Cokin p152 neutral gray nd2 2x1 stop neutral density filter often it is necessary or desirable to control the light intensity within a given frame 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 a neutral density filter will allow you to retain exposure control but will not aff