Canon 430 EZ is a high-performance, electronic flash, especially designed for EOS cameras. It features automatic flash output which responds to a wide range of illumination from dark surroundings to bright (fill-flash) without troublesome operations. Advanced techniques such as bounce and slow-sync flash photography can be used in the automatic mode. The Canon 430EZ uses Advanced TTL (ATTL) automatic flash control. This function provides the appropriate flash control for the background as well as the subject, for conditions ranging from total darkness to fill-in flash.