Porro Prism

Porro Prism is a refracting Prism used in optical instruments to modify the orientation of images.   Porro prism is an isosceles rectangular prism shaped from a block of glass with the end plane facing the right Angle.

In use, the light enters through the largest rectangular surface in the prism, passes through two total reflections of the inclined plane, and then exits through the original incident plane.

Because the light is just in and out of the normal state, the prism does not have the effect of dispersion. But the image that passes through Porro prism will be flipped 180 degrees and will travel in the same direction as it entered, which means the direction of travel of Porro prism will also change 180 degrees. But because the image is reflected twice, the handedness is unchanged.

SPECIFICATION