The full-frame mirrorless Sony Alpha a7S III camera features optimised speed, sensitivity, and video, thanks to a revised 12.1MP Exmor R BSI CMOS sensor and updated BIONZ XR image processor. The redesigned back-illuminated sensor achieves improved clarity and reduced noise, as well an impressive sensitivity range of ISO 80-102400 that can be extended to an even wider range of ISO 40 - 409600. When combined with the revised processor, the sensor-processor pair provides a wide dynamic range of up to approximately 14 stops for still, 15 stops for video, and 10 fps continuous shooting for up to 1000 uncompressed raw files for stills. Other improvements greatly enhance the video capabilities in the Sony Alpha a7S III: twice as fast readout speeds as its precedents, marked reduction in rolling shutter by three times, faster processing of up to eight times, and more efficient camera handling overall. Also available for enhanced video applications are high-bitrate internal recording, 16-bit raw output via the full-sized HDMI port, and flexible control over motion with variable frame rate selection. At the high-speed 120 fps recording, 4x and 5x slow-motion movie recording with frame rate playback set at either 30p or 24p is available; an effective 240p frame rate for even greater motion control is made available when recording at Full HD resolution. The a7S III further frees and empower photographers by removing limits on recording time along with an incorporation of HLG for direct HDR production and S-Log2/S-Log3 gamma profiles for advanced HDR production during editing.
The updated design of the sensor contributes to improved autofocus performance via 759 phase-detection points and 425 contrast-detection areas. It enables fast and accurate focusing in a variety of lighting conditions with sensitivity down to -6 EV and ensures critical focus on moving subjects in all recording modes in the form of intelligent subject tracking and Real-time Eye AF (autofocus). Benefitting handheld shooting of stills and video, a 5-axis SteadyShot INSIDE sensor-shift image stabilisation is incorporated to minimise the appearance of camera shake by up to 5.5 stops. Additionally, video shooting is further enhanced by an Active IS mode that contributes more precise stablilisation methods to achieve even smoother footage straight out of camera. An updated physical design complements the a7S IIIs imaging assets, which includes a rear LCD with a side-open articulating design and an impressive 9.44m-dot OLED electronic viewfinder.
The menu systems updated structure provides for more intuitive navigation and its body design is updated to improve heat-dissipation to support longer possible recording times. The cameras magnesium alloy chassis is robust and durable while remaining lightweight, and an improved lens mount better supports heavier lenses. The a7S III features extensive weather-sealing for reliable operation in inclement weather conditions. Additionally, dual memory card slots that both support working with CFexpress Type A or SD UHS-II memory cards supports flexible and high-speed file storage. Built-in Wi-Fi is available for remote camera control and instant image sharing, and support for both 2.4 and 5 GHz bands also enables wireless tethered shooting support. Via the multi interface shoe, photographers with need for improved and clearer audio recording sound have the option of working with the separately available ECM-B1M Shotgun Microphone or XLR-K3M XLR Adapter Kit. The Sony a7S III is supplied with a rechargeable battery, battery charger, body cap, USB Type-C to Type-A Cable, cable protector, shoulder strap, accessory shoe cap, and an eyepiece cup.