Optimized video, optimized sensitivity, optimized speed, the Sony Alpha a7S III raises the bar for what a full-frame mirrorless camera is capable of. A revised 12.1MP Exmor R BSI CMOS sensor and updated BIONZ XR image processor offer faster performance, improved noise reduction, and a wider dynamic range, along with UHD 4K 120p video recording and internal 10-bit 4:2:2 sampling.
Video is the primary application of the a7S III, and improvements to the sensor and processor enable faster readout speeds and greatly reduced rolling shutter, along with high-bitrate internal recording, 16-bit raw output via the full-size HDMI port, and flexible control over motion with variable frame rate selection. The a7S III also does away with recording time limits and incorporates HLG for direct HDR production as well as S-Log2/S-Log3 gamma profiles for advanced HDR production with editing.
The updated sensor design also brings improved autofocus performance via 759 phase-detection points, which offer intelligent subject tracking and Real-time Eye AF to ensure critical focus on moving subjects in all recording modes. The sensor and BIONZ XR processor also facilitate impressive sensitivity, with an expanded range from ISO 40-409600, as well as fast 10 fps continuous shooting for up to 1000 consecutive raw frames. Additionally, 5-axis SteadyShot INSIDE sensor-shift image stabilization is available, too, which minimizes the appearance of camera shake by up to 5.5 stops.
Complementing the imaging assets, Sony has also made some changes to the a7S III's physical design, including a rear LCD with a side-open articulating design and an impressive 9.44m-dot OLED electronic viewfinder. The camera's menu system has also been updated for more intuitive navigation and the body design helps to promote better heat dissipation for improved continuous recording capabilities. Additionally, dual memory card slots both support working with CFexpress Type A or SD UHS-II memory cards for flexible and high-speed file storage.
A redesigned 12.1MP full-frame CMOS sensor now features a back-illuminated Exmor RS design in order to achieve improved clarity and reduced noise along with the expectedly impressive sensitivity, from ISO 80-102400 with an extended ISO 40-409600 range. The updated sensor design also yields 2x faster readout speeds than previous generations and, when coupled with the revised BIONZ XR image processor, greatly reduces rolling shutter by 3x and up to 8x faster processing and overall camera handling. The sensor and processor combination also helps to achieve a wide dynamic range, of up to approximately 14 stops for stills and 15 stops for video, and 10 fps continuous shooting for up to 1000 uncompressed raw files for stills.
Recording up to UHD 4K is possible with frame rates up to 120p, using full 1:1 pixel readout without binning. Internal 10-bit 4:2:2 sampling is also possible in all recording modes and, if recording externally via the full-size HDMI A port, 16-bit raw output is also possible for even greater tonal reproduction and post-production flexibility. Additionally, two codecs have also been developed: XAVC HS, which uses HEVC/H.265 encoding to retain more detail at smaller bitrates, and XAVC S-I, which is an intraframe codec for consistent performance and quality at bitrates up to 600 Mb/s.
The high-speed, 120 fps recording also enables 4x and 5x slow-motion movie recording with the frame rate playback set to either 30p or 24p or, if moving down to Full HD resolution, an effective 240p frame rate is also available for even greater motion control. Additionally, suiting long-form recording, the a7S III does not have any recording time limits to allow for unlimited clip lengths. The camera's physical design also features an improved heat-dissipating structure to promote longer possible recording times, up to an approximate 60-minute recording time at 4K60p.
Affording extensive customizable color and gamma controls, the a7S III allows users to adjust the gamma, black level, knee, color level, and more. Also, users can use the same S-Log2 Gamma Curve that is found on high end Sony Cinema cameras that squeezes up to 1300% more dynamic range into the video signal then traditional REC709, for increased post-production flexibility. HLG (Hybrid Log-Gamma) support is also available, along with the BT.2020 color space, for recording within a wide color gamut and, in addition to S-Log2, S-Log3 is also available for producing a 15+-stop dynamic range with increased grading control in the shadow to mid-tone regions of the image.
