For example, in spectral instruments, the "dispersion prism" that decomposes composite light into spectra is an equilateral prism; In periscope, binoculars and other instruments, right-angle prism is generally used to change the direction of light and adjust its imaging position.
Extended data
Main section of prism: the plane perpendicular to the side is called the main section. According to the shape of the main section, it can be divided into triangular prism, right-angled prism and pentagonal prism. The main part of a prism is a triangle. A prism has two refracting surfaces, and their included angle is called the vertex angle, and the plane opposite to the vertex angle is the bottom surface.
Polyhedron made of transparent material is an important optical element. The plane in which light enters and exits is called the side surface, and the plane perpendicular to the side surface is called the main section. According to the shape of the main section, it can be divided into triangular prism, right-angled prism and pentagonal prism.
The main part of a prism is triangular, and it has two refracting surfaces. Their included angle is called the vertex angle, and the plane opposite the vertex angle is the bottom surface. According to the law of refraction, the light will deflect to the bottom twice after passing through the prism, and the included angle Q between the emergent light and the incident light is called the deflection angle.
Baidu encyclopedia-prism