"Lens hoods guard against uncontrolled, stray light and unwanted reflections which result in reduced contrast and possible ""ghost Images"". In general, the use of a lens hood is recommended because better contrast improves the appearance of the photograph. This accessory also offers protection for the front lens element against rain and mechanical damage. Wide Angle Rubber Lens Hoods are made from high - quality black rubber for lenses with an angle of view wider than 70 degrees. Due to its shape and size, it prevents vigetting and should only be used without a filter."