It might be safe to say that a circular Polarizing filter doesn’t enhance your image, it actually corrects it. When shooting outdoors there is light being reflected on just about anything. Images will quickly be washed out with glare or sometimes called haze. Contrast will be reduced and saturation will suffer. A polarizer will help cut that reflection so that you can see the true colors in your image.
Unedited image examples of non-polarized and polarized images
We use the same Shutter, Aperture, and ISO settings in both examples above. The difference in image quality was seen when the polarizer was turned to block the stray reflections of light. The ‘blown out highlights’ in image left are not caused by poor shutter or poor aperture settings. This is caused by very bright reflections of light. Without being able to capture the details in this image, the information is lost, and there is no way to correct this in Post Processing. Even HDR photography with different exposures in this case, will not produce satisfactory results. For video capture where the image is captured in real time a CPL is a very important filter to use outdoors in bright daylight.
CPL filters are unlike ND filters that simply cut out the amount of light coming into the lens. A polarizer blocks light that is being reflected from a certain angle. To use a circular polarizer you attach it to the front of your lens. Part of the filter can spin around so would basically turn the filter around until the image looks good. You can see from the video (above) the results are immediate! This is not just for DSLR lenses. You should look into CPL filters for any camera or consumer camcorders (is there an iPhone version yet?). They come in different sizes according to your filter thread size, so shop accordingly.
Excellent quality filters can be found among some names like Tiffen and Hoya, but several inexpensive versions can be found starting at $3 dollars. We are using an inexpensive version for these tests. Cheaper CPL – Circular Polarizing Filters Can be Found Below: