• APS-C 368.2mm2
  • 16.2 megapixels
  • ISO 100 - 6400
  • APS-C 366.6mm2
  • 24.4 megapixels
  • ISO 100 - 51,200

Buy From

Differences

Nikon D5100 advantages over Pentax K-3

  • Tilt-swivel screen
    Tilt-swivel vs none
    Tilt and swivel the screen for maximum shooting flexibility
  • Less expensive
    $499* vs $999
    Save money for lenses or accessories
  • Fast startup
    ~0.50 vs 0.9 sec
    Faster startup lets you catch the moment
  • Bigger pixels
    ~ 4.79 vs 3.91 microns
    Better low-light and dynamic range (all else equal)
  • Lighter weight
    829g vs 1240g
    Lighter weight

Pentax K-3 advantages over Nikon D5100

  • 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 telephoto lens reach
    203 mm vs 83 mm
    Capture objects farther away with the kit lens
  • Shoots 60p video
    Yes vs No
    A faster framerate can give you more editing options
  • Top deck display
    Yes vs No
    Check settings with a screen on top of the camera
  • More viewfinder magnification
    0.63x vs 0.52x
    Get a bigger view of the scene through the eye-level viewfinder
  • More cross-type AF points
    25 vs 1
    Cross-type AF points improve autofocus performance
  • Headphone jack
    Yes vs No
    Monitor audio recording while you shoot video
  • Less shutter lag
    0.14 vs 0.27 sec
    Focus and take a photo quickly (wide angle)
  • More pixels
    24.4 vs 16.2 megapixels
    Higher resolution photos
  • Dual card slots
    Yes vs No
    Gives you more storage flexibility
  • Newer
    4 years vs 6 years old
    Newer cameras often support more advanced features
  • Pentaprism viewfinder
    Pentaprism vs Pentamirror
    Much better viewfinder picture fidelity
  • More AF points
    27 vs 11
    More AF points improve autofocus
  • Optional anti-aliasing filter
    Optional vs Fixed
    Lets you choose sharper photos or reduced moiré
  • Faster JPEG shooting
    7.1 fps vs 3.9 fps
    Faster JPEG shooting (burst mode)
  • Faster RAW shooting
    7.1 fps vs 4.0 fps
    Faster RAW shooting in burst mode
  • Bigger RAW buffer
    24 vs 13 shots
    Larger buffer for RAW shots (burst mode)
  • Higher extended ISO
    51200 vs 25600 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
  • External Mic Jack
    Both provide
    Improved sound fidelity when shooting video
  • HDMI out
    Both provide
    Use an external screen to monitor or review video
  • Hot shoe
    Both provide
    Off-camera flashes open new possibilities
  • Internal flash
    Both provide
    Useful in a pinch for fill flash
  • Bulb shutter
    Both provide
    Hold the shutter open manually for long exposures

Common Weaknesses

  • Touchscreen
    Neither provide
    Interact with your camera just like your smartphone
  • In-camera panoramas
    Neither provide
    Stitches multiple shots into a panoramic photo
  • NFC
    Neither provide
    Simplifies pairing your camera with supported phones
  • Built-in Wi-Fi
    Neither provide
    Share your photos wirelessly
  • 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

Buy From

Review Excerpt

  • Side-mounted tilt / swivel LCD screen; same sensor and processing as the Nikon D7000; good speed and battery life; in-camera HDR and filter effects; Full HD video capture with aperture control; audio levels control and external microphone jack.

  • AF-S lens mount doesn't offer autofocus with screw-drive lenses; popup flash isn't the greatest; no built-in wireless flash control; HDR function doesn't microalign source images.

  • 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 Nikon D3100

Nikon D5100
Nikon D3100
  • $499
  • APS-C
  • Tilt-swivel screen
  • Higher effective ISO
  • $700
  • APS-C
Pentax K-3
Nikon D3100
  • $1024
  • APS-C
  • Focus peaking
  • In-Camera Image Stabilization
  • $700
  • APS-C
  • Fast startup
  • Bigger pixels

Compared to Sony A35

Nikon D5100
Sony A35
  • $499
  • APS-C
  • Lens selection
  • Tilt-swivel screen
  • $567
  • APS-C
  • In-camera panoramas
  • In-Camera Image Stabilization
Pentax K-3
Sony A35
  • $1024
  • APS-C
  • Focus peaking
  • Lens selection
  • $567
  • APS-C
  • Bigger pixels
  • In-camera panoramas

Compared to Sony A57

Nikon D5100
Sony A57
  • $499
  • APS-C
  • Lens selection
  • Tilt-swivel screen
  • $800
  • APS-C
  • Focus peaking
  • In-camera panoramas
Pentax K-3
Sony A57
  • $1024
  • APS-C
  • Lens selection
  • Higher effective ISO
  • $800
  • APS-C
  • Tiltable Screen
  • Bigger pixels

Compared to Nikon D7100

Nikon D5100
Nikon D7100
  • $499
  • APS-C
  • Tilt-swivel screen
  • Less expensive
  • $697
  • APS-C
  • Fast startup
  • Longer stills battery life
Pentax K-3
Nikon D7100
  • $1024
  • APS-C
  • Focus peaking
  • In-Camera Image Stabilization
  • $697
  • APS-C
  • Fast startup
  • Longer stills battery life

Compared to Sony A77 II

Nikon D5100
Sony A77 II
  • $499
  • APS-C
  • Less expensive
  • Lens selection
  • $1198
  • APS-C
  • Focus peaking
  • In-camera panoramas
Pentax K-3
Sony A77 II
  • $1024
  • APS-C
  • Less expensive
  • Lens selection
  • $1198
  • APS-C
  • Tilt-swivel screen
  • In-camera panoramas
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