For a long time I struggled with pale blue skies in my images, even if the sky was actually a deep rich blue that day. Although I have found that adjusting the exposure to make the scene darker helped a little, I still wasn’t getting the results I wanted.

Enter The Polarizer
Finally, I got my hands on a circular polarizer and everything changed. A circular polarizing filter can darken pale blue skies and make them richer. It also adds contrast to the sky so that any white clouds will pop out. I have found it to be an indispensable tool, whenever I go out for daytime photos, and I almost never take it off when I am out.

Who Can Use One
Filters are most often associated with SLRs and their interchangeable lenses. However, I have found that often times camera manufacturers make special add-ons or attachments to allow the use of filters with some of their point and shoot models. Since a polarizer is one of the more popular filters, if your camera can use filters, it is likely that a polarizing filter is available.

For your DSLR you may need different filters for your different size lenses. To see what size filter will fit your lens, check underneath the lens cap, it is usually written there; otherwise check in your lens manual or online.

What To Get
Circular polarizing filters generally run between 25-80 USD and I have seen them go for hundreds more. Your lens manufacturer most likely offers their own filter line, but you may be able to find an equivalent item from a 3rd party manufacturer for less. As long as the filter is the proper size for your lens, it shouldn’t matter which manufacturer made the filter or the lens.

The biggest difference you will find in the filters is the coatings applied to help transmit light or to protect the filter itself. It is really up to you on how much to spend on a polarizer, even the cheapest one will earn its keep.

Using One
Attaching a filter to your lens is easy to do on a SLR lens. Carefully line up the filter’s threads with your lens and screw on.

Once your polarizer is affixed, it is ready to go. When you come across an appropriate scene, turn the outer ring of your circular polarizer and you should be able to see the changes in your viewfinder. If you are pointing your lens at a blue sky and rotating the polarizer, you should be able to see the sky turn lighter then darker.

Things To Keep In Mind
A polarizing filter will have different degrees of effectiveness depending on the angle you are shooting to the sun. If the polarizer seems to be having little effect, try recomposing your shot.

You should be wary of over polarizing. You can actually make an already deep blue sky too unnaturally dark, just tone it down a little by turning the polarizer ring slightly. Of course, that might be what you are looking for, a deep dark, foreboding sky.

Another thing to consider is that polarizing filters typically darken the image by 1 to 2 stops. In certain situations where you can’t shoot at a slower shutter speed, you may need to increase your ISO and if the lighting is just too dark, you might be best off removing the filter.

Finally, when using any kind of filter, be wary of vignetting. The additional height that the filter adds to the end of the lens can get into the image, particularly at wider angles. This can cause unsightly dark corners in your images taken at wide angles.

See For Yourself
The two photographs below were taken seconds apart with the same ISO, shutter speed, and aperture. The only difference between the two was that the first photograph was taken without the use of a polarizer, whereas the second one was taken with a polarizer.

Blue Skies Forever
I actually got one of the cheaper polarizing filters, made by a third party manufacturer, and I do not regret it one bit. Maybe one day I will invest in a more expensive polarizer, but for now I am still excited about the results I am getting with this small inexpensive investment. I instantly got better results once I started using the polarizer outdoors on sunny days.