Howdy All,
I'm looking for some 580EX II serial numbers and their rough date of purchase to use as reference points. This will help me verify the age groups of used ones as I shop for them here and elsewhere. Any years would likely be very helpful to me as well as others 
! Thanks!!
Also, anyone have a recommendation as to how to verify how well a used flash's output spec is holding-up?
Anyone know how many flashes they are supposed to be good for before the unit needs to be serviced? I assume that the output degrades from use and at some point it would become a use-limiting factor.
If I totally blew it and this info is already posted somewhere, please point me in the right direction
.
