Learn More About Circular Polarizing Filters
CPL filters have an amazing ability to capture more detail and bring a dramatic tone.
A CPL filter, or circular polarizer/linear filter, is a type of glass that can minimize glare from reflected surfaces. Although there are many models on the market, the circular model is the most common, partially because it fits easily onto the end of virtually any camera lens.
Standing for circular polarizer/linear, a CPL filter is a glass attachment that’s predominantly used to reduce the glare coming from reflective surfaces. How does it do that exactly? It works by absorbing scattered light, which is often caused by reflections and when sunlight clashes with molecules floating in the air. So whether you’re dealing with windows or water, CPL filters are ideal for reducing bright reflections in your images, which distract from or hide important landscape details.
What Is a Circular Polarizer Filter?
A circular polarizer filter, known as a polarizer, or linear filter can help minimize reflections from the glass. Another model is the “circular“ one since it fits on almost every lens and thus is the most widely used.
Beginner photographers often believe that they don't need to complicate their hobby any further than is absolutely essential. A CPL filter, on the other hand, has the ability to turn otherwise unusable shots into professional-standard photos for those who want to advance their skillset. It accomplishes this by reducing so-called "obstacles" such as unnecessary light, reflections, and color to a certain degree. You'll have more control of what appears in the final product if you can do this. As beautiful as the natural world is, it's much easier from a photography standpoint if you're in control.
Since CPL filters absorb scattered light, they enhance the colors in your frame, resulting in images that are especially vivid. If you use a CPL, you'll notice that your photos have more contrast and show more detail in the scene.
How Does It Work?
Let's get into the details of how does a CPL filter operates to produce such good results:
The sun's visible light travels in a straight line, but it also behaves like waves, traveling in all directions and angles. When this unpolarised light is reflected off something, the reflected wavelength of that light determines the color of the material. Glare is created when reflected light travels in a single, polarised direction, reducing the color strength of a reflected surface.
A quarter-wavelength thick wave-retardation plate is used to make a CPL filter. It can be rotated to help eliminate polarised light by blocking those wave propagation paths. This restores color saturation while also removing glare and reflections. The amount of polarised light filtered is determined by the angle degree and how much the filter is rotated.
Can I use a Circular Polarizing Filter with Wide Lenses?
The polarising effect is at its maximum when shooting at 90 degrees to the sun. You can easily work out where this is by a commonly-used trick whereby you place your thumb and index finger at an L angle (as if shooting a gun), with your index finger pointing towards the sun, or your light source. The thumb then represents where the polarisation effect is at its most extreme.
When you shoot using a CPL filter on a wide-angle lens, particularly over 28mm, this polarising effect can become uneven. This results in one part of a scene that benefits from the maximum polarisation. But, it means another part of the image gets no polarising effect at all. This effect is most pronounced when shooting blue sky scenes, where you may get a blob in the sky.
CPL filters are also quite thick, as they consist of a double ring. This thickness can affect how images appear when using a wide-angle lens. In particular, if the lens is wider than 24mm, you might notice vignetting when using a CPL filter. Vignetting is when the edges of an image appear darker than its center. One way to reduce this from happening is to opt for a thin polariser. This will let you still use a CPL filter on a wide-angle lens.
Frequently Asked Questions (FAQ)
What are Circular Polarizing Filters used for?
GLASS REFLECTIONS ARE REMOVED
When starting out in photography, one of the first things people discover is how difficult it is to take pictures from the inside of a window. A polarizing filter will help you get rid of all those pesky light streaks that blur your subject. It can also do the same thing with light reflecting off the water.
THE SKY BECOMES DARKER
A darker, more menacing-looking sky will help give your landscape shot a more foreboding sense of suspense. The same can be said for interior shots where the aim is to create a sinister atmosphere. You can do this with a strong CPL filter without making the scene appear unnatural.
Since you may want to increase or decrease the amount of color depending on what you're trying to accomplish, this example blurs the distinction between when and when not to use a polarising filter. The CPL would be useful in this situation if you wanted to display a sky that was bluer than it really was.
How much do Circular Polarizing Filters cost?
Our CPL filters are available for a wide variety of Lenses and Needs, their pricing starts at 39.99 for 37mm Lenses.
When not to use a Circular Polarizing Filter?
REFLECTIONS IN COLOR
Reflected light may often improve a photograph, particularly if the light itself is a different color than normal. If the sky is red in the evening, for example, it can produce a vivid effect that should be preserved.
DRAW ATTENTION TO WETNESS
Water is translucent, making it difficult to capture through a prism. As a result, distinguishing between a wet and dry rock, for example, can be difficult. This problem can be solved by allowing light to shine through the droplets.
SHOOTING IN THE DARK
Since there will be very little light illuminating your subject in the first place, you'll probably want to reflect as much light as possible. In this case, a CPL filter will do more harm than good.
Photographers, whether you're an entry-level creator or a professional who's not sure which lens filters would fit best for you and your projects, or if you need recommendations for lenses or accessories brands that will help you achieve the image results you need, please contact our Gear Guides Team firstname.lastname@example.org. We'll pair you with a guide based on your background and needs, and we'll find the right Lens Filter for you.