If desired they can be left on the lens at all times for protection. Haze filters provide additional benefits of correction for Ultraviolet(UV) light which can register on film and videotape as a bluish cast and can obscure distant details. Ultraviolet filters allow you to correct for the UV effect to varying degrees. Haze-1 filters absorb approximately 71 percent of UV.
This filter measures 130 X 170mm and only fits the Cokin X-PRO series holder.
Reviews Cokin X-Pro Series Filter - X231 UV