picsbywayne wrote:
The 420 cannot operate as a master. It can only work as an on camera stand alone or as a slave.
The 580 has to be the master.
If you have a 7D, the pop up flash can work as the master but you don't indicate what model camera you are working with.
Do you know if the 70D can also use the built-in flash as the master? I am using a Canon 600EX speedlite. Thanks