There are so many different types of filters–and even more varieties within the different categories–that it can be hard to decide between them all. So how do you know which ones to invest in? In this article, we walk you through how to choose the best CPL filter for you.
What is a CPL?
Light moves in waves. Untouched lightwaves move in all directions within a 3-dimensional space, but when an abundance of light reaches a highly reflective surface, it becomes linearly polarized and begins radiating in one direction. This is what creates unwanted reflections in water, windows, metallic surfaces, etc., and ruins your otherwise perfect photos. A circular polarizer, or CPL, allows you to separate this unwanted polarized light from the rest. Click here to read more about how CPL filters work.
A high-quality CPL filter will boost the contrast and color saturation of your images in camera, but a lower quality filter may impart an undesirable color cast, leaving your image with inaccurate colors. It is also important to note that a good quality CPL will decrease the amount of light in your image by 1-2 stops depending on the degree of polarization used. Low-quality filters, on the other hand, may not be as effective at blocking out polarized light.
When to use
CPL filters are very versatile in how they can help to improve your photographs. Whether you are shooting glass, windows, or metal that give off a nasty glare or water riddled with unwanted reflections, a CPL will help to remove this, giving your images more detail and clarity. They can also cut through atmospheric haze caused by moisture or pollution in the air, darken overexposed skies for deeper blues, and even boost the color saturation of your image.
To get the maximum benefit of your CPL, you’ll want to make sure your subject is at a 90-degree angle from your light source. If your primary light source is either in front or directly behind you, your filter may have little to no effect. To determine the correct angle, make an “L” with your thumb and index finger and point your thumb towards the light. Your index finger will then be pointing where your scene will be most evenly covered by the polarization of the filter.
Remember, also, that you don’t always need to use your CPL at its maximum value. Experiment with the effects created by its varying degrees of polarization to find the one that’s right for your scene. Take a look at our Top Reasons You Need a CPL Filter for a more in-depth look at all the ways a circular polarizer can enhance your photography.
How to choose
As with all filters, when buying a CPL, you want to be sure to look for a high-quality filter. This means strong, high-quality glass, top-quality coatings, and a sturdy ring. CPLs have a rotating element, so you will want to invest in a high-quality filter to ensure the front ring rotates smoothly.
*Trying to shoot in infrared? Our Kolari Pro CPL and Kolari Pro Dark CPL work with up to a 720nm filter.
CPL Filter Buying Guide FAQs
What Is A CPL Filter?
A CPL, or circular polarizer, is a filter that separates unwanted polarized light from the rest of the light entering the lens. This helps reduce reflections from water, windows, glass, metal, and other reflective surfaces.
When Should You Use A CPL Filter?
Use a CPL filter when you want to reduce glare and reflections, cut through atmospheric haze, darken overexposed skies, deepen blue tones, or increase color saturation in-camera. It is especially useful for landscapes, water, glass, windows, and reflective outdoor scenes.
What Angle Works Best For A CPL Filter?
A CPL filter works best when the subject is about 90 degrees from the main light source. If the light is directly in front of or behind the camera, the polarizing effect may be weak or almost invisible.
How Do You Choose A Good CPL Filter?
Choose a CPL filter with high-quality glass, strong coatings, a sturdy ring, and a smooth rotating front element. The article also highlights anti-reflective coatings, anti-smudge coatings, hydrophobic protection, scratch resistance, slim rings, and good knurling as useful quality features.
What Is A Dark CPL Filter?
A Dark CPL combines circular polarization with built-in neutral density. The article describes Kolari Pro Dark CPL as having the same core CPL features as the regular version, but with an added 5-stop ND, making it useful when you need polarization plus light reduction.
