Hoya 55mm Circular Polarising Filter

These filters offer both the amateur and professional photographer Hoya's famous quality, suppressing reflection and increasing light transmission.

Not only that they also offer unparalleled lens protection, too, thanks to Hoya's high quality filter frame construction. All polarising filters are made of a polarising film (or a polarising film and quarter wave plate in the case of Hoya's Circular Polariser) sandwiched between two layers of glass. Hoya believes the filter frame is an extremely important part of the filter as well.

Hoya uses machined aluminum frames to hold their high quality glass, because it is strong enough to hold up to years of use. Although some argue that brass is the best material to use, Hoya doesn't hold that view because brass is a far more rigid material than either aluminum or the polycarbonates that are being use in today's lens barrels.

This means that, should the front of the lens get hit, the rigid brass filter ring will transfer almost all the force of the shock to the lens barrels and mechanics. An aluminum filter frame will absorb some of the shock by bending and at a certain point the glass will chip or break, which is what the filter is supposed to do, protect the lens. Replacing a filter is always preferable to getting a lens repaired.