Sony Alpha a7S II

Sony a7S II

12.2MP Full-frame CMOS sensor | 2.36M-Dot OLED EVF | Internal 4K recording

What we like:

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

What we don't:

  • Contrast Detect AF struggles in low light and with low contrast subjects
  • Small, finicky, mushy dials and buttons
  • Poor battery life

The a7S II takes the same high-sensitivity 12.2MP full-frame CMOS sensor from the original a7S and carries it in to the second generation a7 lineup, bringing 5-axis IBIS and internal 4K recording as new features. It sits next to the a7 II and a7R II as an option for available light photographers and video shooters, with many of its features benefiting the latter. 

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Autofocus is CDAF only, but is claimed to work down to -4 EV thanks to the nocturnal sensor. 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. Simply put: the lack of depth-aware phase-detect AF (PDAF) points is becoming egregious, especially in the face of compelling mirrorless PDAF implementations such as that of the a7R II, which challenge or even exceed DSLRs in terms of continuous AF and subject recognition and tracking abilities.

Image quality is quite good but on the low side with respect to resolution, which limits cropping and enlargement abilities. Noise levels remain low even to 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. Uncompressed raw is also offered (as is the case with the a7R II and a7 II), allowing as much detail as possible to be recovered from shadows and high contrast edges, without odd compression artifacts. Raw dynamic range, while significantly higher than Canon peers, lags slightly behind its higher resolution siblings as well as Nikon's offerings.

"The new additions to the a7S II make it an even more lust-worthy option for any digital filmmaker"

Where the a7S II really shines is in 4K recording, which it can now do at up to 30p internally. While the a7R II offers similar capability, the a7S II full-frame 4K is far more detailed, thanks to full-sensor readout of every pixel. We've also found this full sampling of the entire sensor to significantly benefit low light video quality relative to the a7R II (which only reads every pixel in Super35 mode), with the a7S II (and a7S) delivering the lowest noise low light video footage we've ever seen. Unlike the a7R II, to which comparisons will undoubtedly be drawn, the a7s II doesn't offer decisive AF in video sans hunting, since it lacks on-sensor phase-detection.

The a7S II also has the ability to shoot 1080p at 24, 30, 60, and 120 fps framerates (although 120p comes with a 2.2x crop factor, beyond even APS-C). Profiles such as S-log utilize the sensor's ISO-invariant nature to enable videographers to cram as much information in to their clips as possible, allowing wide dynamic range scenes to be captured and later color graded to the videographer's taste. The camera also offers ample tools for pro videographers, like zebra stripes, focus peaking and more. And a built-in microphone and headphone jack make the a7S II all the more able to be turned into an all-out video rig.

Given how popular the a7S + Atomos Shogun has been in the movie world, the new additions to the a7S II make it an even more lust-worthy option for any digital filmmaker. Although internal recording is capped at 8-bit 4:2:0 (who wouldn't have loved to see 10-bit 4:2:2?), those that aren't drastically grading challenging footage may not appreciate the difference enough to forego the benefits of internal recording. And even those recording externally: benefits like IBIS and improved log gamma capture (with a lower base ISO) spell serious improvements over the original a7S and make the a7S II one of the most compelling video recording devices currently on the market.

Studio Test Scene | Specifications Compared

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