Hands-on Activity: Create a Pinhole Camera
Educational Standards :
Pre-Req Knowledge (Return to Contents)
Longitudinal and Transverse Waves (Lesson 1), Wavelength and Amplitude (Lesson 2), Frequency (Lesson 3), Light (Lesson 6), Electromagnetic Waves (Lesson 7).
Learning Objectives (Return to Contents)
After this activity, students should be able to:
Materials List (Return to Contents)
Each group needs:
To share with the entire class:
Introduction/Motivation (Return to Contents)
Students, this is the very last activity in our sound and light unit. You have all done a great job learning about sound and light and how engineers use their knowledge of sound and light to help improve our world. Today we are going to create something really neat – our own little cameras!
We learned in our lesson that light travels in straight lines and is inverted when it passes through a small hole. Today we are going to see this principal in action. Let's create a camera!
Vocabulary/Definitions (Return to Contents)
Procedure (Return to Contents)
Hundreds of years ago, images were etched in stone and later, with the advancement of modernization, onto various types of cloth or even paper. At this point, these images might actually have been paintings of landscapes, portraits or still life (such as a bowl of fruit or a plant). By definition, a picture is a precise copy of an image — a duplicate image, not just a redrawn copy.
So, before the creation of what we know today as digital cameras (or film cameras, which are still widely in use), what did people do to have a copy of a certain image? Well, in the mid 1600s, a dark room, also know as a dark chamber or camera obscura, was cleverly used to transfer an outside image onto paper inside a room. To explain, a large room has a hole in one of the walls. When lights enters the small hole, the outside image is reflected onto the opposite wall. An artist, standing in the room, would then draw the image as it appears on the wall onto paper.
Then in the mid 1800s, the use of a pinhole camera became more common. A pinhole camera was portable, allowing a photographer to take (i.e., draw) pictures that were previously unable to have been copied through the dark chamber or camera obscura. The pinhole camera works the same way as the dark chamber in that a small hole in the side of a desktop-sized box imports an image on the opposite wall. Because light rays travel in straight lines, the image is actually inverted. Mirrors inside the pinhole camera box reflect the image to the top of the box at which point an artist transfers the image onto paper.
Today, with the discovery of film and, currently, digital computers encased in small cases the size of a deck of cards allow multiple pictures to be taken in rapid succession. Photographers can pick and chose the pictures to keep and those to be discarded at the flick of a button.
Engineers have played a large role in the development of cameras from the earliest times — from the chemical solutions used to develop film to the state-of-the-art digitization capabilities of today's modern cameras.
Now, let's create our own pinhole camera just like the pioneers of the 19th century!
Before the Activity
Note: Two weeks before the activity, ask students to bring in a ½ gallon milk or juice carton from home. Ask students to thoroughly rinse the container with warm, soapy water. Remind students periodically to remember to bring in the cartons.
With the Students
Note: at the start of this activity, set out some light sources for students to look at through their cameras. Large flashlights work well, as they are bright and can be appropriately directed.
Safety Issues (Return to Contents)
Remind students to be careful when using the pins and not to poke each other with them.
Troubleshooting Tips (Return to Contents)
To see a clearer image, place a patterned piece of paper, or one with shape cut out, over the light source (i.e., over the flashlight lens).
Investigating Questions (Return to Contents)
Assessment (Return to Contents)
Key Ideas Review: Discuss key ideas from the lesson again with the students. Do they remember what kind of engineer works with light? (Answer: an optical engineer) How does light travel? (Answer: in straight lines) What was the first camera called? (Answer: a camera obscura) See if any students would like to volunteer to draw a ray diagram on the board.
Activity Embedded Assessment
How Can We Make it Better? Remind students of the importance of iteration in engineering design, and encourage them as they work with their cameras to ask themselves: "How can we make it better?" Encourage students to experiment with new ideas and to be kind and helpful to each other as they share ideas amongst themselves.
Class Discussion: Whose pinhole camera worked really well? Why? How does the size of the pinhole affect the brightness of the image on the wax paper? (Answer: The bigger the hole, the brighter the image.) How does the size of the pinhole affect the sharpness of the image? (Answer: The bigger the pinhole, the blurrier the image.)
Activity Extensions (Return to Contents)
Students should be encouraged to examine various cameras, inside and out, to see the lenses and how the film is placed to record the images. You may be able to obtain inexpensive old cameras at a local thrift shop, which the students can take apart in class.
Activity Scaling (Return to Contents)
For upper grades, find some volunteers to make a much larger camera obscura. In this camera, the camera body should be completely enclosed with a viewport on the side to see the back where the image falls. It's also possible to buy film and place it at the back of this camera to take a long-exposure picture. Details can be found at http://brightbytes.com/cosite/what.html
For lower grades, activities should still be appropriate, although students may require more help in constructing their cameras.
Additional Multimedia Support (Return to Contents)
For an additional resource on making and using a pinhole camera, see Kodak's website at http://www.kodak.com/eknec/PageQuerier.jhtml?pq-path=11865&pq-locale=en_US&_requestid=45980
References (Return to Contents)
State of Utah, History for Kids, "The Amazing History of Photography," accessed July 31, 2007. http://ilovehistory.utah.gov/index.html
ContributorsLuke Simmons, Frank Burkholder, Abigail Watrous, Janet Yowell, Alison Pienciak
Copyright© 2007 by Regents of the University of Colorado.
Supporting Program (Return to Contents)Integrated Teaching and Learning Program, College of Engineering, University of Colorado Boulder
Acknowledgements (Return to Contents)
The contents of this digital library curriculum were developed under a grant from the Fund for the Improvement of Postsecondary Education (FIPSE), U.S. Department of Education, and National Science Foundation GK-12 grant no 0338326. However, these contents do not necessarily represent the policies of the Department of Education or National Science Foundation, and you should not assume endorsement by the federal government.