ND1000 Square Filter multi-resistant coating technology significantly reducing lens flare and ghosting while making the filter anti-scratch, water repellent, oil & dust resistant fit for the rigors of adventure photography. ND1000 filter provides 10 f-stop reductions and is made with premium Germany Optics glass. Primary color optical glass ND1000- double parabolic mirror. Glass mirrors with no double throw, especially those with longer focal length, are blurred. Scratch Resistant The filter anti-scratch, water repellent, oil & dust resistant fit for the rigors of adventure photography. Primary color glass coating Water droplets are round. Other lenses Water droplets scattered. Double-sided Anti-reflective Coating By double-sided multi-layer anti-reflective coating, the reflected light can be reduced to below 0.4% to eliminate the influence on imaging. Multi-layer Coating Low Reflectivity Reduce glare caused by diffuse reflection.