Certain pieces of gear never leave our camera bag when photographing landscapes and nature. A circular polarizer filter is one of them. Here’s why you should always carry a circular polarizer and a quick method to figure out when you might want to use it.
Circular polarizers are a type of filter that helps to cut reflections and glare, providing more color and contrast to certain scenes. The physics of how these filters work can be pretty technical, but you can learn more about it here. In simple terms, the circular polarizer allows you to block particular directions of polarized light. This is the same technology found in many sunglasses.
Unlike other lens filters, a circular polarizer has a ring that you can spin 360 degrees. Rotating the filter will remove more or less polarized light, increasing or decreasing the filter’s effect depending on the rotation. Always experiment with the rotation of the polarizer before clicking the shutter.
With digital photography, a circular polarizer isn’t always needed. You can achieve some of the color and contrast effects during post-processing instead. While polarizers aren’t required as often as in the film days, there are still times when you will want one.
Determine when a circular polarizer could be used
What impact will a circular polarizer have on your scene? The easiest method is to take the filter out of your bag and hold it up to your eye. Rotate the filter to see how it impacts your scene’s glare, color, and contrast before you put it on the camera. For some scenes, the effect will be subtle or non-existent. For other scenes, the effect can be quite dramatic.
When to use a circular polarizer
One of the most obvious times to try a polarizer is for photographing water, like a flowing river or the surface of a lake. A circular polarizer can reduce or even eliminate the glare and reflection on the water’s surface.
Wet surfaces and foliage
Like the surface of the water, wet rocks or leaves can have significant reflections that hide their underlying color and detail.
Clouds and atmospheric haze
Polarizers can darken skies and brighten clouds. They can also cut through the glare of atmospheric haze. While the effects can sometimes be dramatic, be cautious about how much of the effect to apply, as it can sometimes leave the sky looking unnatural.
Black & white
Black and white photos allow much greater creative freedom in adjusting brightness. A polarizer can be helpful to darken a sky or enhance clouds when shooting for black and white.
When not to use a circular polarizer
Wide-angle lenses can show uneven polarization effects, particularly in the sky, where blotches of different brightness are unattractive and impossible to remove.
Angle of the sun
Polarizers work best when the direction of the sunlight is at a 90-degree angle to the camera. When the sun is directly behind or in front of you, the effect of a circular polarizer is minimal.
Sometimes a reflection is desired as part of your composition. Removing a reflection with a polarizer will make the image look dull. If you still want to use a polarizer to enhance the sky, take another picture without the polarizer to capture the desired reflection. Then merge the images during post-processing.