The SIGMA 20mm F2 DG DN | Contemporary incorporates Nano Porous Coating. What effect does this have?

Nano Porous Coating incorporates a porous silica layer. This has nano-sized holes that ensure a lower reflectance than conventional anti-reflective coatings. By incorporating a Nano Porous Coating, the SIGMA 20mm F2 DG DN | Contemporary achieves clear image quality by suppressing flare and ghosting.