UV blocking filters are a wise investment firstly because they protect your lens element from damage and secondly because they transmit all visible colors of light without loss, but block the ultraviolet rays which are not visible, but which do impact sensors and then produce color distortion. There are no adverse effects on the image quality of your valuable premium lens, no veiling or loss of definition, plus maximum filter effect and ideal color neutrality. With an extremely flat slimline mount with front thread which is free of vignetting even with almost all wide-angle lenses.