Half-Penta prisms are used to deviate the line of sight by 45° without inverting or reverting the image. The reflecting surface is aluminized and over-coated with Inconel and black paint to increase efficiency. Combining a TECHSPEC® Half-Penta Prism with a corresponding size TECHSPEC® Schmidt Prism creates a Pechan prism pair. The Pechan prism pair will invert or revert the image while not deviating the line of sight. It can be used with converging or diverging light for system size reduction.