• 4/3 226.2mm2
  • 20.4 megapixels
  • ISO 200 - 6400
  • APS-C 361.2mm2
  • 25.7 megapixels
  • ISO 100 - 1,600,000

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Differences

Olympus E-M5 III advantages over Pentax K-3 III

  • Less expensive
    $1099 vs $2344
    Save money for lenses or accessories
  • Tilt-swivel screen
    Tilt-swivel vs none
    Tilt and swivel the screen for maximum shooting flexibility
  • On-sensor phase detect
    Yes vs No
    Usually improves live view and video AF performance
  • Thinner
    49 mm vs 73 mm
    Thinner
  • Lighter weight
    414g vs 820g
    Lighter weight
  • Longer exposure
    60 vs 30 sec
    Long exposures for night shots
  • Faster JPEG shooting
    30.0 fps vs 12.0 fps
    Faster JPEG shooting (burst mode)
  • Slow-motion videos
    Yes vs No
    Shoot slow-motion videos
  • Faster shutter
    1/32000 vs 1/8000 sec
    Shoot wide open in bright light

Pentax K-3 III advantages over Olympus E-M5 III

  • Larger sensor
    APS-C vs 4/3
    More sensor area. Bigger is (generally) better.
  • Longer stills battery life
    More info 800 vs 310 shots
    Capture more photos
  • Top deck display
    Yes vs No
    Check settings with a screen on top of the camera
  • Newer
    3 years vs 5 years old
    Newer cameras often support more advanced features
  • Higher-res screen
    540k vs 346k pixels
    More detail on the screen lets you judge focus and composition
  • More viewfinder magnification
    1.05x vs 0.68x
    Get a bigger view of the scene through the eye-level viewfinder
  • More pixels
    25.7 vs 20.4 megapixels
    Higher resolution photos
  • Dual card slots
    Yes vs No
    Gives you more storage flexibility
  • Headphone jack
    Yes vs No
    Monitor audio recording while you shoot video
  • Optional anti-aliasing filter
    Optional vs None
    Lets you choose sharper photos or reduced moiré
  • Higher extended ISO
    1600000 vs 25600 ISO
    Higher extended ISO can give more low-light flexibility

Similarities

Common Strengths

  • Focus peaking
    Both provide
    Your camera will highlight what's in focus
  • Eye-level viewfinder
    Both provide
    You'll be able to frame photos even when the sun is out
  • In-Camera Image Stabilization
    Both provide
    Reduces the effects of camera shake at slower shutter speeds
  • Shoot 4K video
    Both provide
    Make sure you have a fast computer
  • Touchscreen
    Both provide
    Interact with your camera just like your smartphone
  • Built-in Wi-Fi
    Both provide
    Share your photos wirelessly
  • Built-in Bluetooth
    Both provide
    Always-on wireless connectivity
  • External Mic Jack
    Both provide
    Improved sound fidelity when shooting video
  • 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
  • Internal flash
    Neither provide
    Useful in a pinch for fill flash

User reviews

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Your purchases support this site

Buy the Olympus E-M5 III

Your purchases support this site

Buy the Pentax K-3 III

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.

The Competition

Compared to Pentax KP

Olympus E-M5 III
Pentax KP
  • $924
  • 4/3
  • Tilt-swivel screen
  • Shoot 4K video
  • $999
  • APS-C
  • Larger sensor
  • Bigger pixels
Pentax K-3 III
Pentax KP
  • $1847
  • APS-C
  • Shoot 4K video
  • Touchscreen
  • $999
  • APS-C
  • Less expensive
  • Tiltable Screen

Compared to Olympus E-M10 III

Olympus E-M5 III
Olympus E-M10 III
  • $924
  • 4/3
  • Tilt-swivel screen
  • High resolution composite
  • $549
  • 4/3
  • Less expensive
  • Longer video battery life
Pentax K-3 III
Olympus E-M10 III
  • $1847
  • APS-C
  • Larger sensor
  • High resolution composite
  • $549
  • 4/3
  • Less expensive
  • Tiltable Screen

Compared to Canon 90D

Olympus E-M5 III
Canon 90D
  • $924
  • 4/3
  • Less expensive
  • Focus peaking
  • $1199
  • APS-C
  • Larger sensor
  • Longer stills battery life
Pentax K-3 III
Canon 90D
  • $1847
  • APS-C
  • Focus peaking
  • In-Camera Image Stabilization
  • $1199
  • APS-C
  • Less expensive
  • Tilt-swivel screen

Compared to Panasonic G100

Olympus E-M5 III
Panasonic G100
  • $924
  • 4/3
  • In-Camera Image Stabilization
  • High resolution composite
  • $598
  • 4/3
  • Less expensive
  • In-camera panoramas
Pentax K-3 III
Panasonic G100
  • $1847
  • APS-C
  • Larger sensor
  • In-Camera Image Stabilization
  • $598
  • 4/3
  • Less expensive
  • Tilt-swivel screen

Compared to Olympus E-M10 IV

Olympus E-M5 III
Olympus E-M10 IV
  • $924
  • 4/3
  • Tilt-swivel screen
  • High resolution composite
  • $666
  • 4/3
  • Less expensive
  • Longer video battery life
Pentax K-3 III
Olympus E-M10 IV
  • $1847
  • APS-C
  • Larger sensor
  • High resolution composite
  • $666
  • 4/3
  • Less expensive
  • Tiltable Screen
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