Which of these videos is more accurate about how perpendicular polarized filters block out light?

Question

This wiki describes why perpendicular fields block out light: https://en.wikipedia.org/wiki/Polarizer#Wire-grid_polarizers "Electromagnetic waves that have a component of their electric fields aligned parallel to the wires will induce the movement of electrons along the length of the wires. Since the electrons are free to move in this direction, the polarizer behaves in a similar manner to the surface of a metal when reflecting light, and the wave is reflected backwards along the incident beam (minus a small amount of energy lost to Joule heating of the wire).[8] For waves with electric fields perpendicular to the wires, the electrons cannot move very far across the width of each wire. Therefore, little energy is reflected and the incident wave is able to pass through the grid. In this case the grid behaves like a dielectric material. Overall, this causes the transmitted wave to be linearly polarized with an electric field completely perpendicular to the wires. The hypothesis that the waves "slip through" the gaps between the wires is incorrect."

That description aligns with that of this video: https://www.youtube.com/watch?v=1yVlXlgDbSM

https://www.youtube.com/watch?v=mB3_d6wiKfs But this other video, especially at 2:09 to 3:13, says that if the light is oscillating side to side aligned with the filter, it slips through, and if oscillating side to side against the filter's grain it gets blocked. But he's a photographer I think, not a scientist. Is he just wrong? Or is he using different terminology?

Also, let's say you had a solid material with a single square hole with sides the same length as the width of the grids in the polarized filters. Would this single square hole also block out light, or would light seep through?

Likewise if instead of two perpendicular filters creating a checkerboard pattern of squares, let's say you had a single combined filter with a grid of squares. Would this grid of squares block out light in the same fashion as the two 90 degree perpendicular filters, or is there something about using two filters that blocks out the light, and a single filter that has both vertical and horitzontal slits would behave differently?

Answer 1

As an explanation of the physics of polarizers, the photographer's is screwed up. He's presenting a model or metaphor to give photographers something to have in their head as a way to understand the phenomenon. We do this in physics all the time. For example, in some applications it's useful to think of an electron as a tiny shiny sphere. Of course, it is not.

The metaphor approach can be useful. The shame in this case is that he could have easily produced an easily understood metaphor that is pretty close to being correct. Since he didn't do that, I suspect that he doesn't really know how polarizers work.

Now, the two videos you've chosen to present try to describe two different kinds of polarizers. The photographer's polarizer is unlikely to be a wire grid polarizer. The description of the operation of the wire grid polarizer is largely correct, although he does not explain how the perpendicularly polarized light is transmitted. The wire grid is actually a beam splitter, a device that divides a beam of light into two beams.
In the case of a wire grid, the reflected and transmitted beams are linearly polarized in perpendicular directions.

The photographer's polarizer is likely constructed from oriented long molecules. His model as an array of lines is not even wrong, and the picture is so close to that of the wire grid that one might think that that's what he's trying to do: explain a wire grid polarizer. He is not. The molecules absorb light polarized along the length of the molecule, but does not absorb light perpendicular. So only the perpendicular light gets through. The photographer's polarizer is not a beam splitter. The "wrong" polarization is absorbed, not redirected. (I describe the mechanism as absorption in long molecules. There are other constructions that absorb light preferentially in one polarization, so it's not a certainty that photographer's is made of long oriented molecules.) That's not such a difficult picture, I think.