What oes a polarizer filter do?

[Ben-71]

Remember that the 90 deg. only regard the effect on the sky.

To eliminate reflections from glass or other materials, the angle is less than 90 deg.

Also, a polarizer doesn't eliminate glare from metals, or, more accurately - materials that conduct electricity.
In a studio, polarizers are attached to both the light sources and the lens, in order to reduce reflections from such materials.
The lights are turned on, one at a time, to tune each polarizer with the one on the lens.

 

[Valethar]

Now I see that my reply wasn't necessary...

Actually, not true. Your post was definitely a bit better detailed than mine, and probably easier to visualize.

 

[Ben-71]

Actually, not true. Your post was definitely a bit better detailed than mine, and probably easier to visualize.

...If you insist...