Lesson Plans from the ADAPT Program


Date of this Version



1. In an old-fashion film-developing device, it is common to use an aperture to control the exposure area of a film. The following diagram is a simplified version. There is a point light source on the left side of the diagram. We place an opaque plate with a 1 cm square hole in its center and 10 cm away from the light source. Then we place a screen 20 cm away from the light source. The plate and the screen are facing the light source and all these objects are arranged in a straight line.

2. This Halloween picture was taken by Chris Moore, a famous digital photographer of Lincoln. His daughter Ella was asked to guess whether she could see the image of the pumpkin in position A, Band C. Without any knowledge of optics, she had to go to each position to check. With your knowledge of optics, explain what you can see of the pumpkin in the mirror from each of the positions A, B, and C. Explain your reasoning using words and drawings as appropriate.