Filters

Types of polarizing filters

Written by Gail Bjork

Learn the difference between a linear and circular polarizing filter, and why one may be better suited for your digital camera than the other.

polarizerThere are two types of polarizing filters: Circular and Linear. Polarizing filters have several benefits and many photographers consider them an essential accessory.  They are especailly useful for landscape photographers or anyone who likes to take photos outside and wants to reduce unwanted glare.

When purchasing a polarizing filter, choose carefully.

With polarizing filters, you get what you pay for

There are many ways to fabricate a polarizing filter. Inexpensive filters will be made with a tiny mesh grid, while more expensive ones require optical coatings.

Stay away from cheap polarizers as image quality will be strongly degraded. In fact, sometimes you can see the mesh on your pictures.

When buying a polarizing filter, get highest quality of glass you can afford for best picture quality and make sure it’s coated.

Linear or Circular polarizer?

Both types of polarizers affect light in exactly the same way. A Circular polarizer is basically a Linear polarizer with an added optical component on the back.

Why the difference?

Cameras with phase focusing, such as Single Lens Reflex cameras and Digital Single Lens Reflex cameras , need light in two polarization orientations to focus. The added component of a Circular polarizer makes sure the camera gets just that.

If you have more than one lens that have different sized filter-mounts, you may have to buy more than one filter.

If you don’t intend to use a DSLR, save money and buy a Linear polarizer.

Slim polarizer

If you use a wide angle lens, get a “slim” polarizing filter. It is thinner than a standard polarizer and should prevent vignetting.

About the author

Gail Bjork

Gail Bjork, who is passionate about digital photography, is the owner and editor of Digicamhelp.Gail is the author of three illustrated ebooks about digital photography. A number of her photos and digital photography related articles appear at other websites.In 2006, a series of her photos, People in the Louvre, were exhibited at the Underground Photo Gallery
in Iisalmi Finland. Eight of her photos taken in the Florida scrub are on permanent exhibition at Parrish Medical Center in Titusville, Florida.Gail served twelve years as an elected member of The School Board of Palm Beach County, Florida, one of the largest school districts in the U.S. She has also been the editor of a small town newspaper and a free-lance writer. Gail and her husband owned and ran several small businesses.