Have you ever taken a picture on a beautiful day with deep blue skies only to find that the sky in your photo is washed out or pale? Have you ever wondered how the pros get such rich and vivid blues in their skies? The answer is polarizing filters.

If you're an outdoor photographer, the polarizing filter is the single best investment you can make to improve your photos. They are fun and simple and the results are amazing.

The polarizing filter screws on to the end of your lens the same way any other filter attaches to your camera. Once it is in place, however, you can rotate the end of the filter to achieve the desired result. You will actually see the scene change as you look through the viewfinder!

Without Polarizing Filter
 

Polarizing filters have two functions. First, they create a vivid and deep blue sky and, at the same time, they give other colors in your photos more 'pop' or 'sizzle.' If you have ever worn polarized sunglasses, you know how great the world can look with a polarized effect. Simply rotate the filter and you can watch the sky turn from a washed-out white to a deeply saturated blue or anywhere in between. As the sky turns a deeper blue, you will also notice more contrast between the clouds and the sky.

The second function of a polarizing filter is controlling reflections. The polarizing filter can minimize or exaggerate reflections on any non-metallic surface such as glass or water. If you are shooting a mountain lake, you can rotate the filter and watch the lake become a mirror surface reflecting the trees, mountains and sky. Conversely, if you want to shoot a store display through a plate glass window, you can rotate the filter until nearly all of the reflections on the glass are gone, revealing the display inside.

There are two kinds of polarizing filters-- linear polarizers and circular polarizers. You are unlikely to come across a linear polarizer these days, but you should be aware that they are out there because the difference is important. If you have an autofocus camera of any kind, you must use a circular polarizer otherwise the autofocus system will not be as effective.

Likewise, there is a large range of quality differences between various polarizers on the market. For a discussion on optical quality and coatings, please refer to my article on filters in general. As a rule of thumb, however, it is a good idea to purchase the best filter you can afford.

While polarizers are great for landscape shots and travel photography, they are not appropriate for all outdoor shots. Polarizers reduce the amount of light reaching the camera by roughly two stops, so they are probably not a good idea for most sports or action shots. In addition, they should never be used inside.

Also, it is tempting to want to stack the polarizer on your UV filter or other filters. This is a practice to be avoided, however. Try to get in the habit of removing your UV filter and using only the polarizer. The polarizer will function as a protector while it is on your camera and you will get sharper pictures and better color if you use only one filter at a time.

With summer just beginning, you will be presented with more and more outdoor photo opportunities, so it is a perfect time to try out a polarizing filter. If you do, you will notice a huge improvement in your photos!