• 35mm 861.6mm2
  • 36.3 megapixels
  • ISO 64 - 12,800
  • APS-C 361.2mm2
  • 25.7 megapixels
  • ISO 100 - 1,600,000

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Differences

Nikon D810 advantages over Pentax K-3 III

  • Larger sensor
    35mm vs APS-C
    More sensor area. Bigger is (generally) better.
  • Bigger pixels
    ~ 4.88 vs 3.76 microns
    Better low-light and dynamic range (all else equal)
  • Longer stills battery life
    More info 1200 vs 800 shots
    Capture more photos
  • Internal flash
    Internal flash vs None
    Useful in a pinch for fill flash
  • More pixels
    36.3 vs 25.7 megapixels
    Higher resolution photos
  • Bigger JPEG buffer
    57 vs 30 shots
    Take more JPEG shots before waiting (burst mode)

Pentax K-3 III advantages over Nikon D810

  • Focus peaking
    Peaker vs Non-peaker
    Your camera will highlight what's in focus
  • 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
  • Built-in Bluetooth
    Yes vs No
    Always-on wireless connectivity
  • More cross-type AF points
    25 vs 15
    Cross-type AF points improve autofocus performance
  • Newer
    4 years vs 10 years old
    Newer cameras often support more advanced features
  • Higher-res screen
    540k vs 307k pixels
    More detail on the screen lets you judge focus and composition
  • More viewfinder magnification
    1.05x vs 0.70x
    Get a bigger view of the scene through the eye-level viewfinder
  • More AF points
    101 vs 51
    More AF points improve autofocus
  • Optional anti-aliasing filter
    Optional vs None
    Lets you choose sharper photos or reduced moiré
  • Faster JPEG shooting
    12.0 fps vs 5.1 fps
    Faster JPEG shooting (burst mode)
  • Higher extended ISO
    1600000 vs 51200 ISO
    Higher extended ISO can give more low-light flexibility

Similarities

Common Strengths

  • Eye-level viewfinder
    Both provide
    You'll be able to frame photos even when the sun is out
  • Top deck display
    Both provide
    Check settings with a screen on top of the camera
  • External Mic Jack
    Both provide
    Improved sound fidelity when shooting video
  • Pentaprism viewfinder
    Both provide
    Much better viewfinder picture fidelity
  • 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
  • Tiltable Screen
    Neither provide
    Tilt the screen for shooting flexbility
  • NFC
    Neither provide
    Simplifies pairing your camera with supported phones
  • Built-in GPS
    Neither provide
    Geotag your photos
  • On-sensor phase detect
    Neither provide
    Usually improves live view and video AF performance
  • Slow-motion videos
    Neither provide
    Shoot slow-motion videos

User reviews

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Your purchases support this site

Buy the Pentax K-3 III

Review Excerpt

  • Handles even better than its predecessors; Absolutely spectacular images from the 36-megapixel image sensor; Unusually wide sensitivity range for its resolution; Improved performance and buffer depths; Improved video feature set; Impressive low-light autofocus

  • Prone to moire and false color with some subjects; No longer available with a low-pass filter; Demands excellent lenses for the best detail; White balance tends warm under tungsten lighting

The Competition

Compared to Canon 5D Mark IV

Nikon D810
Canon 5D Mark IV
  • $2291
  • 35mm
  • Less expensive
  • Longer stills battery life
  • $2249
  • 35mm
  • Shoot 4K video
  • Touchscreen
Pentax K-3 III
Canon 5D Mark IV
  • $1847
  • APS-C
  • Focus peaking
  • Less expensive
  • $2249
  • 35mm
  • Larger sensor
  • Bigger pixels

Compared to Nikon D800

Nikon D810
Nikon D800
  • $2291
  • 35mm
  • Longer stills battery life
  • Lacks anti-aliasing filter
  • $1850
  • 35mm
  • Fast startup
  • Has anti-aliasing filter
Pentax K-3 III
Nikon D800
  • $1847
  • APS-C
  • Focus peaking
  • In-Camera Image Stabilization
  • $1850
  • 35mm
  • Larger sensor
  • Bigger pixels

Compared to Nikon D800E

Nikon D810
Nikon D800E
  • $2291
  • 35mm
  • Longer stills battery life
  • Faster JPEG shooting
  • $2212
  • 35mm
  • Fast startup
Pentax K-3 III
Nikon D800E
  • $1847
  • APS-C
  • Focus peaking
  • In-Camera Image Stabilization
  • $2212
  • 35mm
  • Larger sensor
  • Bigger pixels

Compared to Pentax KP

Nikon D810
Pentax KP
  • $2291
  • 35mm
  • Larger sensor
  • Bigger pixels
  • $999
  • APS-C
  • Focus peaking
  • Less expensive
Pentax K-3 III
Pentax KP
  • $1847
  • APS-C
  • Shoot 4K video
  • Touchscreen
  • $999
  • APS-C
  • Less expensive
  • Tiltable Screen

Compared to Canon 90D

Nikon D810
Canon 90D
  • $2291
  • 35mm
  • Larger sensor
  • Bigger pixels
  • $1099
  • APS-C
  • Less expensive
  • Tilt-swivel screen
Pentax K-3 III
Canon 90D
  • $1847
  • APS-C
  • Focus peaking
  • In-Camera Image Stabilization
  • $1099
  • APS-C
  • Less expensive
  • Tilt-swivel screen
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