Tiffen 49mm Circular Polarizer Polarizing Lens FilterThe Tiffen 49 mm Circular Polarizing filter has multiple uses, it protects your lens from accidental damage, but most importantly it removes unwanted reflections from non metallic surfaces such as water or glass, and saturates colors providing better contrast. The effect can be seen through the viewfinder and changed by rotating the filter, the filter factor varies according to how the filter is rotated and its orientation to the sun.