Drop Ball Test Movie
Clear Glass Ceramic offers a Vickers hardness number of 700HV.* This is a level of hardness much higher than that of chemically strengthened glass, which is used in conventional high-strength protective filters. Moreover, this higher level of hardness helps prevent scratches and chips, which can lead to breakage of the filter.*In the Vickers hardness test, a diamond instrument is pressed onto a material, and the indentation so produced is used to calculate the hardness of the material, which is expressed as a Vickers Pyramid Number (HV).
Thinner and lighter overall, thanks to advanced new material
Since Clear Glass Ceramic is extremely strong, the SIGMA WR CERAMIC PROTECTOR is up to 50 percent thinner and weighs up to 30 percent less than previous SIGMA filters while offering a higher level of strength.
10 times the strength of a conventional protective filter, 3 times the strength of a chemically hardened glass filter
Made with a special process that evenly precipitates microcrystalline spinel throughout the material, Clear Glass Ceramic offers a Vickers hardness number of 700HV. The new SIGMA filter made with Clear Glass Ceramic offers over 10 times the strength of a conventional protective filter and over 3 times the strength of a high-strength protective filter made with chemically hardened glass of the same thickness.
SIGMA's Clear Glass Ceramic offers very high transmittance, making it ideal for use as optical glass.