I have had the 430er and 580er a flash before the current Canon RT system and had since recourse to third party in order to have good reception Wireless, now is the past! Both my 600 and the ST-E3 can operate together, the amount of light I can easily adjust to the master and have fun at the off-camera flash! No tiresome ture Adjustment behind the soft boxes, everything is easily accessible from the transmitter! And for the future I can use with more features and growing ability to grow it!