• APS-C 355.7mm2
  • 14.2 megapixels
  • ISO 100 - 3200
  • 4/3 226.2mm2
  • 20.4 megapixels
  • ISO 200 - 6400

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Differences

Nikon D3100 advantages over Olympus E-M5 III

  • Larger sensor
    APS-C vs 4/3
    More sensor area. Bigger is (generally) better.
  • Bigger pixels
    ~ 5.01 vs 3.36 microns
    Better low-light and dynamic range (all else equal)
  • Longer stills battery life
    More info 550 vs 310 shots
    Capture more photos
  • Internal flash
    Internal flash vs None
    Useful in a pinch for fill flash
  • Has anti-aliasing filter
    Filter vs No Filter
    Reduces unsightly moiré in photos
  • Bigger JPEG buffer
    100 vs 26 shots
    Take more JPEG shots before waiting (burst mode)

Olympus E-M5 III advantages over Nikon D3100

  • Tilt-swivel screen
    Tilt-swivel vs none
    Tilt and swivel the screen for maximum shooting flexibility
  • 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
  • Shoot 4K video
    4K (DCI) vs 1080p
    Make sure you have a fast computer
  • Touchscreen
    Touch vs No touch
    Interact with your camera just like your smartphone
  • High resolution composite
    Yes vs No
    Combine multiple shots to form a super hi-res version
  • Built-in Wi-Fi
    Wi-Fi vs None
    Share your photos wirelessly
  • Built-in Bluetooth
    Yes vs No
    Always-on wireless connectivity
  • On-sensor phase detect
    Yes vs No
    Usually improves live view and video AF performance
  • Thinner
    49 mm vs 74 mm
    Thinner
  • External Mic Jack
    Jack vs No jack
    Improved sound fidelity when shooting video
  • Newer
    5 years vs 14 years old
    Newer cameras often support more advanced features
  • More dots on screen
    1037k vs 230k dots
    Can mean greater resolution or a brighter screen
  • More viewfinder magnification
    0.68x vs 0.53x
    Get a bigger view of the scene through the eye-level viewfinder
  • More pixels
    20.4 vs 14.2 megapixels
    Higher resolution photos
  • Shoots 60p video
    Yes vs No
    A faster framerate can give you more editing options
  • Lacks anti-aliasing filter
    No Filter vs Filter
    Enjoy sharper photos
  • Longer exposure
    60 vs 30 sec
    Long exposures for night shots
  • Faster JPEG shooting
    30.0 fps vs 2.9 fps
    Faster JPEG shooting (burst mode)
  • Slow-motion videos
    Yes vs No
    Shoot slow-motion videos
  • Faster shutter
    1/32000 vs 1/4000 sec
    Shoot wide open in bright light
  • Higher extended ISO
    25600 vs 12800 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
  • HDMI out
    Both provide
    Use HDMI output 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

  • In-camera panoramas
    Neither provide
    Stitches multiple shots into a panoramic photo
  • NFC
    Neither provide
    Simplifies pairing your camera with supported phones
  • Built-in GPS
    Neither provide
    Geotag your photos
  • 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

User reviews

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Buy the Nikon D3100

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Buy the Olympus E-M5 III
Body Only (Black)
  • Body Only (Black)
  • Body Only (Silver)
  • Kit with 14-150mm Lens (Black)
  • Kit with 14-150mm Lens (Silver)
All E-M5 III Deals

Review Excerpt

  • Improved image quality; Very good dynamic range & high ISO performance for a modern MFT sensor; Very fast AF; Excellent image stabilization; 4K video recording; Weather-sealed build quality.

  • Below average battery life; Small size can be awkward with long, heavy lenses; One SD card slot.

  • Read our Olympus E-M5 III Review

The Competition

Compared to Sony DSLR-A380

Nikon D3100
Sony DSLR-A380
  • $700
  • APS-C
  • Lens selection
  • Less expensive
  • $849
  • APS-C
  • In-Camera Image Stabilization
  • Tiltable Screen

Compare Nikon D3100 vs Sony DSLR-A380

Olympus E-M5 III
Sony DSLR-A380
  • $924
  • 4/3
  • Tilt-swivel screen
  • Lens selection
  • $849
  • APS-C
  • Larger sensor
  • Bigger pixels

Compare Olympus E-M5 III vs Sony DSLR-A380

Compared to Sony A33

Nikon D3100
Sony A33
  • $700
  • APS-C
  • Lens selection
  • Fast startup
  • $540
  • APS-C
  • In-Camera Image Stabilization
  • In-camera panoramas

Compare Nikon D3100 vs Sony A33

Olympus E-M5 III
Sony A33
  • $924
  • 4/3
  • Lens selection
  • Focus peaking
  • $540
  • APS-C
  • Larger sensor
  • Bigger pixels

Compare Olympus E-M5 III vs Sony A33

Compared to Pentax K-r

Nikon D3100
Pentax K-r
  • $700
  • APS-C
  • Less expensive
  • Higher effective ISO
  • $850
  • APS-C
  • In-Camera Image Stabilization
  • Fast startup

Compare Nikon D3100 vs Pentax K-r

Olympus E-M5 III
Pentax K-r
  • $924
  • 4/3
  • Tilt-swivel screen
  • Focus peaking
  • $850
  • APS-C
  • Larger sensor
  • Bigger pixels

Compare Olympus E-M5 III vs Pentax K-r

Compared to Panasonic G100

Nikon D3100
Panasonic G100
  • $700
  • APS-C
  • Larger sensor
  • Bigger pixels
  • $599
  • 4/3
  • Tilt-swivel screen
  • Focus peaking

Compare Nikon D3100 vs Panasonic G100

Olympus E-M5 III
Panasonic G100
  • $924
  • 4/3
  • In-Camera Image Stabilization
  • High resolution composite
  • $599
  • 4/3
  • Less expensive
  • In-camera panoramas

Compare Olympus E-M5 III vs Panasonic G100

Compared to Olympus E-M10 IV

Nikon D3100
Olympus E-M10 IV
  • $700
  • APS-C
  • Larger sensor
  • Bigger pixels
  • $630
  • 4/3
  • Focus peaking
  • In-Camera Image Stabilization

Compare Nikon D3100 vs Olympus E-M10 IV

Olympus E-M5 III
Olympus E-M10 IV
  • $924
  • 4/3
  • Tilt-swivel screen
  • High resolution composite
  • $630
  • 4/3
  • Less expensive
  • Longer video battery life

Compare Olympus E-M5 III vs Olympus E-M10 IV

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