Elements of Geometrical Optics

Figure 2.1 shows a simple optical system that consists of a single, ideal lens, i.e. a thin lens. Such lenses are good approximations when (a) the angles and diameters of the focused, light rays are sufficiently small so that the Gauss approximation is appropriate and (b) geometrical aberrations and other optical defects can be neglected [107]. Next, we consider an optical system consisting of a single thick lens. Using ray optics to extract the basic formulae relating object positions to sensor locations, we will see that by neglecting the effect of blur due to defocus, these optical models can be combined into a single simple geometric model of perspective projection: the so-called pinhole model.