The Schneider 4x4" Graduated Magenta 3 Glass Filter - Some photographic situations require specific color corrections. For example, when shooting daylight film under fluorescent lighting, some magenta correction is needed in order to remove the greenish tint that would otherwise appear. The amount of color correction required is most accurately measured via a color temperature meter. With graduated filters, often it is necessary or desirable to balance the light intensity in one part of a scene with another. This is especially true in situations where you dont have total light control, as in bright contrasty landscapes. Schneider Graduated Color filters are part clear and part color. They are designed to be used in professional matte boxes, so that they are readily positioned at the exact angle required to create desired effects. Used primarily to add color to part of a scene where color may be weak or absent, Schneider Graduated Color filters can also be used for color effects which contribute to the cinematic drama of a scene. They are available in an array of colors. The Soft or Hard label indicates the degree of color graduation. Note: Graduated Magenta filters are available in grades from 1-3 with 3 having the greatest effect Schneider Graduated Color filters, designed to provide a wide range of photographic effects, work well with sky, foliage and skin tones; They can be combined with each other, or with other filters, to provide a virtually limitless range of breathtaking effects