Radio Trigger
A transmitter on the camera and receivers on the flashes that fire them by radio signal.
Measured in
m (range)
In depth
Radio needs no line of sight, works at hundreds of metres, and is unaffected by sunlight, which makes it the professional standard. Modern systems also pass through power settings, TTL metering and high-speed sync, so the whole lighting rig can be adjusted from the camera without walking to each stand.
Examples in practice
A photographer adjusts a light hidden behind a wall from the camera position, changing its power by two stops without moving.