Cokin diffuser filters make skin look softer & hair look more silky & shiny. The surface of Cokin Colourless Diffuser Filters is slightly granulated, which diffuses strong light without affecting the clarity of the image up to about 13.5cm. In portrait work, small skin defects are eliminated. Facial contrast & wrinkles are also softened away. Cokin Colourless Diffuser Filters also soften the contrasts & contours of rugged landscapes. As these filters are principally used for portrait work, the diaphragm should be opened to diminish the depth of field so that the subject stands out well against the background. Choose welllighted subjects. Avoid harsh midday light.