Geometrical Optics

Geometrical Optics uses the concept of rays, which have direction and position but no phase information, to model the way light travels through space or an optical system. This chapter focuses on imaging systems, which cover a broad class of engineering applications. It assumes that an object is viewed as a collection of many pinpoint sources of light and that some of them will be captured by the imaging system. Those captured ray sources will be traced through an optical system to determine what image will be formed. This technique is useful for designing lenses, developing systems of lenses for use in microscopes, telescopes, cameras, and other devices. The chapter talks about the cardinal points of an optical system, which are the first and second focal points, principal points, and nodal points. It describes the various stops and apertures that characterize the imaging performance of an optical system.