Re: Polarizing filters questions

[P3D Greg Erker <erker@xxxxxxxxxxxxxx>]

George T wrote:
>It's been said that one of the weak links in projection is the glasses that
>the audience wears.  Is the material in these glasses about the same
>quality as the filters in the projector?

  I once measured the transmission of some polarized glasses (from
the 80's 3d movie craze) versus a screw in polarizer for a camera lens.

  The glasses measured almost exactly 1 stop reduction in light ( using
a light meter with 0.1 stop resolution) and the camera polarizing filter
measured almost exactly 2 stops.  Kind of surprised me (though I had
noticed that the glasses looked a lot lighter than the camera polarizer).

  Cross polarizing two glasses lenses did seem to black out pretty well
but I didn't measure it or directly compare it against camera polarizers.

Greg E.



------------------------------