Polarizer Filters are a WONDERFUL thing, and on eBay, they are as common as dirt. But, before you go ANY further, its time for a little truth in advertising. There are TWO different types of Polarizing Filters: 

Linear Polarizers and Circular Polarizers. Although the effect is roughly identical when used properly, there is a right and a wrong PLACE to USE them.  

I sell ONLY Circular Polarizers! No Linear.

HOW TO CHOOSE:

Most " modern" Film and Digital Cameras and Camcorders use what is called a " Semi-Silvered Mirror" or Prism, to split the beam of light entering the unit's viewfinder in order to perform proper " Auto-Focus" and Exposure operations. A Linear Polarizer can interact with these operations in an unpredictable manner.

The Linear Polarizer Filter was designed primarily for " Older" Cameras and Camcorders which do NOT have EITHER an Auto-Focus or an Exposure Meter that uses a " Beam-Splitter."  Although you can use a Linear Polarizer on devices with " Beam-Splitter" Auto-Focus and/or Exposure Meters, you will NOT get the best results.

The Circular Polarizer Filter is designed Specifically for modern Auto-Focus Devices and Exposure Meters that DO use " Beam-Splitters." This newer technology is in most modern 35 mm Cameras, some APS Cameras,  and most modern Camcorders and Digital Cameras. Therefore, they SHOULD use the Circular Polarizer. To not use it may mean less focusing and/or metering accuracy.

The Circular Polarizer is a somewhat more expensive type of filter, since it is much harder to make and a much more advanced technology, and therefore some vendors of cheap filters on eBay don't even want you to know that there is a difference. However, this is ONE place where you get what you pay for. If you have an Auto-Focus Camera or Camcorder, or one which uses a " Beam-Splitter"for Exposure Metering, OR BOTH, you really SHOULD use ONLY a Circular Polarizer.

TO PUT IT SHORT: 

You can use a CIRCULAR Polarizer on ANY photographic lens, but you should not use a Linear on some. Check your Manual and then make your decision.

Click on the BOX, below, which takes you to the Tiffen Web-site for SPECIFIC INFORMATION about the use of Polarizer Filters.

I may be the only person on all of eBay who will tell you that there really is a difference (look and see),  but it is up to you to decide which you want. Either one is worth having, in the right place, but they ARE different. So, read the information about the differences. Check your Manual BEFORE Buying! To get the most from your equipment, you SHOULD have a Polarizer of some kind. But, your precious memories are too valuable to not at least CONSIDER what you are dealing with. It is up to YOU!

I do not have information about specific cameras and camcorders. Check your Manual.

Notice the subtle, yet important darkening of the blue patches of sky giving you a more dramatic, some would say, more realistic picture. A Tiffen Polarizer Filter can help keep sky blue from turning your outdoor pictures into a washed out GRAY. Best of all, it does NOT affect other colors except to restore the more saturated, natural, beautiful colors which were washed out without a Polarizer Filter. Some of the ads I see on eBay imply that a Polarizer can turn a GREEN Sky to Blue. Don't expect such nonsense. The effect is as stated above IF it is actually a GOOD Polarizer.

1. Use a Polarizer Filter whenever you photograph the sky. It gives its Best effect when used at right angles to the direction of the sun. It is adjustable in its effect. Rotate it to lighten or darken the effect.

2. Use a Polarizer Filter OUTDOORS whenever you photograph WATER, or through GLASS!

Notice the reflection of the tree and cars. Nice tree, nice cars. But,  is that what you wanted? 
The lady on the other side of the glass makes a much nicer picture

Notice, again, that there is NO difference in the tone or colors in the picture, except, perhaps for a normal and desirable increase in the saturation. Just the reflection is missing when you adjust the Polarizer. Different angles, different reflections make for different results. You may need to move around and rotate the filter for best effect, but with just a little effort you can achieve Excellent results .

3. Use a Polarizer Filter INDOORS whenever you photograph through GLASS.

Notice the reflection of the sheet. But,  is that what you wanted? The model on the other side of the glass makes a much nicer picture.

Tiffen Circular Polarizer Filters can cut, sometimes even eliminate many types of reflections and glare. One thing they can NOT do is cut reflections from bare metal. Something to do with the metal makes it impossible. Glass, water you have a much better chance of good results.

You achieve BEST results when you are shooting at a perfect right angle to the light source, the sun or whatever. Less than a right angle, a lesser reduction.

On a different note, it is possible that you want more, or less of an effect. Once in position, you can rotate the Polarizer filter to increase or decrease the effect.

If you decrease the effect enough, you have NO Polarizer effect. At that point you have only a reduction of overall light reaching your lens, the same effect as if you were using a Neutral Density filter. This, by itself, can be good. Under well lighted situations, adding a neutral density filter causes you or your automatic camera or camcorder to open its lens. The more open, the shallower the " depth of field."  

Ever wonder how professional photographers achieve some of those wonderful pictures where the model's face is sharp and clear but the background and foreground are slightly out of focus and thus less distracting? Well, they opened the lens and got a shallower depth of  field (a smaller area that was IN focus, a larger area in front and behind the subject that is OUT of focus). Neat effect. ALL Polarizer filters act as neutral density filters all the time. It is just the Polarizer effect that varies.

Another effect of a Polarizer filter is increased SATURATION of your Colors. If you have a lot of glare, your colors can become Washed Out. You are not seeing the True Color of your subject, and neither is your camera or camcorder. Using the Tiffen Polarizer Filter, in effect cutting out the glare to one degree or another, you end up with more saturated, NATURAL, beautiful colors. Again, don't expect GREEN Skys to turn Blue as are shown in some ads. Those ads are just nonsense. The pictures aren't even remotely realistic.

All in all, most professionals and many good amateur photographers and videographers carry a Polarizer filter. They wouldn't be caught dead without one on the beach, for instance. In a pack with two filters in it, a Polarizer should definitely be one of them.

Innovative design, consistency and precision engineering make
Tiffen Filters the first choice of NASA, motion picture and video production studios, and photographers the world over.

Tiffen Filters are backed by a ten-year manufacturer's warranty!