Syncronizing flashes

[legali]

Hello,

I was wondering whether anyone would be able to offer some advice in relation to syncing flashes.

I have 2 flash units which will be trigger by radio remote, and a canon 580 which I hope to be able to use off camera (hand held) with a Canon 40D.

I have a hot shoe extension cord (which I had hoped to use with the 580). That is the first thing I seat in the camera hot shoe, and the radio transmitter is then mounted on top of that. I don't have any fancy transceivers (yet!).

I have set the 580 to manual.

My problem is that when I try to AF (either using AF-ON button or shutter button), the flash heads continuously fire. I have not been able to resolve this.

I'm not too sure where I am going wrong. Is it likely to be associated with the 580 AF-assist function?

The flash units have built in optical triggers, but I would like to avoid resorting to using those if possible as I'd like to use this set up at wedding receptions (where other camera flashes are likely to be going off).

Can this problem be resolved with the set up/equipment I am using? Any assistance would be greatly appreciated.

Many thanks.

 

[HoppyUK]

Sounds like a compatibility issue with the trigger and extension.

The way I do it is with Phottix Strato II triggers, with E-TTL pass-though. Transmitter on camera, extension cord on top of that with 580 on the other end. Recievers connected to remote flash heads.

You get full E-TTL with the flash on the cord, and the remote flashes fire in manual mode.