Can't you just say that it makes a pretty rainbow effect and leave it at that. (sorry) But would it be easier to describe what sections of the spectrum are removed.. leaving only these colors? Or since it seems that the pol filters are removing various sections of the spectrum could the perceived colors be untrue due to the quality of the filters themselves. As you know all glass has a different bias towards certain parts of the spectrum. If the pol filters are identical, could they not be adding/coloring what you see? Or could the subject matter (cellophane, plastic etc) be adding something to the equation due to it's inherent impurities? And still further, what about the sensitivity of colors for the viewer? Could it be that they can only see or perceive certain wavelength? So what to some people might look magenta actually look dark pink or other color instead of pure magenta? I usually see this type of effect with my sunglasses, when looking at car windows in the sun. As you may know most car windows are a laminate of two pieces. So does the spectrum come from outer surface or the inner surface as it passes through the first and then bounces back out? The distortion caused by bending the plastic, glass or other subject has lot to do with how the light strikes it and which way it bounces back. So in keeping with that idea how do you determine with all the variables what is causing the shift? I guess if you are starting with a known frequency light source it would help. But sunlight filtered through the air, smog and the time of day could really make duplicating the experiment difficult. See what happens when your Strattera starts to run out.... I am sorry what was the question? Subject: Question about polarization I am trying to prevent making a total ninkompoop of myself (yeah, I know it is too late for that!) and so I need some advice/information on the color seen in a typical stress analysis polarization set-up. Two linear polarizers generally at right angles to each other with a birefringent material (cellophane, stressed plastics, etc.) in between. Under such conditions colors are seen. Explanation? Especially as concerns magenta and green. Possible explanation: Since the spectrum does not contain the color magenta in it, then in a crossed polarizer set up is magenta seen due to the fact that green has been selectively removed from the incident white light beam and we see some red and some blue passing through and thus preceive magenta? Further, if this is so, then all the colors seen in a polarization system are due to the mixture of those wavelengths that pass through the 2nd polarizer. In the case of magenta both red and blue must be passing through while when we see green then in that area green has lined up its plane of polarization with that of the 2nd polarizer and red and blue eliminated. So we see colors both due to subtraction of specific wavelengths and to simple transmission of others. Ideas? Is this correct? If not would you be so kind as to help me understand the process better? Thanks for any assistance beforehand! Andy Andrew Davidhazy, Professor School of Photographic Arts and Sciences/RIT andpph@xxxxxxx http://www.rit.edu/~andpph
