The Twilight soft edge color graduated filter is graduated from darkish blue at the top to a pink horizon. It provides a cool image ideally suited to creating a late afternoon/early evening twilight effect. It is available in 3 densities, 1,2 and 3. These filters are clear in the bottom half of the filter with a gradual transition to the color effect in the top half. They are primarily used for skylines of landscape shots. Graduated filters are available in Soft Edge or Hard Edge varieties. Soft edge grads have a smooth transition from clear to ND. Hard edge grads have a more defined hard lined transition and are usually used for longer focal lengths. Different graduated color filters can be used in combination together or with solid color or neutral density filters to give interesting bespoke effects. This 150mm filter is usable with Lee 150mm holder systems or any similar 150mm holder. The filter is 150mm wide but 170mm long to enable it to be easily moved up and down in the holder. The filter is also available in 85mm, 100mm and 165mm sizes. Hitech filters are made from the highest quality 1.5mm optical resin.