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
