Sigma's weather-resistant (WR) ultra-violet (UV) filters prevent the bluish tone that generates when the weather is fine, by absorbing ultraviolet rays. It is effective in most situations, such as landscape, portrait & general photography on a sunny day. It is also an ideal filter for regular use as it is completely colourless so does not affect colour reproduction. With excellent water & oil repellent functions, the filter surface repels water drops & provides resistance to fingerprints. Even if they appear on the surface they can be easily removed.