Lens Filters Product Guide
Every camera makes it easy to take great pictures of family, friends, and attractions. Photography aims to take picture taking toward a level of art. SLR cameras are the choice tool of the photographer because you see the images directly through the lens. You can change lenses to modify perspectives. A filter may be added to virtually all of these lenses.
A filter is placed in front of a lens to provide certain optical changes to reduce haze, improve color, reduce glare, adjust contrast or add a variety of special effects.
There are many different types of filters. Some seem extremely clear and may also be used as a permanent lens protector. Others have colored glass, or are textured to provide unique imaging effects.
How do you attach a filter to a lens?
The majority of filters mount directly in front of a lens using a screw mount. The size of that mount varies according to the size of the lens and the manufacturer of that lens. A lens with a 50mm focal length by Olympus may require a 49mm size filter, a comparable Nikon lens might require a 52mm filter, and a similar Canon lens might require a 55mm filter.
Filter sizes for particular lenses are usually included in the lens' documentation and may also be found in many of our lens descriptions.
Photographers often place a clear filter (i.e. UV or Skylight) on each lens that they own because the filter helps protect the lens from dust and other particles.
What if my camera doesn't have a lens that accepts screw-mount filters?
Some cameras, particularly Digital Cameras, may not have lenses that offer the ability for adding a filter. A company called COKIN makes a filter system to help you do this. A special adapter connects to the tripod screw mount of your camera. In front of the camera lens, the adapter has a holder for insertable filter gels. These different gels behave very much like filters for SLR camera lenses.
Types of Filters
Technically, this is not a photographic filter. Made from completely transparent superior grade optical glass, it will not affect the color balance or performance of your lenses in the slightest. It is mounted on lenses to act as a protector against dust and other particles.
This filter absorbs ultraviolet rays from sunlight that may produce outdoor photographs that seem hazy and indistinct. It is considered to be a multi-purpose fine-weather filter for color as well as black and white films and for digital cameras. Optically clear, this popular filter is often used as a lens protector.
This popular filter is considered a must-have. It reduces the excessive bluishness that frequently occurs in outdoor color photography, especially in open shade under a clear, blue sky. This filter is especially useful for shooting photos using outdoor color film that tend to lean towards the green end of the color spectrum. With the Skylight, you can achieve superb color balance and clarity under all conditions. It also keeps skin tones free of colored reflections from nearby objects such as the shade of trees. Optically clear, this filter may also be used as a lens protector.
Light rays, reflected from any surface, may become polarized. This can result in uncontrollable glare. Adding a polarizing filter to your lens, you can select which light rays enter your camera's lens. The most popular of these is the Circularizing Polarizer filter. Thicker than most filters, it usually has 2 optical layers and a little knob that allows convenient adjustment. You can move the filters to remove unwanted reflections from non-metallic surfaces such as water, glass etc. A polarizer also enables 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. Appearing like a smoke colored glass, this filter has no effect on overall color integrity.
Adding this filter helps deliver a more distinct contrast between blue sky with clouds and foreground. It's used for scenic photographs to help create a more dramatically appearing sky. Providing a natural tonal rendition, the K2 is often used for subjects at intermediate distances.
This filter is used to increase contrast between reds and yellows. Used in color photography, it helps create spectacular sunset and seascape images. It's particularly useful for distant outdoor shots taken with a telephoto lens.
This filter is used primarily for black and white photography. XO is highly effective for outdoor portraits because red is rendered dark while green appears lighter. It helps promote more natural skin tones.
80A, 80B, and 80C
Films designed for daylight use are sensitive to different colors of the spectrum than those designed for indoor lighting. These are color conversion filters that allow the use of daylight type color films with an 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, 85B, and 85C
These are color conversion filters for the use of tungsten type color films in daylight. 85A 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.
ND Neutral Density
When taking photographs in conditions of extreme light intensity, such as sunshine on snowy mountains or on the beach, or when using a camcorder, ND (Neutral Density) filters are highly recommended. They appear in shades of gray and reduce the amount of light reaching the film. ND filters have no effect on color balance. They offer 4 uses:
- To enable slow shutter speeds to be used, especially with fast films, to help capture movement in subjects such as waterfalls, clouds, cars, snow scapes, and more.
- To decrease depth of field by allowing wider apertures to be used, which helps separate subjects from their background.
- To decrease the effective ISO (light sensitivity) of high speed film (ISO 400, 800, and above) and allow it to be used outdoors under brightly lit conditions.
- To allow cine and video cameras (which have fixed shutter speeds) to film subjects such as snow, sand or other bright scenes which would normally cause over-exposure. ND filters come in 3 different gradients: NDx2, NDx4, and NDx8. NDx2 provides 1 f/stop (aperture) change. NDx4 and NDx8 provide 2 and 3 f/stop changes, respectively
Though they mount like filters, these are available in +1, +2, +3 and +4 diopters for use in close-up photography. Several of these can be combined to produce greater close-up capabilities. Ideal if your lens doesn't offer a close-up (macro) feature and you want to take pictures of flowers (and other objects) up close.
Engraved lines on the filter cross one another to provide a very interesting effect. Ever look at a wedding album and notice how light reflected off a candle or champagne glass seems to sparkle? This filter produces this effect. Used to accentuate the brilliance of jewelry, streetlights, and reflected lighting, cross-screen filters are available to produce 4 point, 6 point, and 8 point starlike reflected images.
You might have seen a portrait where the face is sharp and clear, while the background is diffuse. This effect often helps accentuate facial features in portrait photos. A center spot filter is, essentially, a close-up lens with a hole in the center. The periphery of the picture is rendered a delicate, soft focus effect while the central image is sharply focused.
Made of glass, and provided with rotating frames, this filter consists of 1,270 ultra-fine parallel grooves per inch on the filter's surface. Almost like a Cross Screen, it picks up and diffracts each tiny point of light into a rainbow of color.
This filter seems clear but actually has a line in the middle. One side is a close-up lens with the other half is clear or open. One-half of the picture receives a close-up effect while the other half is normal. Both very close and far subjects can be in focus at the same time. It also offers some other interesting possibilities for creative experimentation.
This filter veils the entire picture in white creating a fog like effect on the image.
This filter provides a soft focus appearance for the entire image.
Digital Cameras and Filters
Most digital cameras (with the exception of SLR digital models) do not accept traditional filters. A special filter system, manufactured by Cokin, permits most digital cameras to use filters.
Photo enhancement software, available for use with digital cameras, allow you to add filter effects after the picture was made and transferred to your computer.
For those of you who are accustomed to using traditional filters in photography (or who find imaging software difficult to use), the Cokin filter system will provide all the effects that you enjoy using.
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