Question #124

We got to thinking about Otto the other day and came up with a couple more problems with the old boy. If you have not yet done an Otto set, click to go to Question 97, Question 99, Question 102, Question 105, Question 108, or Question 114, the previous Otto exercises. Shown in the drawing below is the face of Otto, the object for the optics exercises to follow. By clicking your mouse here you may view or print out the array of possible image faces that Otto might create when he positions himself at the appropriate place relative to the optical component under consideration. Again your job is to determine the characteristics of the image and answer questions about it. You may use any available technique, such as ray tracing, calculation, experience, looking it up in a textbook, or even building your own experiment.

You are to determine the following image characteristics:

• 1. the orientation and the relative size and shape of the image, by selecting from among the 28 examples given in the page linked above.
• 2. the magnification of the image.

Other details that you might want to ascertain include:

• 1. the location of the image.
• 2. any way of describing the optical systems involved here.

The two optical systems for this week are:

• 1. Otto stands facing the observer who is located a large distance from Otto. The observer then looks at Otto right-to-left through the lens system shown in the photograph below: the eye of the observer is positioned close to a 5cm focal length convex lens (at right in photograph) that is positioned 25 cm from a 20cm focal length large-diameter convex lens.
  

• 2. Otto stands facing the observer who is located a large distance from Otto. The observer then looks at Otto right-to-left through the lens system shown in the photograph below: the eye of the observer is positioned close to a 10cm focal length concave lens (at right in photograph) that is positioned 10 cm from a 20cm focal length larger-diameter convex lens.
  

  Click here for Answer #124 after October 14, 2002.

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