A UV filter is used to reduce UV rays from entering the lens and striking the film. Modern lenses often have UV protection built into them as well as digital sensors, however, UV filters are commonly used to help protect the surface of the lens from scratches, smudges, dirt and other hazards.
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. With an SLR, you can actually observe this change through the viewfinder. Polarizers reduce glare from water, glass, or any non-metallic surface. 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.
With the Flower/ Crown/ Petal shape designed, it offers the same prevention of flare as the corresponding circular or rectangular design, but with a smaller size and a lighter weight. With screw mount can be attached to the 58mm lens or filter thread. This can lower the contrast of the image, and enables you to shoot towards the light source, and being reflected inside the lens, without excessive flare. It stops light coming into the lens at extreme angles and being reflected inside the lens.