The Schneider 6.6x6.6" Graduated Coral 3 Glass Filter is considered to be both a color-correction and color-effects filter. Schneider Coral filters are used to warm cool lighting situations such as overcast days and scenes in open shade.
Different strengths of Schneider Coral filters can be used during filming to achieve the same degree of apparent warmth under different light conditions. This makes them particularly useful for maintaining a consistent color balance throughout an entire day of shooting, or to create a sunset or dawn effect during the day.
Schneider Coral filters can be used to under-correct a scene in order to create an excessively blue look for added drama, and can also be used as warming filters to create other dramatic effects. Cinematographers who own a complete set of Schneider Coral filters have the ability to control just about any outdoor lighting situation.
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 don't 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.