Sorry I should have put this in my first post, I already own a larger strobe kit at the moment I need something a little smaller more portable. I own I 580EX and the wireless transmitter from Canon, and use it on a 20D and 1Dmk2n. I plan on buying 1 or maybe even 2 more flash heads. As of now the only thing I do to control the spread of the light is move the flash head closer or further away from the subject and adjust the FEC, or set up light blocking panels. I was looking for something like a scrim (grid) to focus the flash beam even more, or even barndoors that I could attatch. I'm even open to a DIY if anyone has any ideas.