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CHAPTER 6. The Camera > 6.6 The Prime Lens - Pg. 105

The Camera CHAPTER 6 A lens designed to have a long focal length (long focus) behaves as a narrow angle or telephoto system. the subject appears much closer than normal, but you can only see a smaller part of the scene. depth and distance can look unnaturally compressed in the shot. when the lens has a short focal length (short focus), this wide- angle system takes in correspondingly more of the scene. But now subjects will look much farther away; depth and distance appear exaggerated. the exact coverage of any lens depends on its focal length relative to the size of the camera's sensor (figures 6.9, 6.10, and 6.11). 105 6.6 THE PRIME LENS the prime lens, which stands for primary lens, is a fixed-focal- length lens (figures 6.13 and 6.14). only the iris (diaphragm) within the lens barrel is adjustable. changing its aperture (f-stop) varies the lens's image brightness, which controls the picture's exposure. the focus ring varies the entire lens system's distance