• 35mm 861.6mm2
  • 36.3 megapixels
  • ISO 100 - 6400
  • APS-C 366.6mm2
  • 24.4 megapixels
  • ISO 100 - 51,200

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Differences

Nikon D800 advantages over Pentax K-3

  • Larger sensor
    35mm vs APS-C
    More sensor area. Bigger is (generally) better.
  • Bigger pixels
    ~ 4.88 vs 3.91 microns
    Better low-light and dynamic range (all else equal)
  • Fast startup
    ~0.30 vs 0.9 sec
    Faster startup lets you catch the moment
  • Higher effective ISO
    2,853 vs 1,216 iso
    Take photos in low light with less noise
  • Longer stills battery life
    More info 900 vs 560 shots
    Capture more photos
  • More viewfinder magnification
    0.70x vs 0.63x
    Get a bigger view of the scene through the eye-level viewfinder
  • More pixels
    36.3 vs 24.4 megapixels
    Higher resolution photos
  • More AF points
    51 vs 27
    More AF points improve autofocus

Pentax K-3 advantages over Nikon D800

  • 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
  • More cross-type AF points
    25 vs 15
    Cross-type AF points improve autofocus performance
  • Newer
    4 years vs 6 years old
    Newer cameras often support more advanced features
  • Less shutter lag
    0.14 vs 0.21 sec
    Focus and take a photo quickly (wide angle)
  • Optional anti-aliasing filter
    Optional vs Fixed
    Lets you choose sharper photos or reduced moiré
  • Faster JPEG shooting
    7.1 fps vs 4.0 fps
    Faster JPEG shooting (burst mode)
  • Faster RAW shooting
    7.1 fps vs 4.0 fps
    Faster RAW shooting in burst mode
  • Higher extended ISO
    51200 vs 25600 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
  • Internal flash
    Both provide
    Useful in a pinch for fill flash
  • 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 an external screen 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
  • Touchscreen
    Neither provide
    Interact with your camera just like your smartphone
  • In-camera panoramas
    Neither provide
    Stitches multiple shots into a panoramic photo
  • Tiltable Screen
    Neither provide
    Tilt the screen for shooting flexbility
  • Built-in Wi-Fi
    Neither provide
    Share your photos wirelessly
  • NFC
    Neither provide
    Simplifies pairing your camera with supported phones
  • Built-in Bluetooth
    Neither provide
    Always-on wireless connectivity
  • 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

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Buy the Pentax K-3

Review Excerpt

  • Rugged build; Excellent controls; Extremely high resolution; Dual cards; Surprising high ISO performance.

  • Very large files; Slower frame rate; Custom white balance gives a greenish tint; Battery life lower than D700.

  • 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

The Competition

Compared to Canon 5D Mark III

Nikon D800
Canon 5D Mark III
  • $1850
  • 35mm
  • Fast startup
  • Higher effective ISO
  • $2817
  • 35mm
  • Bigger pixels
  • More cross-type AF points
Pentax K-3
Canon 5D Mark III
  • $836
  • APS-C
  • Focus peaking
  • Less expensive
  • $2817
  • 35mm
  • Larger sensor
  • Bigger pixels

Compared to Sony A99

Nikon D800
Sony A99
  • $1850
  • 35mm
  • Lens selection
  • Fast startup
  • $1998
  • 35mm
  • Tilt-swivel screen
  • Focus peaking
Pentax K-3
Sony A99
  • $836
  • APS-C
  • Lens selection
  • Less expensive
  • $1998
  • 35mm
  • Tilt-swivel screen
  • Larger sensor

Compared to Nikon D600

Nikon D800
Nikon D600
  • $1850
  • 35mm
  • More cross-type AF points
  • More pixels
  • $1497
  • 35mm
  • Bigger pixels
  • Faster JPEG shooting
Pentax K-3
Nikon D600
  • $836
  • APS-C
  • Less expensive
  • Focus peaking
  • $1497
  • 35mm
  • Larger sensor
  • Bigger pixels

Compared to Nikon D7100

Nikon D800
Nikon D7100
  • $1850
  • 35mm
  • Larger sensor
  • Bigger pixels
  • $697
  • APS-C
  • Lacks anti-aliasing filter
  • Faster JPEG shooting
Pentax K-3
Nikon D7100
  • $836
  • APS-C
  • Focus peaking
  • In-Camera Image Stabilization
  • $697
  • APS-C
  • Fast startup
  • Longer stills battery life

Compared to Nikon D7200

Nikon D800
Nikon D7200
  • $1850
  • 35mm
  • Larger sensor
  • Bigger pixels
  • $997
  • APS-C
  • Built-in Wi-Fi
  • NFC
Pentax K-3
Nikon D7200
  • $836
  • APS-C
  • Focus peaking
  • Less expensive
  • $997
  • APS-C
  • Fast startup
  • Built-in Wi-Fi
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