• APS-C 366.6mm2
  • 24.4 megapixels
  • ISO 100 - 51,200
  • 35mm 861.6mm2
  • 42.4 megapixels
  • ISO 100 - 32,000

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Differences

Pentax K-3 advantages over Sony A7R III

  • Less expensive
    $999 vs $3596
    Save money for lenses or accessories
  • Lens selection
    Excellent vs Good
    Better lens selection gives you more options
  • Fast startup
    ~0.90 vs 1.7 sec
    Faster startup lets you catch the moment
  • Internal flash
    Internal flash vs None
    Useful in a pinch for fill flash
  • Top deck display
    Yes vs No
    Check settings with a screen on top of the camera
  • Less shutter lag
    0.14 vs 0.25 sec
    Focus and take a photo quickly (wide angle)
  • Optional anti-aliasing filter
    Optional vs None
    Lets you choose sharper photos or reduced moiré

Sony A7R III advantages over Pentax K-3

  • Larger sensor
    35mm vs APS-C
    More sensor area. Bigger is (generally) better.
  • Bigger pixels
    ~ 4.51 vs 3.91 microns
    Better low-light and dynamic range (all else equal)
  • 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
  • Tiltable Screen
    Tiltable vs Fixed
    Tilt the screen for shooting flexbility
  • 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
  • Higher effective ISO
    3,523 vs 1,216 iso
    Take photos in low light with less noise
  • On-sensor phase detect
    Yes vs No
    Usually improves live view and video AF performance
  • Newer
    12 months vs 5 years old
    Newer cameras often support more advanced features
  • More viewfinder magnification
    0.78x vs 0.63x
    Get a bigger view of the scene through the eye-level viewfinder
  • More pixels
    42.4 vs 24.4 megapixels
    Higher resolution photos
  • Faster JPEG shooting
    9.9 fps vs 7.1 fps
    Faster JPEG shooting (burst mode)
  • Faster RAW shooting
    9.2 fps vs 7.1 fps
    Faster RAW shooting in burst mode
  • Slow-motion videos
    Yes vs No
    Shoot slow-motion videos
  • Higher extended ISO
    102400 vs 51200 ISO
    Higher extended ISO can give more low-light flexibility

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
  • In-Camera Image Stabilization
    Both provide
    Reduces the effects of camera shake at slower shutter speeds
  • 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
  • Headphone jack
    Both provide
    Monitor audio recording while you shoot video
  • 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

User reviews

Buy From

Your purchases support this site

Buy the Sony A7R III

Review Excerpt

  • Top-notch image quality; Great ergonomics in a compact body; Unique on-demand low-pass filtering; Broad sensitivity range; Large and bright viewfinder for an APS-C camera; Dual card slots; Optional Wi-Fi remote control

  • AE Lock button is poorly located; Below-average battery life for a DSLR; Rather dated-looking menu system; Requires a different battery grip accessory than its predecessors; Less third-party support than some rivals

  • 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.

The Competition

Compared to Nikon D7100

Pentax K-3
Nikon D7100
  • $699
  • APS-C
  • Focus peaking
  • In-Camera Image Stabilization
  • $795
  • APS-C
  • Fast startup
  • Longer stills battery life
Sony A7R III
Nikon D7100
  • $2798
  • 35mm
  • Focus peaking
  • Larger sensor
  • $795
  • APS-C
  • Less expensive
  • Lens selection

Compared to Nikon D5300

Pentax K-3
Nikon D5300
  • $699
  • APS-C
  • Focus peaking
  • In-Camera Image Stabilization
  • $662
  • APS-C
  • Less expensive
  • Tilt-swivel screen
Sony A7R III
Nikon D5300
  • $2798
  • 35mm
  • Focus peaking
  • Larger sensor
  • $662
  • APS-C
  • Less expensive
  • Tilt-swivel screen

Compared to Nikon D7200

Pentax K-3
Nikon D7200
  • $699
  • APS-C
  • Focus peaking
  • In-Camera Image Stabilization
  • $797
  • APS-C
  • Fast startup
  • Built-in Wi-Fi
Sony A7R III
Nikon D7200
  • $2798
  • 35mm
  • Focus peaking
  • Larger sensor
  • $797
  • APS-C
  • Less expensive
  • Lens selection

Compared to Sony A7R II

Pentax K-3
Sony A7R II
  • $699
  • APS-C
  • Lens selection
  • Less expensive
  • $1598
  • 35mm
  • Larger sensor
  • Bigger pixels
Sony A7R III
Sony A7R II
  • $2798
  • 35mm
  • Touchscreen
  • High resolution composite
  • $1598
  • 35mm
  • Less expensive
  • In-camera panoramas

Compared to Canon EOS R

Pentax K-3
Canon EOS R
  • $699
  • APS-C
  • Less expensive
  • In-Camera Image Stabilization
  • $2299
  • 35mm
  • Tilt-swivel screen
  • Larger sensor
Sony A7R III
Canon EOS R
  • $2798
  • 35mm
  • In-Camera Image Stabilization
  • High resolution composite
  • $2299
  • 35mm
  • Tilt-swivel screen
  • Bigger pixels
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