1. Measurements:
1. All measurement should be from the lens.
   Measure the distance from the lens to the image, when the object is infinitely far (like the sun or a tree, where rays from it are almost parallel).
   Call that the focal distance, f, for your particular lens.
2. Call the distance from lens to object, D_o, and distance from lens to image, D_i.
3. The height of the object (light filament) is H_o, and the height of image is H_i.
2. Describe the image each time as
1. real or virtual,
2. right-side-up or inverted
3. enlarged, reduced, or same size.
3. So that we can compare our results with different lenses, place your object at 4f, 3f, 2f, 1.5f, 1f, 0.5f.
   (If you cannot find an image at 1f and/or 0.5f, get a hint from one of the leaders.)
4. Make a data table and record your findings.
5. Decide what would be interesting to graph and do so on your white board, or talk to a leader so that we have different graphs.
6. Compare your numerical results with your qualitative ones earlier.

Results:

7. * Graph H_i on vertical axis and D_o /D_i on the horizontal. Find the slope.
   It should = H_o.

Other graphs, not as useful:


8. Graph H_i on vertical axis and D_o on the horizontal.
   Is it direct or inverse relationship?
   Does anything relate to f?
9. Graph H_i on vertical axis and D_i on the horizontal.
   Is it direct or inverse relationship?
   Does anything relate to f?

Equations:
  and  
(For virtual images and virtual focal points, use negative numbers.)

Andria Erzberger
2/1/01