Hi Camera Lovers 👋 If you buy a camera through our referral links, you support our site at no cost to you 😉 Full info here.

Pentax 645Z vs Sony a7R III Comparison

Storage & Battery

Pentax 645Z

Pentax 645Z

Sony a7R III

Sony a7R III camera image
Pentax 645Z
Sony a7R III
Refers to the year this camera was officially made available for sale.
Announcement Date
Refers to the date the manufacturer publicly announced the upcoming release and general specs of this camera.
April 15, 2014
October 25, 2017
Camera Type
Camera Size
Camera Weight

The Sony a7R III outperforms the Pentax 645Z with a score of 83/100 compared to 73/100. Both cameras share some common specifications, such as their release years (2014 and 2017) and launch prices ($8,499 and $3,200). The Pentax 645Z, a DSLR, is larger and heavier, measuring 156 x 117 x 123mm and weighing 1550g. On the other hand, the Sony a7R III, a mirrorless camera, is more compact and lightweight at 127 x 96 x 74mm and 657g.

The Sony a7R III’s higher score shows that it is a better camera overall, offering advantages such as its mirrorless design and lighter weight. However, the Pentax 645Z may still be preferred by some users, particularly those who prefer the DSLR format. Ultimately, the choice between these two cameras depends on individual preferences and needs.

Pentax 645Z vs Sony a7R III Overview and Optics

The Sony a7R III wins the optics comparison with a score of 84/100, while the Pentax 645Z scores 79/100. Both cameras share similarities in specifications, such as having a CMOS sensor and a range of compatible lenses due to their respective lens mounts (Pentax 645AF2 for the 645Z and Sony FE for the a7R III).

The Sony a7R III boasts several advantages over the Pentax 645Z. Despite having a slightly lower megapixel count (42.4 vs 51.4), the a7R III has a faster shooting speed of 10 frames per second, compared to the 3 frames per second of the 645Z. This makes the Sony a7R III more suitable for action and sports photography. Additionally, the a7R III features image stabilization, which greatly reduces the chances of blurry images caused by camera shake. The a7R III also has a full-frame sensor, which provides better low-light performance and a shallower depth of field.

On the other hand, the Pentax 645Z has a larger medium format sensor, which allows for higher resolution and more detailed images. The 645Z also has a slightly higher DXOMARK score for its sensor (101 vs 100), indicating better overall image quality. However, the lack of image stabilization and slower shooting speed may limit its versatility in certain situations.

Considering these factors, the Sony a7R III is the better option for photographers who value speed, image stabilization, and low-light performance. The Pentax 645Z may still appeal to those who prioritize high-resolution images and are willing to compromise on speed and versatility.

The higher the number of megapixels, the more detail the cameras sensor can capture.
51.4 MP
42.4 MP
Image Resolution
Image resolution is measured in pixels and megapixels, width by height. The higher the number, the higher its resolution.
8256 x 6192 px
7952 x 5304 px
Sensor Type
The camera sensor captures light and records the image. Sensors vary in physical size, the number of pixels, and quality.
Sensor Size
The sensor size contributes to the overall quality as well as the dynamic and tonal range a camera can capture. As a rule of thumb, the more surface there is to read the light, the more information it will capture.
32.8 x 43.8 mm
24 x 35.9 mm
Sensor Format
Refers to the most commonly used sensor sizes.
Medium Format
Full Frame
Frame Rate
The number of sequential frames per second the camera can write to the memory card when shooting in burst or continuous mode.
3 fps
10 fps
Lens Mount
The lens mount will tell you what type of lens range you can fit onto the camera body. Often the same camera company will have different lens ranges for different cameras.
Pentax 645AF2
Sony FE
Image Processor
The image processor in the camera converts the information collected on the sensor for digital storage on the memory card.
Prime III
Bionz X
Aspect Ratio
The aspect ratio refers to the proportional difference between width and height. The most popular aspect ratios are 3:2 and 4:3.
Minimum ISO (Native)
Refers to the lowest native (or 'base') ISO setting. Lower ISO are less sensitive to light but make a cleaner image.
Maximum ISO (Native)
Refers to the highest native (or 'base') ISO setting. Higher ISO is necessary for low-light situations or night photography, but higher ISOs often introduce grain or noise.
Minimum ISO (Expanded)
Expanded (or extended) ISO is a digitally enhanced feature available on some cameras. It allows you to push beyond the native ISO range if necessary.
Maximum ISO (Expanded)
Expanded (or extended) ISO is a digitally enhanced feature available on some cameras. It allows you to push beyond the native ISO range if necessary.
Minimum Shutter Speed
The minimum shutter speed will tell you the longest exposure your camera can take without using an external accessory.
30 s
30 s
Maximum Shutter Speed
The maximum shutter speed tells you the length inside 1 second the camera will capture. These can sometimes be extended with accessories such as extra external batteries.
1/ 4000 s
1/ 8000 s
Autofocus Points
Autofocus points show where the camera is focusing graphically as squares or brackets in Live View or on an electronic viewfinder. These points are also used for light meter readings.
In-body Stabilization
In-body Stabilization means the camera has a certain technology embedded that counteracts camera shake.
Viewfinder Type
The viewfinder type is either electronic or optical. Electronic viewfinders will have a small screen in the viewfinder. Optical viewfinders will use prisms and mirrors to look through the lens.
Optical (pentaprism)
Viewfinder Resolution
3,686,400 dots

