A 49mm Haze (UV) MRC Filter is a wise initial investment. It helps protect your valuable investment from dust, moisture and scratches, which can lead to costly repairs. If desired it can be left on the lens at all times for protection. A haze filter provides additional benefits of correction for Ultraviolet (UV) light which can register on film and videotape as a bluish cast and can obscure distant details. An ultraviolet filter allows you to correct for the UV effect to varying degrees.