PURPOSE: Demonstrate a pinhole "image" using a TV camera.

DESCRIPTION: A pinhole of either 0.032 inch or 0.020 inch is positioned on the front of a TV camera, replacing the lens. The resulting image on the videcon of the TV camera is a "pinhole image." Change pinholes to vary the resolution of the image. It can be used with other objects as long as they are well lighted.

SUGGESTIONS: The two pictures below are the images from the video camera, using 0.020" (left) and 0.032" (center) pinholes. The photograph at the right shows one of the pinholes positioned where a lens would normally be threaded in.

Hey, wait a minute! A pinhole image is supposed to be upside down, and these are right side up. Ask your students to explain this one.

In fact, a "pinhole image" is not actually an "image," because the rays do not focus at the the plane of the "image."

REFERENCES: (PIRA unknown.)

EQUIPMENT: TV camera with pinholes, monitor.

SETUP TIME: 5 min.