The Photo Info

By Rebecca Hiatt

Photographers often use polarizing filters to improve the appearance of the images they capture. With digital cameras many filters are no longer necessary and do not always work correctly. There is one filter, however, that is the most often used filter, and it is considered a necessity to a landscape photographer. Whether using a digital or a film camera a polarizing filter will increase color and eliminate reflections in your images.

To unlock the secret of the polarizing filter, you must use the filter correctly.
To use your filter, find the correct size filter to fit the lens you are currently using. (a 55mm polarizer for a 55mm lens etc). Secondly, screw the filter onto the front end of the lens (nearest the subject). After the filter is snugly attached to the lens, rotate the filter. Look through the viewfinder as you rotate the filter and you will see the results immediately. Your landscape images will take on a whole new look; skies will become more deep blue, clouds more brilliant and grass greener. If you stand at a 90-degree angle to the sun you will get the maximum effect from your filter. Do not stand with the sun in front of you or behind you to take the shot.

A polarizing filter, used properly, on an overcast day will saturate the colors of the wet leaves giving life to the image. Of course, you must be very careful on a low light day as a filter can make your images too dark. A polarizer will cut the amount of light reaching your film or sensor. To counteract the decreased light reaching the sensor or film, open the aperture or slow your shutter speed to compensate.

Even though using a polarizing filter has many benefits, which far outweigh the pitfalls, there are several pitfalls of using a polarizing filter. Most of the pitfalls can be avoided with a bit of knowledge.

The first thing one needs to know about a polarizing filter is that there are 2 different types. One is the linear polarizing filter the other is the circular polarizing filter. A circular or a linear filter will do exactly the same thing for your images; enhance them. To compare them, the circular filter is more expensive and the linear filter may not be the best choice for most cameras that use auto focus.

A linear filter will often ruin the performance of auto focus; the camera is unable to transform the information correctly coming from the filter. A circular polarizing filter has an added layer which scrambles the filtered light coming from the polarizer and the camera is able to read the information more clearly.

The extra layer in the circular filter is the main reason the circular is more expensive. But as you can see it is often well worth the extra expense. Also, be sure when you purchase a filter that there is no color cast in the filter. Some filters come with an odd cast, green or yellowish color; make sure your filter has only a neutral grey cast.

Another problem encountered with polarizing filters is found when using wide-angle lenses (28mm or wider). A wide-angle lens may see the rim of your filter, causing a darkening at the edges of the image. Also, the sky can become unevenly polarized as polarization varies with the angle of the sun and a wide-angle lens covers a wider area of the sky.

Even with a few pitfalls, the results achieved with a circular polarizing filter are definitely well worth the price of the filter. Using a polarizing filter will take your images to a whole new level.

The author is a landscape and nature photographer and offers her photography for purchase or viewing at http://www.naturesglory.ifp3.com