COMMON FILTER TYPES AND THEIR USE
TYPE	DESCRIPTION
UV	Absorbs the ultraviolet rays which often makes outdoor photographs hazy and indistinct. A muliti-purpose fine-weather filter for color as well as black and white films. Also serves as a permanent lens protector.
SKYLIGHT	Reduces the excessive bluishness that frequently occurs in outdoor colour photography, especially in open shade under a clear, blue sky. The absorption peak is in the range which corresponds to the film's green spectrum. This means outstanding outdoor shots with superb colour balance and clarity under all conditions. Also keeps skin tones free of coloured reflections from nearby objects such as the shade of trees.
PL/PR CIRC	Light rays which are reflected by any surface become polarised and polarising filters are used to select which light rays enter your camara lens. PL (Linear Polarising) and PL-CIR (Circular Polarising) filters have the same effect, but it is important that you choose the correct version for your camera. They allow you to remove unwanted reflections from non-metallic surfaces such as water, glass etc. They also enable colors to become more saturated and appear clearer, with better contrast. This effect is often used to increase the contrast and saturation in blue skies and white clouds. Polarising filters do not affect the overall color balance of a shot.
80 A,B C	These are color conversion filters for the use of daylight type color films with artificial light source. 80A increases the color temperature from 3200°K to 5500°K for the use with 3200°K lamps. 80B increases the color temperature from 3400°K to 5500°K for the use of photoflood lamps. 80C increases the color temperature from 3800°K to 5500°K for the use of clear flash bulbs.
85A B,C	These are color conversion filters for the use of tungsten type color films in daylight. 85 decreases the color temperature from 5500°K to 3400°K for the use of Type A color films. 85B decreases the color temperature from 5500°K to 3200°K for the use of Type B color films. 85C decreases the color temperature from 5500°K to 3800°K. The effect obtained is the same as with daylight type color films used in daylight.
82A B C	These are light balancing filters used to increase the color temperature slightly for a cooler (bluer) tone. Corrects the tendency toward reddish tones. For example, select the 82B when using tungsten Type B color film (3200°K) with ordinary household 100W electric bulbs (2900°K). These series filters are also used to prevent the reddish tones in early morning or late evening light for natural skin tones. These filters can be used together, but do not mix 81 and 82 series filters since they cancel out each other.
81 A B C	These are light balancing filters used to decrease the color temperature slightly for a warmer (redder) tone. Corrects the tendency toward bluish tones. For example, the 81A should be selected when using tungsten Type B color film (3200°K) with photoflood lamps (3400°K) These filters can be used together.
K2	Especially useful for clear contrast between blue sky with clouds and foreground. Provides a natural tonal rendition. Often used for subjects at intermediate distances.
ORANGE	Increases contrast between reds and yellows. Particularly useful for distant outdoor shots taken with a telephoto lens. Also useful in color photography for spectacular sunsets, seascapes, etc.
25A RED	Especially effective for increasing contrast. Ideal for dramatic cloud effects in landscapes. Can also be applied creatively in color and infrared photography.
NEUTRAL	Made from completely transparent  optical glass, it will not affect the colour balance or performance of lenses but will protect your valued lenses from expensive front element damage which could be caused by dirt, knocks and scratches.
XO YELLOW GREEN	Used primarily for black and white photography. XO is highly effective for outdoor portraits because red is rendered dark while green appears lighter.
X1 GREEN	Great for correcting skin tones, bringing out facial expressions in close-ups and emphasizing the feeling of liveliness. X1 is highly effective for indoor portraits under tungsten lighting.
FL-W FL-DAY	Used to correct the greenish tone that appears when daylight type films are used under fluorescent lighting. FL-W is for use with warm white or white type fluo-rescent lamps.