Sigma 105mm UV Filters
Sigma Imaging (UK) Ltd, a leading provider of photographic lenses, digital cameras and accessories, all made at SIGMA's Aizu factory in Japan.
UV Filters fit to the front of your camera lens and block ultraviolet rays from entering the lens. They are particularly useful on older cameras which may not have auto white balance systems, without a UV filter these cameras can produce images with a blueish haze. Many photographers still use UV filters on more modern digital cameras for a variety of reasons.