550 as master without light emission...

[EightyFive]

Hello I'd like to use the 550 as transmitter without light emission to control a 430ex but I had problems.
I've followed the guide instructions but the 550 shot light anyway.
Could you please tell me what I've to do?
Someone use the same flash?
Thanks a lot

[Curtis N]

With the Canon wireless flash system, the master fires a command flash to fire the slaves, even when it's set to "master off".

This is a low-powered flash and won't affect the exposure in most cases.

[EightyFive]

many many thanks!
I didn't understand that before!
Ok so..
thank you again!!!