UV filter protects your camera lens from damage. OPTICS, Optical Glass Filter with metal ring. Ultraviolet filters absorb UV light generally without affecting light in the visible region thereby reducing or eliminating distortion A UV filter serves to protect your lens from all dust, dirt, scratches and fingerprints. Polarizer filter eliminated unwanted color reflection from sun or bright light, increases color saturation, enhances contrast ratio. FLD Filter: A Fluorescent filter is a photographic filter that improves the color of all skin tones and absorbs blue cast often caused by electronic flash or outdoor shade. Adds warmth to pale, washed-out flesh tones and are ideal for portraits as they smooth facial details while adding warmth to skin tones (for color imaging) In general, they suppress blue casts on overcast days and on subjects lit by blue sky. Why Coated filters are worth it.......