So i'm about to buy a G9 and i would also like to buy a external flash for it. After looking around i found some older canon speedlite's for a more reasonable price, i'm just wonder if it work the same with the older type ones.
I have a G9 and recently got a SpeedLite 430ex. It works great. I got a cheap clone that claimed Canon ETTL-II compatibility at first, but it wasn't really (performed more poorly than the built-in flash
) I borrowed a friend's 430ex to try it, and decided to return the clone and upgrade.
If you're worried about compatibility with an older flash, either try to borrow one and try first, or make sure it's returnable.