ABSTRACT
The standard lens designed for general use with professional cameras, known as the prime lens, has a wide aperture, an angle of view of some 50°–60° to match the width of scene taken in by the average human eye, and all aberrations reduced to a minimum. Most amateur compact cameras are instead equipped with a zoom lens as standard. The telephoto and retrofocus principles were discussed in Chapter 4. However, there are a number of lenses that are designed for more specific purposes. This chapter examines types of specialized lenses (apart from telescope and microscope objectives, which are dealt with in their own chapters) in terms of these specific purposes.
