KnightX CPL Circular Polarizing Filter (C-PL) 67mm PL Filter Circular PL Polarizing Filter Compatible with Wide-Angle Lenses Materials Filter: High-quality optical glass Filter Ring: High-quality aircraft-grade aluminum alloy (6061) * Laser-engraved font, will not wear or fade. Product Features PL filters are filters that remove surface reflections from the subject and enable very vivid color expression. Effects include removing surface reflections from water surfaces and glass, deepening the color of the blue sky, and making the colors of foliage, mountain surfaces, buildings, etc., very vivid. Circular polarizing filters (circular PL) cut out light of specific polarization directions and convert the transmitted polarized light into circular polarized light. Using a linear polarizing filter with a digital camera may cause malfunctions in autofocus and other operations, so circular polarizing filters are used. Polarizing (PL) filters remove unwanted reflected light, vividly capturing the colors of the subject. They deepen the blue sky, make clear streams and seas clearer, and reproduce the vivid colors of fresh greenery and autumn leaves as they are. An indispensable filter for landscape photography in spring, summer, autumn, and winter. It is housed in a rotating filter frame, and the degree of reflection removal can be controlled by slowly rotating the front frame. [Reference] What is a PL (Polarizing) Filter? PL (Polarizing) filters are short for Polarized Light filters, and are lens filters that utilize a polarizing film. They generally have a structure in which a polarizing film is sandwiched between two pieces of glass, and a rotating frame structure for rotating the direction of the polarizing film. PL (Polarizing) filters remove surface reflections of light and provide very vivid color effects. In addition to the "reflection removal" effect on water surfaces and glass, they also provide a "color contrast" effect that deepens the color of the blue sky and makes the colors of foliage, mountain surfaces, buildings, etc., very vivid. 108