In photography what does a polarizing filter do?

Answer 1

Un-polarized white light typically vibrates in all directions radially from its axis of travel (think of a bicycle wheel with spokes radiating from the centre; the spokes represent the vibrations or transverse waves, the wheel hub is the direction of the light ray). When this light ray reflects off of a NON-METALLIC surface, the vibrations are cancelled out, except for those that are still reflected because they have the right incidence. Now think of a bunch of wood strips nailed to a pole for climbing. The strips represent the remaining transverse waves, the pole is the ray of light.

How the polarizing filter's coating works is a subject too complicated to enter into here. Suffice to say that when we turn it and orient it correctly, it will now "cancel out" most of the remaining transverse waves, which our eyes see as a sort of "haze". Some say it "darkens colours" such as in fall foliage or the sky but this is not accurate. The removal of the haze essentially "purifies" the colours, seemingly enriching them. You can also remove reflections from glass windows or water using this filter. The filter works best/only when your angle of view is equal to the angle of incidence of the reflected light. Thus, pointing it at one scene at one time of day can produce very different results at another time.

If you've absorbed this, try a trick question. I told my students that the surface had to be non-metallic, but was initially surprised to see that the filter would remove my reflection from a metal car fender. Why did it? Because the reflection is bouncing off of paint, not metal!
It reduces glare because all of the light waves are vibrating in the same direction.
A polarizing filter is a handy Photography accessory that can be used with both film and digital cameras.

The filter is used to reduce or eliminate glare, increase overall saturation, and darken blue skies in photographs.

Answer 2

A polarizing filter can eliminate glare. A good example is taking a picture of a lake or river. There is usually so much glare that you can only see the surface of the water. When you use a polarizing filter and rotate it, you will see the glare disappear and may even be able to see below the surface! Be careful when purchasing a polarizing filter as there are two different types. Make sure that you buy the correct type for your particular camera. For DSLRs, buy a circular polarized filter. Otherwise, a linear polarized filter is less expensive, but won't work properly with a DSLR.

Make sure you get the highest quality glass you can afford! Some of the cheaper filters use a mesh design, which can show up in your pictures!

Answer 3

The polarizing filter works with both color photography and black and white photography. It is meant to filter light and many cameras can either minimize or maximize the the level of light. So it can darken parts of the picture, like sky to contrast with other objects, like a cloud or a plane.