I often use a polarising filter on my digital camera because I know that without it the bright glary sunlight here in Australia can ruin a lot of my photos and the deep blue sky and water won’t be accurately depicted.
Unfortunately camera filters like the polarising filter mentioned on this page can only be used on “prosumer” and professional SLR digital/film cameras where the lens is threaded so if you have a small point and shoot digital camera with a retractable lens then you can’t use a polarising filter.
Remember also that a polarising filter is the one filter that cannot be replicated in Photoshop so you must use it when taking a photo because if you take a photo without a polarising filter you cannot post-process in a graphics program and achieve the same effect.
According to HOYA (a prominent manufacturer of camera filters):
Light rays which are reflected by any surface become polarised and polarising filters are used to select which light rays enter your camara lens. PL (Linear Polarising) and PL-CIR (Circular Polarising) filters have the same effect, but it is important that you choose the correct version for your camera.
To demonstrate here is an example of the same photo taken :
|With a Polarizing Filter||Without a Polarizing Filter|
As you can see using the polarising filter removed the unwanted reflection from the corner of the building, reduced glare which made the photo look clearer and the colours more saturated and with better contrast. This polarising effect is most effective when used to increase the contrast and saturation in blue skies and make clouds more visible.
It’s also great for use at at the beach, snowfields and other locations where there’s a lot of glare.
Note: Polarising filters are generally more effective when used at roughly 90 degree angle to the sun (so the sun is directly LEFT or RIGHT of you) rather than straight at the sun or with the sun behind you.
Also be careful not to twist the filter to hard when screwing it on or off the thread of your camera lens because it can break apart into its separate layers.
A professional guide to using a Polarizing Filter correctly can be found at the Luminous landscape website’s tutorial: Understanding Polarizers – Care, Feeding & Proper Use