Plumtree Photo
EST. 2006



A polarizing filter is perhaps the most useful filter a photography enthusiast can own and becoming familiar with its use can greatly improve the color and quality of your photographs. This article intends to explain what a polarizer filter can do for your photos, how a polarizer filter works, the difference between a circular and a linier polarizer, and to help you determine what size filter you will need for your lens.
Without Polarizer Filter
With Polarizer Filter
Perhaps the most noticeable effect of a polarizing filter is the enhancement of color saturation. In the photograph above it is very easy to see that the sky is bluer, the foliage is greener, and the different shades of similar colors are more pronounced. Notice how the mountain ridge against the sky is much clearer in the photo using the polarizer and the different shades of yellow and brown in the ground cover stand on their own. In the photo taken without the polarizer similar colors tend to blend together and make the scene appear more washed out by the suns rays.
Without Polarizer Filter
With Polarizer Filter
Another effect of a polarizing filter is the reduction of glare and reflection on surfaces such as glass and water.  As you can see in the two photographs above the reflection in the windows of the scene outside the building in the photo without the polarizer distracts the viewer.  The photo with the polarizer has almost no reflection in the glass and allows the viewer to focus on what the photographer intended.  The same effect will be seen when photographing fish in a shallow pond, or photos taken across a body of water.  In digital photography many of the effects of a polarizing filter can be replicated by software after the photo has been taken, but removing reflections is especially difficult.

A polarizing filter works exactly the same way that polarized sunglasses work.  Put simply the sunglasses, and the filter, block out some of the suns rays that tend to make things appear to be washed out by to much light.  The amount of the polarizing effect depends on the angle of the polarizer to the light source.  The most pronounced effect is when the filter is turned to a 90-degree angle from the light source.  For this reason any good polarizing filter will rotate on its lens mount ring.  One trick with shooting with polarized filters is to wear polarized sunglasses to get a preview of how your photograph will look.  It is recommended that you remove the sunglasses before shooting so you will see what the camera is getting, and it is possible for the two filters to line up in a way that you will see nothing but black through the viewfinder.

What is the difference between a linier polarizer filter and a circular polarizer filter?  The main difference is that a circular polarizer filter is made for use with today's autofocus lenses, but can be used with a manual focus lens.  A linier polarizer is for use with a manual focus lens.  If you would like a technical explanation as to why please let us know and we will refer you to a number of very technical web sites that do a much better job explaining this.