Fast Hybrid AF System
Covering 92% of the image area, a Fast Hybrid AF system incorporates 759 phase-detection points along with 425 contrast-detection areas for quick and precise focusing in a variety of lighting conditions with sensitivity down to -6 EV. This focusing system is available for use in all recording modes, to benefit both video and stills applications. Additionally, it is able to lock onto subjects quickly and can use Real-time Tracking for AI-based tracking on moving subjects or touch tracking for manual selection of the subject. Real-time Eye AF, suitable for both humans and animals, also ensures critical sharpness when shooting portraits. Helping to fine-tune how the focusing system performs, seven-step AF transition speed and five-step AF subject shift sensitivity controls let you refine how quickly focus shifts from point to point and how smoothly focusing shifts occur.
5-Axis SteadyShot INSIDE Image Stabilization
The a7S III incorporates an enhanced 5.5-stop effective 5-axis SteadyShot INSIDE image stabilization system, which compensates for five different types of camera shake encountered during handheld shooting of stills and video. This allows users to confidently use any lens, even adapted lenses, for critical imaging without encountering blur from camera shake.
For long focal lengths, the system will correct for pitch and yaw adjustments. Macro and high-magnification imagery, on the other hand, will benefit from the inclusion of horizontal and vertical shift compensation. All shooting styles will get usage out of the roll compensation. All 5 axes of stabilization will function at all times, even when used with third-party lenses and adapters or lenses with built-in optical stabilization.
Additionally, specifically for video, there is also an Active IS mode that adds even more precise stabilization methods for even smoother footage straight out of camera.
Body Design and Connectivity
- An impressive QXGA OLED Tru-Finder EVF features a high 9.44m-dot resolution and 0.9x magnification for exceptionally bright, clear, and detailed eye-level viewing. This viewfinder has a dedicated 120 fps High Quality setting for smooth motion rendering and the finder's physical design has a long 25mm eye point, 41° field of view, and features a fluorine coating on the outermost viewfinder element to benefit cleaning.
- A first for a7-series cameras, a side-opening 3.0" 1.44m-dot vari-angle articulating screen benefits working from high and low angles as well as a front-facing position for vlogging or other self-recording needs. This LCD is a touchscreen, too, for intuitive shooting control and menu navigation.
- Dual memory card slots both accept either CFexpress Type A or SD-type memory cards. The dual slot design allows for flexible file saving and handling and can be configured to partition file types or can be used for overflow recording. Additionally, both of the card slots are rated to support UHS-II memory cards for faster transfer speeds.
- Redesigned menu structure is more intuitive and complements having different workflows and settings selections for movie recording and stills shooting. The menu system also works in conjunction with the touchscreen design of the rear LCD.
- Magnesium alloy chassis assures rigidity, durability, and stability while remaining lightweight. The lens mount has also been improved to better support heavy lenses, and the grip rigidity has been improved for more comfortable hand-holding.
- Extensive weather-sealing, including enhanced sealing around the battery cover, terminal cover, and chassis joints, has been employed to resist dust and moisture for reliable operation in harsh weather conditions.
- Accepts the high-capacity NP-FZ100 rechargeable lithium-ion battery, which provides approximately 510 shots/80 minutes of recording per charge when using the viewfinder or 600 shots/95 minutes of recording per charge when using the rear LCD.
- Full-size HDMI A port offers a more reliable connection when working with external recorders.
- A USB 3.2 Gen 1 Type-C port has been added, in addition to a micro-USB port, for faster, more reliable tethering support. The USB - Type-C connection allows the camera to be charged or powered from the host power source while connected.
- Both 3.5mm headphone and external microphone ports facilitate greater control over audio recording.
- Multi Interface Shoe supports working with the optional ECM-B1M Shotgun Microphone or XLR-K3M XLR Adapter Kit, which provide improved, clear audio recording sound by sending a digital audio signal to the camera, opposed to an analog signal.
- Built-in Wi-Fi enables the remote camera control and instant sharing of imagery to mobile devices for direct sharing online, and support for both 2.4 and 5 GHz bands also enables wireless tethered shooting support. This connectivity also provides remote camera control
- USB Type-C port can be paired with an optional Ethernet wired LAN adapter to provide 1000BASE-T connectivity, wired remote shooting, or FTP transferring.
New image sensor with double the readout speed
The newly developed back-illuminated full-frame Exmor RTM CMOS sensor, with 12.1 effective megapixels, boasts a readout speed up to twice as fast as that of the α7S II, along with high sensitivity and wide dynamic range. An advanced colour filter array boosts colour reproduction accuracy, while focal plane phase-detection AF enables substantial increases in autofocus stability and precision, all of which contribute to outstanding image quality.
