Polarizer Alignment Card

When placed on the copy board for a polarized lighting setup, the lines on the card will turn dark when the camera's polarizer is crossed with the light polarizers. The lines will be darkest at the point where the camera's polarizer is exactly crossed making it possible to get precise polarizer alignment. The parallel lines can also be used to help set the focus for scanning cameras (such as a Better Light), or with instant capture cameras (Canon, Nikon, etc.).