Dark-room pictures
Materials
blanket or cloth (heavy)
coffee can
hammer
nail (small)
rubber band
waxed paper
What does the camera \”see” when you take a picture? You can’t climb
inside it to find out. But you can make a viewer called a camera obscura
that will show you a picture as a camera would view it.
Camera is Latin for \”room,” and obscura (ahb [skyoor]{.smallcaps}
uh) is Latin for \”dark.” That’s exactly what the first camera obscura
was—a
dark room made for viewing. But your camera obscura will be much smaller
than a room.
First, turn the coffee can upside down. Use the hammer and the nail to
punch a small hole in the center of the bottom. The smaller and smoother
the hole is, the sharper the picture will be. So try not to let the nail
wiggle or bend when you pound it.
Now turn the can right side up. Cut a piece of waxed paper big enough to
cover the top. Put the waxed paper over the top of the can and fasten it
in place with the rubber band. Try to keep the paper as smooth and tight
as possible.
Find a window with a bright, sunny view. Set your camera obscura so that
the hole faces the window. Now put the blanket over your head and the
part of the coffee can nearest you. Keep your eyes about a foot from the
waxed paper. Move the can until it points at something that is in bright
sunlight. You will see a picture of that thing on the waxed paper—but
the picture will be small, and it will be upside down.
And that is what your camera \”sees”! Light waves coming in through the
lens cross each other. A small, upside-down picture reaches the film
when you snap the shutter. After the film is developed, a print of the
picture is made. And, of course, the picture you get is right side up.
