Ultraviolet filters. Ultraviolet rays will affect photo quality (making the picture bluish). So UV is a must for traditional photographer. However, according to users of digital cameras, UV is merely a piece of parallel lens as CCD or CMOS is not as sensitive to UV rays as traditional films. Exploded in the air, the front lens are damaged by dust, finger prints and other factors. If the lens are scratched or damaged, the imaging quality will be permanently affected. Thus, UV can protect the lens effectively, which is more useful as a protector than as a filter