New image-processing engine with up to 8x the processing performance
The BIONZ XR image-processing engine boasts a performance level up to eight times that of the previous processor, minimising latency while markedly improving real-time processing capabilities for both movies and stills. The engine performs real-time processing of AF, image recognition and image-quality adjustments, while also handling data transfer, user interface and other camera operations.
High sensitivity, wide dynamic range
The full-frame 12.1-megapixel configuration enables high sensitivity with low noise throughout the camera's sensitivity range by optimising the output signal from the sensor. The standard ISO range is 80-102400, which is further expandable to 40-409600 (80-409600 for movies). The dynamic range is an impressively wide 15 stops, for beautiful, true-to-life images without blown highlights. Together, the camera's high sensitivity and wide dynamic range expand your creative freedom during shoots.
All-Intra internal recording
In addition to Long GOP inter-frame compression, the α7S III supports internal intra-frame (All-Intra) recording for the first time in an α-model body, where each frame is recorded independently at a high bitrate of up to 600Mbps. This can be useful for certain types of shoots as it allows maximum flexibility in post-production editing.  All-Intra (All-I)  Long GoP  Group of Pictures.
Full-frame 4K recording at 120p
Full-frame 4K recording at 120fps with autofocus is possible thanks to the high-speed readout capabilities of the new image sensor working in tandem with the newly developed, powerful BIONZ XR processor. This high image-quality 4K, with full-pixel readout without binning, allows for clear post-produced slow motion (up to x5 slower than real time), as well as bokeh effects typical of full-frame cameras, all with smooth, high-precision autofocus. Despite the α7S III's compact size, it provides impressive scope for your creativity.
Recording movies with 10-bit depth and 4:2:2 colour sampling
The camera is capable of performing 4K internal recording with 10-bit depth and 4:2:2 colour sampling when using either Long GOP or All Intra compression. This makes it possible to push your colour grades further, stretching video out for ultimate HDR realism while still retaining natural gradation, for true editing freedom.
HEVC codec with high compression efficiency
Available for the first time, XAVC HS format recording using the MPEG-H HEVC/H.265 codec roughly doubles the compression efficiency. Compared to a normal 4K XAVC S format, XAVC HS allows for detailed 10-bit video with 4:2:2 colour sampling at comparable or lower data rates, delivering even better image quality as well as manageable file sizes.
S-Log2 and S-Log3 with 10bit 4:2:2 support
S-Log2 and S-Log3 gamma curves are available, with S-Log3 designed for better reproduction of gradations from shadows to the mid-grey range (18% grey), enabling a dynamic range of up to 15 stops. Three colour gamut settings (S-Gamut, S-Gamut3, and S-Gamut3.Cine) are provided, and the latter two settings make it easier to match the colours of footage shot with Sony's professional cinema cameras. Because the colours match, colour grading is easier in post-production editing, making it more convenient to use the α7S III along with other pro cameras.
16-bit RAW data output
Facilitating improved image quality and more flexible and efficient editing in post production, the camera supports 16-bit RAW data output to an external recorder via HDMI, for the first time in the α series. The output is full-frame 4264 x 2408 (16:9 aspect ratio) 16-bit data from the image sensor, with a choice of frame rates (60p/50p/30p/25p/24p).
10-bit HLG picture profile
An HLG (Hybrid Log-Gamma) HDR picture profile, complete with the wide-gamut BT.2020 colour space, can be used for direct HDR (HLG) playback on compatible TVs. The result is true-to-life imagery close to what the naked eye can see, with detailed shadows and highlights, less blackout and less whiteout, all without the need for colour grading. In particular, 10-bit recordings reproduce a level of fine gradation and detail for extraordinary realism.  High flexibility to fine-tune images as desired (colour grading required)  Instant high-quality image (colour grading not required) .
Enhanced movie image quality
Thanks to the improved capabilities of the α7S III's new image-processing engine, colours and textures of foliage and human skin can be more consistently reproduced without over-dependence on light sources. Gradation rendering has also been refined, for better-looking skin tones and highlight roll-off in portraits. When shooting 4K, the new image sensor and processing engine reduce rolling shutter distortion to as little as one-third that of the α7S II.
