Camera and the art of photography is probably one of the most revered inventions of today. Although the idea of capturing an image is hardly a novelty anymore, with the advent of film cameras and recently the digital camera, the truth is that cameras have changed the way we view the world. It allows us to preserve and retain the precious moments for years together. So how does a camera preserve and capture our beautiful memories? Here is a look at the basic functions and working of a camera.
How do Film Cameras Work?
The word camera is derived from the word “chamber” and that is what the earlier cameras were placed in. With the technological revolution, cameras have come a long way from the “camera obscura” or the “dark chamber” cameras in the 1900s. However, the basic functioning of the camera remains the same. So every camera essentially is a lightproof box encasing three elements, the mechanical, chemical (the film), and the optical element or the lens.
The working of a camera is based on the fundamentals of reflection. As we know, light travels through different media at different speeds. So the speed of light would vary when it travels in air than when it travels through a glass medium. When you focus your camera on an object, the light bounces of it, and strikes the glass or plastic lens. This slows down the speed of light and allows the rays to bend as they enter the lens. As the light rays diverge from the source, the lens allow the rays to converge on a single point where the image can be formed. Commonly known as the film surface of a camera, this light-sensitive material records the image. Later when processed with certain chemicals, the image is visible.
Along with this basic structure, a manual camera may also contain an aperture control, a diaphragm that regulates the amount of light that enters a lens, and shutter just before the light sensor. The function of the shutter is to expose the light sensor to a consistent amount of light. The amount of time the shutter is open determines the amount of light that reaches the film/light sensor surface. The shutter speed or rather the time that the shutters are left open, is how photographers control picture quality and certain effects such as the picture of a moving object with the blurring.
How does a Digital Camera Work?
Compact and slim with superior image quality (This is debatable. I love my manual Pentax), digital cameras have revolutionized the photography industry. Most of all, it has overcome the problems that photographers faced with a manual 35mm camera.
The working of a digital camera is the same as a manual one except that instead of using a film, digital cameras record the images on a digital sensor array, also known as a CCD or CMOS. This digital sensor converts the light rays into electric current. These pieces of computer chips consist of millions of tiny sensor points laid out in rows and columns called pixels or “picture elements.” A mathematical calculation of the pixel rows and columns determine the megapixel count of the camera. The more the “megapixels” of the camera, more dots of light are stored and higher is the image resolution. The digital camera also has a set of filters that correct the white balance, color, and aliasing. The images are stored initially in a buffer memory in the camera and then transferred to a memory card storage device.
The benefits of a digital camera over a manual 35mm camera include the ability to take a large number of pictures without having to continually change the 36 exposures film roll, and the ability to zoom in or out by moving the lens elements to change the focal length. Also, most of the digital cameras have a video monitor on the back of the camera that not only helps you during photography, but also helps you decide whether the picture is a keeper or not. From the simplest homemade pinhole box camera to the snazzy new digital cameras, the working of a camera remains essentially the same. All of them have a lens system to obtain the image, a light-sensitive sensor for recording the image, and a mechanical system to control the image exposure.