Penta Prism

This diagram shows the path lights takes in going through a penta prism.  The penta prism will neither invert nor reverse the image.  Its function is to deviate the direction of the light beam by 90 degrees.  It has the valuable property of being a constant deviation prism in that it deviates the line of sight through the same angle regardless of its orientation to the line of sight.

The data for this demonstration was generated by Professor Roland Shack.

Use the mouse to grab the LiveGraphics3D plot and rotate. Press s to see stereo pictures.  Press shift and move mouse to zoom or rotate about an axis perpendicular to the picture.  Press control key and move mouse to change 3-D aspect.