## Exploration 36.1: Camera

This animation can be used to demonstrate the basic operation of a camera (position is given in arbitrary units and angle is given in degrees). Various lenses and light sources can be added by clicking on the appropriate links. The camera is "focused" by dragging the lens to change the lens-to-film distance.

1. Click on the link for "Normal Lens" and add a near source. What is the closest position an object could be and still be focused on the film?
2. Remove the near source and add an object source. When the object source is at its original location (x = 2.3, h = 1.2), where should a normal lens be placed to focus this object? Where must a telephoto lens be placed? Where should a wide-angle lens be placed?
3. Rank the height of the images from (b), from smallest to largest.
4. Based on your answer for (c), which lens would you use if you wanted to take a picture in which the object took up most of the photographed area (zoom in)? Explain.
5. Based on your answer for (c), which lens would you use if you wanted to take a picture of the object and much of its surroundings (zoom out)? Explain.
6. Rank, from smallest to largest, the focal lengths of the three lenses.

Exploration authored by Melissa Dancy and Wolfgang Christian.

Physlets were developed at Davidson College and converted from Java to JavaScript using the SwingJS system developed at St. Olaf College.