A lot of people ask me how I get the sky in my images to be so blue. While there are many variables involved in making the sky look natural, a polarizing filter can actually make the sky look more dramatic, and it's easy to learn how to use it properly.
Basically, a polarizer can reduce reflections from objects such as water and glass and can be used to darken the sky and bring out the clouds, making the scene look much more vivid. It can also help reduce haze. For all normal lenses that have a filter thread in the front, you can get a circular polarizing filter, also known as a “circular polarizer”. A circular polarizer is very easy to use and once you attach it on the front of your lens, all you need to do is rotate it clockwise or counter-clockwise to get a different amount of polarization.
Rotating a polarizer allows certain types of light waves to pass through, while blocking other ranges of light waves. This way, you can turn a sky from light blue to very dark blue or increase/decrease reflections by simply rotating the filter. For anyone taking landscape images, I can highly recommend this filter!