SeaLife SPORTDIVER COLOR-CORRECTION FILTER The filters are designed to restore and correct color-loss underwater. They're made of optical acrylic that uses proprietary color pigments. These filters are most effective at depths of 10ft / 3m to 60ft / 18m and are easily attachable and removable to the SportDiver optical lens frame while underwater. Depending on the shooting distance and water conditions, the color filters may be used with or without external underwater lights. The filter also serves as a protective cover for the SportDiver's optical glass port. A lanyard is included for attaching the filter to the housing to prevent loss. All divers know - the deeper you go underwater, the less natural light is available. Everything is seen in green and blue as the warm colors are filtered out. Using the red filter (SL40007) in blue water will help you bring warm tones back into your photos and videos so that they become more vivid and saturated. The magenta color-correction filter (SL40003) is great for scuba diving in green water. When making photos or videos in freshwater or algae-rich saltwater, they turn out very green. The magenta filter helps the camera color balance everything and capture vivid underwater colors. SeaLife developed the world's first commercially available underwater digital camera and is the only imaging and lighting brand focusing entirely on diving, snorkeling, and watersports.