Filters – protective glasses, which photgraphers screw into the lense. Hoya, Marumi, B&W – at this moment most popular filters. Filters may be various kind.
Infrared filters – there two types of these filters – filters, which pass IR, and filters, which do not pass IR, but pass daylight.
Various colors – used for different light sources colors correction.
Circular Polarising – used to remove negative reflections from non-metallic surfaces such as water, glass etc.
UV – protects from UV light, gives to photo more sharpness. Right choose of filter is very important to photographer. Bad quality filter reduce quality of photos.