I think I'll go ahead and order it this week. It's not so heavy that I'll need rails or anything, right? I can just snap it on and shoot away as is? Gracias.

I ordered one last week and it showing up tomorrow. I'm certainly not using it with anything special for support as it only weighs 12 oz. I don't know how one would use rails with it anyhow since it's just a simple circular adapter. The stock sunshade will need to come off obviously while it's on since it's a bayonet mount.

Thanks Rich! That's the answer I was hoping to hear. What prompted my question was seeing Steve Cahill's blog showing a photo of it on his EX1 and I saw rails, ha! It also looks pretty big from the photo, but I know it's pretty light, so I just wanted to make sure because I don't have rails (nor do I want them at this point).

http://web.mac.com/stevecahill/Steve_Cahills_Blog/Blog/Entries/2008/7/15_Schneider_Fish_Eye_for_the_EX1.html

The rails on my EX1 are for the Letus Ultimate and NOT for the fisheye. I just leave the rails on.