Pinhole Camera and Reflection of Light

We all know what a camera is. We often use the camera to click pictures. But do you know what a pinhole camera is? You can also make a camera which is a pinhole and it is that simple that you can make it yourself. Let us study more about the pinhole camera.

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Pinhole Camera

The name itself tells us that the pinhole camera has a single pin, with a tiny aperture. Let us see how it works.

Look at this above image. Here the tree is the object and the box-like structure is the pinhole camera. This box is completely dark inside, with just one single hole. Light rays will enter the hole and will create an image, but the image will be an inverted image. This inverted image which is created will be created on the opposite face of the box. This is how the pinhole camera works.

Construction of pinhole camera is a very easy task. All we need is a box which is completely dark inside with a small hole. Unlike the other camera, with a pinhole camera, there is no lens used. So what happens here is light enters through the tiny hole and projects an inverted image on the opposite side of the box.

Browse more Topics under Light Shadows And Reflections

• Light and Shadows

How do we make the pinhole camera?

Take a box which is cuboid in shape and keep one side of the box open. Make a tiny hole on the opposite side of the box through which the light is supposed to enter inside. Now take another box which is small in size than the previous box.

Select the box in such a manner it perfectly fits into the bigger box. Now cut one side of the box and cover it with a transparent or photographic film. Insert the smaller box inside the bigger box and now you can see the image through the film. The image we get is an inverted image.

Reflection of Light

When a ray of light falls on any object (polished, smooth, shiny object), light from that object bounces back those rays of light to our eyes and this is known as “Reflection” or “Reflection of Light”.

In the diagram given above, the ray of light that approaches the mirror is the “Incident Ray”. The ray that leaves the mirror is the “Reflected Ray”. At the point of incidence where the incident ray strikes the mirror, a perpendicular line is the “Normal”. This normal is what divides the incident ray and the reflected ray equally and gives us the “Angle of Incidence” and “Angle of Reflection”.

Hence the above information gives us the “Laws of Reflection of Light” which state that :

• The angle of incidence is equal to the angle of reflection.
• The incident ray, the normal and the reflected ray, all lie in the same plane.

Question For You

Q1. Reflection can occur on:

1. Transparent surfaces
2. Glass
3. Opaque surfaces
4. A and B

Answer: C. Light can pass through transparent materials, such as glass or air. It cannot pass through the opaque material and gets reflected.