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RET- COMPUTER VISION - 2006
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Pinhole Camera

A Web Quest for 6-8th Grade (Instructional Technology)

Designed by

Mrs. Brennan
sjbrennan@phila.k12.pa.us

Introduction | Task | Process | Evaluation |  | Credits |


Introduction

A pinhole camera is the simplest camera possible. It consists of a light-proof box, some sort of film and a pinhole. The pinhole is simply an extremely small hole like you would make with the tip of a pin in a piece of thick aluminum foil.

A pinhole camera works on a simple principle. Imagine you are inside a large, dark, room-sized box containing a pinhole. Imagine that outside the room is a friend with a flashlight, and he is shining the flashlight at different angles through the pinhole. When you look at the wall opposite the pinhole, what you will see is a small dot created by the flashlight's beam shining through the pinhole. The small dot will move as your friend moves his flashlight. The smaller the pinhole (within limits), the smaller and sharper the point of light that the flashlight creates.

Now imagine that you take your large, dark, pinhole-equipped room outside and you point it at a nice landscape scene. When you look at the wall opposite the pinhole, what you will see is an inverted and reversed image of the scene outside. Each point in the scene emits light and, just like the flashlight, the beam of light from that point passes through the pinhole and creates a point of light on the back wall. All of the points in the scene do that at the same time, so an entire image, in focus, is created on the back wall of the room. The image is very dim because the pinhole is so small, but you can see it if the room is very dark.

A pinhole camera is simply a smaller version of that room, and the film inside the camera replaces you. The film/photographic paper records the image that comes in through the pinhole. The camera records a nice, in-focus image of the scene that you point the camera at. Usually, you have to expose the film/photographic paper for a long time because the pinhole lets so little light through.

The pinhole in a pinhole camera acts as the lens. The pinhole forces every point emitting light in the scene to form a small point on the film, so the image is crisp. The reason a normal camera uses a lens rather than a pinhole is because the lens creates a much larger hole through which light can make it onto the film, meaning the film can be exposed faster.


The Task

  1. Learn the three basic parts of the camera
  2. Build and use a pinhole camera with the three basic parts
  3. Learn about the relationship of lighting and exposure time
  4. Learn how a pinhole camera works
  5. Follow safety guidelines
  6. Share your experience with the class

 
The Process

1.              The class will be divided into 8 teams of 4 students. Each team will make one pinhole camera. 

 

2.              The pinhole cameras will be made out of paint cans. It is very important that the paint can does      not let any light through when we are loading/unloading the photographic paper. Any light that enters the camera before or after the picture is taken, will ruin the picture.

 

3.                Go to the following link and read through the procedure:

http://www.kodak.com/global/en/consumer/education/lessonPlans/pinholeCamera/pinholeCanBox.shtml

4.           Each group will paint the inside of their can black to keep out any reflective light.

5.         One group at a time, under the supervision of the teacher, will use an awl to make a hole in the paint can.

6.      Each group will make a pinhole with a #10 needle in the aluminum foil. The reason that we make two pinholes is so that we can experiment with different size pinholes and also because it is difficult to make a very small pinhole in the hard surface of the paint can.

7.          We will then attach the foil to the paint can matching the holes so light can get through the holes.

8.          Next we will make a flap to cover the hole so that no light can get in until we are ready to take the picture. The flap will be a heavy black piece of paper that we cut into a one inch square and tape to the outside of the can, over the pinholes.

9.           Next we will decorate our cameras with markers and stickers and label them with the names of the groups.

10.                       We will take the cameras outside to the playground, and each group will decide where to place their camera depending on what they want as the subject of their picture.

11.                       After we wait the required amount of time, we will close the flap and seal it with tape. We will all return to the classroom.

12.                       I will develop the pictures and return them to you.

13.                       Upon seeing your pictures each group will analyze the picture quality and determine if they need make adjustments for the next time.

14.                       Each group will then take turns showing the class their picture and talking about their experience.


Evaluation

Pinhole Camera Grading Rubric

Total points – 40

 

Excellent

O.K.

No Way

Light tight camera body

10

 

0

Light tight lid

10

 

0

Effective shutter

10

5

3-0

Craftsmanship/ Construction

5

3

2-0

Decoration

5

3

2-0

Followed safety guidelines

Yes

 

No

 


Conclusion

So now you have made your first pinhole camera and you have seen your first pinhole camera picture. Don’t be discouraged if your picture didn’t turn out as well as you expected. It can often take many tries with varying pinhole sizes and varying exposure times and varying weather conditions, to get it just right.

Every year, on the last day in April, is Worldwide Pinhole Day. Go to this site to see some pinhole shots.

http://www.pinholeday.org/gallery/index.php


Credits & References

http://science.howstuffworks.com/question131.htm

http://www.pinholeday.org/gallery/index.php

http://www.kodak.com/global/en/consumer/education/lessonPlans/pinholeCamera/pinholeCanBox.shtml

http://jonathan.mueller.faculty.noctrl.edu/toolbox/examples/photo1parrish00/pinhole.htm

http://www.pdnonline.com/pdn/newswire/article_display.jsp?vnu_content_id=1002502150


Last updated on August 15, 1999. Based on a template from The Web Quest Page