Proxy recording for more efficient editing workflow
When shooting movies, low bit-rate HD proxy files can be recorded simultaneously with higher bit-rate formats such as XAVC S-I 4K, and these smaller proxy files can then be used for editing and previewing prior to final production delivery. This reduces computer load and allows faster and more efficient workflows. Proxy files can be captured in either 10-bit XAVC HS (1920 x 1080) or 8-bit XAVC S (1280 x 720).
AF support in manual-focus mode
The camera's autofocus support can be useful even when you're primarily using manual focus. For full AF speed, half-press the shutter button or press the AF-ON button, as you would when shooting stills. Alternatively, slower, more cinematic AF transitions can be achieved by initiating AF via the touch focus feature or Real-time Eye AF via a custom button assignment, resulting in slow, smooth autofocus at the preset AF Transition Speed.
Game-changing tracking features to revolutionise movie shooting
Real-time Tracking and Real-time Eye AF make movie-making much easier. Touch Tracking initiates subject tracking with an intuitive touch to the LCD monitor, processing data on colour, pattern (brightness), distance (depth) and facial information to keep your subject in steady focus. You can then concentrate more fully on composition, which can be especially useful when you're shooting solo or using a gimbal. Touch operations can be used to temporarily engage AF even when you're shooting manually.
Fast Hybrid AF for dependable focus during movie shooting
Inheriting technology and performance standards from Sony's large-format FX9 pro camcorder, Fast Hybrid AF combines focal plane phase-detection AF with contrast-detection AF. This results in highly precise, smooth tracking of fast-moving subjects even over a wide range with a shallow depth of field, taking full advantage of Sony E-mount lenses' smooth linear-motor focusing and power-zoom operations. Newly added AF Transition Speed and AF Subject Shift Sensitivity parameters allow more flexible focus control, as requested by professional users. Both allow preset settings to be recalled during recording by using a customisable button.
Active Mode optical image stabilisation for handheld shooting
Relying on a new high-precision stabilisation unit, gyro sensors, and optimised image stabilisation algorithms, the camera's Optical SteadyShotTM Active Mode provides the precise degree of optical image compensation needed during movie shooting, even for 4K video. With this unprecedented level of stabilisation it's possible to shoot with the camera only, taking advantage of the compact size and mobility of the α system.  Track of camera shake  Standard  Active.
New heat-dissipation design for extended recording times
The camera's design has been optimised to prevent overheating even during extended recording sessions. A unique Sony Σ (sigma) shaped graphite-alloy heatsink is built into the image stabilisation unit, allowing the sensor to dissipate heat five times more effectively than in previous models, while allowing it to move freely and avoiding interference with the stabilisation system.
Enhanced audio quality
A digital audio interface is incorporated in the camera's Multi Interface (MI) Shoe, to facilitate cleaner, clearer audio recordings without loss of quality. The XLR-K3M XLR Adaptor Kit additionally provides the camera with 4-channel 24-bit digital audio recording capability. Three recording formats can be selected from a menu: 48 kHz/16-bit 2-ch, 48 kHz/24-bit 2-ch, and 48 kHz/24-bit 4-ch, with the XLR-K3M XLR Adaptor Kit required for the latter two formats.
Dedicated settings menu for movie shooting
A subset of the camera's settings can be changed independently for movie or still shooting, which can be useful if you want to use different ISO, Iris (aperture) and other settings depending on the shooting mode. Another convenient feature is the use of Flexible Exposure Mode instead of normal PASM Mode when Movie or S&Q mode is selected. This allows quick switching between auto and manual control of Iris (aperture) and shutter speed, and the function can be assigned to a custom button to allow one-touch toggling between auto and manual.
Fast Hybrid AF for still shots
The Fast Hybrid AF uses a high-density array of 759 phase-detection AF points (covering around 93% of the imaging area) in conjunction with 425-point contrast-detection AF. Real-time Eye AF (for humans and animals) and Real-time Tracking features are also available for the first time in the S series. Advanced AF algorithms facilitate precise AF down to light levels as low as EV-6, for accurate focus even when the subject would be difficult to see clearly with the naked eye.
Designed for smooth movie-making
Flexibility in positioning the camera and framing shots is provided by the side-opening, vari-angle monitor, which incorporates a bright 3.0-type, 1.44 million-dot LCD screen. The MOVIE button is within easy reach on the camera's top panel, and a durable HDMI Type-A terminal ensures reliable connections to external monitors. The item arrangement and initial settings on the mode dial have also been adjusted to meet the needs of pro users.
