Sony Alpha 7S sensor review: New low–light champ

By Kevin Carter - Tuesday June 17 2014

Camera Review
Introduction | Sony A7S: Best Low-Light ISO score in our database | Sony A7S versus Nikon Df: New low light champion | Sony A7S versus Sony A7 versus Sony A7R | Conclusion
Sony Alpha 7S sensor review: New low–light champ

If you read the forums on colleagues’ sites lots of users lament the selling of their old full-frame Canon EOS 5D, Nikon D700 or even their bulky Nikon D3 or D3s. Practically every user, so it seems, says their pictures from those old models had something special that the newer models lack.  Sony think they may be on to something and have introduced the A7S a full-frame model with a newly-developed 12.2-Mpix CMOS sensor. Read on to find out well this new model performs?

Sony has added a third model to the firm’s innovative full-frame A7 mirrorless camera line-up, concentrating on high sensitivity, low noise and a wide-range of video capture options including 4K from its full-frame sensor.

Shunning the hi-res’ imaging of the A7 and A7R, the A7S adopts a sensor with a mere 12.2-million pixel count but with an expansive stills sensitivity of 100-102,400 (expandable to ISO 50-409,600).  The new specially developed sensor is also the first to deliver UHD (4K) video from the full width of the sensor without pixel binning, albeit limited to HDMI only. With third-party external recorders starting just under $2,000 (for the recently announced Atomos Shogun), though that makes it an expensive option.

Fortunately the A7S has a complement of Full HD (1920x1080) video modes recording to the SD card at frame rates up to 60 fps with a range of recording formats including XAVC S with bitrate encoding up to 50 Mbps.  Native sensitivity in movie capture echoes that of stills, and it can be expanded to ISO 100-409,600. Other features include the 25-point contrast-detection AF system from the A7R albeit modified with sensitivity to a unusually low Ev-4, XGA OLED EVKF, WiFi with NFC capability and Sony are developing a new XLR-type microphone adaptor kit using the camera’s multifunction shoe.

The A7S is available for pre-order at $2,498 body only.

For more information, please see our preview at http://www.dxomark.com/Reviews/Sony-A7S-Preview-A-low-resolution-marvel-for-low-light-video

Key specifications

 

  • 12.2Mpix CMOS Sensor with gapless microlens design
  • 5fps continuous shooting with autofocus (up to 200 frames)
  • 25 point contrast AF module with sensitivity to -4 Ev.
  • 2.36M dot OLED viewfinder
  • Pull-out tilting 1.23m dot LCD screen
  • 1/8000th top shutter speed, 1/250th flash sync.
  • ISO 100-102,400, 50 – 409,600 (Extended)
  • 1080p up to 60 fps movies
  • 4:2:2 UHD 4K output (only via HDMI to external recorder)
  • Built-in Wi-Fi with NFC

Sony A7S: Best Low-Light ISO score in our database

Sony A7S versus Nikon Df: New low light champion

Sony A7S versus Sony A7 versus Sony A7R

Conclusion