Polarizing filters are generally used in landscape photography, as they can both control polarized light – commonly known as "light reflection" and contrast. There are two types of polarizing filters: PL (Polarized Light) and C-PL (Circular Polarized Light), but C-PL filters are generally the most used.
The main feature of ND filters is their ability to give you control on the shutter speed.
ND filters come in wide range of values, from ND2 to ND100000, but can be generally summarized in 3 main categories: light, middle and heavy.
By star-shaping light sparkling from light sources like holiday illuminations or water surfaces, star filters can confer your photos a more scenic and impressive effect. In the same way as for C-PL filters, star filters come in a two-filters rotating structure that, by rotating the filter’s frame, allows adjusting the angle of the light rays hitting the filter's surface.
Also known as close-up lenses, close-up filters prove to be convenient filters to have at hand. By installing these filters on whatever lens you are using at the moment, you can easily but effectively shoot macro. Or, by installing them on your macro lens, you can further shorten the working distance and get closer to your shooting object, thus making it look bigger on the final image.
Originally developed to perform and enjoy infrared photography with black-and-white and color infrared films during the film era of photography, IR filters can also be effectively and enjoyably used in infrared photography with nowadays DSLR cameras that no longer use films.
Originally developed to enhance red tints in color reversal film, red enhance filters have been largely used so far in landscape photography and portrait photography as well. In recent years red enhancer filters are also used to cut off unwanted light pollution.
Andrew Leggett http://bit.ly/a_leggett made this long exposure shot using wideangle Tokina AT-X 116 F2.8 PRO DX II (11-16mm) lens http://bit.ly/tokina116. ND1000 neutral density filter allowed to increase the exposure on 10 f-stops. To stabilize the camera during long exposure Andrew used a tripod.
Torres del Paine National Park (Chile). Anton Petrus' http://anton-petrus.lj.ru made this shot using wideangle Tokina AT-X 17-35 F4 PRO FX lens http://bit.ly/tokina_1735 with neutral density filter. To stabilize the camera during long exposure Anton used a SLIK tripod http://bit.ly/sliktripods.
[Camera]: Canon 5D mark II
[Filter]: HOYA PROND64 http://bit.ly/prond + HOYA HD CIR-PL http://bit.ly/hoya_pl
[Comments]: We've named this photo - "What stones don't speak about when the sun is down?".
It was shooted at the Gulf of Finland using 2 filters - HOYA PROND64 to smooth the water and HOYA HD CIR-PL to remove reflections from the water at the foreground (to make it more clear) and to make wet stones more beautiful.
Shutter speed was 120 sec at 16mm, f/13 and ISO100.
The long exposure shot using Tokina AT-X 24-70 F2.8 PRO FX lens http://bit.ly/tokina2470 and HOYA ND8 filter http://bit.ly/hoya_nd. To stabilize the camera during long exposure, the author used a tripod.