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Homework Help: Why is a telephoto lens considered to have a longer focal length than that of single?

  1. Sep 17, 2010 #1
    1. Why is a telephoto lens considered to have a longer focal length than that of a single convex lens?

    A lens combination, such as a diverging and a convex lens, is referred to as a telephoto lens. Suggest why a telephoto lens is considered to have a longer focal length than that of a single convex lens.
     
  2. jcsd
  3. Sep 19, 2010 #2

    Delphi51

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    Re: Why is a telephoto lens considered to have a longer focal length than that of sin

    If you just look at a camera with a telephoto lens, the distance from the front of the lens to the sensor inside the camera is very large.
     
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