So I was playing around a bit with the built-in wireless capabilities of the 580EX's and ran into a couple of problems.
1. I was under the impression that when changing FEC on the master unit it would affect the lighting output of the slave unit as well. This is not the case with mine. What am I doing wrong? Both units are set to ETTL
2. In the manual it says that you can disable the master unit from firing, but allow the slave unit to still fire. When I set the master unit to "oFF", it still fires anyways. Any ideas??
Just got a thought about this...maybe I am seeing the pre-flash? EDIT after more testing it is not the pre-flash I see. I shot into a mirror and can see the flash in the picture.