photo of lens filter by Sergey Sokolov on Unsplash

An Essential Guide to CPL Filter: What, Why | How to Use

A circular Polarizing Filter (CPL) is one of the essential accessories for mastering the art of photography. But what is definitely a CPL filter? Why should you use one and when to use it and when not? This article will discuss all this related information for a CPL filter.

What is CPL Meaning?

A CPL filter is a circular polarizer lens filter, one of the most commonly used camera lens filters.  It helps to reduce or eliminate the effects of glare and reflections. It comprises two pieces of the polarizing film, which are mounted at perpendicular angles to each other.

When light hits the filter, the polarized light waves are blocked, resulting in a darker image. CPL filters are commonly used by landscape photographers as they can help to improve the contrast and saturation of colors.

They can also be helpful in situations where there is a lot of reflected light, such as when shooting near water or snow. While CPL filters can be a useful tool for photographers, it is important to note that they will also darken the overall image.

photo of CPL filter

Photo by Chris Lynch on Unsplash

It is important to experiment with different settings before taking final photographs. With a bit of practice, CPL filters can help you capture stunning high-quality photos that accurately reflect your creative vision.

CPL Filters VS. ND Filters

ND filters and CPLs are considered essential filters for landscape photography because they allow photographers to take more stunning, realistic pictures.

What Distinguishes One From Another?

First, ND filters are solid grey and block out an equal amount of light across the visible spectrum. CPLs, on the other hand, have a circular polarizing layer that only selectively eliminates certain wavelengths of light.

This results in two different effects. First, ND filters make it possible to reduce the amount of light entering the camera sensor, which allows for a longer exposure time.

CPLs, on the other hand, can be used to reduce reflections and glare from water or glass surfaces. In addition, CPLs can also increase color saturation and contrast in an image.

Photo Effects of Using CPL Filter

Some of the most common effects that CPL filters can have on an image include:

1. Removal of Reflections

photo of holding CPL filter in front of a stream in the mountain

Photo by Stephen Leonardi on Unsplash

Whether you're a professional photographer or a casual hobbyist, you'll want to avoid reflections in your photos. A common cause of reflections is shooting through glass, but they can also be caused by shooting in bright sunlight or near water. One way to eliminate reflections is to use a CPL filter.

A CPL filter, sometimes called a circular polarizing filter, is a type of polarizer lens filter that helps to reduce or eliminate reflections. It does this by absorbing light that is polarized in a certain direction.

When light reflects off a surface, it becomes polarized, meaning that the light waves are aligned in the same direction.

A CPL filter can absorb light polarized in one direction while allowing light polarized in another direction to pass through. This allows you to reduce or eliminate reflections without affecting the overall brightness of your photo.

2. Increasing Color Saturation

CPL filters are great for increasing the color saturation in your photos. By cutting out the glare and reflection from the sun, CPL filters allow more light to enter the camera lens. This results in more vibrant colors.

photo of holding CPL filter in front of a city

Photo by Eugene Chystiakov on Unsplash

In addition, CPL filters can also help to reduce the appearance of haze. By increasing the contrast between the foreground and background, CPL filters can help your photos pop.

3. Enhancing Contrast

Many photographers use a CPL filter to enhance the contrast in their photos. This can be particularly effective when photographing landscapes, as it can help bring out the scene's detail.

The CPL filter works by blocking out certain wavelengths of light, which results in greater contrast between the light and dark areas of the image.

This can be an effective way to improve the overall look of a photo, and it is something that many professional photographers use in their work. If you want to enhance the contrast in your images, then a CPL filter is something to consider.

4. Darkening Blue Skies

Using a CPL filter can have a dramatic effect on your photos, especially when it comes to the sky. By darkening the sky's blue, you can create an incredibly striking image that pops.

This polarizing effect is especially pronounced when there are clouds in the sky, as the contrast between the dark sky and the white clouds can be very striking.

photo of holding CPL filter in front of a mountain

Photo by Danny Mc on Unsplash

Of course, using a CPL filter will also reduce the overall amount of light that enters your camera, so you'll need to compensate for this by increasing your ISO or using a slower shutter speed. But if you're looking for a way to add some drama to your photos, using a CPL filter is worth considering.

When to Use CPL filters

You might want to use a CPL filter in a few different scenarios.

If you're shooting on a bright sunny day, the CPL filter can help to reduce glare and reflections on non-metallic surfaces. This can be particularly useful when shooting through glass or near water/ waterfalls. In addition, the CPL filter can also help to increase color saturation and contrast.

If you're shooting landscapes, the CPL filter can help to darken the blue sky and bring out the detail in the scene. This can be a great way to add some drama to your photos. Of course, you'll need to compensate for the reduced light transmission by increasing your ISO or using a slower shutter speed.

Finally, if you're looking to reduce the appearance of haze in your photos, the CPL filter can be a great option. By increasing the contrast between the foreground and background, the CPL filter can help your photos pop.

When Not to Use CPL Filters

While CPL filters can be a great way to improve your photos, there are also a few situations where you might want to avoid using them.

photo of holding CPL filter in front of colorful sky

Photo by Jakob Owens on Unsplash

While Photographing Light

If you're shooting in low light conditions, the CPL filter can make your photos appear darker. This is because the CPL filter blocks out some light that would otherwise enter your camera. As a result, you'll need to compensate for this by increasing your ISO or using a slower shutter speed.

When There Is No Enough Light

If you're already struggling to get enough light into your camera, then using a CPL filter will probably not help. It will likely make the situation worse. This is because the CPL filter blocks available light, resulting in an even darker image.

When You’re Using a Wide-Angle Lens

When it comes to lenses, photographers can choose from a few different types. One type is the wide-angle lens, which is often used for landscape photography.

While wide-angle lenses have many benefits, there are also some situations when you should not use them. For example, if you're shooting with a wide-angle lens, you shouldn't use CPL filters.

CPL filters can cause vignetting when the image's corners appear dark. Additionally, a polarizer lens filter can reduce the amount of light that enters the lens, making it more challenging to get a clear image. So, if you're planning on using a wide-angle lens for your next photo shoot, leave the CPL filter home.

If You Want the “Wetness” to Stay Visible

If you're trying to capture the appearance of water, then using a CPL filter is probably not the best option. This is because the CPL filter will increase the contrast between the foreground and background, making the water appear darker. As a result, you may want to avoid using a CPL filter if you're trying to capture the appearance of water.

photo of holding CPL filter in front of a lake

Photo by Stephen Kraakmo on Unsplash

When You Need to Maintain a Reflection

For example, using a CPL filter will eliminate the reflection if you are trying to capture a reflection in the water. In cases like this, it is better to forgo the CPL filter and allow the reflection to be captured naturally.

Similarly, if you are shooting through glass, using a CPL filter will again eliminate any reflections that may be present.

In general, a CPL filter should only be used when you want to reduce or eliminate reflections. Otherwise, leaving the polarizer lens filter off is best and allows reflective surfaces to appear naturally in your photograph.

When Utilizing Variable (ND) Filters

If you're using a variable ND filter, you'll need to be careful when using a CPL filter. This is because the CPL filter can cause color cast issues when used in conjunction with a variable ND filter. As a result, you may want to avoid using a CPL filter if you're using a variable ND filter.

Conclusion

CPL filters are an important part of photography, and by understanding what they are, why they’re used, and how to apply them in your work, you can create better images with greater impact.

We hope this guide has been helpful and that you will continue experimenting with these polarizer lens filters to find the best ways to use them for your photos.

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