using a umbrella with 580 exII

My question is, what zoom should I set the flash to? I am not using a shoot through if it makes a difference.
Thanks, Dave

I would gather that the widest angle would give you the best coverage through the umbrella but shooting at a longer flash focal distance would just mean the flash is contained more to the middle w/ less coverage

I pop 2 550's into a umbrella all the time. One will work fine. To find the best setting for you flash, set everything up as you are going to use it. Point it at a shaded wall step back and take a shot ( from an angle to minimize the flare). You will be able to see the flash in the umbrella zoom in or out till you almost fill the Umbrella. You can also move the umbrella in the bracket. That way you almost fill it without spilling over.

F4 is right. Another thing to consider is making sure you don't have the 580 too close to the umbrella. What I mean is when you mount the umbrella to the lightstand, don't push it through very far. Do some testing by adjusting the distance between the 580 and umbrella and you'll see what I mean.

@ 24mm zoom without the wild angle diffuser works best for me.

Lotto wrote in post #7044495
@ 24mm zoom without the wild angle diffuser works best for me.

I'm a tele fan too

Do some test shots. I find that I get softer shadows on 24mm but 105mm produces a hotter/sharper light. Similar results with shooting through- but even softer and more uniform shadows. I end up manually adusting zoom on flash pretty regularly now depending on what i am after.