“This is a live image of the diatom Arachnoidiscus. The picture shows the diatom’s silicified cell wall, which forms a pillbox-like shell composed of overlapping halves that contain intricate and delicate markings. The picture was taken with a polychromatic polscope. Using that instrument, an eye or camera can directly see the colored polarization image through the ocular, with brightness corresponding to retardance and color corresponding to the slow-axis azimuth.”