Recs Wanted: 580EX RF Slaves

[amccomis]

I know the 580EXII flashes can do Infrared remoting built-in, but I've never shopped the RF Radio slaves before and have no idea what I'm looking at.

I have a 5D and a 20D (full gear list in sig)...

I want to be able to use a second (and third if I have one available to me) as remote radio slaves.

So what is the master? Does it fit on the shoe with the body and the first flash?

Any advice on what to buy that works well, and how to set it up would be great. (Or a link to this if it's already spelled out somewhere.)

[Jim G]

There's a difference between what you do for remote radio slaves and using the 580's own triggering system...

If you want to get off-camera flashes using the 580's built-in triggering system you need to buy 580s/430s etc. and use the master/slave settings built into the flashes. A 580/ST-E2 will need to be on the camera for this to work, generally.

If you want to use cheap radio triggers look into something like the Gadget Infinity "poverty wizards" for the low-end stuff and Pocket Wizards for the other end of things... for this option you can have a trigger on your camera and the rest of your flashes wherever you like them, within limits.

[amccomis]

I could use the first 580ex on the shoe in master mode... and 2nd/3rd units in slave mode, but isn't the built-in infrared system line-of-sight capable only?

What if I'm intending to use a 2nd 580exII to light a backdrop? (thusly, it's behind the group of people being photographed)

And, practically speaking, how far can I trigger a 2nd in slave mode from (a) a 580ex on the shoe, or (b) the ST-E2 (I've heard the 580ex can throw the trigger signal farther but I don't know what that means... is it 10m? 20m? 50m?)