Sigma WR Ceramic Protector

Interchangeable lenses are essential elements of photographic expression and are part of a photographer's valuable personal equipment. Sigma has developed innovative filters for front lenses that meet the company's high-quality standards and help photographers utilize their lenses for years, into which they have invested significant time, experience, and money. In developing the new protective filter for front lenses, Sigma collaborated with a glass manufacturer to produce a new type of material, clear glass-ceramic. The Sigma WR Ceramic Protector, made from this advanced material, is an extremely reliable filter that offers excellent protection.

Clear glass-ceramic is a highly resistant, crystallized glass that forms the basis of this new material and is widely used in aerospace and other industries. This advanced material combines a higher hardness than chemically tempered glass with greater flexibility than sapphire glass while providing the high light transmittance required for optical devices. These properties make clear glass-ceramic the ideal material for lens protection filters.

Conventional high-strength protective filters typically use chemically tempered glass, which is only hardened on the surface through chemical processes. In contrast, clear glass-ceramic undergoes a special heat treatment that ensures an even distribution of mineral spinel, giving the entire filter a consistent hardness. The combination of higher hardness than chemically tempered glass and greater flexibility than sapphire glass makes clear glass-ceramic the perfect choice for protective filters. Additionally, clear glass-ceramic is shatterproof, reducing the risk of shards breaking into small fragments and providing a higher level of safety.