From Pinhole to Pixel
The word camera comes from Latin and means ” dark chamber”. The first camera was a very dark room with a tiny hole in the window shutter. Light passing through this ‘pinhole’ produced an image on the far wall that was bright and upside down. It was called a “camera obscura.” The invention of camera obscura was attributed to an islamic mathematician, astronomer, and physicist named Ibn al-Haitham or better known as Alhazen, in the 11th century Egypt. However, the principle of camera obscura was probably known to thinkers as early as Aristotle (300 BC).
Artists used the camera obscura or pin-hole to project an upside-down image of a brightly-lit scene onto a canvas and they could then trace the outlines of the scene.
“Camera obscura” or pinhole camera is an example of how our eye works: the “small hole” in our eye is the iris. Light enters the iris and is projected on to the back of the eye, the retina which is just like the wax paper. Everything you see, including the words you’re reading right now, is projected upside-down on the retina. The brain takes this signal from the retina and flips it “right side up.” Camera does the same functions like our eye and brain.
Later in early 19th century, inventors such as Joseph Niépce, Jacques Daguerre, and William Fox Talbot made advances in recording permanent images made by light, and each of these advances changed the form and function of the camera.
Cameras started to change the world with the introduction of the “Brownie” camera by Eastman Kodak of America in 1900. With the Brownie, photography was no longer just for professional photographers; the average family could now own a camera. Snapshots, spontaneous, and un-posed images started to record everyday life. This miniature camera was inexpensive and easy to use, and versions of the Brownie were sold till 1960s. Today, digital cameras use an integrated circuit that scans each point or “pixel” of an image, produces electrical signals and saves images on storage media. Digital cameras are beginning to change photography at least as much as the Brownie did over a hundred years ago. With digital photography, not only can pictures be taken at will, but they can be downloaded to a computer and sent all over the world with just a few clicks of the mouse.
Over 200 years, camera has changes dramatically but the principle method of producing an image on film or memory card remains exactly the same as projecting an image on a wall of a room through pin-hole camera.
Still today alternative camera made of match box, beer cans, cardboard boxes and crude lens are used to create images directly on photographic paper or films. Below video shows how primitive camera works and anti-crisp pictures taken by it.
How Camera Works
A camera is made of three basic elements: an optical element (the lens), a mechanical element (the camera body itself) and chemical element (the film). The functional of camera is to calibrate and combine these three elements in such a way that they record a recognizable image.
Light passing through the lens reaching the film is control by the size of aperture of lens (size of hole) and speed of the camera’s shutter curtain (you can hear the sound of shutter movement on every “click”). When shutter button (right top of camera) is pressed the shutter curtains opens, light passes through the aperture / hole of the lens to hit the film making a permanent image. If object is bright light, less light is required to make a picture (shutter speed will be fast and aperture/ hole size will be small). If object is in low light more light is required to make a picture (shutter speed will be slow and aperture / hole size will be big). You can differentiate sound of shutter in different lighting conditions. Film’s ISO value is the light sensitivity of the film, 100 ISO or lesser ISO film is used in bright light condition and film with 400 ISO or higher ISO film is used for low light condition.
To learn more about camera and glossary click here
Types of Camera Apart from early pin-hole camera below are other types of camera avaiable today –
Point-And-Shoot Camera:Is also called a compact camera, it is a still camera designed primarily for simple operation. Most use focus free lenses or autofocus for focusing, automatic systems for setting apeature and shutter speed, and have flash units built in. Point-and-shoots are by far the best selling camera after camera phones. They are popular with people who don’t consider themselves photographers but want an easy to use camera for vacations, parties, reunions and other events.
SRL Camera: Single Lens Reflex (SLR) camera is probably the most popular type among people who are interested in taking more than just “snapshots”. It allows the photographer to manually adjust many features such as shutter speed, aperture, and ISO value. In digital SLR the film is replaced by memory card, other handful of new features and increasing pixel value of camera (mega pixel factor in digital decide the image quality). The biggest advantage of digital camera is that picture taken can seen instantly but it has taken away the joy of working in darkroom.
Camera Phone: The typical camera phone has a fixed focus lens; behind it is a small CMOS sensor, capable of capturing images and converting them into digital data. Once the picture has been taken, it is stored in the camera phone’s flash memory (in JPEG format), where it can be viewed on the camera phone’s screen and can be transmitted or down loaded. One of the fastest growing and most popular cameras is the camera phone.
How to handle a Camera
Visually impaired people have to touch a camera thoroughly, touch will reveal the type of camera. Lens of a camera is always round in shape, the side of the camera fitted with lens is always the side one should point it towards the object. Top right side of the camera has the shutter button, one have press it to take picture. Back chamber of the camera should be closed and battery should be loaded before taking pictures.
For the visually impaired camera is tactile (touch) experience and one comes to know about the placement of parts. Initially one can taken help from a sighted friend / companion. After camera is used for sometime, visually impaired can operate it independently. There is no camera that “speaks” (like JAWS or vOICE), however specially designed camera is made by Samsuang China which yet to launch commercially across the world. To know more this specially designed camera click here.