Ikelite 6182.71 Underwater Camera Housing for Nikon Coolpix P7100 Digital CameraThe housing port is designed to accept color filter, wide angle, and macro options for 3. 9 inch diameter ports. Light is absorbed very quickly as it passes through water. A subject will look darker, less colorful and somewhat grainy when viewed through even a few feet of water. The addition of a compatible wide angle accessory expands the camera's field of view underwater, providing the opportunity to get as close as possible to the subject and