<Käsemann polarisers which I think is specially developed for wide angle lenses to give an even filtration of the sky to eliminate the surreal effect with normal polarisers. I have emailed to Heliopan to enquire what is the widest focal length the Käsemann polariser is designed for. Has anyone used the Käsemann filters ?> Käsemann polarizers are not designed specifically for wide angle lenses. All pol filters are a sandwich -- a piece of pol materiel between two pieces of optical glass. Käsemann models are sealed around the edges to reduce the liklihood of foreign matter, moisture, condensation etc. entering within the sandwich and mucking up the filter. regards, Henry Posner/B&H Photo-Video http://www.bhphotovideo.com We will be closed March 31 - April 8, 1999. Please plan accordingly.
