Polarising filter - linear

[Outbacknomad]

I bought 4 Garmin 56 cameras for each side of the car.

As I already had various polarising filters I thought I would test them out. I also had a sheet on optical linear polarising film for a lens from a couple of decades ago, so cut out 3 discs for 3 of the 4 cameras. I also had a 30.5mm linear polarising filter and 30 to 30.5mm step-up ring for a pocket camera which I ended up rarely using, so stuck that on the front camera. Actually under different circumstances the film performs better with less internal reflections than the Heliopan filter. But the Heliopan filter is a bit clearer, but the optical polarising film is about 95% as good as an expensive filter so I would not stress out too much over the cheap option.

I don't have a extreme wide angle dashcam, but a curved sunglasses lens cut to fit will probably be quite acceptable quality. At least worth an experiment if one has a pair of old polarising sun glasses without scratches.

The step up ring needed a 1mm aluminium shim (spacer) wrapped around the lens to fill the gap between the lens & stepup ring to fill the gap & hold the step-up ring on tightly. I then ran around a piece of engine bay electrical tape (Tessa 51036) which I already had, for additional security, not really needed, but the black colour is better.

So far absolutely no issues with either the linear polarising film or linear 30.5mm filter.

I used a scalpel & 10A scalpel blades & Staedtler-Mars Combo Circle Template to cut the discs, being careful not to cut the template in the process.

30.5mm Heliopan linear polarising filter (also cut down Garmin bracket).


Linear polarising film (about 1mm thick) & some polarising filters.

The polarising discs, I wrapped around a bit of Tessa 51036 tape to hold on the other 3 camera's lenses. Works fine so far so will leave it a that.

 

[DT MI]

I bought 4 Garmin 56 cameras for each side of the car.

As I already had various polarising filters I thought I would test them out. I also had a sheet on optical linear polarising film for a lens from a couple of decades ago, so cut out 3 discs for 3 of the 4 cameras. I also had a 30.5mm linear polarising filter and 30 to 30.5mm step-up ring for a pocket camera which I ended up rarely using, so stuck that on the front camera. Actually under different circumstances the film performs better with less internal reflections than the Heliopan filter. But the Heliopan filter is a bit clearer, but the optical polarising film is about 95% as good as an expensive filter so I would not stress out too much over the cheap option.

I don't have a extreme wide angle dashcam, but a curved sunglasses lens cut to fit will probably be quite acceptable quality. At least worth an experiment if one has a pair of old polarising sun glasses without scratches.

The step up ring needed a 1mm aluminium shim (spacer) wrapped around the lens to fill the gap between the lens & stepup ring to fill the gap & hold the step-up ring on tightly. I then ran around a piece of engine bay electrical tape (Tessa 51036) which I already had, for additional security, not really needed, but the black colour is better.

So far absolutely no issues with either the linear polarising film or linear 30.5mm filter.

I used a scalpel & 10A scalpel blades & Staedtler-Mars Combo Circle Template to cut the discs, being careful not to cut the template in the process.

30.5mm Heliopan linear polarising filter (also cut down Garmin bracket).
View attachment 56209
View attachment 56208
Linear polarising film (about 1mm thick) & some polarising filters.
View attachment 56210
The polarising discs, I wrapped around a bit of Tessa 51036 tape to hold on the other 3 camera's lenses. Works fine so far so will leave it a that.

Yep, linear polarization works just fine - no need for CPL. Tested this out a few years ago before polarizing filters became as common as they currently are for dash cams.