haroldross wrote:
The Canon Ex line of Speedlites work with the Canon digital DSLRs. The 550EX and the 580EX can act as master flashes and the 430EX and 420EX can work as slaves. On the Canon flash models, the guide number of the flash is also the first 2 digits of the model number, i.e., the 580EX has aguide number of 58.
BE more picific about the guide number ! It 58 m(mteres)That could confuse some non metric thinking people...