How Do Digital Cameras Work
Digital cameras have been around for some time now; the technology is not new, although it gets upgraded frequently.
In 2016, 63% of American households owned a digital camera. Most of these digital camera owners possess the technical knowledge required to operate the camera.
While this knowledge is sufficient to produce high-quality pictures, one might wonder how digital cameras achieve the bright, crisp, and vivid images they are known to produce. In other words, how do digital cameras work?
To answer the question of how digital cameras work, we must first identify the essential parts of the camera. Besides the lens and shutter, which both film and digital cameras have in common, all digital cameras must possess the following components.
In place of film, digital cameras have sensors that transform light into electrical charges (electrons). The image sensor is a semiconductor chip containing millions of light-sensitive pixels, each one measuring the light striking it. Sitting above the image sensor is the color filter that only permits specific pixels to measure certain colors of light waves.
The most widely used image sensor in digital cameras is a charge-coupled device (CCD). Some digital cameras may use the complementary metal-oxide-semiconductor (CMOS) technology instead. Either CMOS or CCD converts light into electrons.
A digital converter is a computer chip that converts the data collected in each pixel into a digital signal.
The circuit board houses all the computer chips that the digital camera uses to record data. The circuitry of the board transfers data from the image sensors and other chips to the memory card.
The display screen allows photographers to make desired changes to the camera settings and to review already captured. Some digital cameras may also have a viewfinder to compose and focus on the scene.
Notwithstanding the make or brand, price or quality of the camera or whether it is waterproof or not, the process of recording digital images, and then storing the data on a memory card remains the same. A digital camera works in these steps.
- Light Measurement
On pressing the shutter button, the shutter opens, allowing light to travel through the lens and strike the image sensor. The millions of pixels on the image sensor then measure the intensity of light at different points on the image sensor, thereby producing accurate measurements.
- Light Focusing
Light from the physical object traveling through the lens must be focused directly on the image sensor, as beams that are not well focused will result in a blurry image. Focusing gets achieved through several rotating glass elements in the lens. Digital cameras can focus automatically where the camera spins the glass elements in the lens, or manually, where the photographer adjusts the glass elements by twisting a ring on the camera.
- Light Conversion
Individual pixels convert the measured light into electrical charges. Brighter light means more electrons; thus, pixels that measure more intense beams will get more electrically charged compared to those pixels with dim lighting.
An ADC (analog to digital converter) chip converts the light signal at individual pixels into binary values.
- Data Storage
After the ADC converts light to a digital value, the camera then moves these data just as any computer chip will. Data moves through the circuitry and the circuit board and reaches the memory card. The camera then utilizes firmware to write the data on the memory card.
The amount of detail a camera is capable of capturing per time is called the resolution, measured in pixels. A camera with more pixels will obtain more information and will not cause larger pictures to become blurry or “grainy.”
Typical camera resolutions include:
- 256×256 – Found on the cheapest cameras, the picture quality is almost always unacceptable. It has a total of 65,000 pixels.
- 640×480 – This resolution is suited for e-mail and web site pictures.
- 1216×912 – Cameras having with this resolution are “megapixel” cameras. This resolution is a good one for printing pictures. It has a total of 1,109,000 pixels.
- 1600×1200 – High resolution, with almost 2 million total pixels.
- 2240×1680 – Found on 4-megapixel cameras, this is the current standard It allows good quality prints up to 16×20 inches.
- 4064×2704 – A digital camera with this resolution can create 13.5×9 inch prints with no apparent loss of picture quality.
Seeing as digital cameras save images as digital bits of data, sharing pictures with other devices and people becomes an easy task as photographs stored as digital bits get the same treatment as any regular computer file. Changes can also be made to the images using any of the editing software available. This ability to make changes to images means that minor errors can be corrected, and if necessary, photographers can enhance pictures with special effects.
Whether the camera is one of the best rated digital cameras on the market with a hefty price tag, or whether a relatively unknown company makes it. The essential components (image sensor, digital converter, circuit board, and the display screen) are the same, albeit with varying quality. The working principles also remain the same; first, the light gets measured, then it’s focused, after which it gets converted, and finally, it’s stored.
So, the next time you pick up a camera and take a shot, you can tell how clear the picture is likely going to be, and how the light from the physical object will get transformed into an image on your screen.