NSC 101 Laboratory for 3/24/98

OPTICS

Overview:

Using a variety of optical devices, you will gain first-hand experience of reflection, refraction, and image production. The first part of the lab consists of building a pinhole camera and doing some basic raytracing with plane mirrors. For the second part of the lab, you will wander around to each of several "device" stations and try to explain what you see on the basis of what you've learned from the first part. A discussion period will follow.

Equipment:

Pin hole cameras, light sources; pairs of flat mirrors, pins, rulers and cardboard; convergent lenses; a periscope, a corner reflector, several cut crystals, and a kaleidoscope.

PART I:

  1. Using toilet paper tubes, wax paper, aluminum foil and rubber bands, make a pinhole camera. Start with a tiny hole and observe the image of the clear glass light bulbs that will be around the room. Slowly enlarge the hole and note the effect on the images. Change the distance to the object and note the effect.
  2. Set a flat mirror on edge on top of a sheet of paper with cardboard underneath. Place a pin in front of the mirror and sight the image at several angles. Verify that the lines of sight all intersect at a point equidistant behind the mirror from the object. Discuss the image.
  3. Each group will have two convergent lenses of different focal lengths. Determine the focal length for each using a distant object. Create a telescope using the two lenses and discuss the results.
PART II:

Visit the following stations and develop explanations for each.

  1. Two plane mirrors are mounted upright on bookends. Observe the images produced when the mirrors face one another.
  2. Look at the three different images of your face in the corner reflector. Explain what is different about each.
  3. Look through the periscope and rotate the tube. Explain the results.
  4. Look at the real image projector and try to draw a ray diagram to explain how the image is formed.
  5. Look through a cut crystal and the "flys eye" viewer and explain how all the images are produced.
  6. Explain the construction of the kaleidoscope.