Does anyone know where/how to find the USB power specifications (i.e. how much power is available from the camera) from various manufacturers?i.e. if I want to power something from the camera (e.g. light), what voltage/amps should I expect from the USB socket?is there some standard?
In the USB 1.0 and 2.0 specs, a standard downstream port is capable of delivering up to 500mA (0.5A); with USB 3.0, it moves up to 900mA (0.9A). The charging downstream and dedicated charging ports provide up to 1,500mA (1.5A). USB 3.1 bumps throughput to 10Gbps in what’s called SuperSpeed+ mode, bringing it roughly equivalent with first-generation Thunderbolt. It also supports power draw of 1.5A and 3A over the 5V bus.
