Does the E-420 support the Olympus wireless RC flash system?
Yes. The cameras built-in flash acts as a controller that sends data commands to the (optional) FL-36R and FL-50R electronic flash units. The system can control up to three groups of flash units. The camera and flashes have four control channels to choose from so the flashes and camera will not receive signals from other Olympus wireless RC flash systems operating nearby. The photo below shows the main setup screen for the wireless flash system in the E-420.