NotesFAQContact Us
Search Tips
Peer reviewed Peer reviewed
Direct linkDirect link
ERIC Number: EJ926922
Record Type: Journal
Publication Date: 2011-Apr
Pages: 1
Abstractor: As Provided
Reference Count: 1
ISSN: ISSN-0031-921X
The Opaque Projector: The Inverse of the Camera Obscura
Greenslade, Thomas B., Jr.
Physics Teacher, v49 n4 p241 Apr 2011
Many years ago I was running the standard laboratory experiment on thin lens optics. The source was the usual self illuminated object mounted on an optical bench, and a converging lens formed a real image on a screen. One of the students sitting near one wall of the darkened lab was having some trouble with the idea of image formation. Her face was lit by the light from a shaded gooseneck lamp, and as she looked at me holding the lens in my hand, the inverted image of her face appeared on a nearby wall. And, the image was in color! Not only was this a classic teaching moment, but I realized that, by chance, we had set up an opaque projector.
American Association of Physics Teachers. One Physics Ellipse, College Park, MD 20740. Tel: 301-209-3300; Fax: 301-209-0845; e-mail:; Web site:
Publication Type: Journal Articles; Reports - Descriptive
Education Level: N/A
Audience: Teachers
Language: English
Sponsor: N/A
Authoring Institution: N/A