• APS-C 372.9mm2
  • 12.3 megapixels
  • ISO 200 - 3200
  • APS-C 366.6mm2
  • 20.1 megapixels
  • ISO 100 - 51,200

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Differences

Nikon D90 advantages over Pentax K-S1

  • Bigger pixels
    ~ 5.50 vs 4.29 microns
    Better low-light and dynamic range (all else equal)
  • Longer stills battery life
    More info 850 vs 480 shots
    Capture more photos
  • More telephoto lens reach
    158 mm vs 83 mm
    Capture objects farther away with the kit lens
  • Top deck display
    Yes vs No
    Check settings with a screen on top of the camera
  • Bigger JPEG buffer
    Unlimited vs 20 shots
    Take more JPEG shots before waiting (burst mode)

Pentax K-S1 advantages over Nikon D90

  • 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 cross-type AF points
    9 vs 1
    Cross-type AF points improve autofocus performance
  • Newer
    5 years vs 11 years old
    Newer cameras often support more advanced features
  • Lighter weight
    765g vs 1133g
    Lighter weight
  • Shoots 1080p video
    Yes vs No
    You'll want this if you shoot video
  • More pixels
    20.1 vs 12.3 megapixels
    Higher resolution photos
  • Shoots 60p video
    Yes vs No
    A faster framerate can give you more editing options
  • Optional anti-aliasing filter
    Optional vs Fixed
    Lets you choose sharper photos or reduced moiré
  • Faster JPEG shooting
    5.4 fps vs 4.5 fps
    Faster JPEG shooting (burst mode)
  • Faster shutter
    1/6000 vs 1/4000 sec
    Shoot wide open in bright light
  • Higher extended ISO
    51200 vs 6400 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
  • Internal flash
    Both provide
    Useful in a pinch for fill flash
  • Pentaprism viewfinder
    Both provide
    Much better viewfinder picture fidelity
  • 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

  • Tilt-swivel screen
    Neither provide
    Tilt and swivel the screen for maximum shooting flexibility
  • Touchscreen
    Neither provide
    Interact with your camera just like your smartphone
  • In-camera panoramas
    Neither provide
    Stitches multiple shots into a panoramic photo
  • Tiltable Screen
    Neither provide
    Tilt the screen for shooting flexbility
  • 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
  • External Mic Jack
    Neither provide
    Improved sound fidelity when shooting video
  • 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

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Buy the Pentax K-S1

Review Excerpt

The Competition

Compared to Nikon D300S

Nikon D90
Nikon D300S
  • $1300
  • APS-C
  • Higher effective ISO
  • Bigger JPEG buffer
  • $1663
  • APS-C
  • External Mic Jack
  • More cross-type AF points
Pentax K-S1
Nikon D300S
  • $500
  • APS-C
  • Less expensive
  • Focus peaking
  • $1663
  • APS-C
  • Bigger pixels
  • Longer stills battery life

Compared to Sony DSLR-A550

Nikon D90
Sony DSLR-A550
  • $1300
  • APS-C
  • Lens selection
  • Fast startup
  • $859
  • APS-C
  • Less expensive
  • In-Camera Image Stabilization
Pentax K-S1
Sony DSLR-A550
  • $500
  • APS-C
  • Lens selection
  • Focus peaking
  • $859
  • APS-C
  • Bigger pixels
  • Tiltable Screen

Compared to Sony DSLR-A500

Nikon D90
Sony DSLR-A500
  • $1300
  • APS-C
  • Lens selection
  • Fast startup
  • $850
  • APS-C
  • Less expensive
  • In-Camera Image Stabilization
Pentax K-S1
Sony DSLR-A500
  • $500
  • APS-C
  • Lens selection
  • Focus peaking
  • $850
  • APS-C
  • Bigger pixels
  • Tiltable Screen

Compared to Nikon D5500

Nikon D90
Nikon D5500
  • $1300
  • APS-C
  • Bigger pixels
  • Fast startup
  • $461
  • APS-C
  • Tilt-swivel screen
  • Touchscreen
Pentax K-S1
Nikon D5500
  • $500
  • APS-C
  • Focus peaking
  • In-Camera Image Stabilization
  • $461
  • APS-C
  • Less expensive
  • Tilt-swivel screen

Compared to Pentax K-S2

Nikon D90
Pentax K-S2
  • $1300
  • APS-C
  • Bigger pixels
  • Fast startup
  • $499
  • APS-C
  • Tilt-swivel screen
  • Focus peaking
Pentax K-S1
Pentax K-S2
  • $500
  • APS-C
  • Higher-res screen
  • $499
  • APS-C
  • Tilt-swivel screen
  • Built-in Wi-Fi
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