Objectives

Chapter 3 explains the functions of the camera lens. It discusses lenses of different focal length and what they do; special purpose lenses and the effects they create; and how depth of field is related to the type of lens used. Techniques for focusing manually and autofocus equipment are discussed as well. Methods for shooting close-ups are covered in detail with tips for the care and protection of lenses. After reading this chapter you should be able to:

1. Know what a lens is and how it works.
2. Understand the differences between lenses of different focal lengths.
3. Identify special purpose lenses.
4. Be familiar with both methods of focusing (manually and automatically).
5. Understand the relationship between focus and depth of field.
6. Understand the relationship between focal length and perspective.
7. Work effectively in close-up situations.
8. Know how to purchase lenses for a variety of purposes and care for them properly.