Pentax 645Z vs Sony A7R III

Cameras
Compare Cameras
Pentax 645Z vs Sony A7R III

Leave Feedback

Medium format 1,436.6mm²
51.4 megapixels
ISO 100 - 204,800

Go in depth with our full Pentax 645Z Review.
How does it shoot? Pentax 645Z in the real world.
See real-world photos taken with the 645Z.
Compare Pentax 645Z image quality against competitors.
What’s the bottom line? Read our Pentax 645Z conclusion.

35mm 861.6mm²
42.4 megapixels
ISO 100 - 32,000

Go in depth with our full Sony A7R III Review.
How does it shoot? Sony A7R III in the real world.
See real-world photos taken with the A7R III.
Compare Sony A7R III image quality against competitors.
What’s the bottom line? Read our Sony A7R III conclusion.

Succeeded by the Sony A7R IV
Compare A7R III vs A7R IV
Compare Pentax 645Z vs Sony A7R IV

Buy From

Differences

Pentax 645Z advantages over Sony A7R III

Larger sensor
Medium format vs 35mm
More sensor area. Bigger is (generally) better.
Bigger pixels
~ 5.31 vs 4.51 microns
Better low-light and dynamic range (all else equal)
Higher effective ISO

Higher effective ISO

Maximum effective ISO is an estimate of the highest sensitivity at which a camera can capture excellent quality photos.

Cameras with higher effective ISO will be better choices for indoor photography, night shooting, and indoor sports photography, especially if you intend to make large prints.

You can learn more at our glossary entry.

Maximum effective ISO test data courtesy of DxO Mark.
645Z test data on DxO Mark A7R III test data on DxO Mark

4,505 vs 3,523 iso
Take photos in low light with less noise
Top deck display
Yes vs No
Check settings with a screen on top of the camera
Less shutter lag
0.16 vs 0.25 sec
Focus and take a photo quickly (wide angle)
More pixels
51.4 vs 42.4 megapixels
Higher resolution photos
Higher extended ISO
204800 vs 102400 ISO
Higher extended ISO can give more low-light flexibility

Sony A7R III advantages over Pentax 645Z

Lens selection
Good vs Limited
Better lens selection gives you more options
Less expensive
$1635 vs $4694*
Save money for lenses or accessories
In-Camera Image Stabilization
Yes vs No
Reduces the effects of camera shake at slower shutter speeds
Shoot 4K video
4K (UHD) vs 1080p
Make sure you have a fast computer
Touchscreen
Touch vs No touch
Interact with your camera just like your smartphone
High resolution composite
Yes vs No
Combine multiple shots to form a super hi-res version
Built-in Wi-Fi
Wi-Fi vs None
Share your photos wirelessly
NFC
Yes vs No
Simplifies pairing your camera with supported phones
Built-in Bluetooth
Yes vs No
Always-on wireless connectivity
On-sensor phase detect
Yes vs No
Usually improves live view and video AF performance
Thinner
73 mm vs 123 mm
Thinner
Higher max flash sync
1/250 vs 1/125 sec
Reduce the effect of ambient light in flash shots
Newer
7 years vs 11 years old
Newer cameras often support more advanced features
Lighter weight
657g vs 1555g
Lighter weight
Headphone jack
Yes vs No
Monitor audio recording while you shoot video
Faster JPEG shooting
9.9 fps vs 3.1 fps
Faster JPEG shooting (burst mode)
Bigger JPEG buffer
82 vs 12 shots
Take more JPEG shots before waiting (burst mode)
Faster RAW shooting
9.2 fps vs 3.1 fps
Faster RAW shooting in burst mode
Bigger RAW buffer
30 vs 10 shots
Larger buffer for RAW shots (burst mode)
Slow-motion videos
Yes vs No
Shoot slow-motion videos
Faster shutter
1/8000 vs 1/4000 sec
Shoot wide open in bright light

Similarities

Common Strengths

Focus peaking
Both provide
Your camera will highlight what's in focus
Eye-level viewfinder
Both provide
You'll be able to frame photos even when the sun is out
Tiltable Screen
Both provide
Tilt the screen for shooting flexbility
External Mic Jack
Both provide
Improved sound fidelity when shooting video
HDMI out
Both provide
Use HDMI output to monitor or review video
Hot shoe
Both provide
Off-camera flashes open new possibilities
Dual card slots
Both provide
Gives you more storage flexibility
Bulb shutter
Both provide
Hold the shutter open manually for long exposures

