Construction of ray diagrams using thin lenses
Construction of ray diagramsThree rays are of particular importance in the construction of ray diagrams.1. A ray of light travelling parallel to the principal axis passes through the principal focus on refraction through the lens. In case of a concavelens the ray is diverged in a way that it appears to come from the principal focus.2. A ray of light travelling through the optical centre goes un-deviated along the same path.3. A ray of light travelling through the principal focus is refracted parallel to the principal axis on passing through the lens. The construction of the rays isillustrated below.