In a previous post, my theory (otherwise known as a WAG--wild assed
guess) was that part of the perceived difference in Pol effects circ
vs linear was due to differential effects on color balance. The
extinction coeff. of the pol materials vary by wavelenght, thus the
cooling effect. The quarter wave retarder in the Circ Pol also has an
effect on color balance-rewarming it a bit. This depends on brand
etc. Remember Chuck's Pol quality tests? These color balance shifts
would have different effects on the sensor depending on their
construction/software as well as different films of course with the
different spectral sensitivities. I can't see how the pol effect per
se would vary film to digital. Thus perhaps the perceived differential
pol effect on an E1 vs film is a color balance issue.
The "digital Pol" is largely a marketing ploy, but they likely
multicoat the rear surface to reduce flare--more of a problem with
reflective sensors. Whether it matters, I don't know.
Perhaps you'll figure it out. Wish I were closer.
http://www.clarkvision.com/photoinfo/evaluating_polarizing_filters/
I'm equally dismayed with my results of polarized digital images. It's
something that I've fought and remain flummoxed. Maybe we can figure
this
out this weekend.
AG
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