More Photo Tips/Suggestion: Filters

A filter is a seemingly simple piece of glass that screws onto your lens in a rotating mount, and has an effect on your image. Filters come in various sizes according to the needs of your specific lens.

Polarizing Filter

Note how the above polarizing filter enhances the color of the sky in contrast with white clouds. (Source: richkoppphotography.com)

There are few more important things a nature photographer can do to improve his or her photography than using a circular polarizing filter.

This is one filter you must have for your landscape photos especially in Red Rock Country. The polarizer is the only filter that I use.

To understand how it works would require a seminar in the physics of light. But using a polarizer is easy; simply screw it on the front of your lens, look through your viewfinder, and rotate it until you see the effect you want, and then shoot.

The way a polarizer works is simple but the results produced can be extraordinary. A polarizing filter removes glare—the distracting light waves that radiate from smooth surfaces like shiny leaves or reflections on water. With the glare eliminated, you capture the true color and texture of the subject.

Polarizing filters also deepen blue skies without altering the color of the clouds. Color saturation is also significantly enhanced. Brilliant red and orange foliage really pops when framed against a deep blue sky.

With the help of a polarizing filter, pale blue skies can become saturated almost to an inky black. (Source: dslrlensauctions.com)

A polarizer doesn’t give the same effect everywhere in the sky. Optimum polarization is when the light source is 90 degrees from the direction you are pointing your camera, i.e. side lit. But when the sun is directly in front or in back of the direction your camera is pointed, it renders virtually no effect at all.

There are two types of polarizing filters—linear and circular.

If you’re shooting with autofocus lenses, you need a circular polarizing filter. Linear polarizers are designed for manual focus lenses only.

In summary, polarizing filters:

  • Darkens a blue sky and brightens white clouds
  • Reduces haze and glare in the atmosphere
  • Reduces reflections from glass, water, rocks, and metal
  • Enhances color saturation
  • Eliminates stray light and glare from reflective surfaces
  • Increases contrast
  • Helps reduce incoming light, when you need longer shutter speeds

Take care to use sky-darkening in moderation; too much saturation can actually make skies look almost black.

However, there is one downside to polarizing filters: you lose approximately two stops of light.

Beware when shooting with a wide-angle lens. Because of the 90-degree rule, a wide angle lens often will show wide variations in the sky.

Since polarizing filters are frequently quite thick, beware of vignetting, the darkening of the corners relative to the centre of the image. Choosing a thin polarizer helps, but the thinner models tend to cost more. The degree of vignetting varies from camera to camera and lens to lens.

I never leave home without my polarizer; actually I leave it on my camera all the time. By never removing the polarizing filter from the lens, I’m always prepared when that great photo opportunity arises. And since I use my standard lens almost exclusively for landscape shots I really don’t have a good reason to remove it.

Filter Manufacturers

When purchasing a polarizing filter you have the choice of a number of quality manufacturers.

The Cokin Creative Filter System has been around for 30 years. Filters fit in a special holder that attaches to the lens via an interchangeable metal ring.

B+W filters are widely recognized for outstanding quality as well as technological innovation.

Tiffen produces professional-quality filters. It takes a lot of know-how to win two Technical Achievement Awards and a Scientific and Engineering Award from the Academy of Motion Picture Arts and Sciences, as well as an Emmy Award from the Academy of Television Arts & Sciences. That proficiency is apparent in every Tiffen product.

Polarizing filters are the single most important piece of equipment a photographer needs in his arsenal. This is one filter whose effects cannot be duplicated in any stage or level of post processing. (Source: enchantingkerala.org)

Hoya is one of the world’s largest manufacturers of optical glass, including glass used for camera lenses, eyeglasses, and photographic filters. Their production process involves the introduction of raw elements and chemicals to molten optical glass to produce a filter of uniform coloration.

Singh-Ray calls its polarizers “lighter, brighter,” meaning that they transmit more light than average.

Heliopan filters are made from glass supplied by Schott (wholly owned by Carl Zeiss) and set in black anodized brass rings that screw in with precision. They’re available in every conceivable size and configuration, including 13 different types of polarizers and special-effects filters.

Please Note: This is the twenty-ninth in a series of stories on Digital Photography and RVing

Worth Pondering…

A polarizing filter is the most productive accessory that a photographer can have in his kit, second only to a decent tripod and head. Don’t leave home without one.

—Michael Reichmann

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