• APS-C 366.6mm2
  • 20.1 megapixels
  • ISO 100 - 51,200
  • 4/3 226.2mm2
  • 20.4 megapixels
  • ISO 200 - 25,600

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Differences

Pentax K-S1 advantages over Olympus E-M1 II

  • Larger sensor
    APS-C vs 4/3
    More sensor area. Bigger is (generally) better.
  • Bigger pixels
    ~ 4.29 vs 3.36 microns
    Better low-light and dynamic range (all else equal)
  • Internal flash
    Internal flash vs None
    Useful in a pinch for fill flash
  • Optional anti-aliasing filter
    Optional vs None
    Lets you choose sharper photos or reduced moiré
  • Higher extended ISO
    51200 vs 25600 ISO
    Higher extended ISO can give more low-light flexibility

Olympus E-M1 II advantages over Pentax K-S1

  • Tilt-swivel screen
    Tilt-swivel vs none
    Tilt and swivel the screen for maximum shooting flexibility
  • 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
  • Higher effective ISO
    1,312 vs 1,061 iso
    Take photos in low light with less noise
  • On-sensor phase detect
    Yes vs No
    Usually improves live view and video AF performance
  • External Mic Jack
    Jack vs No jack
    Improved sound fidelity when shooting video
  • More viewfinder magnification
    0.74x vs 0.63x
    Get a bigger view of the scene through the eye-level viewfinder
  • Dual card slots
    Yes vs No
    Gives you more storage flexibility
  • Headphone jack
    Yes vs No
    Monitor audio recording while you shoot video
  • Longer exposure
    60 vs 30 sec
    Long exposures for night shots
  • Faster JPEG shooting
    60.6 fps vs 5.4 fps
    Faster JPEG shooting (burst mode)
  • Bigger JPEG buffer
    51 vs 20 shots
    Take more JPEG shots before waiting (burst mode)
  • Faster shutter
    1/32000 vs 1/6000 sec
    Shoot wide open in bright light

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
  • 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 Bluetooth
    Neither provide
    Always-on wireless connectivity
  • Built-in GPS
    Neither provide
    Geotag your photos
  • Top deck display
    Neither provide
    Check settings with a screen on top of the camera
  • Slow-motion videos
    Neither provide
    Shoot slow-motion videos

User reviews

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Review Excerpt

  • Excellent image quality; Very good dynamic range & high ISO performance; Fantastic C-AF performance; Incredible burst rates, even with RAW; 4K UHD & Cinema 4K (DCI) video; Clean HDMI; Dual SD card slots.

  • Expensive; Menus still confusing; UHS-II support only on one card slot; No optical low-pass filter means greater risk of moire; No built-in flash.

  • Read our Olympus E-M1 II Review

The Competition

Compared to Fujifilm X-T2

Pentax K-S1
Fujifilm X-T2
  • $502
  • APS-C
  • Lens selection
  • In-Camera Image Stabilization
  • $999
  • APS-C
  • Shoot 4K video
  • In-camera panoramas

Compare Pentax K-S1 vs Fujifilm X-T2

Olympus E-M1 II
Fujifilm X-T2
  • $899
  • 4/3
  • Lens selection
  • Less expensive
  • $999
  • APS-C
  • Larger sensor
  • Bigger pixels

Compare Olympus E-M1 II vs Fujifilm X-T2

Compared to Sony A58

Pentax K-S1
Sony A58
  • $502
  • APS-C
  • Lens selection
  • Higher effective ISO
  • $598
  • APS-C
  • Less expensive
  • In-camera panoramas

Compare Pentax K-S1 vs Sony A58

Olympus E-M1 II
Sony A58
  • $899
  • 4/3
  • Lens selection
  • Tilt-swivel screen
  • $598
  • APS-C
  • Larger sensor
  • Bigger pixels

Compare Olympus E-M1 II vs Sony A58

Compared to Nikon D5500

Pentax K-S1
Nikon D5500
  • $502
  • APS-C
  • Focus peaking
  • In-Camera Image Stabilization
  • $697
  • APS-C
  • Tilt-swivel screen
  • Touchscreen

Compare Pentax K-S1 vs Nikon D5500

Olympus E-M1 II
Nikon D5500
  • $899
  • 4/3
  • Focus peaking
  • In-Camera Image Stabilization
  • $697
  • APS-C
  • Less expensive
  • Larger sensor

Compare Olympus E-M1 II vs Nikon D5500

Compared to Pentax K-S2

Pentax K-S1
Pentax K-S2
  • $502
  • APS-C
  • Higher-res screen
  • $499
  • APS-C
  • Tilt-swivel screen
  • Built-in Wi-Fi

Compare Pentax K-S1 vs Pentax K-S2

Olympus E-M1 II
Pentax K-S2
  • $899
  • 4/3
  • Shoot 4K video
  • Touchscreen
  • $499
  • APS-C
  • Larger sensor
  • Bigger pixels

Compare Olympus E-M1 II vs Pentax K-S2

Compared to Panasonic G7

Pentax K-S1
Panasonic G7
  • $502
  • APS-C
  • Larger sensor
  • In-Camera Image Stabilization
  • $498
  • 4/3
  • Tilt-swivel screen
  • Shoot 4K video

Compare Pentax K-S1 vs Panasonic G7

Olympus E-M1 II
Panasonic G7
  • $899
  • 4/3
  • In-Camera Image Stabilization
  • High resolution composite
  • $498
  • 4/3
  • Less expensive
  • In-camera panoramas

Compare Olympus E-M1 II vs Panasonic G7

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