• 2.17 inch 1,452.0mm2
  • 40.0 megapixels
  • ISO 200 - 1000
  • 35mm 861.6mm2
  • 36.3 megapixels
  • ISO 100 - 6400

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Differences

Pentax 645D advantages over Nikon D800

  • Larger sensor
    2.17 inch vs 35mm
    More sensor area. Bigger is (generally) better.
  • Bigger pixels
    ~ 6.06 vs 4.88 microns
    Better low-light and dynamic range (all else equal)
  • More viewfinder magnification
    1.08x vs 0.70x
    Get a bigger view of the scene through the eye-level viewfinder

Nikon D800 advantages over Pentax 645D

  • Lens selection
    Excellent vs Limited
    Better lens selection gives you more options
  • Fast startup
    ~0.30 vs 0.7 sec
    Faster startup lets you catch the moment
  • Higher effective ISO
    2,853 vs 1,262 iso
    Take photos in low light with less noise
  • More dynamic range
    14.4 vs 12.6 evs
    Retain detail in highlight and shadows
  • Shoots 60p video
    Yes vs No
    A faster framerate can give you more editing options
  • More cross-type AF points
    15 vs 11
    Cross-type AF points improve autofocus performance
  • External Mic Jack
    Jack vs No jack
    Improved sound fidelity when shooting video
  • Headphone jack
    Yes vs No
    Monitor audio recording while you shoot video
  • Thinner
    81 mm vs 119 mm
    Thinner
  • Shoots 1080p video
    Yes vs No
    You'll want this if you shoot video
  • More AF points
    51 vs 11
    More AF points improve autofocus
  • Higher max flash sync
    1/250 vs 1/125 sec
    Reduce the effect of ambient light in flash shots
  • Shoots 24p video
    Yes vs No
    Gives your movies a big-screen feel
  • Lighter weight
    1008g vs 1480g
    Lighter weight
  • Internal flash
    Internal flash vs None
    Useful in a pinch for fill flash
  • Bigger JPEG buffer
    54 vs 19 shots
    Take more JPEG shots before waiting (burst mode)
  • Faster JPEG shooting
    4.0 fps vs 1.1 fps
    Faster JPEG shooting (burst mode)
  • Faster RAW shooting
    4.0 fps vs 1.1 fps
    Faster RAW shooting in burst mode
  • Higher extended ISO
    25600 vs 1600 ISO
    Higher extended ISO can give more low-light flexibility
  • Faster shutter
    1/8000 vs 1/4000 sec
    Shoot wide open in bright light

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
  • Dual card slots
    Both provide
    Gives you more storage flexibility
  • HDMI out
    Both provide
    Use an external screen to monitor or review video
  • Hot shoe
    Both provide
    Off-camera flashes open new possibilities
  • Bulb shutter
    Both provide
    Hold the shutter open manually for long exposures

Common Weaknesses

  • Focus peaking
    Neither provide
    Your camera will highlight what's in focus
  • Tilt-swivel screen
    Neither provide
    Tilt and swivel the screen for maximum shooting flexibility
  • Tiltable Screen
    Neither provide
    Tilt the screen for shooting flexbility
  • NFC
    Neither provide
    Simplifies pairing your camera with supported phones
  • Touchscreen
    Neither provide
    Select your focus point more intuitively.
  • In-camera panoramas
    Neither provide
    Stitches multiple shots into a panoramic photo
  • In-Camera Image Stabilization
    Neither provide
    Reduces the effects of camera shake at slower shutter speeds
  • Built-in Wi-Fi
    Neither provide
    Share your photos wirelessly
  • 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

Buy From

Review Excerpt

  • Very high-resolution 40-megapixel sensor; Plentiful controls with great placement; Excellent optical viewfinder; Dual SDHC card slots; Infrared remote sensors front and back.

  • High price tag; Aliasing artifacts; Produces ~70MB RAW files.

  • 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.

The Competition

Compared to Leica S2

Pentax 645D
Leica S2
  • $3866
  • 2.17 inch
  • Less expensive
  • More cross-type AF points
  • $10000
  • 2.13 inch
  • Thinner
Nikon D800
Leica S2
  • $1850
  • 35mm
  • Lens selection
  • Shoots 60p video
  • $10000
  • 2.13 inch
  • Larger sensor
  • Bigger pixels

Compared to Sony A99

Pentax 645D
Sony A99
  • $3866
  • 2.17 inch
  • Larger sensor
  • Longer battery life
  • $1987
  • 35mm
  • Tilt-swivel screen
  • Less expensive
Nikon D800
Sony A99
  • $1850
  • 35mm
  • Lens selection
  • Fast startup
  • $1987
  • 35mm
  • Tilt-swivel screen
  • Focus peaking

Compared to Nikon D600

Pentax 645D
Nikon D600
  • $3866
  • 2.17 inch
  • Larger sensor
  • More viewfinder magnification
  • $1196
  • 35mm
  • Less expensive
  • Lens selection
Nikon D800
Nikon D600
  • $1850
  • 35mm
  • More cross-type AF points
  • More pixels
  • $1196
  • 35mm
  • Bigger pixels

Compared to Leica S

Pentax 645D
Leica S
  • $3866
  • 2.17 inch
  • Less expensive
  • Higher effective ISO
  • $10000
  • 2.13 inch
  • Thinner
  • Newer
Nikon D800
Leica S
  • $1850
  • 35mm
  • Lens selection
  • Higher effective ISO
  • $10000
  • 2.13 inch
  • Larger sensor
  • Bigger pixels

Compared to Pentax 645Z

Pentax 645D
Pentax 645Z
  • $3866
  • 2.17 inch
  • Less expensive
  • Fast startup
  • $8054
  • 2.15 inch
  • Focus peaking
  • Tiltable Screen
Nikon D800
Pentax 645Z
  • $1850
  • 35mm
  • Lens selection
  • Fast startup
  • $8054
  • 2.15 inch
  • Focus peaking
  • Larger sensor
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