Pentax 645Z vs Sony a7R III Video Performance

The Pentax 645Z outperforms the Sony a7R III in video capabilities with a score of 70/100, compared to the Sony’s 56/100. Both cameras have distinct features and advantages for video recording, making them suitable for different users and purposes.

Both the Pentax 645Z and the Sony a7R III share some common video specifications. They both provide Full HD (1920 x 1080) video resolution, and the Pentax 645Z has a slightly higher maximum frame rate of 60fps, while the Sony a7R III offers a maximum of 30fps.

The Pentax 645Z excels in its video features with a built-in time-lapse functionality, which the Sony a7R III lacks. This makes the Pentax 645Z a better choice for videographers who require time-lapse capabilities without the need for additional equipment or software.

On the other hand, the Sony a7R III offers a higher maximum video resolution of 4K (3840 x 2160), which is not available on the Pentax 645Z. This gives the Sony a7R III an advantage for users who prioritize higher video resolution for their projects.

Considering the video capabilities of both cameras, the Pentax 645Z is a better choice for those who need time-lapse functionality and a higher frame rate for smoother video playback. However, the Sony a7R III is more suitable for users who prioritize higher video resolution, such as 4K, for their projects. Ultimately, the choice between the two cameras depends on the specific requirements and preferences of the videographer.

Indicates if this camera is capable of recording video.
Max Video Resolution
The best resolution this camera can capture video in. Modern cameras can capture up to 8K video.
Full HD
Max Video Dimensions
Video resolution measured by the greatest number of pixels possible in each frame, width by height. A higher resolution means more detail or clarity in your video.
1920 x 1080 px
3840 x 2160 px
Max Video Frame Rate
How many frames per second your video will capture. Most cameras have options for multiple frame rates, depending on the resolution you shoot in. For a general video, 24p or 30p is the standard, but more serious filmmakers may need a higher frame rate for creative effect.
60 p
30 p
Time-Lapse Built In
A built in time-lapse mode will allow continuous shooting throughout a prolonged period of time to be compressed into a sped up video.
Video File Format
Different cameras can record in various video file formats. The File format you record in can impact how you edit and use the files.
XAVC S, AVCHD Ver. 2.0, MP4

Pentax 645Z vs Sony a7R III Features and Benefits

The Sony a7R III emerges as the winner with a feature score of 83/100, while the Pentax 645Z scores 59/100. Both cameras share some specifications, such as having Wi-Fi connectivity, flip screens, and no GPS. However, the Sony a7R III outperforms the Pentax 645Z in several aspects, making it the superior camera in terms of features.

The Sony a7R III has a higher screen resolution of 1,440,000 dots, compared to the Pentax 645Z’s 1,037,000 dots. This results in a sharper and clearer display on the Sony camera. Additionally, the Sony a7R III has a touchscreen, making it more user-friendly and convenient for photographers to navigate through settings and review images. The Pentax 645Z lacks this feature.

