Our filters are made of multi-layer substrates on which film coatings with different refractive indices are applied. Filters can range from 240 nm to 850 nm with a magnitude of 10 nm and typically have a blocking power of six optical density units (OD), or 999,999 parts per million. Thus, a filter has the ability to block unwanted light going in the wrong direction down to 0.0001%.
VI