Center Spot Filter: (all mfg.) A heavy diffusion filter with a clear circular center spot. Ideal for facial portraits or other situations where a clear central subject with a diffused, less distracting background is desired. Hoya's are a close up lens with a drilled out center.

Circular Polarizer: (all mfg.) A polarizer designed for cameras with "beam-splitting" metering systems and auto focus systems. Dslr cameras use a beam splitting prism in the light path to direct the light to the meter. Beam splitters polarize light. If a conventional polarizing filter is added to the light path, the combination of two polarizers will give underexposure to the picture. Many cameras including most slr auto focus cameras require the use of a circular polarizer. See your camera instruction manual to see if your camera model is a type that requires a circular polarizer. Circular Polarizers are now also available from most mfg. with multi-coated surfaces or built in warming filtration. 

Close up lens: (all mfg.) Single element diopter lenses enable focusing on subjects much closer than the standard lens allows. Great for detail photos of nature subjects and a wide range of situations. Available in several diopter strengths from .025 to 10+

Color Compensating Filter: (Tiffen, B+W, Hitech, Cokin) Used to compensate for deficiencies in the color quantity of light sources, deficiencies in film, reciprocity failure caused by long time exposures, etc. Available in primary colors- red, blue, and green and in secondary colors the most commonly used - cyan, yellow, magenta. Color Compensating Filters are available in different strengths and may be combined to achieve precise color rendition.

ND Gradual Filters: (all mfg.) Half ND-half clear, with a smooth transition no hard line. Creates deep blue skies. No landscape photographer should ever be without one. Gradual type filters also come in a wide choice of enhancing colors. Create brilliant sunsets with the burnt orange tone graduals, Tiffen calls theirs Sunrise ColorGrad. You can also selectively tone down bright areas with the Neutral Density. Available round Rotatable mounts for proper alignment with your image, in squares 4x4, 6x6 or rectangles 84x100, 104,120 165mm, 4x5, 4x6. 

Cross Screens: (Hoya, B+W,) also called star filters in 4, 6, 8 and 16 point.

Diffuser: (Hoya, Cokin) Overall soft effect due to its irregularly uneven surface, effective in portrait photography.

Double Fog Effect Filter: (Tiffen) combines a soft fog with a heavy low contrast effect. This allows clearer detail than the standard fog filter, while maintaining a dense fog appearance. Available in several densities.

Dual Color: (Hoya) Two half colors together in one filter available in red/blue, yellow/pink and orange/green only in 49, 52, 55mm sizes.

Duto: (Hoya, B+W soft focus 1,2, ) Filters have fine concentric lines etched on the surface, The center is usually sharp, effective in portrait photography.

Enhancing/Intensifier (didymium) Filter: (Tiffen, Hoya, B+W, Sunpak) Made of special didymium glass creates warm vibrant color by selectively improving saturation of reds and oranges, with a diminished effect on other colors. This one is made for Fall, but very useful thou out the year. Red things like, rock canyons, barns, flowers, SUNSETS, cars, all become interesting subjects.

Fluorescent Light Filters: (all mfg.) Color correction filters that give natural color renditions with daylight film, eliminating the blue green cast ordinarily resultant from shooting color films under average fluorescent lighting without a flash. Useful for cityscapes at night.

Fog Effect Filter: (all mfg.) Creates or enhances the effect of a natural fog. Fog filters cause highlights to flare and "mist" or fog. An even mist density is produced throughout the image. Available in several densities. Now being sold by most companies as soft focus "mist" filters

Low Contrast Filter, Ultra contrast: (Tiffen) Consists of a special material evenly distributed between two laminated layers of glass causing light to spread from highlighted areas to the shadow areas. Lower contrast, mutes colors, white areas remain, and blacks become lighter. Allows more detail in dense shadow areas. Ideal for slide duplication work. Available in several densities.

Multi-Image Lenses: (Hoya,Cokin, B+W ) Multi-faceted polished optical glass (except Cokin and Ambico) lens that produces multiple images of your subject all in one picture. Varying depth-of-field can produce different effects. Available in several multi-image patterns.

Neutral Density Filters: (all mfg.) Used to reduce the amount of light reaching the film with no selective absorption of colors. Available in several densities. The classic waterfall filter used to slow down the speed to create the satin look on the water.

Polarizer Filter: (all mfg.) Reduced glare and reflections, saturates colors and darkens blue sky. Reduces reflections when photographing water or through glass windows. The polarizer can be rotated to determine the amount of reflection to be removed. When photographing scenic's, rotate the polarizer to change blue-sky densities from light to dark blue. Creates a dramatic contrast between blue skies and white clouds. Also available in warm versions

Sepia Tone Filter: (Tiffen, Cokin, Hitech, Hoya) Creates a warm brown tone and offers a "turn of the century" look to your image. Sepia filters do allow some unwanted colors to pass so monochromatic scenes are recommended.

Black Diffusion FX Filter: (Tiffen) Net material laminated between optical clear glass. Creates a soft diffusion effect while causing no halation from highlights. Dark areas remain dark. Available in several densities 1/2, 3 & 5.

Softner A, B: (Hoya) Randomly arranged minute lens,  on the surface of the acrylic filter. Creates a picture with a clear focus and soft gradation. Softeners can be used together to increase the soft effect.

Soft Contrast Filters: (Tiffen) Contrast is reduced while allowing black areas to stay black; also produces softer, less intense colors. Available in several densities. Also called mist filters

Soft/FX^TM Filter: (Tiffen) Used in portraits to retain overall image clarity while softening unwanted details. Will tone down wrinkles and skin blemishes, while leaving the eyes appearing sharp. Available in several densities. And in warm versions 

Softar I, II Ziess: (B+W ) Special lenses with mini diffuser lenses randomly arranged Softar's can be used at any f/stop without changing the degree of softness. Softar's can be used together to increase the softness. Not available in 60E size

Split Field: (all mfg.) A close up lens cut in half allowing close up focusing on one portion of the image while retaining clear focus on the background. 

Star Effect Filter: (all mfg.) Produces a star effect from pinpoint light sources (sun reflections, city lights, holiday lights, etc.) Available in effects of 4 point, 6 point 8 point stars. New multi radial stars The best star filters are made of optical glass, with lines engraved on the surface, forming grid patterns.

IR Filters 87, R72, 89, 093: (Hoya Tiffen, B+W) Transmits infrared with no visual transmission.

812 Filter: (Tiffen only) A warm tone filter ideal for enhancing colors in ordinary cool (bluish) lighting situations. Ideal for usage with electronic flash, outdoor shade and as an all around filter. This is the color tone Tiffen is using in their warm soft focus filters and polarizers.