The Hoya PRO1 Digital UV 55mm Filter is a wise initial investment. It helps protect your valuable investment from dust, moisture and scratches, which can lead to costly repairs. Digital camera CCD or CMOS sensors are highly susceptible to reflections. This stray light can ruin your photographs with flare and ghosting. Hoya Digital Multi-Coating reduces any internal reflections, which means a clearer image with greater contrast.A UV filter not only minimizes the bluish cast sometimes found under daylight conditions, but is also the best available protection against accidental damage to the front element of your lens. A lens that accidentally gets dropped on its front element while hiking can potentially be saved by purchasing this item. Some people refer to it as "cheap insurance". As a lens protector, it should be left on at all times. Aside from that more-than-significant benefit, UV filters render your photos clearer, sharper and more contrasty. For those who enjoy outdoor photography, especially distant vistas, a UV filter can produce a more distinct and acceptable image by removing much of the blue tint normally associated with atmospheric haze.The advantage of most Hoya filters is that Hoya puts, at least, one layer of anti-reflective coating on each side of their glass. It is not bare glass. Even if the glass is not multi-coated, this kind of production tends to minimize flare and ghosting. Digital Multi-Coating takes this protection to a higher level. Hoya is one of the largest manufacturers of glass in the filter industry. In collaboration with its parent company, Tokina Optical, Hoya continues to strive to produce some of the best glass on the market. Currently, they hold 40% of the world's market for optical glass.