550ex as master for 430ex Problems

I just picked up a 550ex to use as a master for my 430ex
I disabled the firing of the 550ex but it still fires. Can anyone help?

That is normal and there is no way around the 550EX firing even when it's been set not to fire (the main flash) because the 550EX uses the flash (albeit at a lower power level) to communicate with the slave. Without this communication via the command flash, there would be no way to control the slave flash and to make it fire at the moment when the shutter is fully open. However, unless you are in a very dimly lit environment or using a very high ISO, the command flash should not have much of an effect on your exposure.

Are you sure? I mean the manual says on pg 104, "The setting (Master flash OFF) prevents the master flash unit from firing a flash. It can still transmit wireless signals to trigger the slave units." I do have the 550ex set to "Master flash off"

brippeon wrote in post #8715547
Are you sure? I mean the manual says on pg 104, "The setting (Master flash OFF) prevents the master flash unit from firing a flash. It can still transmit wireless signals to trigger the slave units." I do have the 550ex set to "Master flash off"

Yes, I'm very sure. What they mean is that the main flash is not fired by the flash. The main flash is the flash that illuminated the subject. However, as also stated in the the manual, the flash will still transmit the wireless signals to trigger the slave. As I said in my previous post, the wireless signal is transmitter via the flash (in the form of a series of light pulses). So, the flash you are seeing is not the main flash but the command flash. You can easily verify this by turning off the slave and then trying to photograph something using just the master with it set to "Master flash off". If the main flash were still firing, it should light up the subject. But if it's working as it should be, the main subject will not be properly lit.

Oh I see now, sorry for the disbelief and thank you for the explanation.