Circular Polarizing Filters (CPL)
Sports photographers, especially new ones, often concentrate so much on capturing action that they neglect factors that affect image quality. One way to improve the vibrance and saturation of colors while reducing haze is to use a circular polarizing filter when conditions warrant. Landscape photographers often use them in their work but they are rarely seen at sporting events. I like them in sports photography whenever my images will include a lot of sky or if I am dealing with low sun angles where reflected light may be an issue. Those days when the skies are an ugly milky white can't always be avoided but a CPL will draw out whatever definition in the clouds is possible.
A circular polarizing filter is a photographic filter that screws on to the end of a lens (usually) and reduces or eliminates reflected sunlight. The size will depend on the size of the lens. Both 77mm and 82mm are popular sizes. Quality is variable and so are the prices. Read the reviews and get a good one. These filters rotate to maximize their effect and so it will be necessary to recalibrate when changing from portrait orientation to landscape. It is important to note that the effect is apparent as one looks through the viewfinder. Simply look in the viewfinder while rotating the filter and you will see the polarizing effect maximize, then minimize, then maximize again. WYSIWYG so when the scene has the best appearance to your eye, that will be the best for your capture. When reflections are gone, the colors will appear richer, skies bluer, clouds whiter, and haze will be reduced. It comes at the expense of 1 to 2 stops of light.
Light loss is less of an issue than you might expect. Remember that we are talking about reflected sunlight so by definition we won't be using it for indoor, night, or even overcast days. That means there will be ample light for fast shutter speeds at fairly low ISOs for good image quality. The polarizer has minimal effect when shooting into the sun or with the sun at your back and it's most useful when shooting at 90 degrees to the sun. It's also possible to have variable effects when shooting with extremely wide angled lenses because different areas of the image will be at different angles to the sun. Check and double check the viewfinder!
What types of sports images can use a circular polarizer?
Pole vault. To the naked eye, the sky was almost all a murky white with no definition. With the polarizer, the sky became at least a little interesting.
Long jump
And the high jump
Try a circular polarizing filter for your landscape images and then use those polarizing properties to best advantage in sports. Nearly everyone loves images with bold colors that are free of glare or haze.
Phil Zivnuska
I'm already working on my updated "How to Photography Football" that will be published August 15, 2014. The original version has nearly 50,000 hits and the updated tutorial will be even better with 5 more years of expertise.