Pinhole Image - Ground Glass Screen

Purpose

To view individually a pinhole "image."
 

Equipment

Box with pinhole and movable ground glass screen.

 

Suggestions

Point out that a pinhole "image" is not really an image at all. What is it?
 

Images

l1-12

Description

A pinhole in the back end of the outer box casts an "image" on a ground glass screen at the enclosed end of the inner box. The image is viewed through the open end of the box as the inner box is slid back and forth to change the size of the image. 
 

References

M. Young, Pinhole Imagery, AJP 40, 715-720 (1972). ◙Reuben E. Alley, Jr., The Camera Obscura in Science and Art, TPT 18, 632-638, (1980). ◙D. Bissonnette, P. Rochon, and P. Somers, The Complementary Pinhole Camera, TPT 29, 214 (1991). ◙Thomas B. Greenslade, Jr., Pinhole Images of the Eclipsing Sun, TPT 32, 347 (1994). ◙Victor Kriss, Measuring Pinhole Images of the Sun, TPT 34, 190-191 (1996).