I currently shoot with a single 430 or 580 flash during wedding ceremony's. For the stuff closer up where I can bounce it up it's pretty decent but for longer distance shots where I have it running straight through a gary fong lightsphere to soften it up some but still straight at them it's not as nice an effect. I've been thinking of getting a third flash (we shoot with 2 cameras) and I'm wondering if it would be weird to have another slave flash off camera just bringing up the ambient light in the room or if that's too distracting. Anybody have thoughts on this or done something like that before?
I don't think it would be weird at all.
As the guy who got married not that long ago, the photos were one of the big ticket line items in the wedding budget (I think it was third and not too distant third after food and drinks), so I was quite happy to help the photographers do the job that we were paying good money for.
In fact I'd be all for going slightly further and putting one on either side in front of the altar.
Regarding larger apertures -- depth of field doesn't just depend on aperture. For example, with a 50mm lens, f/22 at 3 feet gives you less
depth of field than f/1.4 at 15 feet. At mfd with 50mm f/1.4 or 85mm f/1.4, you have less than 1 inch dof, but when you're at those longer working distances, it is much more manageable (1ft-2ft).