WHOOPS
Sorry guys-the flash is a 550 EX!!
As I said-this was bought 2nd hand and has never been used so not been out of the box.
I have no idea where the 480 came from or how it got into my head-is there a smilie that says "thick"
I assume it's the same principle i.e. I'll need something "more sustantial"
I will start with the 36" umbrella (thanks for the pointer) as I'm sure it won't go to waste. I will try with the 550 flash-this should give me some indication of what I need.
Again-thanks for the advice-any more advice is more than welcome