To know the working of Pin Hole Camera
Just let the light from an object go through a small hole in a card and on the other side you can pick up a real image on a screen. Make the simple pin hole camera and see which objects can be imaged and which cannot.
The camera we make is a PVC pipe piece of few cm length. At one end we fix a paper with a small hole of about one mm of diameter and at the other end we fix a slightly oily butter paper.
- Put up two LEDs, one blue and one red, side by side. Connect them to adapters and lit them.
- Face your camera towards the LEDs, the hole towards the LEDs. Can you see the image?
- Check, which of the image is on left and which is on right. Is it in the same order as the actual LEDs or it gets reversed in order?
- Check if you can see the details of an LED in the image, its round body and so on.
- Increase the distance of the camera from the LEDs. What happens to the image?
- Face the camera towards other objects like a photo on your mobile screen. Are you able to see the image?
An image is formed when at any point on the screen, you get light coming from a definite point of the object. In a lens, refraction ensures that. In pin hole the small size of the hole ensures that. The image is faint as only a small pencil of light from a given point of object reaches the screen.