The Intova Red Filter for SP1-CUL Sport HD Close Up Lens is a 67mm threaded red filter for underwater use with Intova's SP1-CUL Sport HD Close Up Lens. It screws onto the front of the lens to preserve the color red in videos and photos shot below 20 ft underwater.
The blue and green colors of the color spectrum substantially stand out in images shot underwater, and they block a high percentage of the red colors. This filter in turn blocks and neutralizes the blue and green colors so that enough red will be visible. The result is a more normal color balance.