The long awaited Sony a7S III brings high frame-rate 4K video with incredible low-light sensitivity to the A7 full frame mirrorless lineup. The video-centric follow up to the a7S II adds internal 10-bit 4:2:2 4K capture at up to 120fps while building on the a7S II's already segment leading low-light capabilities. Upgrades also extend to the 9.44M dot OLED viewfinder, 759-point phase detection autofocus and reduced rolling shutter.
THE SONY ALPHA A7S III CAMERA
Built around a new 12.1MP Exmor RS BSI CMOS sensor coupled with a BIONZ XR image processor, the a7S III is a powerful video oriented mirrorless full-frame camera. The long awaited follow up to the a7 SII, which set the standard for low-light capabilities in the full-frame mirrorless segment, brings not only improvements to that key spec but also a host of other notable upgrades.
Key Camera Specs
- 12.1MP Exmor RS BSI CMOS sensor
- ISO sensitivity of 40-409600
- 4K Video Capture at up to 120fps
- Internal recording at up to 10-bit 4:2:2 color sampling
- No recording time limit
- 16-bit raw video output over HDMI-A
- 759-Point phase-detection autofocus with 92% coverage
- Dual UHS-II card slots
- S-Log2/3 or HLG/BT.2020 gamma curves
- 5.5 Stop IBIS
The new sensor features 759 phase-detection and 425 contrast-detection autofocus points that cover approximately 92% of the image area and promises sensitivity down to -6 EV. Customizable seven-step AF transition speed and five-step AF subject shift sensitivity allows for fine tuning of the autofocus system. As expected, ISO sensitivity is expanded to ISO 40-409600.
A 5-axis in-body stabilization system provides 5.5 stops of camera movement, even with adapted lenses, which combined with the 120fps frame-rates help deliver ultra-smooth handheld video.
Video can be recorded in either All-I XAVC S-I at up to 600Mbps or XAVC HS which uses H.265 compression for smaller file sizes. Internal 4K recording uses 1:1 pixel readout at up to 120fps with 10-bit 4:2:2 sampling. The a7S III offers extensive color customization including the S-Log2 and S-Log3 gamma curves that can deliver 15+ stops of dynamic range. HLG and BT.2020 color spaces are also available. Recording time limits have been removed and improved heat dissipation has been added to the camera body's design. Internal recording is to UHS-II rated dual card slots that support CFexpress Type A or SD cards. External recording of 16-bit raw video is possible via the full size HDMI port when used with compatible Recorders.
NAUTICAM NA-A7SIII UNDERWATER HOUSING
Nauticam is the leader in producing intuitively designed precision manufactured aluminum underwater housings for the Sony a7 camera line and continues to innovate with the new NA-A7SIII housing.
The NA-A7SIII is designed to maximize the video-centric capabilities of the Sony a7S III camera while maintaining it's strong still image potential. The NA-A7SIII is built around the N100 port system that is shared with the rest of the Nauticam housing lineup for the Sony full-frame mirrorless a7 series. The N100 system includes a dull range of both macro and wide-angle ports as well as delivering access to the lineup of Nauticam's professional wet optics that are optimized for underwater imaging such as the WACP-1/2 and the SMC-1/2 lenses. These optics deliver unparalleled image quality underwater expanding what is possible with the powerful a7S III camera.
HDMI Output
The a7S III can output 16-bit raw video signal over HDMI and the NA-A7SIII features an M24 bulkhead that supports the HDMI 2.0 standard. This allows the NA-A7SIII to be used in conjunction with either a recording monitor such as the Atomos Ninja V in the NA-NinjaV housing via HDMI 2.0 or standalone monitors such as the SmallHD 502 Bright in the NA-502B housings via HDMI 1.4.
Optional Magnifying Viewfinder
The a7S III camera features an updated 9.44M-dot OLED viewfinder with a 120fps refresh rate. Nauticam's line of optional magnifying viewfinders, available in both an angled 45º (32203) or straight 180º (NA32201) configuration provide enhanced viewing ability as well as a dioptric adjustment knob that can used underwater. Installation can be achieved without tools in less than a minute.
Mission Control
Nauticam engineer's Mission Control design philosophy means controls are intuitively placed where they are needed most regardless of their position on the camera. The NA-A7SIII features a double thumb lever within easy reach of the right handle that triggers the AF-ON and RECORD controls of the camera. A thumb lever on the left side toggles the PLAYBACK button. The back panel of the housing provides access to all other rear camera controls including a multidirectional pad.
Vacuum Check and Leak Detection System
The Nauticam vacuum check and leak detection system is shipped with NA-A7SIII as standard equipment. With the addition of the optional M14 Vacuum Valve (NA25624) this monitoring system provides constant updates on the water tight and safe-to-dive status of the housing. A simple color coded LED lighting system lets the user know that the vacuum is solid, or that the housing is losing vacuum. Leak detection is built into the same circuit, so if there is water intrusion, an audible and visual indication will occur. The Nauticam system is temperature compensated, eliminating false alarms caused by a change in outside temperature, or from a camera heating up on an action packed dive.
