This is why expert reviews are important. The table below provides a synthesis of the camera assessments of some of the best known photo-gear 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.
Camera Model |
AP score |
CL score |
DCW score |
DPR score |
EPZ score |
PB score |
Camera Launch |
Launch Price |
Street Price |
||
---|---|---|---|---|---|---|---|---|---|---|---|
1. | Pentax K-3 III | 4/5 | .. | 3/5 | .. | 4.5/5 | .. | Mar 2021 | US$ 1 999 | amazon.com | |
2. | Sony A9 III | 4.5/5 | .. | .. | .. | .. | .. | Nov 2023 | US$ 5 999 | amazon.com | |
3. | Fujifilm X-H1 | .. | + | 5/5 | 86/100 | 4.5/5 | 4.5/5 | Feb 2018 | US$ 1 899 | ebay.com | |
4. | Fujifilm X-T4 | 5/5 | + + | 5/5 | 88/100 | 5/5 | 5/5 | Feb 2020 | US$ 1 699 | ebay.com | |
5. | Nikon Z6 II | 4.5/5 | .. | 4/5 | 89/100 | 4.5/5 | 4.5/5 | Oct 2020 | US$ 1 999 | amazon.com | |
6. | Panasonic S5 | 4.5/5 | + + | 4.5/5 | 88/100 | 4.5/5 | 4.5/5 | Sep 2020 | US$ 1 999 | amazon.com | |
7. | Pentax K-3 | 4/5 | .. | .. | 83/100 | 5/5 | 5/5 | Oct 2013 | US$ 1 299 | ebay.com | |
8. | Pentax K-3 II | 4.5/5 | .. | .. | .. | 5/5 | 5/5 | Apr 2015 | US$ 1 099 | ebay.com | |
9. | Pentax K-5 II | 5/5 | .. | .. | 80/100 | 5/5 | 4.5/5 | Sep 2012 | US$ 1 099 | ebay.com | |
10. | Pentax K-70 | 4.5/5 | .. | 4/5 | 79/100 | 4.5/5 | 4.5/5 | Jun 2016 | US$ 649 | ebay.com | |
11. | Pentax KP | 4/5 | .. | 3/5 | 82/100 | 5/5 | 4.5/5 | Jan 2017 | US$ 1 099 | ebay.com | |
12. | Pentax K-S2 | 4.5/5 | .. | .. | .. | 5/5 | 4.5/5 | Feb 2015 | US$ 749 | ebay.com | |
13. | Sony A1 | 5/5 | o | 4.5/5 | 93/100 | 4.5/5 | 5/5 | Jan 2021 | US$ 6 499 | amazon.com | |
14. | Sony A7 II | 5/5 | + | 4/5 | 82/100 | 4.5/5 | 5/5 | Nov 2014 | US$ 1 999 | ebay.com | |
15. | Sony A7 III | .. | + + | 4.5/5 | 89/100 | 5/5 | 5/5 | Feb 2018 | US$ 1 999 | amazon.com | |
16. | Sony A9 | 5/5 | + + | 4.8/5 | 89/100 | 5/5 | 5/5 | Apr 2017 | US$ 4 499 | ebay.com | |
17. | Sony A9 II | .. | .. | 5/5 | 90/100 | 5/5 | 5/5 | Oct 2019 | US$ 4 499 | amazon.com | |
Note: (+ +) 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? In case you are interested in seeing how other cameras pair up, just make your choice using the following search menu. As an alternative, you can also directly jump to any one of the listed comparisons that were previously generated by the CAM-parator tool.
- Canon M6 Mark II vs Pentax K-3 III
- Fujifilm X100F vs Sony A9 III
- Leica C-LUX vs Sony A9 III
- Leica D-LUX 7 vs Sony A9 III
- Nikon D6 vs Pentax K-3 III
- Nikon Z7 vs Pentax K-3 III
- Panasonic G3 vs Pentax K-3 III
- Panasonic GH5 vs Pentax K-3 III
- Pentax K-3 III vs Sony A6100
- Sony A6400 vs Sony A9 III
- Sony A7S III vs Sony A9 III
- Sony A9 II vs Sony A9 III
Specifications: Pentax K-3 III vs Sony A9 III
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-3 III | Sony A9 III |
---|---|---|
Camera Type | Digital single lens reflex | Mirrorless system camera |
Camera Lens | Pentax K mount lenses | Sony E mount lenses |
Launch Date | March 2021 | November 2023 |
Launch Price | USD 1,999 | USD 5,999 |
Sensor Specs | Pentax K-3 III | Sony A9 III |
Sensor Technology | CMOS | Stacked 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/120p Video |
ISO Setting | 100 - 160,000 ISO | 250 - 25,600 ISO |
ISO Boost | no Enhancement | 125 - 51,200 ISO |
Image Processor | PRIME V | Dual BIONZ XR |
Screen Specs | Pentax K-3 III | Sony A9 III |
Viewfinder Type | Optical viewfinder | Electronic viewfinder |
Viewfinder Field of View | 100% | 100% |
Viewfinder Magnification | 0.70x | 0.9x |
Viewfinder Resolution | 9440k dots | |
Top-Level Screen | Control Panel | no Top Display |
LCD Framing | Live View | Live View |
Rear LCD Size | 3.2inch | 3.2inch |
LCD Resolution | 1620k dots | 2100k dots |
LCD Attachment | Fixed screen | Fully flexible screen |
Touch Input | Touchscreen | Touchscreen |
Shooting Specs | Pentax K-3 III | Sony A9 III |
Focus System | Phase-detect AF | On-Sensor Phase-detect |
Manual Focusing Aid | Focus Peaking | Focus Peaking |
Max Shutter Speed (mechanical) | 1/8000s | 1/80000s |
Continuous Shooting | 12 shutter flaps/s | 120 shutter flaps/s |
Electronic Shutter | no E-Shutter | up to 1/80000s |
Time-Lapse Photography | Intervalometer built-in | Intervalometer built-in |
Image Stabilization | In-body stabilization | In-body stabilization |
Fill Flash | no On-Board Flash | no On-Board Flash |
Storage Medium | SDXC cards | CFexA or SDXC cards |
Single or Dual Card Slots | Dual card slots | Dual card slots |
UHS card support | Single UHS-II | UHS-II |
Connectivity Specs | Pentax K-3 III | Sony A9 III |
External Flash | Hotshoe | Hotshoe |
Studio Flash | PC Sync socket | PC Sync socket |
USB Connector | USB 3.2 | USB 3.2 |
HDMI Port | micro HDMI | full HDMI |
Microphone Port | External MIC port | External MIC port |
Headphone Socket | Headphone port | Headphone port |
Wifi Support | Wifi built-in | Wifi 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 III |
Environmental Sealing | Weathersealed body | Weathersealed body |
Battery Type | Pentax D-LI90 | Sony NP-FZ100 |
Battery Life (CIPA) | 800 shots per charge | 530 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) |
136 x 97 x 83 mm (5.4 x 3.8 x 3.3 in) |
Camera Weight | 820 g (28.9 oz) | 702 g (24.8 oz) |
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