V5.00 firmware for the Sony A7s III adds a whole range of new features including AF improvements, accommodations for vertical shooting, USB streaming, and more.
Before we get to the new features, there are perhaps more warning flags than usual supplied by Sony for the new v5.00 firmware for the A7s III. You can have a look here, but essentially users on any older versions than Ver 3.00 or later must follow an upgrade path from Ver. 2.15 to Ver. 3.01 first before proceeding to the latest Ver. 5.00.
It also advises that even if you previously saved your settings using features such as Save/Load Settings, these settings will not be carried over to cameras with Ver. 5.00 or later. Sony recommends writing down your settings in advance before proceeding.
So, presuming you've done all that, what do you get for your trouble?
Alongside the increasingly standard ability to switch seamlessly between horizontal and vertical shooting, the chief new features relate to autofocus. Spot: XL has been added, along with the ability to define three custom areas in both the focus and tracking menus and save them as presets.
Accessibility features get a boost with the option to enlarge the menu screen display, while the camera can also be used as a streaming device over USB-C. The Write Digital Signature function for movies has been implemented as part of Sony’s Camera Authenticity Solution, while the Volume Photography License gains support for Scan and Tag, Photo Cropping, and Volume Photography Commands.
Here's the complete list...