This fourth volume presents a survey of the known different types of optical systems, based on the principles of image formation, aberration control, quality criteria and realization aspects, which are covered in the first three volumes. Starting with the human eye, binoculars, eyepieces and elementary systems, more complex system types, such as photographic lenses, systems for the infrared, zoom setups, microscope optics and telescopes are discussed. Furthermore, special aspects of lithographic projection lenses, relay optical lenses and optical scan systems as well as more general projection systems are outlined. Finally, more specialized aspects are treated, including interferometer optics, auto focus control systems and spectroscopic setups. The various system types are described in a coherent manner to provide readers with a thorough background for their own developments.