• 35mm 858.0mm2
  • 24.6 megapixels
  • ISO 100 - 25,600
  • APS-C 361.2mm2
  • 25.7 megapixels
  • ISO 100 - 1,600,000

Buy From

Differences

Sigma fp advantages over Pentax K-3 III

  • Less expensive
    $1599 vs $2344
    Save money for lenses or accessories
  • Larger sensor
    35mm vs APS-C
    More sensor area. Bigger is (generally) better.
  • Bigger pixels
    ~ 5.98 vs 3.76 microns
    Better low-light and dynamic range (all else equal)
  • Thinner
    45 mm vs 73 mm
    Thinner
  • Lighter weight
    422g vs 820g
    Lighter weight
  • Faster JPEG shooting
    18.0 fps vs 12.0 fps
    Faster JPEG shooting (burst mode)
  • Slow-motion videos
    Yes vs No
    Shoot slow-motion videos

Pentax K-3 III advantages over Sigma fp

  • Eye-level viewfinder
    Eye-level vs Rear display only
    You'll be able to frame photos even when the sun is out
  • 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
  • Top deck display
    Yes vs No
    Check settings with a screen on top of the camera
  • Higher max flash sync
    1/200 vs 1/30 sec
    Reduce the effect of ambient light in flash shots
  • Newer
    4 years vs 5 years old
    Newer cameras often support more advanced features
  • 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
  • Bigger JPEG buffer
    30 vs 12 shots
    Take more JPEG shots before waiting (burst mode)
  • Higher extended ISO
    1600000 vs 102400 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
  • 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
  • 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

  • Tilt-swivel screen
    Neither provide
    Tilt and swivel the screen for maximum shooting flexibility
  • In-camera panoramas
    Neither provide
    Stitches multiple shots into a panoramic photo
  • Tiltable Screen
    Neither provide
    Tilt the screen for shooting flexbility
  • NFC
    Neither provide
    Simplifies pairing your camera with supported phones
  • Built-in GPS
    Neither provide
    Geotag your photos
  • On-sensor phase detect
    Neither provide
    Usually improves live view and video AF performance
  • Internal flash
    Neither provide
    Useful in a pinch for fill flash

User reviews

Buy From

Your purchases support this site

Buy the Sigma fp
Body Only
  • Body Only
  • Kit with 45mm f/2.8 lens
All fp Deals

Your purchases support this site

Buy the Pentax K-3 III
Body Only
  • Body Only
  • Kit with 20-40mm F2.8-4 Lens
  • Kit with 55-300mm f/4.5-6.3 Lens
All K-3 III Deals

Review Excerpt

The Competition

Compared to Pentax KP

Sigma fp
Pentax KP
  • $1485
  • 35mm
  • Larger sensor
  • Bigger pixels
  • $999
  • APS-C
  • Less expensive
  • Eye-level viewfinder

Compare Sigma fp vs Pentax KP

Pentax K-3 III
Pentax KP
  • $1847
  • APS-C
  • Shoot 4K video
  • Touchscreen
  • $999
  • APS-C
  • Less expensive
  • Tiltable Screen

Compare Pentax K-3 III vs Pentax KP

Compared to Canon EOS RP

Sigma fp
Canon EOS RP
  • $1485
  • 35mm
  • Focus peaking
  • Less expensive
  • $949
  • 35mm
  • Tilt-swivel screen
  • Eye-level viewfinder

Compare Sigma fp vs Canon EOS RP

Pentax K-3 III
Canon EOS RP
  • $1847
  • APS-C
  • Focus peaking
  • In-Camera Image Stabilization
  • $949
  • 35mm
  • Tilt-swivel screen
  • Larger sensor

Compare Pentax K-3 III vs Canon EOS RP

Compared to Canon 90D

Sigma fp
Canon 90D
  • $1485
  • 35mm
  • Focus peaking
  • Larger sensor
  • $1099
  • APS-C
  • Less expensive
  • Tilt-swivel screen

Compare Sigma fp vs Canon 90D

Pentax K-3 III
Canon 90D
  • $1847
  • APS-C
  • Focus peaking
  • In-Camera Image Stabilization
  • $1099
  • APS-C
  • Less expensive
  • Tilt-swivel screen

Compare Pentax K-3 III vs Canon 90D

Compared to Sony A7C

Sigma fp
Sony A7C
  • $1485
  • 35mm
  • Thinner
  • More dots on screen
  • $1598
  • 35mm
  • Tilt-swivel screen
  • Eye-level viewfinder

Compare Sigma fp vs Sony A7C

Pentax K-3 III
Sony A7C
  • $1847
  • APS-C
  • Lens selection
  • High resolution composite
  • $1598
  • 35mm
  • Less expensive
  • Tilt-swivel screen

Compare Pentax K-3 III vs Sony A7C

Compared to Sigma fp L

Sigma fp
Sigma fp L
  • $1485
  • 35mm
  • Bigger pixels
  • Higher max flash sync
  • $2499
  • 35mm
  • Newer
  • More pixels

Compare Sigma fp vs Sigma fp L

Pentax K-3 III
Sigma fp L
  • $1847
  • APS-C
  • Eye-level viewfinder
  • High resolution composite
  • $2499
  • 35mm
  • Larger sensor
  • Thinner

Compare Pentax K-3 III vs Sigma fp L

Compare Other Cameras?