Now, go to a real camera store and bring your equipments with you.
Say to them:
I have a Canon 580EX Flash and wanted to know if you have the Quantum Turbo Battery with the Adapter Cord for my 580EX?
Ask to see if you can test them out.
This adapter does not go into the 4AA battery hold but to the flip out cover, AC Adapter. You need to plug it into the flash.
Press "On" from the Q battery, then set flash to "Master" on camera and other EX to "Slave".
Turn all three on(1st flash, 2nd flash and camera.
Do not press shutter button but press the pre-flash(pre-auto lock/flash) on camera body. On the EOS-1Ds Mark III has "*".
Both flashes should come on.
Now, press the camera shutter using "ETTL Modes" and look at the image from the LCD screen...is exposure correct?
Address to this address from now, please: [email protected]
PS: You did set both flashes into same channel and with no exposure adjustment, right?