High-speed continuous shooting performance
Mechanical and electronic shutters are each capable of continuous shooting at up to 10fps with AF/AE. Continuous shooting of over 1000 uncompressed RAW images is possible thanks to increases in the buffer memory of the BIONZ XR processor and memory-card writing speed.
Creative Look feature to set the mood and atmosphere
The new Creative Look feature is a quick way to establish a particular mood in still shots and movies by altering parameters like brightness, contrast and colour saturation. Ten Creative Look presets are available in-camera, and each of these can be used as is, or further customised using eight individual parameter settings. Custom Creative Look settings can be easily saved and stored for later use.
Enhanced image quality for stills
The new image sensor and image-processing engine deliver an extraordinary degree of sensitivity, a defining characteristic of the S series, and significantly better reproduction of colour and textural details. Improved rendering capability provides realistic-looking images with reduced noise, particularly in the mid-to-high sensitivity range. A new Visible Light and IR Sensor improves auto white balance, and HEIF file options and an HLG Still Image Mode (for 8-bit and 10-bit HEIF stills) have been added.
Two CFexpress Type A-compatible media slots
The camera's two media slots are compatible with new CFexpress Type A cards as well as SDXC/SDHC cards supporting UHS-I and UHS-II speed classes. CFexpress Type A cards are the next standard for compact storage with fast write/read speeds suitable for both high-speed continuous still shooting and 4K movie recording at high bit rates. They are capable of quickly clearing camera buffers even when high volumes of still image and movie data are being generated.
New touch-driven menu with workflow-based navigation
Responding to requests from pro photographers and videographers, the menu structure has been designed to allow professionals to work more efficiently. Menu tabs are on the left side of the display, while parameter groups and parameters related to the selected tab appear on the right. Up to three levels can be displayed together, making the menu structure more clearly visible. Touch-responsive menu operations enable fast, intuitive control.
Boasting the highest resolution in its class, the α7S III's viewfinder rivals the resolution of the human eye. It provides category-leading 0.90x viewfinder magnification, a 41º diagonal field of view, and a 25mm high eyepoint for clear, low-distortion viewing. Improvements in sealing greatly reduce the chance that even drastic ambient temperature fluctuations will cause interior condensation.
Reliable, durable construction
To maximise dust and moisture resistance, additional sealing has been applied to all body seams and to the battery compartment cover, and the media slot cover has been redesigned to handle harsh outdoor environments. A filter in front of the image sensor oscillates at an ultrasonic frequency of 70,000 cycles per second to remove dust from the sensor surface. The camera chassis is highly durable thanks to full magnesium-alloy construction.
Data communications to support on-site workflow
Wired and wireless communications features support FTP transfer for still and movie files as well as remote shooting capability, to facilitate professional workflows during shoots. Wireless 5GHz/2.4GHz LAN connections are supported, and wired connectivity to 1000BASE-T Ethernet networks is available via a USB-to-Ethernet adaptor cable connected to the camera's USB Type C® port supporting SuperSpeed USB 5Gbps (USB 3.2). Remote shooting can be controlled from a PC with Sony's Imaging Edge DesktopTM application, or from a mobile device with Imaging Edge Mobile.
USB Power Delivery
The camera supports USB PD (Power Delivery), to enable continuous shooting for extended periods without draining the internal battery. PD-compatible USB chargers and mobile batteries can be connected to the camera's USB Type C port, to supply power or to recharge the internal battery at 3 to 4 times the speed of conventional power supplies.
External flash control from the camera body
It is now possible to configure the settings of a compatible attached flash or Wireless Radio Commander (both sold separately) from the camera. Most settings, including light output, can be accessed and easily changed directly from a camera menu, for high-performance flash control with these genuine Sony accessories. Flash parameters are shown in the selected camera display language.
Capture One for Sony
Capture One Express (for Sony) is free award-winning editing software that provides RAW development, easy management and powerful editing tools. Capture One Pro (for Sony) is also available for even more editing tools and remote shooting capability.
Imaging Edge Desktop
Elevate your photography with Imaging Edge Desktop applications. Use ‘Remote’ to control and monitor shooting live on your PC screen; ‘Viewer’ to quickly preview, rate, and select photos from large image libraries; and ‘Edit’ to develop RAW data into high-quality photos for delivery. Get the best from Sony RAW files, and manage your productions more efficiently.