Need help quickly, about to place order...

I am ordering a 430EX for my S5 and need to know what kind of diffuser you recommend? You can purchase the flash and this Sto-Fen OMEW Omni-Bounce Diffuser in combination from Amazon. Is this a good choice?

I don't consider a diffuser exactly an essential. And the purpose of a diffser is to markedly increase the light-emitting area; that Sto-Fen won't do very much that way. You can use a white 3x5 card rubber-banded to the head so it sticks up and get pretty much the same effect,or better since you'll be bouncing off the ceiling as well as putting a "kicker" into the eyes.

Ok, what about using it as fill for outdoors? Will the card work for that or is a diffuser better?

While I have never used the sto-fen defuser on the 430EX Canon flash, I do use them on two different Nikon flashes, and also on some older Sunpak and Vivitar flashes. Under certain conditions, I find them to be very good. And yes, I use them for outside fill all the time. They're not magic or anything, but they do come in handy, when sometimes an index card and rubber band ain't so handy!

Gary

I use variously the Lumiquest ProMax or the PhotoFlex SoftBox, both of which give a (somewhat) larger area light source if I need a diffuser. They also fold pretty much flat.