What are the types of lines?

In geometry there are four types of lines: Horizontal Line Vertical lines Parallel lines Perpendicular lines

A ray is a part of a line with one endpoint (i.e., starting point) and continues forever in the other direction.

What is perpendicular lines?

When two straight lines meet or intersect at an angle of 90 degrees, they are perpendicular to each other.

What is parallel lines?

Parallel lines are two straight lines that are always the same distance apart. They never meet or intersect at any point, even at infinity.

Pinhole Camera

In this article, we will discuss the topics mentioned below:
What is pinhole camera?
How to make a pinhole camera with shoebox DIY
Principle of pinhole camera
Pinhole camera image characteristics
Natural pinhole camera
What are the Uses of a pinhole camera?

What is Pinhole Camera?

Pinhole cameras are based on light travelling in a straight line – a principle called the rectilinear theory of light. This device is also known as camera obscura, which means ‘darkroom’ in Latin.

A pinhole camera is a simple camera that forms an image without using a lens or a mirror.

It consists of a light-proof box with a tiny hole in one end and some film or photographic paper on the other end. When light rays go through the tiny hole, it forms an upside-down (inverted) image at the back of the box.

In the picture above, light ray ‘a’ travels in a straight line, passes through the pinhole and falls at ‘a1’ on the screen. Similarly, light ray ‘b’ falls at ‘b1’. Thus ‘b1a1’ is the upside-down (inverted) image of the tree that is formed on the screen.

If you increase the number of holes, the number of images also will increase.

How to Make a Pinhole Camera with Shoebox DIY

Take an empty shoebox
Paint the inner part of the shoebox in black color to make it light-proof.
Cut one end of the shoebox and fix a wax paper or tracing paper over the open end.
With the help of a sharp pencil or small nail, make a tiny hole at the center of the opposite side.
Point the tiny hole towards a bright object like candle flame or tree.
You will see an inverted image of a tree or candle on the wax paper screen.

Principle of Pinhole Camera

The pinhole camera works on the principle that light travels in a straight line that is rectilinear propagation of light.
When we open the shutter, light illuminates to form an image on photographic paper placed at the camera’s back.

Pinhole Camera Image Characteristics

The image in a pinhole camera is upside down (inverted) as compared to the object.
The image in a pinhole camera is real; hence it can be formed on the screen.
The size of the image obtained is comparatively smaller than the actual object.
The image is of the same color as the object.
Pinhole cameras are based on the fact that light travels in a straight line.

Natural pinhole camera

We can see a wonderful pinhole camera in nature. Have you ever seen the bright spherical patch of sunlight on the ground when you go under a large number of leaves-covered trees? I’m sure you must have seen this.

These patches of light are the Sun’s pinhole images. The tiny gap between the leaves acts as pinholes, groundworks as a screen, and the Sun acts as an object. When the light comes from the Sun passes through these pinholes and makes images (patches) on the ground.

What are the Uses of a Pinhole Camera?

We can project the image formed by a pinhole camera on a translucent surface for real-time and safe solar eclipse observation.
To capture the movement of the Sun over a long period of time (a process known as Solagraphy).
We can use this device for surveillance purposes as they are difficult to detect.
Pinhole cameras are helpful to observe the reflected image of a dazzling object.
A pinhole camera is also helpful for the artist to view a scene from a unique perspective.