The Schneider 138mm True-Polarizing Glass filter is by far the most effective polarizer for motion picture and television cameras. Having an extinction ratio of ER 374, the Schneider True-Pol is 12- times more effective than other polarizing filters, and is unmatched in its ability. The polarizing film in a Schneider True-Pol filter is laminated between two pieces of Schneiders crystal-clear, water-white optical glass. The filter is protected against edge-chipping and delamination by Schneiders unique Edge Seal, which also effectively reduces edge-reflections and flare. The absolute clarity of the glass combined with advanced polarizing material make True-Pol filters particularly effective on demanding scenes, as when shooting through windshields in rigged-cars. On such shots, Directors of Photography have found that Schneider True-Pol filters capture more color saturation, wider tonal range and much more contrast inside the car. Like all filters in the Schneider line, True-Pol filters are precision polished to the highest possible standards, meeting the most demanding specifications for optical flatness.