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๐ฌ Think about it
Poke a tiny hole in cardboard, face it at a candle in a dark room, and a small image of the flame appears on a screen — upside down! How can a little hole make a picture? Let us build a pinhole camera.
What is a pinhole camera?
- A pinhole camera is a device with a tiny hole.
- Light rays from an object pass through this hole.
- They form an image of the object on a screen.
- The image formed is upside down, that is, inverted.
Example:
Light from a candle flame passes through the pinhole and makes an inverted image of the flame on the screen.
In this Activity, we will see the image a small hole makes of a candle flame.
Materials needed
A piece of cardboard, a candle (used under adult supervision), and a screen.
Procedure
1. Make a small hole in the cardboard.
2. In a dimly lit room, place the cardboard a short distance from a screen.
3. Place a lighted candle in front of the cardboard.
4. Observe what appears on the screen.
2. In a dimly lit room, place the cardboard a short distance from a screen.
3. Place a lighted candle in front of the cardboard.
4. Observe what appears on the screen.
Observation
An image of the candle flame appears on the screen, and it is upside down.
Explanation
Light from the flame travels straight through the hole and crosses over, so the image is inverted.
โ Summary
- Small hole in cardboard
- Candle in front
- Image on screen
- Image is inverted
In this Activity, we will build a sliding pinhole camera to look at distant objects.
Materials needed
Two cardboard boxes (one sliding into the other), thin translucent (tracing) paper, and a dark cloth.
Procedure
1. Cut open one side of each box.
2. Make a small hole in the middle of the opposite face of the larger box.
3. Cut a square in the smaller box and cover it with tracing paper to form a screen.
4. Slide the smaller box inside the larger one, screen-side inside.
5. Point the pinhole at a distant object and cover your head and camera with a dark cloth.
6. Slide the smaller box to and fro until an image appears on the tracing paper.
2. Make a small hole in the middle of the opposite face of the larger box.
3. Cut a square in the smaller box and cover it with tracing paper to form a screen.
4. Slide the smaller box inside the larger one, screen-side inside.
5. Point the pinhole at a distant object and cover your head and camera with a dark cloth.
6. Slide the smaller box to and fro until an image appears on the tracing paper.
Observation
An image of the distant object appears on the tracing paper, in colour and upside down.
Explanation
Light rays from the object pass straight through the pinhole and form an inverted image on the screen.
โ Summary
- Two sliding boxes made
- Pinhole and paper screen
- Image on tracing paper
- Image upside down
๐งฌ Dive Deeper
- A pinhole camera gives an upside-down image.
- A plane mirror image is laterally inverted, left to right.
- But a mirror image is not upside down.
- You will learn more about this in higher grades.
Important Points
- A pinhole camera forms an image through a tiny hole.
- The image formed is inverted (upside down).
- It can show the colours of the object.
โ Test Yourself
-
What is a pinhole camera?
View Answer
A device that forms an image through a tiny hole. -
Is the pinhole camera image erect or inverted?
View Answer
Inverted, that is, upside down. -
What forms the screen in the sliding camera?
View Answer
Thin translucent tracing paper. -
Why cover your head with a dark cloth?
View Answer
To block stray light so the image is clear. -
Does the pinhole image show colour?
View Answer
Yes, it shows the colours of the object.
Important Definitions
- Pinhole camera — a device in which light rays from an object pass through a tiny hole to form an inverted image on a screen.
๐ NCERT Question 3 — Sahil, Rekha, Patrick,
Sahil, Rekha, Patrick, and Qasima are trying to observe the candle flame through the pipe shown in Fig. 11.16. Who can see the flame?
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๐ NCERT Question 7 — Suppose you view the
Suppose you view the tree shown in Fig. 11.19 through a pinhole camera. Sketch the outline of the image of the tree.
View Answer →
