The Sony a7S III is a full-frame mirrorless camera, part of the Sony E Mount lens system, designed for high-quality video production featuring specialized low-light performance (“S” for sensitivity). It is part of the Alpha 7 series of cameras and was announced on July 28, 2020. The a7S III builds on the legacy of the a7S II, which was released in 2015, and brings several significant improvements and new features that make it a highly capable and versatile tool for both filmmakers and photographers.
Key Features and Improvements:
- Sensor and Image Quality: The a7S III features a 12.1-megapixel back-illuminated full-frame Exmor R CMOS sensor. While the resolution remains similar to the a7S II, the new sensor design enhances low-light performance and minimizes noise at high ISO settings. The camera’s native ISO range is 80-102,400, expandable to 40-409,600.
- Video Capabilities: The a7S III’s primary focus is on video performance, offering a wide range of professional-grade video features. It can record up to 4K resolution at 120fps with 10-bit 4:2:2 color sampling, providing high-quality, detailed footage with excellent color reproduction. The camera also supports various codecs, including XAVC S, XAVC HS (H.265), and XAVC S-I (All-Intra), allowing for flexibility in post-production workflows.
- Autofocus System: The a7S III uses a Fast Hybrid AF system with 759 phase-detection autofocus points and 425 contrast-detection points, covering 92% of the image area. This system enables fast and accurate autofocus, including real-time Eye AF and real-time Tracking for both stills and video.
- In-Body Image Stabilization: The camera features a 5-axis in-body image stabilization system, providing up to 5.5 stops of shake reduction. This enables smoother handheld video recording and sharper images in low-light situations or when using longer focal length lenses.
- Electronic Viewfinder and Rear Monitor: The a7S III is equipped with a 9.44-million-dot OLED electronic viewfinder (EVF), one of the highest-resolution EVFs available in a mirrorless camera. The rear monitor is a 3.0-inch side-opening vari-angle touchscreen with 1.44-million-dot resolution, which offers flexibility in shooting angles and enhanced usability.
- Memory Card Slots and Recording Options: The a7S III has two memory card slots that support both UHS-II SD and CFexpress memory cards. This allows for faster write speeds and the ability to record high-bitrate video formats without interruption.
- Build and Design: The a7S III inherits the familiar design language of the Alpha series, with a magnesium alloy body that is both lightweight and durable. The camera is dust and moisture resistant, making it suitable for use in challenging environments.
The Sony a7S III has been well-received by both professional filmmakers and enthusiasts for its video capabilities, low-light performance, and improved autofocus system.
The a7S III has further solidified Sony’s position in the mirrorless camera market, particularly in the domain of video production.