ABSTRACT
Imaging generally records the interaction of light or radiation with the subject, except for self-luminous or emissive subjects and uses lenses or optical systems to form an image at the photoplane of a camera. There are four principal effects of the interaction of light with an object, namely absorption, reflection, transmission, and chemical change. The first two of these always occur to some extent: transmission occurs in the case of translucent or transparent matter; and chemical change occurs under appropriate circumstances. The absorbed light energy is not destroyed, but converted to another such as heat, or sometimes electrical or chemical energy. This chapter details the behaviour of reflected or transmitted light, and the formation of an optical image.
