The Twilight Hard Edge Gradient Filter is graduated from dark blue top to a pink horizon. It offers a cool image, ideal for creating a twilight effect in the late afternoon or early evening. It is available in 3 densities, 1.2 and 3. These filters are in the lower half of the filter with a gradual transition to the color effect in the upper half. They are mainly used for skylines of landscape shots. Graduated filters are available in SoftEdge or Hard Edge variants. Soft edge colour gradations have a smooth transition from clear to ND. Hard-edge gradient filters have a defined hard transition and are typically used for longer focal lengths. Different color filters can be used in combination with or with full-color or neutral density filters to achieve interesting tailored effects. This 100mm filter is suitable for Hi-Tech 100mm holder systems or all 100mm mounts. The filter is also available in sizes 85 mm, 150 mm and 165 mm. Hi-tech filters are made from high quality 1.5mm optical resin.