On Mon, Aug 24, 2009 at 6:22 PM, <usher99@xxxxxxx> wrote:
> 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?
Yes, and I've wondered if what I'm seeing is just a disagreeable
incompatibility between my Hoyas and my E sensorsl The only other
circ pol I've got is a thin B&W circ pol in 49mm. It's a bit more of
a standout on Chuck's list, whereas the Hoyas are not nearly as good,
apparently. Get what you pay for I guess.
>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.
Me too. Geez, I rarely get out of my own county.
>
> http://www.clarkvision.com/photoinfo/evaluating_polarizing_filters/
Thanks for the link, Mike.
Joel W.
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