Sigma WR Ceramic Protector

that meet the company's high quality standards and help photographers use the lenses they have invested a lot of time, experience and money in for years. In developing the new protective filter for objective front lenses, SIGMA used the cooperation with a glass manufacturer for the first time to produce a new type of glass, clear glass ceramics. The SIGMA WR CERAMIC PROTECTOR made of this advanced material is an extremely reliable filter with an outstanding protective function. Glass-ceramic is an extremely resistant, crystallized glass that serves as the basis for clear glass ceramics and is widely used in space travel and other industries. This advanced new material combines greater hardness than chemically hardened glass and greater flexibility than sapphire crystal glass and has the high light transmission required for optical devices. These properties make clear glass ceramics the ideal material for lens protection filters. The chemically hardened glass used for conventional high-strength protective filters is only hardened at the surface by chemical processes. In contrast, clear glass ceramic is manufactured with a special heat treatment that ensures an even filling with the mineral spinel and thus gives the entire filter a continuous hardness. Due to the combination of greater hardness than chemically hardened glass with greater flexibility than sapphire crystal glass, clear glass ceramic is the ideal material for protective filters. Clear glass ceramic is also break-resistant if small scratches or chippings occur. Since the risk of fragmentation into small fragments is reduced, it offers a higher degree of security.