Progressive graduation from the bottom to the top of the filter, same colour & tone than 121. According to the classic rules of landscape layout, the sky occupies 3/5 of the space above the line of horizon, whether real or imaginary. In photography, this is interpreted by major differences in luminosity between the sky & the rest of the image. COKIN Graduated Filters, by reducing the difference, re-balance the luminosity between the upper & lower part of the image. They put an end to disappointment from washed-out skies & underexposedlandscapes. Since the sky & the clouds are changeable & varied, Cokin Graduated Filters invite you to imitate them in your own interpretation of colours.