By the end of class students will be familiar several varieties of lenses as evidenced by finding definitions of the following terms:
- FIELD OF VIEW: is the extent of the observable world that is seen at any given moment. In case of optical instruments or sensors it is a solid angle through which a detector is sensitive to electromagnetic radiation.
- NORMAL LENS: is one which produces an image that roughly matches what the human eye sees, and which looks natural to the viewer. It sits between the telephoto lens and the wide angle lens, which produce unnaturally zoomed-in and zoomed-out images respectively.
- WIDE LENS : of or pertaining to a lens having a relatively wide angle of view, generally 45° or more, and a focal length of less than 50 mm.
- TELEPHOTO LENS : a lens constructed so as to produce a relatively large image with a focal length shorter than that required by an ordinary lens producing an image of the same size: used to photograph small or distant objects.
- FISH EYE LENS: a hemispherical plano-convex lens for photographing in a full 180° in all directions in front of the camera, creating a circular image having an increasing amount of distortion from the center to the periphery.
- MACRO LENS : a lens used to bring into focus objects very close to the camera.
- PRIME LENS: a lens of fixed focal length.
- ZOOM LENS: a lens allowing a camera to change smoothly from a long shot to a close-up or vice versa by varying the focal length.