Reflection by Porro Prisms
Students all know that reflection from a plane mirror produces an image that is reversed right to left and so cannot be read by anyone but Leonardo da Vinci, who kept his notes in mirror writing. A useful counter‐example is the Porro prism, which produces an image that is not reversed.
“Reflection by Porro Prisms”, The Physics Teacher, 48, 240 (2010)
The Physics Teacher