CPL lens filter: Ultimate guide for photographers
Tags: Filters, Gear, Tips, Smugmug, Lenses

Photo by Yusuf Evli

If you’re just getting started in outdoor photography you should invest in a circular polarized/linear (CPL) filter. Why? A CPL filter reduces glare from polarized light-which you get a lot of in the outdoors. Polarized light is any light reflected off a semi-transparent or reflective surface, such as water or windows.

A CPL filter is easy to use. Attach the filter to your lens and turn it to block light from different directions to achieve your desired effect. Adjusting the amount of light in your photo enhances color and contrast, making your images appear sharper and more vivid.

When should I use a CPL filter?

A CPL filter works best when you expect a lot of unwanted glare or reflected light in your shot. For example:

When you want to remove glare or reflection from bodies of water. If you’re shooting the shore of a lake, for example, a CPL filter will allow you to see details like rocks and fish below the water’s surface.

If you’ve ever tried to shoot through glass without a CPL filter, you know how difficult it can be to get a shot without reflections interfering with your subject. If you’re photographing a framed painting, a CPL filter will eliminate the glare from the glass, giving you a clear image of the painting.

If you’re shooting landscapes during the day, a CPL filter gives you bluer, darker skies and more intense greens from trees and grass.

Photo by Guille Pozzi

When shouldn’t I use a CPL filter?

Sometimes using a CPL filter will take away from rather than enhance your shot. For example, if you want strong reflections in your photo (like in drops of water, or a mountain reflected in a lake) a CPL filter would not be good to use. If you’re shooting a scene with lots of reflected color, like a sunset, you may want to leave the CPL filter at home as well.

You should also know that CPL filters reduce the light reaching your camera by one to two stops, so low-light situations are a no go. To compensate for this when shooting other scenes, you’ll want to slow down your shutter speed, open up the aperture, or increase the ISO.

Since a polarizing filter only removes light from a specific direction, it also doesn’t work well with a wide-angle lens that captures a much broader perspective. If you’re shooting a landscape with a wide-angle lens and a CPL filter, you can end up with halos and uneven color in the sky.

Photo by Scott Gummerson

What’s the difference between a CPL filter and a neutral density (ND) filter?

An ND filter reduces all light in the frame, rather than reducing only polarized light. Controlling the total amount of light that hits your camera’s sensor gives you the ability to take longer-exposure shots during the day, but it won’t affect color or glare in your photos. It’s used mostly in wildlife photography, landscapes, or action shots.

Situations for using an ND filter can include the following:

Shooting long exposures in manual mode.

Photographing action shots in bright sunlight to make your subject crisp and clear without overexposing.

Reducing your depth of field — when you want to open up your aperture to gain clarity in the foreground and blur the background.

Similarly, when shooting a portrait in bright light an ND filter will allow you to play around with depth of field.

Photographing a waterfall or moving body of water when you want the motion to have a smooth, blurred look.

Can I use a CPL filter and an ND filter at the same time?

You can, but this should be done with caution. You may end up with photos that are too dark or look unrealistic.

If you’re only going to buy one filter to start out with, make it a CPL. Using a CPL filter will help you be more mindful and intentional about how you shoot reflected light, and it can help you take your photos to the next level.