Dash Cam CPL Filters: What They Do, When to Use Them, and How to Set One Up

Dash Cam CPL Filters: What They Do, When to Use Them, and How to Set One Up

Sick of reflections ruining your footage?

If your dash cam captures more of your dash glare than the road ahead, you likely need a CPL filter. A circular polarising filter tames harsh windscreen glare, reduces reflections from the dash and seats, and can make number plates and road markings pop - especially in bright Aussie sun.

Why it matters for Australian drivers

Our roads dish out intense sunlight, long summer days, and low-angle glare that bounces off dashboards and shiny trims. Tall utes and SUVs with steeply raked windscreens are worst for reflections. A CPL helps your camera see past the glass, so daytime footage is clearer and more usable if you ever need to share a clip with police or your insurer.

The Quick Tips

  • What a CPL does: Blocks polarised light - tones down reflections from your dash and windscreen so the camera records more of the scene outside.
  • When it shines: Bright daytime driving, wet roads after rain, low sun near sunrise/sunset, and any car with a light-coloured dash or shiny trim.
  • Adjustable effect: Most CPLs rotate. Turn the ring until the reflection on the screen preview is minimised.
  • Image trade-offs: A small light loss in daylight - your dash cam's exposure compensates. At night, rotate to the weakest effect or remove the CPL if your routes are poorly lit.

How to set up your CPL

  1. Clean first: Wipe the dash cam lens and the CPL with a microfibre cloth. Clean the inside of the windscreen too.
  2. Mount the CPL: Clip or magnet it onto the dash cam lens as designed by the manufacturer.
  3. Use live view: With the car parked facing a bright scene, place a white sheet of paper on the dash to exaggerate reflections. Rotate the CPL until the reflection fades.
  4. Fine-tune for your hours: If you mostly drive mornings, point the car in that sun direction and tweak again.
  5. Night check: Do a quick night test. If footage looks too dim, rotate to reduce the CPL effect or remove it for after-dark runs.

FAQ

Do I really need a CPL for my dash cam?

If you see your dash or vents reflected in footage during the day, a CPL will help. If you mostly drive at night on lit roads and have a dark dash, it's optional.

Will a CPL make night footage worse?

It slightly reduces light. In very dark areas you may prefer to rotate the effect down or remove the filter after dark.

Can I leave the CPL on all year?

Yes. Many drivers set it for daytime and leave it. If your night footage looks too dim in winter, rotate to minimum effect or remove it.

Last updated: January 2026.