I'm looking to pick up another umbrella or two. I have a small (43" foldable) umbrella and a medium umbrella (not sure what size it is off hand) and I'm thinking about getting something a bit bigger. I think my options are 60" and 86" - but 86 seems like it would be huge and impossible to prevent from blowing away.

Secondly - what are the chances that I'll get enough light from an SB-800 or 600 to make a 60" umbrella useful? Anyone have any experience? I know my AB's will work, but I want to know how versatile a 60" umbrella would be.