2x550ex 1x580ex what trigger to fire all

This is the plan. Wife as model. 580ex main light on stand with umbrella. 1 550ex as fill on stand with umbrella and the last 550ex as hair light.

How can I trigger them all to fire. Will the ST-E2 work. Main and hair light 1 group the fill a second group (2 groups) or will it only fire 2 speedlights.

You can fire as many slave flashes as you want. However, with the ST-E2 you can only set them up into two groups, A and B. Why not use one of the 550EX flashes as the master on the camera (or use the off-shoe cord 2 cable) and set it up as Group A fill. Set up the 580EX as Group B main and the other 550EX as Group C background/hair light? This way, you can control the hair light independently from the main light. This will also keep the hair light from influencing your overall exposure determined by the camera.

Personally I hate having a flash on my 20D for portraits in my lounge. Its heavy and I feel trapped if that makes any sence. I always turn the master off from flashing anyway.

ST-E2 will do it if you don't want a flash on-camera, but like Leo said, you'll need to decide whether you want the hair light to be A or B group, since main and fill will probably be different groups. Can't use them on Manual either, since ST-E2 doesn't support manual either (I vaguely recall someone posting a kludge to get something like that going, but it was just that).

Since I don't have the ST-E2 I can't be certain but I thought you could set the flashes to manual mode and set their respective powers on the flashes and then fire them off with the ST-E2.

The hair light is the issue for me. Should it be the same as the main or fill?

I just got the ST-E2 the other day. I am starting to mess with it. I only have a 550EX and 420EX at this point. I really would like another 550EX though.

I would think you could put the main and fill in group A. Just physically move the fill further back (maybe use a shoot-through umbrella to soften even more)to get the desired effect you are looking for. The hair light could then be put into group B.

I tried firing mine in manual and the 550EX did not go off.

Thats an idea as my umbrellas are shoot through. Buy any chance does any one have a pdf manual of the ST-E2? Checked the web and came up blank

Unfortunately, when you put flashes in groups, all the flashes in the group will be fired so that they all contribute equal amounts of light on the subject, or the background in the case of Group C. So moving one flash in a group farther away is not going to make a difference until it's set so far away that it runs out of flash reach.

It's a different story when you set the flashes to manual mode, though. But you can't use the 420EX in manual mode.

Sorry, no pdf. What section do you need? I saw Adorama has a used manual for sale.

Then wouldn't it soften if you shoot-through (fill) versus bounce (main)?

I just like reading techie stuff before I buy.

Unfortunately, there is not much there to read. The book is thick, but that is because is includes 4 other languages than English.

Was Master/Slave switch on the 550EX set to slave mode before you switched it to Manual mode?

Yes, it'll soften it but the lighting intensity will still be the same.