The 77mm Graduated Neutral Density 0.6 Filter from Heliopan helps to darken specific areas of an image, such as bright skies, while allowing for a normal, unaffected exposure in the other regions of the image. The filter is densest on one half and clear on the other to permit aligning the horizon in the center of the frame in order to achieve a balanced, even overall exposure. This 0.6 density graduated ND filter provides a 2 stop reduction in light across half the frame, and neutral density filters do not affect the overall coloration of the image for greater consistency. This filter is constructed from Schott glass for optical clarity, and the glass is mounted within a brass filter ring for added durability as well as resistance to jamming while mounting.