About This Item
Where photographic expression is concerned, the quality and protection of your lenses are paramount. The 72mm WR Ceramic Protector Ultra Thin Clear Glass Lens Filter, developed by Sigma, is a testament to this principle. This innovative lens filter is designed to safeguard your valuable lenses, ensuring their longevity and performance.Crafted from a revolutionary material known as Clear Glass Ceramic, this Sigma WR Ceramic Protector stands as a beacon of reliability and superior protection. This material, born from a unique partnership with a glass manufacturer, is a new breed of glass that offers unprecedented toughness. Clear Glass Ceramic is widely used in aerospace and other industries, demonstrating its robustness and reliability.Unlike conventional high-strength protective filters that only strengthen the surface through chemical processes, Clear Glass Ceramic undergoes a special heat treatment. This process precipitates microcrystals of a mineral called spinel throughout the filter, providing consistent strength across the entire filter. This results in a filter that is not only harder than chemically strengthened glass but also more flexible than sapphire crystal glass, making it the ideal material for protective lens filters.Clear Glass Ceramic is also highly resistant to cracking from minor scratches or chips, reducing the risk of shattering and increasing safety. With a Vickers hardness number of 700HV, it offers a level of hardness significantly higher than chemically strengthened glass used in conventional high-strength protective filters. This high hardness level helps prevent scratches and chips that could lead to filter breakage.The Sigma WR Ceramic Protector, made with Clear Glass Ceramic, is up to 50% thinner and 30% lighter than previous Sigma filters, yet offers superior strength. It also boasts high transmittance, making it ideal for use as optical glass.Sigma has ensured the compatibility of the WR Ceramic Protector with all Sigma lenses, confirming that this protective filter allows light to pass evenly throughout the image, from center to edge. The filter is also manufactured to meet Sigma's exacting standards, checked with Sigma's proprietary Modulation Transfer Function (MTF) measuring system using 46-megapixel Foveon direct image sensors.The WR coating of this filter reflects only 0.24% of visible light, minimizing flare and ghosting. It also excellently repels both water and oil, making fingerprints easy to wipe off and water drops bounce right off. The coating's antistatic function helps prevent static electricity from attracting dust and other particles, which can easily be blown off the filter when they do adhere.Finally, the Sigma WR Ceramic Protector is proudly made in Japan, with all individual processes used in its manufacture carried out domestically. It comes with a specially designed storage case made of a stronger and more flexible acrylic than conventional filter storage case materials, ensuring your filter remains protected for many years..
