PINHOLE INVESTIGATIONS
Making a Pinhole
Viewer
©1998 Exploratorium
This activity
allows teachers to make "mobile" pinholes, so that they can go
outside or wander around a building and examine familiar everyday
objects through a pinhole. It's probably best to do this activity
after teachers have already spent a good deal of time investigating
pinholes with the materials from the Inquiry Starting Point-Tabletop
Light Source Activity. Through this exploration, teachers will
have begun to form hypotheses about what they are observing, and
about what they can predict about pinholes. By using the mobile
pinhole viewer, they can now look at familiar objects like trees
and doorways to confirm for themselves that the image that comes
through a pinhole is reversed-top to bottom, and left to right.
Materials
Needed
(per viewer)
- 1 sheet of
black construction paper, 9" x 12"
- 1 cardboard
toilet tissue tube
- 1 piece of
aluminum foil, approx. 4" x 4"
- 1 piece of
waxed paper, approx. 4" x 4"
- 4 rubber bands
Making the
Viewer
Place the aluminum
foil over one end of the toilet tissue tube and secure it with
a rubber band.
Place the waxed
paper over the other end of the toilet tissue tube and secure it
with a rubber band. Care should be taken to keep the waxed paper
as smooth as possible; this will be the screen.
Roll the black
construction paper lengthwise around the tube, keeping the aluminum
foil end flush with the end of the construction paper. The waxed
paper end of the tube will now be in the middle of the black construction
paper tube. This black tube will allow you to see the images more
clearly
Use a pin to
make a hole in the aluminum foil. Sometimes the hole must be enlarged
to see the image more distinctly, but it's better to start with
a small hole and then make it larger if needed.
To Do and
Notice
Take the viewer
outside and look at houses, trees, cars, etc. through the open
end of the tube. What do you notice about them?
Try the viewer
inside. Look at a light or a candle. Try two light bulbs, one red
and one green, placed at opposite ends of a light strip. What do
you see through the viewer?
Discussion
Questions that
come after looking through the viewer include:
- why is the
image reversed?
- how can I
make it turn right-side up?
- how can I
make the image clearer?
- how can I
make the image larger?
- what if I
used a larger tube, (longer tube, larger hole, etc.)?
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