Comparison of Half Penta Prisms and Standard Penta Prisms
Properties	Half Penta Prism	Standard Penta Prism
Number of reflection	1	2
Optical path deflection angle	45°	90°
The direction of the image	Possible reversal (correction required)	Remain unchanged
Volume	Smaller (space-saving)	Larger
Cost	Lower (less material)	Higher

How to select materials for Half Penta Prisms?
Laser processing systems: Fused Silica(UV) or ZnSe(IR) with laser high reflectivity coating.
Imaging systems: primary choice BK7 optical glass with wavefront correction optics.
Extreme environments: Fused Silica (high-temperature and radiation resistant) or Ge (anti infrared interference).