Two must have filters for shooting outdoors are the UV and polarizer. You should keep a UV filter on the lens to protect it from being damaged or scratched at all times. The UV filter does little to affect the quality of the images, but it will slightly improve your color tones by helping block some of the UV light rays outdoors. It’s mainly used for protecting the glass on the lens. When shooting in bright sunlight outdoors, I  prefer to use a polarizing filter.

Both filters screw  on the end of a lens easily.  A polarizing filter will make your outside photos pop. It helps eliminate haze, reflections on glass, water, and makes the sky appear a rich darker blue. You will get the best results when you are approximately 90 degrees to the sun. You turn the lens filter as you look through the viewfinder until you achieve the desired position. Compare the images below with and without a polarizing filter.

Above: See how the bottom photo has more detail, especially in the clouds using the polarizer.

Below: The image below shot using a polarizer changed the outcome of the photo dramatically. It changed the color and appearance of the water, made the trees pop in a brighter green, and turned the sky into a much ricer blue.

Finally, look at the picture on the right. The glare on the water is minimized, the sky is a darker blue, and the foilage is slightly greener. The polarizer filter will not help much with the detail in the shadow areas, but it pays dividends in other areas when shooting on bright sunny days.