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. Rubber Lens Hood are made out of a high quality matte black rubber. It folds down and protects against contrast - reducing, uncontrolled, stray light.