• 1/2.3 inch 28.1mm2
  • 10.0 megapixels
  • 36.00mm - 180.00mm (35mm eq.)
  • Medium format 1,452.0mm2
  • 40.0 megapixels
  • ISO 200 - 1000

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Differences

Nikon S550 advantages over Pentax 645D

  • Less expensive
    $230 vs $9996 (MSRP)
    Save money for lenses or accessories
  • Internal flash
    Internal flash vs None
    Useful in a pinch for fill flash
  • Thinner
    22 mm vs 119 mm
    Thinner
  • Lighter weight
    120g vs 1480g
    Lighter weight

Pentax 645D advantages over Nikon S550

  • Larger sensor
    Medium format vs 1/2.3 inch
    More sensor area. Bigger is (generally) better.
  • Eye-level viewfinder
    Eye-level vs Rear display only
    You'll be able to frame photos even when the sun is out
  • Bigger pixels
    ~ 6.06 vs 1.69 microns
    Better low-light and dynamic range (all else equal)
  • RAW file ability
    Yes vs No
    Gives you more flexibility to develop your photos later
  • Longer stills battery life
    More info 800 vs 200 shots
    Capture more photos
  • Manual focus
    Yes vs No
    AF is for the weak. Real photographers focus manually.
  • HDMI out
    HDMI out vs None
    Use HDMI output to monitor or review video
  • More dots on screen
    921k vs 230k dots
    Can mean greater resolution or a brighter screen
  • Hot shoe
    Hot shoe vs None
    Off-camera flashes open new possibilities
  • More pixels
    40.0 vs 10.0 megapixels
    Higher resolution photos
  • Dual card slots
    Yes vs No
    Gives you more storage flexibility
  • Bulb shutter
    Bulb vs No bulb
    Hold the shutter open manually for long exposures

Similarities

Common Strengths

  • Rear display
    Both provide
    Review photos on the back of the camera

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
  • In-Camera Image Stabilization
    Neither provide
    Reduces the effects of camera shake at slower shutter speeds
  • 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
  • Integrated ND filter
    Neither provide
    Shoot in daylight with a large aperture or slow shutter
  • External Mic Jack
    Neither provide
    Improved sound fidelity when shooting video
  • Headphone jack
    Neither provide
    Monitor audio recording while you shoot video
  • Slow-motion videos
    Neither provide
    Shoot slow-motion videos

User reviews

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Buy the Nikon S550

Your purchases support this site

Buy the Pentax 645D
Pentax 645D
All 645D Deals

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.

  • Read our Pentax 645D Review

The Competition

Compared to Pentax M50

Nikon S550
Pentax M50
  • $195
  • 1/2.3 inch
  • More pixels
  • $140
  • 1/2.35 inch
  • Manual focus
  • Higher extended ISO

Compare Nikon S550 vs Pentax M50

Pentax 645D
Pentax M50
  • $3599
  • Medium format
  • Larger sensor
  • Eye-level viewfinder
  • $140
  • 1/2.35 inch
  • Less expensive
  • Internal flash

Compare Pentax 645D vs Pentax M50

Compared to Ricoh R50

Nikon S550
Ricoh R50
  • $195
  • 1/2.3 inch
  • $250
  • 1/2.3 inch
  • Manual focus
  • Higher extended ISO

Compare Nikon S550 vs Ricoh R50

Pentax 645D
Ricoh R50
  • $3599
  • Medium format
  • Larger sensor
  • Eye-level viewfinder
  • $250
  • 1/2.3 inch
  • Less expensive
  • Internal flash

Compare Pentax 645D vs Ricoh R50

Compared to Nikon S560

Nikon S550
Nikon S560
  • $195
  • 1/2.3 inch
  • Longer stills battery life
  • $250
  • 1/2.33 inch
  • In-Camera Image Stabilization
  • Wider angle lens

Compare Nikon S550 vs Nikon S560

Pentax 645D
Nikon S560
  • $3599
  • Medium format
  • Larger sensor
  • Eye-level viewfinder
  • $250
  • 1/2.33 inch
  • Less expensive
  • In-Camera Image Stabilization

Compare Pentax 645D vs Nikon S560

Compared to Leica S (Typ 006)

Nikon S550
Leica S (Typ 006)
  • $195
  • 1/2.3 inch
  • Less expensive
  • Internal flash
  • $10535
  • Medium format
  • Larger sensor
  • Eye-level viewfinder

Compare Nikon S550 vs Leica S (Typ 006)

Pentax 645D
Leica S (Typ 006)
  • $3599
  • Medium format
  • Less expensive
  • Higher effective ISO
  • $10535
  • Medium format
  • Thinner
  • More viewfinder magnification

Compare Pentax 645D vs Leica S (Typ 006)

Compared to Pentax 645Z

Nikon S550
Pentax 645Z
  • $195
  • 1/2.3 inch
  • Internal flash
  • Thinner
  • $4845
  • Medium format
  • Focus peaking
  • Larger sensor

Compare Nikon S550 vs Pentax 645Z

Pentax 645D
Pentax 645Z
  • $3599
  • Medium format
  • Fast startup
  • Longer stills battery life
  • $4845
  • Medium format
  • Focus peaking
  • Tiltable Screen

Compare Pentax 645D vs Pentax 645Z

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