Canon 580EX - whats its do that my 420EX doesn't?

[Jon K]

Hey guy s- getting back into photography. I currently have a Canon 420EX Speedlite which has served me well, but with my new 50D, grip, 16-35 F2.8L, and other new hardware, I feel my 420EX is dated.

I am a bit out of the loop, but getting back in it - what does the 580EX offer me that my 420EX doesn't? Thanks guys!

 

[CxThree]

This should tell you all you need to know.

DPanswers: Buying Flash for the Canon System

 

[Big Mike]

It has more power
It recycles faster
The new 580EX II has weather sealing
The 580 can be a wireless 'Master' unit (or a slave unit) in Canon's wireless flash system. While your 420 can only be a slave (needs a master).
I'm not sure if the 420 can be set to manual power settings
I think the 420 is compatible with an external battery pack, but the newer version, the 430EX isn't while the 580 is.
The 580 has a control wheel on the back, which makes it very easy to change the settings and go through the menu.