Common Weaknesses

Tilt-swivel screen
Neither provide
Tilt and swivel the screen for maximum shooting flexibility
In-camera panoramas
Neither provide
Stitches multiple shots into a panoramic photo
Built-in GPS
Neither provide
Geotag your photos
Internal flash
Neither provide
Useful in a pinch for fill flash

User reviews

Amazon
Adorama
Read 645Z User Reviews

Amazon
Adorama
Read A7R III User Reviews

Buy From

Your purchases support this site

Buy the Pentax 645Z

Body Only

All 645Z Deals

Your purchases support this site

Buy the Sony A7R III

Body Only

Body Only
Kit with 24-70mm f/2.8 GM lens
Kit with 24-70mm f/4 lens

All A7R III Deals

Review Excerpt

Phenomenal resolution and detail; Great high ISO performance; Rugged, weather-sealed body; Huge, bright viewfinder; Fast autofocus works well in low light; Swift performance for a medium-format camera; Good battery life; Shoots Full HD video
Quite bulky compared to an APS-C or full-frame DSLR; Autofocus points clustered near center of frame; Most lenses aren't weather-sealed or optimized for digital; Prone to aliasing artifacts (but so are most high-end cameras these days); Attracts a lot of attention from passers-by
Read our Pentax 645Z Review

Fantastic image quality; Improved dynamic range over its predecessor; Very good high ISO performance; Much improved real-world AF performance; Class-leading burst rates, even with RAW; Improved 5-axis in-body image stabilization; Better 4K video quality; 1080/120fps video; Dual card slots; Significantly better battery life.
Expensive; Menus still confusing; UHS-II support only on one card slot; No optical low-pass filter means greater risk of moire; No built-in flash; Buffer clearing still slow despite UHS-II support.
Read our Sony A7R III Review

The Competition

Compared to Pentax 645D

Pentax 645Z

Pentax 645D

$4845
Medium format

Focus peaking
Tiltable Screen

$3599
Medium format

Fast startup
Longer stills battery life

Compare Pentax 645Z vs Pentax 645D

Sony A7R III

Pentax 645D

$2066
35mm

Lens selection
Focus peaking

$3599
Medium format

Larger sensor
Bigger pixels

Compare Sony A7R III vs Pentax 645D

Compared to Leica S (Typ 006)

Pentax 645Z

Leica S (Typ 006)

$4845
Medium format

Focus peaking
Tiltable Screen

$10535
Medium format

Thinner
More viewfinder magnification

Compare Pentax 645Z vs Leica S (Typ 006)

Sony A7R III

Leica S (Typ 006)

$2066
35mm

Lens selection
Focus peaking

$10535
Medium format

Larger sensor
Bigger pixels

Compare Sony A7R III vs Leica S (Typ 006)

Compared to Leica S-E (Typ 006)

Pentax 645Z

Leica S-E (Typ 006)

$4845
Medium format

Focus peaking
Tiltable Screen

$16900
Medium format

Built-in GPS
Thinner

Compare Pentax 645Z vs Leica S-E (Typ 006)

Sony A7R III

Leica S-E (Typ 006)

$2066
35mm

Lens selection
Focus peaking

$16900
Medium format

Larger sensor
Bigger pixels

Compare Sony A7R III vs Leica S-E (Typ 006)

Compared to Sony A7R II

Pentax 645Z

Sony A7R II

$4845
Medium format

Larger sensor
Bigger pixels

$2348
35mm

Less expensive
Lens selection

Compare Pentax 645Z vs Sony A7R II

Sony A7R III

Sony A7R II

$2066
35mm

Touchscreen
High resolution composite

$2348
35mm

In-camera panoramas

Compare Sony A7R III vs Sony A7R II

Compared to Nikon Z7 II

Pentax 645Z

Nikon Z7 II

$4845
Medium format

Larger sensor
Bigger pixels

$2330
35mm

Less expensive
In-Camera Image Stabilization

Compare Pentax 645Z vs Nikon Z7 II

Sony A7R III

Nikon Z7 II

$2066
35mm

Less expensive
High resolution composite

$2330
35mm

Top deck display
Newer

Compare Sony A7R III vs Nikon Z7 II

Compare Other Cameras?