Cokin z pro 121m gradual gray 2 neutral density nd4 medium resin filter often it is necessary or desirable to balance the light intensity in one part of a scene with another this is especially true in situations where you dont have total light control as in bright contrasty landscapes exposing for the foreground will produce a washed out over exposed sky while exposing for the sky will leave the foreground dark and under exposed cokin graduated gray nd filters are part clear part ne