Timpe, Jim wrote:
> I believe the circular polarization of that filter was to keep unwanted
> harsh reflections from flat stock/printed media from being an issue.
> Don't remember now where I read/heard that, but it makes sense.
>
Been thinkin' on this. Testing mine does show both parts to be
circularly polarized.
Part of that makes little sense to me. You see, both parts are mounted
with the circular effect in the same direction, at least on mine*. Makes
sense on the inner part that goes over the lens, assuming that the OM-2s
was at least in the planning stages when it was designed. It's an
ordinary C-POL effect; first layer selectively passes light based on its
polarization, second unpolarizes what came through so it won't mess up
the metering.
With the outer ring, though, the point is less clear. The light from the
flash tube goes first through the scrambler layer, then through the
polarizer. Unless the light from the tube is polarized, the effect is
just the same as a linear polarizer. So why spend what must be quite a
bit on such a large piece of C-POL? Is ring flash tube light polarized?
Moose
*Mounting the outer ring the opposite way would just kill the whole effect.
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