Right angle prism is the most widely used prisms. It utilizes the inherent total internal reflection (TIR) at the hypotenuse to invert the image and achieve a 90° change in direction. This produces a ...

This right angle prism belonged to the American hydraulic engineer, Clemens Herschel (1842-1930). The widow of Albert Haertlein (1895-1960), professor of civil engineering at Harvard University, gave ...