The Cokin Filter P232 Skylight 1B reduces excessive blue cast in outdoor photography. The filter's light pink colour reduces the blue colour of daylight and provides a pleasant and warmer colour tone. Ideal for portraits under clear blue skies. The Skylight filter offers several advantages. It reduces ultraviolet light that can cause a blue cast when shooting on film and video tape, obscuring details in the image. The filter can also be used to reduce the bluish tint of some reportage flashes.