[Physics Class Notes] on Pinhole Camera Pdf for Exam

The Pinhole camera is the elementary camera that doesn’t have a lens, however it comes with a small aperture, and has a light-proof box with a small hole on one side. The light from the object goes through the aperture and it projects the inverted image on the opposite end of the box, which is known as camera obscura effect. 

Ibn Al-Haytham, an Arab scholar, was one of the first persons to demonstrate how we see, and for that purpose Al-Haytham came up with camera obscura, which is the predecessor to pinhole camera. He provided a demonstration on how light is able to project the image on a flat surface. Some of the materials that you require in the making of the pinhole camera includes aluminum foil, tape, paper clip or pin, and two pieces of the white cardstock.

 

Principle of pinhole camera

The principle of pinhole camera, also referred as camera obscura, is as follows. 

• The image that is formed by the pinhole camera displays rectilinear light propagation which means pinhole cameras work on the theory that light moves in the straight line.

• When the window or shutter is opened, the light illuminates thus forming the image on the film or photographic paper, which is placed on the back side of the camera.

 

Construction of pinhole camera

If you want to construct the pinhole camera then you must follow these steps.

1) Cut a square hole at the center of one of the pieces of the white cardstock. Next you must tape a foil on the hole. 

1. Now cut a square-shaped aluminum foil and then tape it on the cardstock hole.

2. Make a hole on the foil and use a pin or paper clip for prodding the hole in aluminum foil. 

3. Now place a second piece of the cardstock on the turf and hold it with the aluminum foil facing up above it.

4. Next view projected image appearing on cardstock below with the sun behind your back.

5. The farther the camera is held, the bigger the projected image becomes.

6. To have the projection more outlined, you can place the bottom piece of the cardstock in the area covered by shadow while the other piece is held in sunlight. You can explore by making different holes in the foil, thereby making distinct patterns, shapes and designs. 

Uses of pinhole camera

• The pinhole camera is utilized for projecting the specific image on the translucent surface and this facilitates the safe as well as real-time observation of the solar eclipse. 

• These cameras can be used for surveillance since they are hard to detect.

• The pinhole camera can be used for observing reflected images of glittery objects like the sun.

• Most of the applications make use of pinhole camera models for the study of sun’s movement over a lengthy period of time. This process is called solargraphy.