• APS-C 368.2mm2
  • 16.2 megapixels
  • ISO 100 - 6400
  • APS-C 369.0mm2
  • 14.8 megapixels
  • ISO 100 - 6400

Buy From

Differences

Nikon D5100 advantages over Sigma SD1

  • Lens selection
    Excellent vs Limited
    Better lens selection gives you more options
  • Less expensive
    $499 vs $1799
    Save money for lenses or accessories
  • Tilt-swivel screen
    Tilt-swivel vs none
    Tilt and swivel the screen for maximum shooting flexibility
  • Fast startup
    ~0.50 vs 4.5 sec
    Faster startup lets you catch the moment
  • External Mic Jack
    Jack vs No jack
    Improved sound fidelity when shooting video
  • HDMI out
    HDMI out vs None
    Use an external screen to monitor or review video
  • Shoots 24p video
    Yes vs No
    Gives your movies a big-screen feel
  • More dots on screen
    922k vs 460k dots
    Can mean greater resolution or a brighter screen
  • Shoots 1080p video
    Yes vs No
    You'll want this if you shoot video
  • Bigger JPEG buffer
    100 vs 7 shots
    Take more JPEG shots before waiting (burst mode)
  • Higher extended ISO
    25600 vs 6400 ISO
    Higher extended ISO can give more low-light flexibility

Sigma SD1 advantages over Nikon D5100

  • Pentaprism viewfinder
    Pentaprism vs Pentamirror
    Much better viewfinder picture fidelity
  • More viewfinder magnification
    0.63x vs 0.52x
    Get a bigger view of the scene through the eye-level viewfinder
  • Doesn't require an AA filter
    Yes vs No
    A unique sensor design provides sharp photos without moiré
  • 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
  • Internal flash
    Both provide
    Useful in a pinch for fill flash
  • 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
  • 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
  • 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
  • Top deck display
    Neither provide
    Check settings with a screen on top of the camera
  • Dual card slots
    Neither provide
    Gives you more storage flexibility
  • Headphone jack
    Neither provide
    Monitor audio recording while you shoot video
  • 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.

The Competition

Compared to Nikon D300S

Nikon D5100
Nikon D300S
  • $499
  • APS-C
  • Less expensive
  • Tilt-swivel screen
  • $1697
  • APS-C
  • Fast startup
  • Longer stills battery life
Sigma SD1
Nikon D300S
  • $1799
  • APS-C
  • More pixels
  • Doesn't require an AA filter
  • $1697
  • APS-C
  • Lens selection
  • Fast startup

Compared to Sony DSLR-A550

Nikon D5100
Sony DSLR-A550
  • $499
  • APS-C
  • Lens selection
  • Tilt-swivel screen
  • $859
  • APS-C
  • In-Camera Image Stabilization
  • Longer stills battery life
Sigma SD1
Sony DSLR-A550
  • $1799
  • APS-C
  • Pentaprism viewfinder
  • More viewfinder magnification
  • $859
  • APS-C
  • Lens selection
  • In-Camera Image Stabilization

Compared to Nikon D3100

Nikon D5100
Nikon D3100
  • $499
  • APS-C
  • Tilt-swivel screen
  • Higher effective ISO
  • $700
  • APS-C
Sigma SD1
Nikon D3100
  • $1799
  • APS-C
  • Pentaprism viewfinder
  • More dots on screen
  • $700
  • APS-C
  • Lens selection
  • Fast startup

Compared to Sony A35

Nikon D5100
Sony A35
  • $499
  • APS-C
  • Lens selection
  • Tilt-swivel screen
  • $567
  • APS-C
  • In-Camera Image Stabilization
  • In-camera panoramas
Sigma SD1
Sony A35
  • $1799
  • APS-C
  • Doesn't require an AA filter
  • Faster shutter
  • $567
  • APS-C
  • Lens selection
  • In-Camera Image Stabilization

Compared to Sony A57

Nikon D5100
Sony A57
  • $499
  • APS-C
  • Lens selection
  • Tilt-swivel screen
  • $800
  • APS-C
  • Focus peaking
  • In-Camera Image Stabilization
Sigma SD1
Sony A57
  • $1799
  • APS-C
  • Doesn't require an AA filter
  • Faster shutter
  • $800
  • APS-C
  • Lens selection
  • Focus peaking
Compare Other Cameras?