• 0.98 inch 285.7mm2
  • 4.7 megapixels
  • ISO 100 - 1600
  • APS-C 369.7mm2
  • 24.3 megapixels
  • ISO 100 - 16,000

Buy From

Differences

Sigma SD15 advantages over Sony A77

  • Bigger pixels
    ~ 7.84 vs 3.95 microns
    Better low-light and dynamic range (all else equal)
  • Doesn't require an AA filter
    Yes vs No
    A unique sensor design provides sharp photos without moiré

Sony A77 advantages over Sigma SD15

  • Tilt-swivel screen
    Tilt-swivel vs none
    Tilt and swivel the screen for maximum shooting flexibility
  • Lens selection
    Good vs Limited
    Better lens selection gives you more options
  • Focus peaking
    Peaker vs Non-peaker
    Your camera will highlight what's in focus
  • Larger sensor
    APS-C vs 0.98 inch
    More sensor area. Bigger is (generally) better.
  • In-Camera Image Stabilization
    Yes vs No
    Reduces the effects of camera shake at slower shutter speeds
  • In-camera panoramas
    Yes vs No
    Stitches multiple shots into a panoramic photo
  • Built-in GPS
    GPS vs None
    Geotag your photos
  • Longer stills battery life
    More info 530 vs 250 shots
    Capture more photos
  • External Mic Jack
    Jack vs No jack
    Improved sound fidelity when shooting video
  • More cross-type AF points
    11 vs 1
    Cross-type AF points improve autofocus performance
  • HDMI out
    HDMI out vs None
    Use HDMI output to monitor or review video
  • Shoots 24p video
    Yes vs No
    Gives your movies a big-screen feel
  • More dots on screen
    922k vs 460k dots
    Can mean greater resolution or a brighter screen
  • Shoots 1080p video
    Yes vs No
    You'll want this if you shoot video
  • More viewfinder magnification
    0.73x vs 0.53x
    Get a bigger view of the scene through the eye-level viewfinder
  • More pixels
    24.3 vs 4.7 megapixels
    Higher resolution photos
  • Shoots 60p video
    Yes vs No
    A faster framerate can give you more editing options
  • More AF points
    19 vs 5
    More AF points improve autofocus
  • Faster JPEG shooting
    11.6 fps vs 3.0 fps
    Faster JPEG shooting (burst mode)
  • Faster shutter
    1/8000 vs 1/4000 sec
    Shoot wide open in bright light
  • Higher extended ISO
    16000 vs 3200 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
  • Top deck display
    Both provide
    Check settings with a screen on top of the camera
  • Hot shoe
    Both provide
    Off-camera flashes open new possibilities
  • Bulb shutter
    Both provide
    Hold the shutter open manually for long exposures

Common Weaknesses

  • Touchscreen
    Neither provide
    Interact with your camera just like your smartphone
  • 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
  • On-sensor phase detect
    Neither provide
    Usually improves live view and video AF performance
  • 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

Buy From

Your purchases support this site

Buy the Sony A77

Review Excerpt

  • Very fast top frame rate; full-time phase-detect autofocus; Full 60p HD video; Excellent kit lens; Very good high-resolution sensor.

  • Heavy; EVF appears dim when used in bright light; AF tracking in Movie mode was unreliable in our testing.

The Competition

Compared to Olympus E30

Sigma SD15
Olympus E30
  • $1500
  • 0.98 inch
  • Larger sensor
  • Bigger pixels
  • $1299
  • 4/3
  • Lens selection
  • In-Camera Image Stabilization
Sony A77
Olympus E30
  • $1899
  • APS-C
  • Focus peaking
  • Larger sensor
  • $1299
  • 4/3
  • Less expensive
  • Longer stills battery life

Compared to Sony DSLR-A330

Sigma SD15
Sony DSLR-A330
  • $1500
  • 0.98 inch
  • Bigger pixels
  • Top deck display
  • $530
  • APS-C
  • Lens selection
  • Larger sensor
Sony A77
Sony DSLR-A330
  • $1899
  • APS-C
  • Tilt-swivel screen
  • Focus peaking
  • $530
  • APS-C
  • Less expensive
  • Bigger pixels

Compared to Canon 7D

Sigma SD15
Canon 7D
  • $1500
  • 0.98 inch
  • Bigger pixels
  • Doesn't require an AA filter
  • $1499
  • APS-C
  • Lens selection
  • Larger sensor
Sony A77
Canon 7D
  • $1899
  • APS-C
  • Tilt-swivel screen
  • Focus peaking
  • $1499
  • APS-C
  • Lens selection
  • Fast startup

Compared to Olympus E-5

Sigma SD15
Olympus E-5
  • $1500
  • 0.98 inch
  • Larger sensor
  • Bigger pixels
  • $1700
  • 4/3
  • Lens selection
  • In-Camera Image Stabilization
Sony A77
Olympus E-5
  • $1899
  • APS-C
  • Tilt-swivel screen
  • Focus peaking
  • $1700
  • 4/3
  • Less expensive
  • Longer stills battery life

Compared to Sony A77 II

Sigma SD15
Sony A77 II
  • $1500
  • 0.98 inch
  • Bigger pixels
  • Doesn't require an AA filter
  • $1198
  • APS-C
  • Tilt-swivel screen
  • Lens selection
Sony A77
Sony A77 II
  • $1899
  • APS-C
  • Built-in GPS
  • $1198
  • APS-C
  • Built-in Wi-Fi
  • NFC
Compare Other Cameras?