Tru Digital Filters, made from the finest solid optical glass, are ground and polished to the most practical thinness. In addition, they are heat-treated to avoid any distortion or focal shift, and each filter is subject to strict tests in order to ensure a flawless, even surface, which is essential to a quality filter and exceptional photographs. * Fits 72mm lenses * Ideal for protecting your valuable lens from scratches and dust * UV filter absorbs ultraviolet rays to produce crisp, clear photographs * Circular Polarizing filter eliminates reflections from non-metallic surfaces, and increases contrast and color saturation * FLD filter helps balance light in outdoor situations or where fluorescent lights are used A UV filter is used to reduce UV rays from entering the lens and striking the film. A polarizer is different than most filters in that it is composed of two pieces of glass, mounted independently inside a round frame so that one can be rotated relative to the other. As it is rotated, it increasingly cuts out glare and haze. You can also use a polarizer filter to darken blue skies. A FLD filter (fluorescent light correction) provides the perfect solution for obtaining pleasing skin tones and correct color while shooting without a flash under fluorescent lighting. This filter gives true-to-life color rendition by removing the harsh yellow-green cast ordinarily resulting from fluorescent bulbs. When shooting under natural light, a fluorescent filter dramatically increases color saturation of subjects such as sunrises and sunsets.