X121M Graduated Medium Gray G2 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 the foreground will produce a washed-out, over-exposed sky while exposing the sky will leave the foreground dark and under-exposed. Cokin graduated grey 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 for the average bright sky-to-foreground situation and is also the most popular density of the series. X164 Circular Polarising Filter Light rays which are reflected become polarised. Polarising filters are used to select which light rays enter your camera lens. They can remove unwanted reflections from non-metallic surfaces such as water or glass and also saturate colours providing better contrast. The effect can be seen through the viewfinder and changed by rotating the filter. The filter factor varies according to how the filter is rotated and its orientation to the sun. Filter factor is between 2.3 and 2.8 (approx. +1.3 stops). Circular polarizers are specifically designed for use with auto-focus SLR cameras (They will also work on manual systems without problems). What's in the box: - XL (X-PRO) Series filter holder (BX100A) - Gradual Neutral Grey G2 Medium (ND4) XL (X) Filter (X121M) - Circular Polarizer XL (X) Filter (X164)