The discussion about the need for filters is actually idle. For me it is clear: a (good) UV filter or Protector causes no or at least no visible (to me) a loss of quality. But is crucial for me that I have dirt and stains, drops of the spray or simply does not have to shave off the front lens from the fog with a microfiber cloth but an inexpensive barrier in front of it.
Just my opinion. The Pro 1 Digital Series of Hoya I think is the best (B + W filters do not play in my price range).
