Theoretically, a camera is a simple device that converts visual imagery into photographs, video signals, films, etc. However, the practical implications of a camera and photography are much beyond the scope of this simple definition.
Photography has given us new means of communication and education, which was all possible because of one principal equipment–the camera. While cameras can have complex designs, it is interesting to know the basic working principle of a camera. As all of us are fascinated by what a camera does, we should also know how the camera works. So, let’s learn it here.
Working of Old Generation Cameras
The most crucial part of an old generation camera is the film. Several flexible plastic reels are mounted together to make one single film for an old generation camera. All these have a silver-based chemical coating that has extra sensitivity towards light. The film of the camera is inside a plastic cylinder, visible from the outside.
1. The Shutter Mechanism
The old-style cameras use the shutter mechanism for clicking pictures. When you want to click a picture, you press a button that widens the aperture and lets light fall onto the lens. The lens in these cameras could be a glass lens or a plastic lens. When the light falls on the lens and passes on to the film of the camera, the chemicals on the film undergo a series of reactions that forms the image in front of you.
2. Developing a Film
Once you click pictures, you have to get the film developed. For this, put the film into an automated developing machine. The machine opens the film container and dips the reel into various chemicals. These chemicals convert the pictures into a negative form. In a negative image, the dark spots appear as light and vice versa. It is with these negative forms of the image that the final image gets printed.
The problem with these cameras is that printing a single photograph from the film is a cumbersome process. That’s why most users have to click unnecessary photos, just to get the reel full and then put it in an automated machine for getting the negatives.
Working of a Digital Camera
Although a digital camera has a design similar to an old generation camera, the working is completely different.
The process of understanding how cameras work is easier when you know about their components. A digital camera consists of the following items:
The battery compartment of the digital camera can hold two 1.5 volt batteries at a time.
b. Flash Capacitor
The Flash capacitor stores charge in the camera.
c. Xenon Lamp
The Flash lamp is a Xenon lamp that draws power from the flash capacitor during indoor photography. It is the reason why using the flash discharges the battery quickly.
The lens catches the light when the aperture Is wide and then passes it on to the sensors.
There can be two types of sensors in a digital camera- a CMOS image sensor or a charge-coupled device (CCD). These sensors convert light energy into electrical energy.
f. Processor Chip
The processor chip is the brain of the digital camera.
In a digital camera, when you press the button to click a picture, it widens the aperture and lets the light pass through the lens. However, the light does not fall on the film because there is no film reel in a digital camera. Instead, digital cameras have an electronic chip that receives the light and converts it into electrical signals. This electronic chip is called a CMOS image sensor or a charge-coupled device (CCD).
A digital camera is an input device for several other output devices like an LCD television or a laptop. You see a combination of several pixels that form the image on the screen. In the digital camera, when light enters through a wide aperture and passes through the lens, then the electronic chip breaks the image down into single pixels. A sensor in the camera measures the color and brightness of each pixel. This information is stored in the form of numbers.
When you combine a large string of these numbers, then an image is seen on the output device. On a screen, each of these pixels turns on and off rapidly and the light coming from them is perceived by the brain as a single image.
The sensors in the digital camera compress every image before you can see them. The need for compressing the image arises because every image, simple or complex, has millions of pixels in it. Now, when the pixels are broken down and their color and brightness are stored in the form of numbers, you will end up with millions of numbers to store. To solve this problem every image is compressed in a digital camera first.
Not just digital cameras, but other devices like digital computers and laptops also use this technique of compression. These devices simply squeeze a digital image so that it occupies less memory and involves fewer numbers. However, when an image is squeezed and compressed, some amount of detail is lost from it. So, you never really get an original image from the digital camera. After compression, you can store the image in a different file format like JPG or JPEG.
Resolution of the Image
Digital cameras have an option to click pictures in high resolution or low resolution. If you click a picture in high resolution, then it occupies more space than a low-resolution image. Accordingly, you can only store a few high-resolution pictures on the camera.
How Does A Camera Work? – Conclusion
In this article, we took a close look at the working of a camera. Read and understand the working principles and explain it to those who still don’t know how a camera works. The camera brought about a revolution in the world. It is due to the development of several types of cameras over the years that so many new avenues could come up and flourish. It is, therefore, interesting to know how different cameras work and what goes into making a camera.