Lighting can be one of the most challenging aspects of photography. An external flash with radio capabilities not only gives photographers the upper hand to counter tricky lighting conditions, but also enables them to experiment with different lighting techniques and expand their creative horizons.
Some flashes make use of wireless radio to receive data via electromagnetic waves from a transmitter device. This technology allows flashes to be controlled remotely up to distances of 30 metres or 98 feet1.
A wireless accessory (e.g. WR-R10 and WR-A10) alongside a compatible camera2, is required to communicate wirelessly with the flash using radio signals instead of optic light pulses.
1 Based on line of sight without obstacles
2 DSLR that supports radio flash feature
Previously, camera-based transmitters (e.g. Wireless Speedlight Commander SU-800) and remote flashes communicated through a direct line of sight via transmission and reception of optical light pulses. This meant that external flashes were limited by the shooting environment and could not communicate in less-than-ideal situations, such as behind walls or around corners.
Flashes with radio capabilities can be controlled even in the presence of obstacles, giving users more room to experiment with different lighting angles during a shoot. Photographers no longer have to rely on the built-in flash, and can even use the wireless flash as an extra secondary flash for additional or creative lighting.
Users should take note of electronic interference from televisions and radios that may affect the transmission of data, thereby reducing the effectiveness and efficiency of the communication between the camera and flash.
Another factor would be the distance between the camera and the flash. If the devices are placed too far apart, the distance could affect the radio triggering.