The Pinhole Camera
BEFORE YOU START THE
EXPERIMENT READ THROUGH THE INSTRUCTIONS
PURPOSE OF THE
EXPERIMENT
This experiment is designed to help you understand the working of a
simple pinhole camera.
YOU WILL NEED
A pinhole camera, a pin, a lens, some
sticky tape and the use of a light bulb (filament lamp).
(A projector is also useful for
experiment 4).
EXPERIMENT 1
WHAT TO DO
Collect the pin-hole camera
and make a small hole with the pin in the black paper.
Hold the camera about 30cm from
the filament lamp and look through the camera at the lamp.
You should see an image of
the lamp on the tracing paper screen. Write down what the lamp looks like (you may only be
able to see the glowing filament). Is it:
(a) Up side down or the right way up
(b)
In colour or black and white
(c) The same size as the lamp itself or
not
EXPERIMENT 2
WHAT TO DO
Change the distance of the pin-hole
camera from the lamp.
How does this affect:
(a) The size of the image
(b)
How clear the image is
EXPERIMENT 3
WHAT TO DO
Make another
pinhole about 1cm from the first one
Describe what you see
now.
EXPERIMENT 4
WHAT TO DO
Make ONE of the pin-holes
bigger using a pencil point.
What affect does it have on:
(a) How bright the
image is
(b) How clear the image is
(c) How big the image
is
EXPERIMENT 5
WHAT TO DO
Take off the black paper and stick a lens
over the hole in the cardboard, INSIDE the box.
Repeat experiments 1 and 2 using the
lens.
EXPERIMENT 6
WHAT TO DO
1. Look at the windows through the
pin-hole camera especially if it is a sunny day.
2.. Sit someone in the beam of a projector
and look at them with the pinhole camera
3. Try lenses with different focal lengths (large
or small curvatures).
QUESTIONS
1. Why was the inside of your camera
painted black?
2. Why was a light shield used?
3. Why was the image so much
better with a lens?
FOLLOW UP TOPICS
1. Try to take an actual photograph
with your pin-hole camera
2. Draw ray diagrams to show how the
image is formed on the tracing paper screen.