Furthermore, the Sony a7R III has Bluetooth connectivity, which allows for seamless and quick file transfers to compatible devices. The Pentax 645Z does not offer this option. In terms of screen size, the Pentax 645Z has a slightly larger screen at 3.2 inches, compared to the Sony a7R III’s 3-inch screen. However, this minor advantage does not outweigh the benefits provided by the Sony a7R III’s superior features.

The Sony a7R III’s higher feature score of 83/100 reflects its better performance and user-friendly design. On the other hand, the Pentax 645Z’s lower score of 59/100 highlights its limitations in comparison to the Sony a7R III. Therefore, the Sony a7R III is the better camera in terms of features and functionality.

Built-in Flash
A built-in flash will often be positioned right above the lens. This will automatically pop up when you activate it.
External Flash
External flashes are often connected through a hot shoe at the top of a camera, or a cable at the side of the camera.
GPS features in a camera will include location metadata to each of your photographs.
Weather Sealing
Weather sealing capabilities will give you more confidence when shooting in unfavourable conditions.
Screen Type
Touch Screen
Touchscreen allows you to change camera settings and access menus with a swipe of your finger, instead of using buttons.
Screen Size
Screen Resolution
Screen dots indicate the resolution of the LCD screen by including each sub pixel.
1,037,000 dots
1,440,000 dots
Flip Screen
A flip screen (or articulating screen) is a second screen which can flip out from the side or top of the camera. This rotating screen allows you more freedom to take photos at different angles.
Live View
Live View feature allows you to see a continuous live video of what is being seen through your lens.
Bluetooth capabilities allow you wireless control of your camera with other external devices.

Pentax 645Z vs Sony a7R III Storage and Battery

The Pentax 645Z and the Sony a7R III have the same storage and battery score of 65/100. Both cameras feature two memory card slots and accept SD, SDHC, and SDXC memory cards. Additionally, they share the same battery life of 650 shots.

Despite their similar scores, the Sony a7R III has an advantage in storage as it is compatible with UHS-II cards, which offer higher reading and writing speeds. This can be beneficial for photographers who need to transfer large amounts of data quickly.

On the other hand, both cameras use different battery types: the Pentax 645Z uses a D-LI90 battery, while the Sony a7R III uses an NP-FZ100 battery. However, this difference does not affect their performance or battery life, as both cameras provide 650 shots per charge.

Neither camera offers USB charging, which could be a drawback for some users. In terms of storage and battery, the Sony a7R III has a slight advantage due to its UHS-II compatibility, while the Pentax 645Z matches the Sony in all other aspects.

Storage and Battery
Storage and Battery
Memory Card
SD / SDHC / SDXC (UHS-II compatible)
Dual Memory Card Slots
Battery Type
Battery Life
Approximately how long this cameras battery will last measured by how many photographs you will be able to take.
650 shots
650 shots
USB Charging
Sensor scores tested by DXOMARK
Overall Score
DXOMARK overall sensor score.
Portrait (Color Depth)
As described by DXOMARK 'The Portrait score in our camera sensor reviews defines color depth performance and its unit is a number of bits. A color depth of 22 bits is excellent; differences below 1 bit are barely noticeable.'
26 bits
26 bits
Landscape (Dynamic Range)
As described by DXOMARK 'The Landscape score in our camera sensor tests defines the maximum dynamic range of the camera sensor and its unit is an exposure value (EV). A value of 12 EV is excellent with differences below 0.5 EV usually not noticeable.'
14.7 EVs
14.7 EVs
Sports (Low-Light ISO)
Described by DXOMARK as 'The maximal value of ISO sensitivity needed to reach a given value of Signal-to-Noise Ratio (SNR). The greater the value, the better'

Pentax 645Z vs Sony a7R III – Our Verdict

Pentax 645Z vs Sony a7R III Comparison image.

Are you still undecided about which camera is right for you? Have a look at these popular comparisons that feature the Pentax 645Z or the Sony a7R III:

User Scores
B&H photo video
Spotted a mistake with these camera specs? Please let us know so we can update it!