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 don't 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 neutral density. They allow the transition to be blended into the scene, often imperceptibly. A ND.6-to-clear, with a two stop differential, will generally compensate the average bright sky-to-foreground situation and is also the most popular density of the series.
The Z-PRO Series is recommended for focal lengthsof 20mm onwards (in the 35mm format). This filter is made of CR39 Resin which is a reputable lightweight and unbreakable optical material also used for ophtalmic glasses.
Note!This filter measures 100 x 150mm (4 x 6") and fits the Cokin Z-Pro filter holder