CameraPlus&reg; PC580TTL E-TTL Speedlite Flash ith LCD Screen for Canon SLR 580EX II Canon 1Ds,5D,5DII,5D Mark II,Mark III,6D,7D,40D,50D,60D,70D,450D,500D,550D,600D,650D,700D,1100D,1000D etc Quick Recharge Time: 3sec // Front / Rear curtain sync // LCD backlit screen-for sharp and clear interface Guide Number: GN 58 (ISO 100,105MM focus distance)-tested good figure Support Canon wireless flash system (master/slave) // high-temperature alarm Support wireless output setting for different groups-in M mode //Stroboflash, Parameter memory function TTL Auto Exposure, with exposure compensation :-EV-3.0EV to +3.0EV