CPL Explained

What is a Circular Polarizing Lens (CPL) Filter?

CPL stands for circular polarizing lens filter, which is a lens that dramatically maximizes video quality by reducing glare, reflection, and bounced light in footage caught in bright situations. By eliminating glare and reflections, and letting in natural light. you get better image quality and color saturation - contrasted image with vivid colors in bright daylight.

What Can a CPL Filter do?

These filters work their best when the outside lighting conditions are at their worst. For example, when the sun is high overhead and causing reflections of your dashboard on the inside of your windshield. Lens flares, light reflections, and windshield glares can significantly impact the quality of your dash cam footage, which can be distracting and make details like license plates and the vehicle makes/models harder to pick up - this issue is actually quite prevalent for many vehicles. Polarizing filters can also help reduce the glare when facing directly into the sun. Also, even at night, streetlights can still cause the same sort of reflection as sunlight during the day - the CPL filter can help with that too. 

Check out our comparison footage below, showing the exact same scene with and without the filter over the dash cam lens.

When NOT To Use a CPL Filter? 

While polarizers can considerably enhance the quality of daytime images, they do have one disadvantage: as they block out some light, the camera's sensor receives less illumination. A darker image results from less light. That is not a problem during the daytime when ambient light is more than adequate. However, at night, as the sensor must boost the ISO sensitivity to make up for the lack of light, this may result in a substantially darker or noisy image. These factors make it unwise to employ any CPL filters at night.

Overall, CPL Filter can effectively reduce reflections, enhance contrast and boost saturation while retaining neutral color rendition in all your shots.