Well, I suppose you COULD use a slave flash, but it's not very convenient because you'd have to move it for basically every single picture. If you were taking pictures of the same thing, from the same position it'd work, but at a wedding you want all angles, and you don't have time to be messing around with multiple flashes. You need to get where you need to be to get the shot, before it's over and gone.


Are you worried about shooting inside the church? I did a wedding last week. It was a small church, and my 580ex II flash, bounced off the ceiling, lit pretty much the whole area I needed. I don't think multiple flash units, is really an option, unless you want to have everyone positioned at the same place, with the same angle. Kind of boring really.


Keep in mind, there's not a lot of action at a wedding....at least, not usually inside the church....so you might be able to get away with some shutter speeds of 1/60 when you're zoomed in. If you have IS definitely. If not, maybe if you have a good hand.


The only real way to speed things up, is to crank up the ISO! What camera do you have?