I recently took some waterfall shots for the first time when I was out hiking. I experimented with shutter speeds etc, just trying to get the different effects you can get with the moving water. When I got home and reviewed the shots, I noticed that there was a lot of glare coming from random places (it was a little sunny out) that I felt distracted from the shots. I've been reading "understanding exposure" (a great recommendation from this forum :thumbup and Peterson mentions using a polarizing filter in situations like this. Well, I went to the store to grab a polarizer, and after telling the girl why I wanted it, she said "That's not what you want, you want a neutral density filter." She said it would help smooth out the waterfall shots. The packaging for the filter even had a side by side comparison shot of waterfalls. (it was a sunpak platinum plus filter). Long story short, I bought both of them, but I was wondering which one is REALLY the one I want to use. I guess I'm just having trouble understanding the true difference between the two. Which filter do you guys use for waterfall shots and why? I appreciate the input!