Optics Unit Project - By Arjan Cambo

What is a Camera?

In short terms, a camera is a device for recording visual images in the form of photographs or film (video).

Historical facts

First traces of cameras...

In the fifth century B.C. a Chinese philosopher Mo Ti noted that a pinhole (a box with a small hole on one side) can form an inverted and focused image when light passes through the hole and into a dark area. The light from a scene passed through this single point/hole and projected an inverted image on the opposite side of the box. Mo Ti is the first recorded person to have come upon this phenomenon.

By who and when was the camera invented? Who took the first Photograph?

The camera was designed in 1685 by Johann Zahn but the first photograph was taken in 1814 by Joseph Nicephore Niepce, who is also credited as the inventor as well. But even before this, there is evidence that lead up to the creation of the photographic camera. Earlier cameras could not save the image but followed the principle of how the camera works today. The forerunner to the camera was the camera obscura. This was a device that consisted of a box with a hole on one side. The light from the hole striked the surface inside where it was inverted (turned upside down), it is the same concept as the pinhole. The image was projected onto to paper where it was then traced. After the first photograph, more practical photography was in the making. The camera’s around 1814 were huge in size and not portable for the average person.

Practical Photography

The first practical photography was invented by Louis Daquerre in 1829. It took Louis 10 years to produce an effective method to obtain a picture. He named the process daquerreotype. Daquerreotype was the process of obtaining a picture on a silver-coated copper sheet, the light reacted with this sheet and saved the image. After this was released many people worked on improving the technology of the camera. In 1841, Henry Fox Tablot invented calotype which was the process of getting number of positives from a single negative ( The negative is the strip or sheet of transparent plastic film and the lightest areas of the photographed subject appear darkest and the darkest areas appear lightest (picture of a negative film strip:

More important events

  • Hamilton Smith got patent for tintypes which is a photograph made by creating a direct positive (black and white) on a thin sheet of metal coated with a dark lacquer or enamel in 1856.
  • The year 1851 witnessed the development of wet plate negatives by Frederick Scoff Archer followed by the invention of dry plate negatives in 1879.
  • George Eastman invented the flexible film roll in 1889.
  • The color photography at commercial level started in the year 1940. This was the beginning of comfortable photography with hand held, portable cameras.

Why was the camera invented?

The camera was invented to preserve an image. To save a special moment in life, to keep it forever and to look back at it. At first the camera was for saving pictures but it has now developed for being used in various industries and different purposes.

Analyzing the Camera

Digital or film cameras use light to create an image. A camera is made of various parts and components. The technology in a camera is fairly simple to understand. A film camera is made of simple three basic elements: an optical element (the lens), a chemical element (the photo film) and a mechanical element (the camera body itself). Other smaller pieces include the eyepiece you look through, a mirror and finally the shutter.

How ordinary film cameras work

The overall look of how a camera works is there is a lightproof box (able to block out light) that lets a bit of light at the right moment. Once the light enters the camera, it creates an image by causing a chemical reaction on photo film, but now cameras have changed to digital. More in depth, first the light goes through the lens. The light path depends on the the angle of the light rays entry into the lens and the also the structure of the lens. The angle of light entry changes when you move the object closer or farther away from the lens. When you want to see the image in the viewfinder the outdoor light reflects on surfaces, bouncing through the lens and onto a plane mirror. The light then bounces off the mirror into a five-sided piece of glass and the light passes through the eyepiece and into your eye. This allows the user to see exactly what will appear on film. Finally, when you take the picture the mirror flips up getting out of the way for the shutter (hole or an opening through which light travels) to allow in light and then the light hits the film.

Properties of Light and Reflection Used

We can see plane mirrors are used in the camera which shows that the Law of Reflection is taking place. The first mirror reflects the light the camera is pointing toward to another five sided mirror. We know that the light coming in (incident ray) will have to reflect at the same angle (reflected ray) so the mirror has to be positioned at the right angle so it hits the five sided mirror perfectly.

The Lens - Refraction and Type of Lens

Refraction - The lens bends light beams to a certain total degree because the light changed from one medium (air) to another (glass). This is the total bending angle which is determined by the structure of the lens. A lens with a rounder shape (a center that extends out farther) will have a sharper refracting angle (bending angle) and converge at a shorter distance.

Convex Lenses - Camera use converging lenses because the light needs to be focused onto the mirror. Convex lens cause the rays to meet a focus point which is either the mirror or film. Convex lenses also play a role in focusing the image. Today the lenses and adjust for focusing. (Diagram -

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How digital cameras work

Digital cameras today save photos in memory and they work similarly to a film camera but store the image in a different way. When you press the button to take a photograph with a digital camera, an shutter opens at the front of the camera and light streams in through the lens. So far, it's just the same as a film camera, But from this point on everything is different. Instead of the film, there is a piece of electronic equipment that captures the incoming light rays and turns them into electrical signals. This light detector is called a charge-coupled device (CCD). The incoming picture you are taking hits the CCD, which breaks it up into millions of pixels. The CCD measures the color and brightness of each pixel (light coming in) and stores it as a number. In other words, the digital photograph is a bunch of numbers describing the exact details of each pixel it contains.
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Benefits gained from the Camera

how the camera has benefited society

Throughout the years camera’s have developed and have changed to be used for many other purposes. Almost everyone today has a device (phone, tablet) that includes a camera. Cameras have advanced and developed more than just to take pictures and save memories and to the point where they can be used in many industries. Here are some ways they have benefited society.

To Conclude

Overall, cameras have benefited society in many aspects of life and are used for many things. Without cameras we would not have entertainment, security, and much more but most importantly we would not be able to save memories. The camera is a great example of a device that related to optics. It uses light through mirrors and lenses which follow the properties of reflection and refraction. The camera has come a far way and is still improving and becoming better.


Information from:

All Pictures from Google Images (in order of pictures from top to bottom)

What is a camera (Canon Camera)

First Traces of Cameras... (Pinhole) -

By who and when was the camera invented? Who took the first Photograph? (Joseph Nicephore Niepce)

Practical Photography (Daguerreotype camera)

Why was the camera invented?

Analyzing the Camera

How ordinary film cameras work

Properties of Light and Reflection used


Camera Diagram

How digital cameras work







To Conclude