Precision Ultra Optics 3 Piece Filter Kit (Multi Coated) 500 Series High Resolution High Definition UV filter: To protect eyes and equipment from dangerous ultra-violet rays. Polarizing filter: Reduces amount of light entering camera. FD filter: Corrects color when shooting under fluorescent lighting, avoiding greenish effect. Precision Ultra Optics 3 Piece Filter Kit (Multi Coated) 500 Series High Resolution High Definition