ETTL slave

[Robin Usagani]

OK, I am still confused with ETTL and slave. I finally just started messing around with it. My question is:

Lets say im not using that much ambiance so my exposure is dark without the flash. Both master and slave FC are set to 0. Now lets say the slave is pretty much next to master pointing at my subject(shooting to the same direction about from pretty much the same place as the master on the hot shoe), the subject wont be overexposed correct? Both master and slave work together with the preflash? Now lets say the master i set the FC to -2, assuming the slave isnt using full power, the flash exposure should pretty much be the same as the first scenario correct?

Im going to another charity event tomorrow and I was thinking about using one flash on a monopod that I can hold high in an angle. I was thinking about turning the master off or make it like -2 FC and keep the slave at around 0 FC. Will that work to give it more depth?

 

[Robin Usagani]

anyone?