OK, I see where the differences are. Sunlight as such is unpolarized, but once reflected, refracted or scattered you may have a partial separation of some polarization modes depending on the direction. So, if you look at a blue sky through a window of polarizing materials, and at the right angle from the sun, you can see the effect. If you use polarizing sun glasses you dont need the polarized light from the sky.
If you really want to go into theory light particles, photons, have circular polarization, so if you want linear polarized light you have to superimpose them in pairs. .-) DagT > fra: Don Williams <[EMAIL PROTECTED]> > > If sunlight (skylight) were not > polarized, then polarizing filters would > have no effect and would not improve > your nice cloudy skies. The highest > percentage of polarized light from the > sky is to be found at about 90 degrees > to the sun's direction. To get the best > effect, have the sun to the right or > left of you when you start rotating your > filter to get that nice dark blue. > Sunlight that is reflected from a water, > or metallic or glass surface is further > polarized so that a polarizing filter > will (almost) completely eliminate the > reflection. > > Don > > [EMAIL PROTECTED] wrote: > > No, sunlight is unpolarized, but as such it contains all polarizations and > > you can extract anyone you want. > > > > The reason why you can see the effect in some windows (and ice and a lot of > > transparent hard plastic) is that the material acts as a polarizor. So if > > you have the window of a polarizing material and you add another polarizer > > you can get the effect. The reason why you get the colours is that the > > polarization is wavelength dependent. > > > > DagT > > > >> fra: Don Williams <[EMAIL PROTECTED]> > >> > >> Sunlight is partially plane polarized. > >> > >> Don > >> > >> Peter Lacus wrote: > >>> Hi Jostein, > >>> > >>>> To see the motif in the viewfinder just pop out as I turned the > >>>> polariser was an amazing experience. > >>>> > >>>> Large version: 1000x668 pixels, 315 Kb > >>>> http://www.oksne.net/paw/sprekk1000.html > >>> very nice, one time I did some shooting through the window of the > >>> airplane and I've got similar rainbow effects. I still don't understand > >>> how it works, though... > >>> > >>> Bedo. > >>> > > > > > > > > > > -- > Dr E D F Williams > _______________________________ > http://personal.inet.fi/cool/don.williams > See feature: The Cement Company from Hell > Updated: Print Gallery -- 16 11 2005 > >
