• Medium format 1,436.6mm2
  • 51.4 megapixels
  • ISO 100 - 204,800
  • 35mm 861.6mm2
  • 42.4 megapixels
  • ISO 100 - 32,000

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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
    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
    $2498 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 10 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

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Buy the Pentax 645Z
Body Only
All 645Z Deals

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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
  • $2204
  • 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)
  • $2204
  • 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)
  • $2204
  • 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
  • $2898
  • 35mm
  • Less expensive
  • Lens selection

Compare Pentax 645Z vs Sony A7R II

Sony A7R III
Sony A7R II
  • $2204
  • 35mm
  • Less expensive
  • Touchscreen
  • $2898
  • 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
  • $2204
  • 35mm
  • High resolution composite
  • NFC
  • $2330
  • 35mm
  • Top deck display
  • Newer

Compare Sony A7R III vs Nikon Z7 II

Compare Other Cameras?