digital rebel slave flash

[rovinco]

Can anyone tell me why I am having so much trouble getting slave flashes to sync? I believe there may be a pre flash that is firing the slaves and not lighting the image. Is there any way around this other than buying more stuff like the infrared transmitter,etc,etc and more Speedlites?
The slaves do fire but they do not fire while the shutter is opening ( I believe)
thanks
ROVINCO[/b]

[robertwgross]

You have it already figured out.

Yes, there is a pre-flash. If you have non-Canon flash units that are being slave triggered from the pre-flash (instead of from the main flash), then there you go.

There are adapters that will "see" the pre-flash, wait a time, and then trigger the slave flash so that it will meet up with the main flash/shutter time.

---Bob Gross---