Pentax K-3 Mark III vs Pentax K-r

In this comparison, we will evaluate the Pentax K-3 Mark III and the Pentax K-r, highlighting the advantages of each over the other, discussing their pros and cons, shared strengths and weaknesses, and providing a rating based on their available features and specifications to assist you in choosing the one that best suits your needs.

Pentax K-3 Mark III was introduced in March 2021 and Pentax K-r was introduced in March 2011. Let us first list highlights of the models.

Now that we've looked at the most essential specifications and gained a basic understanding of these cameras, we can delve into more details and see the differences between them.

This section shows those features and specifications which are the reason to choose Pentax K-3 Mark III over Pentax K-r.

This section shows those features and specifications which are the reason to choose Pentax K-r over Pentax K-3 Mark III.

We already listed pros and cons of each model. However, you may also find useful to look at their common strengths and weaknesses shown side-by-side.

Screen

Pentax K-3 Mark III has a 3.2" screen with 1,620k dot resolution and Pentax K-r has a 3.0" screen with 921k dot resolution. Both have Fixed screens. Pentax K-3 Mark III also features touchscreen which has advantages such as easy menu navigation, intuitive controls, quick setting adjustment and most importantly a Touch-to-Focus functionality allowing users to select a specific point on the screen where they want the camera to focus. This feature can be helpful for achieving precise focus in both photo and video recording.

Viewfinder

Pentax K-3 Mark III has a built-in Optical (pentaprism) viewfinderPentax K-r has a built-in Optical (pentamirror) viewfinder. Pentax K-3 Mark III has 100% coverage with 1.05x (0.70x 35mm equivalent) magnification and Pentax K-r has 96% coverage with 0.85x (0.57x 35mm equivalent) magnification.

Pentax K-3 Mark III features a 25.73 megapixel APS-C CMOS sensor with dimensions of 23.3 x 15.5 mm and a total area of 361.2 mm². Its native ISO range is 100 - 1,600,000. Pentax K-r features a 12 megapixel APS-C CMOS sensor with dimensions of 23.6 x 15.8 mm and a total area of 249.6 mm². Its native ISO range is 200 - 12,800 and expands to 100 - 25,600 in boosted mode.

Here is a sensor size comparison chart where you can see how different sensors compare with each other:

Sensor size chart

	Sensor	Dimensions	Area	Aspect Ratio	Crop Factor
	Medium Format	44 x 33 mm	1452 mm2	4:3	0.79x
	Full Frame	36 x 24 mm	864 mm2	3:2	1x
	APS-H	27 x 18 mm	486 mm2	3:2	1.3x
	APS-C	23.6 x 15.6 mm	368.2 mm2	3:2	1.5x
	APS-C (Canon)	22.3 x 14.9 mm	332.3 mm2	3:2	1.6x
	Micro Four Thirds	17.4 x 13 mm	226.2 mm2	4:3	2x
	1-inch	13.2 x 8.8 mm	116.2 mm2	3:2	2.7x
	1/1.7-inch	7.44 x 5.58 mm	41.5 mm2	4:3	4.7x
	1/2.3-inch	6.17 x 4.55 mm	28.1 mm2	4:3	5.6x

Pentax K-3 Mark III is equipped with PRIME V processor and can take pictures up to 6192 x 4128 resolution. Pentax K-r is equipped with PRIME II processor and can take pictures up to 4288 x 2848 resolution. It can also take pictures with lower resolution like 3936 x 2624, 3072 x 2048, 1728 x 1152 with 3:2 aspect ratios.

Lens Mount

Cameras have Pentax K_AF2 lens mount. Due to their APS-C sensor their crop factor (also called lens multiplier) is equal to 1.5x. This means that a 35mm equivalent focal length of the mounted lens will be equal to its actual focal length times 1.5.

No Low-Pass Filter on Pentax K-3 Mark III

There is no optical low-pass filter (OLPF), also known as an anti-aliasing filter, in front of the sensor on Pentax K-3 Mark III. This results in a slightly sharper image but may also introduce moiré patterns and aliasing artifacts when photographing subjects with fine, repetitive patterns or details.

