So I've always wondered what's the deal with that black foamie thingy, and how different is it really from just flash pointing up.
Being a real newb as far as flash is concerned, I spent some time figuring out how to setup the Nissin di466 (Micro Four Thirds mount) to pair with my X100s. I was finally able to make them work by:
(a) Setting up my X100s to fire the flash as a "master";
(b) Setting up my Nissin to the S2 mode;
(c) holding the Nissin in front of me where it can "receive" the fire flashed by the X100s.
As far as the black foamie thingy -- I bought a $0.99 8x11 piece of black foam in an arts and crafts store, and cut a roughly 4x6 piece and attached it to the flash head pointing up. When I fired the flash with the foam attachment, it is facing me as the Nissin does not have a swiveling head.
The results speak for themselves! (Images are all OOC, ISO 200, f/2.8)