Dash Cam CPL Filter: Cut Glare for Good
Picture this. You are cruising down the highway on a bright afternoon, someone cuts you off, and your dash cam catches the whole thing. Then you play it back and the footage is a washed-out mess. The sun is bouncing off your dashboard, the windscreen is throwing back a ghostly reflection of your air vents, and the one detail you actually needed, the other car's number plate, has vanished into a wall of glare. Annoying, right? The good news is there is a cheap little fix for exactly this problem, and it is called a dash cam CPL filter.
A dash cam CPL filter is a small polarising lens that sits over your camera's lens and cuts out reflections and glare. Think of it as a pair of polarised sunnies for your dash cam. When you slip on a good pair of sunglasses, your eyes get relief from harsh glare. A CPL filter gives your camera the exact same treatment. In this guide we will walk you through what it does, when you need one, when to leave it off, and which filter suits your camera. No worries, we will keep it simple.
What is a dash cam CPL filter, in plain English?
CPL stands for Circular Polarising Lens. That sounds technical, so here is the everyday version. Light that bounces off shiny surfaces, like your dashboard, the inside of your windscreen, or a wet road, gets scattered and turns into glare. A polarising filter is a special piece of glass that blocks that scattered light while letting the useful light through. The result is footage with less reflection, richer colour, and sharper detail.
Here is a metaphor that sticks. Glare is like static on an old radio. The song you want to hear is still playing underneath, but the crackle drowns it out. A dash cam CPL filter turns the static down so the signal comes through clean. On the road, that means readable number plates, clear road signs, and proof you can actually use if a stoush over a prang ever lands on your desk.
When do I actually need a dash cam CPL filter?
Not every drive calls for one, but plenty do. A CPL filter earns its keep when reflections are wrecking your footage. The usual suspects are bright sunny days when the sun sits low and glares off the glass, light-coloured or glossy dashboards that mirror straight back into the lens, and wet roads that glint like a mirror after rain.
If you own a light grey, tan, or high-gloss dashboard, you are the poster child for a CPL filter. Those surfaces act like a mirror on the inside of your windscreen, so the camera ends up filming your dash instead of the road ahead. A polarising filter for your dash cam quietly makes that reflection disappear.
Pro Tip: Do a quick test before you buy. On a sunny day, sit in the driver's seat and look at your windscreen from where the camera is mounted. If you can see your dashboard reflected in the glass, your camera can see it too, and a CPL filter will clean it up.
When should I leave the dash cam CPL filter off?
A CPL filter is brilliant in daylight, but it has one honest trade-off. Because it blocks some light, less light reaches your camera's sensor. In bright conditions that is a good thing. At night, or in a dark car park, it can make your footage (slightly) darker than you would like.
The same goes for heavily tinted windscreens. A dark tint already cuts the light coming in, so stacking a filter on top can leave night footage too dim to be useful. It's not that noticeable for most, be something to be aware of.
Which dash cam CPL filter suits my camera?
This is the part people get wrong, so listen up. A CPL filter is not one-size-fits-all. Each filter is machined to clip or thread onto a specific camera lens, so you need the right one for your make and model. Grabbing a filter that fits is the difference between a five minute win and a fiddly return.
Here is how our range breaks down. If you run a VIOFO, the model number is your map. The VIOFO CPL-100 and CPL-200 suit front cameras, the CPL-300 and CPL-600 are built for rear cameras, and the CPL-400 is made for the screenless VS1 Mini. You can see the full lineup and check compatibility on our VIOFO dash cam and accessory range.
Driving a Vantrue? The Vantrue 40 mm CPL filter clips onto compatible Vantrue front cameras and does the same glare-busting job. And if you run a WOLFBOX mirror dash cam like the G840S, G850, or G900, the WOLFBOX CPL filter is the one for you. The easiest way to match a filter to your setup is to browse our full CPL filter collection and filter by your camera brand.
How do I install and adjust a dash cam CPL filter?
Fitting a CPL filter is a doddle, but a little care goes a long way. Start with a clean lens. Any dust trapped between the filter and the camera will show up on every video, so give both sides a quick clean with an air blower or a soft cloth before you attach it.
Once it is clipped or screwed on, you need to dial it in. A polarising filter only works its magic when it is rotated to the right angle. Park somewhere sunny, open your dash cam's screen or WiFi app, and slowly rotate the filter ring while you watch the live view. You will see the glare fade as you turn it. Stop when the reflection is at its weakest and the picture looks its clearest.
Pro Tip: Adjust the filter with your camera mounted in its normal spot, not held in your hand. The angle that kills glare depends on how the camera sits against your windscreen, so set it up exactly the way you drive.
Is a dash cam CPL filter worth it?
For a small one-off cost, a dash cam CPL filter is some of the cheapest insurance you can buy for your footage. A camera is only as good as the proof it captures, and a number plate lost to glare is proof you cannot use. A filter turns a maybe into a definitely on a sunny day, and that can be the whole ballgame when you are sorting out who was at fault.
The catch is simply matching the right filter to the right camera, and that is where we come in. If you are not sure which one fits your setup, or whether you need a front filter, a rear filter, or both, have a chat with Michael or Harrison through our contact page and we will point you to the exact match. Prefer to have it fitted and tuned for you? Our installer finder will connect you with an independent local installer. Either way, we will get you sorted.
Last reviewed: 19 August 2026. If a specification, a feature or a price on this page is wrong or has gone out of date, tell us and we will correct it.