Sony a7S III Firmware Update Version 5.00 Released with Expanded Autofocus Customization

Firmware Update

by Alexandra ThompsonFebruary 3^rd, 2026

Subscribe to News - Cameras

Sony has released firmware Version 5.00 for their a7S III. While firmware updates can sometimes be minor maintenance releases, this one requires attention for two reasons: it changes the update method, and it resets certain camera settings during installation. If you’re using the a7S III professionally, this is not something to install casually shortly before a shoot. Let’s look at what’s actually changing and what you need to know before updating.

The Sony a7S III has been a core part of the company’s video-focused mirrorless lineup for several years. Our coverage has included a review with low-light sample footage and a CineD Lab Test. Firmware Version 5.00 does not alter its core recording formats or performance characteristics, but it introduces workflow changes and functional additions.

Firmware v5.00 – overview

Firmware Ver. 5.00 introduces updates across autofocus customization, display behavior, USB connectivity, authentication features, and stability improvements.

• Among the more interesting changes is the expanded autofocus configuration. Sony adds Spot: XL, along with three custom focus area presets under both the Focus Area and Tracking menus. That means you can define and store specific AF behaviors instead of rebuilding them mid-shoot.
• The shooting information display now adapts to both horizontal and vertical orientations. If you’re delivering vertical content, that’s simply easier to work with.
• There’s also a small but useful change: when recording in simultaneous or relay modes, the camera can now show the remaining capacity of both media cards.
• USB streaming support has been added as well, allowing the camera to function as a streaming device over USB-C.
• On the more specialized side, Ver. 5.00 supports Sony’s Write Digital Signature function for movies as part of its Camera Authenticity Solution, along with Scan and Tag and related commands under the Volume Photography License. These are aimed at institutional and enterprise workflows rather than typical narrative or commercial production.

The update process itself has also changed. The firmware is now provided as a memory card–based update file, replacing the previous computer-connected updater method.

Benefits and improvements at a glance

• Adapts the shooting information display for both horizontal and vertical orientations
• Adds Spot: XL under Spot in the Focus Area menu
• Adds Custom 1, Custom 2, and Custom 3 under Custom in the Focus Area menu
• Adds Tracking: Spot XL, Tracking: Custom 1, Tracking: Custom 2, and Tracking: Custom 3 under Tracking in the Focus Area menu
• Adds an option to enlarge the menu screen display
• Allows the remaining capacity of both storage devices to be displayed during movie recording when using simultaneous or relay media modes
• Adds support for USB streaming
• Supports the Write Digital Signature function for movies as part of Sony’s Camera Authenticity Solution
• Supports Scan and Tag, Photo Cropping, and Volume Photography Commands under the Volume Photography License (paid license required)
• Fixes an issue where audio could still be recorded when Audio Recording was set to Off
• Improves overall operational stability

Important: settings reset during update

Certain settings will be reset during installation. These include specific network streaming and cloud connection settings, selected custom key assignments, and certain My Menu registrations. Sony also states that previously saved settings will not carry over to cameras running version 5.00 or later. If you rely on customized setups, make a note of your configuration before updating.

Note: Before installing, check Sony’s official support notes. If your camera is running Ver. 2.11 or earlier, the required update path is Ver. 2.15 → Ver. 3.01 → Ver. 5.00. Attempting to install Ver. 5.00 directly will result in an error.

How to install the firmware

Sony now requires updating via memory card. Here is the direct link, but the basic steps are:

1. Download the firmware file from Sony’s official support page.
2. Format an SD card in-camera.
3. Copy the firmware file to the root directory of the card.
4. Insert the card into the camera.
5. Navigate to Setup → Version → Software Update.
6. Follow the on-screen instructions.

Sony recommends a fully charged battery before beginning the update. Also, do not power off the camera during installation. The process may take several minutes.

Who should install it now?

If your Sony a7S III is stable and you are mid-production, it may make sense to wait until downtime to install the update. If you’ve experienced operational inconsistencies or system glitches, this update may be worthwhile.

Price and availability

The firmware update is available now as a free download via Sony’s official support website.

Have you already installed Ver. 5.00 on your Sony a7S III? Did the expanded autofocus presets change how you configure your focus setup? Let us know in the comments.