Cokin Z Pro 121M Gradual 2 Medium Resin Filter Z121M

@@ Grey Neutral Density filters compensate for bright light. @@ By under-exposing the sky, they give a better relief to the surfaces and colors of landscapes and architecure. @@ They are indispensable in summer, for seaside and mountain photos. @@ They are available in six choices to cover every situation. 120 - 2X graduated neutral density filter reduces the light 1 stop 121 - 8X graduated neutral density filter reduces the light 3 stops. 121L - 2X Light starts with the same neutral density as 120, but feathers the grey almost from the color edge and more gently graduates to clear. One stop of compensation. 121M - 4X Medium is the same gentle graduation as 121L but with twice in density. Requires 2 stops of compensation. 121S - 8X Soft is twice the density of 121M and the graduation extends to 3/4 of the filter. Requires 3 stops. 121F - 8X Full is the same as 121S except that the neutral density grey cover the entire filter. Requires 3 stops