Circular Polarizer

I recently purchased a circular polarizer for my camera (Hama Circular Polarizer Filter 55mm) and it's great.
You've seen all those photos on magazines with lovely blue skies, you've probably wondered how they managed to do it. This is where the polarizer comes in, it darkens blue skies turning them a lovely deep, rich blue.
Polarizers are also great with greenary, making leaves less shiny by removing the reflections.

They are also great for removing reflections in water. If for instance you were shooting a river scene and you wanted to see the river bottom, a polarizer will allow you to do this. It does this by removing the reflections in the water.

Even if you are not shooting in any of these situations polarizers will enhance the colour saturation with almost any subject making the colours looking more intense. Polarizers are the second most used filters simply because the effects they create can not be replicated digitaly yet.

You are probably now thinking 'I bet this mother of all filters is really expensive'.
But it is not, I bought mine for just £20. Here is the filter i bought a Hama Circular Polarizer Filter 55mm. It did everything I hoped it would do (everything above) and the cherry on the icing was that it was £10 cheaper than Jessops own brand and £20 cheaper than the same one in Jessops.

Some other Circular Polarizers.

More info on Polarizers