Sony Alpha a7S II

Sony a7S II

12.2MP full-frame CMOS sensor | 5-axis image stabilization | 4K video capture

What we like:

  • Incredible low light sensitivity, particularly for video
  • Internal 4K recording
  • 5-axis image stabilization

What we don't:

  • Autofocus struggles in low light and with low contrast subjects
  • Small, finicky and mushy buttons and dials
  • Poor battery life
The a7S II lifts the same high-sensitivity 12.2MP full-frame CMOS sensor from the original a7S and carries it into the second generation a7 lineup, adding in-body 5-axis and internal 4K recording as new features.
While a substantial improvement over its predecessor, the a7S II hasn't aged well, with cheaper competitors offering superior video quality and features
Autofocus is contrast-detect only, but is claimed to work down to -4EV - something that we've found is borne out in testing. The algorithms in video have been changed to make AF smoother and quicker to rack between subjects. Still, for still shooters wishing to acquire focus in very dark scenarios, or continuously focus on moving subjects, the a7S II's AF system can prove frustratingly sluggish compared to (for example) the a7R II.
Image quality is quite good but resolution is obviously somewhat low, which limits scope for cropping and large prints. Noise levels remain low even at seemingly insane ISO levels. It's important to note though that the low light, high ISO stills performance of the a7S II is not unique: even higher resolution cameras show fairly similar low light performance at all but the highest ISOs in Raw comparisons at common viewing size. Raw dynamic range, while significantly higher than Canon peers, lags slightly behind its higher resolution siblings as well as Nikon's offerings.
The a7S II was launched as the video-focused a7 model. It offers UHD 4K footage from its full sensor width or 1080 at up to 120p (from a smaller than Super35 2.2x crop). It includes support tools such as zebras and peaking, and can shoot Log footage but only in 8-bit. It has an edge over its rivals at very high ISO but its specs and performance no longer stand out, even compared with less expensive rivals.
While it still has compelling video features and excellent 1080 quality, the a7S II faces steep competition from cheaper models that out-do it in terms of detail capture.

Studio Test Scene | Specifications Compared