When you buy a set of ND filters for your action camera or FPV camera, you’ll often find it comes with additional UV and CPL filters. If you’re wondering what these filters do, and whether you really need them, you’ve come to the right place. In this post, we’ll break down what each type of filter is for, when to use them, and how they can help you get better-looking FPV footage.
Table of Contents
UV Filter
UV (Ultraviolet) filters were originally used in film photography to block ultraviolet light that could cause haze and reduce image clarity. In the digital age, camera sensors aren’t as sensitive to UV light, so UV filters no longer serve a strong optical purpose.
For FPV cameras and action camera, UV filters mostly just act as a protector for your camera lens, especially when flying debris or crashes are common. It’s also easier to replace or clean a UV filter than your actual lens. They look transparent and doesn’t impact video quality much. When you are not using an ND filter, you can just leave the UV filter on as protection.
CPL Filter
CPL (Circular Polarizing Filter) helps reduce reflections and glare from any shiny surfaces like water, glass, snow, or car bodies. It also enhances color contrast, making skies look bluer and foliage richer. They are great for outdoor shooting on sunny days when you want to eliminate glare from surfaces or punch up the colors in your scene.
CPL filters use polarization to selectively block certain light waves. Some more expensive filters even allows you to rotate and find the angle where reflections are reduced the most.
However, CPL filters are not commonly used for FPV flying since FPV cameras only allow one filter to be installed, and ND filter is usually more important. But again, like UV filters, you may use CPL filter as lens protector if an ND filter isn’t needed.
ND Filters
ND (Neutral Density) filters are like sunglasses for your camera. They reduce the amount of light entering the lens without altering color balance. ND filters are crucial for motion blur and controlling exposure in bright conditions. In bright daylight, your camera may default to a fast shutter speed, resulting in footage that looks too sharp or jittery. ND filters slow down the shutter speed, creating natural motion blur—essential for smooth, cinematic footage.
Check out my detailed guide on how to select and use ND filters: https://oscarliang.com/nd-filter-fpv/
Final Thoughts
While all three filter types have their uses, ND filters are the most critical for FPV and action camera filming. UV filters are great for lens protection, and CPLs can work wonders in specific cinematic scenarios but are best suited for static or slow-moving shots.
When buying a filter set for your DJI O3/O4 or action cam, getting a kit that includes ND4 to ND32, a UV, and a CPL gives you the flexibility to handle almost any lighting condition.