I agree with the above we have discussed this before. You get what you pay for so if you get a decent make like Hoya you will not notice anything to worry about.. The glass on your lens is worth protecting and they also cut out haze on sunny days so add better colour in my view

Danny O'Byrne  http://www.digitalartzone.co.uk/

"All the technique in the world doesn't compensate for the inability to notice" Eliott Erwitt