I've been using B+W filters all my life and I can guarantee this top notched filters are worth every penny paid. There was just once I bought a Kenko filter for one of my cheap lens. It gave me so much fogging prob that I freaked out. I still had to clean the water stains on the filter. I never had fogging probs with B+W filters. But please beware that the authentic B+W(made in germany) filter have gold inscriptions around their rims. I've seen made in china/taiwan ones with white inscriptions which are sold slightly cheaper but I'm not so sure about their quality.