In-Body Image Stabilization

The cameras have a built-in Sensor Shift in-body image stabilization (IBIS) (5.5 stops of compensation in Pentax K-3 Mark III). This means that you are still getting vibration reduction when cameras are paired with non-image stabilizied lenses. It also works with lenses with optical image stabilization and in combination can achieve even better compensation.

Built-in Wi-Fi on Pentax K-3 Mark III

Pentax K-3 Mark III has a built-in Wi-Fi (802.11b/g/n, 2.4 GHz) which allows to easily transfer photos and videos from the camera to other Wi-Fi-enabled devices, such as smartphones, tablets, printers, or computers. This eliminates the need for cables and allows for quick and convenient media sharing and social media integration. It gives you the ability to control your camera remotely using a smartphone or tablet. This is particularly useful for taking self-portraits, group shots, or capturing images in challenging conditions without having to touch the camera. Firmware updates can also be downloaded and installed wirelessly.
  Check out the cameras in our database that have built-in WiFi.

Bluetooth on Pentax K-3 Mark III

Pentax K-3 Mark III has a built-in Bluetooth which lets you to connect the camera to a smartphone or a dedicated remote control device. This allows you to remotely trigger the camera, adjust settings and controls remotely through a paired mobile app. While Wi-Fi is generally faster for transferring larger files, Bluetooth can be used for small, selective transfers, it can provide real-time information about your camera's battery status, memory card capacity, and other key settings directly on your paired smartphone or smartwatch.
  Check out the cameras in our database that have built-in Bluetooth.

USB Inputs and HDMI Outputs

Both models have USB inputs for data transfer. connector for video signal output.

Battery

Pentax K-3 Mark III comes with D-LI90 battery pack with battery life of 800 shots and Pentax K-r comes with D-LI109
4 x AA battery pack with battery life of 470 shots.

External Storage Slots

Pentax K-3 Mark III has two card slots - one for SD/SDHC/SDXC (UHS-II) and one for SD/SDHC/SDXC (UHS-I). Pentax K-r has a single SD/SDHC/SDXC (UHS-I) card slot.

Shutter

Pentax K-3 Mark III has Electronic shutter. Shutter speed can go up to 1/8000 sec on Pentax K-3 Mark III, and up to 1/6000 sec on Pentax K-r. Pentax K-3 Mark III can shoot continuously up to 12.0 fps. Pentax K-r can shoot continuously up to 6.0 fps.

Focusing

Pentax K-3 Mark III has 101 (25 cross-type) focusing points and Pentax K-r has 11 (9 cross-type) focusing points. Pentax K-3 Mark III has detection range from -4 to +18 EV.

Exposure

Exposure meterings of Pentax K-3 Mark III ranges from -3 to +20 EV and you can set the exposure compensation within the ±5 EV range on Pentax K-3 Mark III and ±3 EV range on Pentax K-r. You can also do exposure lock, exposure bracketing and manual exposure adjustment on Pentax K-3 Mark III and exposure bracketing and manual exposure adjustment on Pentax K-r.

Flash

Pentax K-r has a built-in flash with maximum range of 12.00 m at ISO 100 and also accepts external flash which can be connected via Hot Shoe or Wireless connection. Pentax K-3 Mark III has no built-in flash but an external flash may be connected via Hot Shoe or PC Terminal. The fastest flash synchronization speed is 1/200 sec on Pentax K-3 Mark III and 1/180 sec on Pentax K-r.

Pentax K-3 Mark III body has dimensions of 135 x 104 x 74 mm (5.31 x 4.09 x 2.91") and Pentax K-r body has dimensions of 125 x 97 x 68 mm (4.92 x 3.82 x 2.68"). Pentax K-3 Mark III weighs 820 g (1.81 lb / 28.92 oz) and Pentax K-r weighs 598 g (1.32 lb / 21.09 oz).

Pentax K-3 Mark III

Pentax K-r

135 mm

104 mm

125 mm

97 mm

104 mm

97 mm

74 mm

68 mm