I was frustrated at getting OOF pictures with my 70-200 lens. After reading reviews saying it's actually pretty sharp, I finally got fed up today and took off the UV filter just to try. WOW it is so much sharper. I remember back to Sabbath999's post about cheap UV filters...but this is a Hoya. Any ideas? Do I just fork over another fifty-something bucks, or do I just not use one?