How Do Webcams Work?
- In their most basic function, webcams work much like other cameras, both film and digital. When light shines on objects, the object absorbs certain color spectrums and reflects others, creating the object's perceived shape and color. On a digital camera, like a webcam, these light reflections are recorded as electrical signals and then fed to a processor to be converted into an electronically stored digital image. Depending on how the webcam is connected, it then passes the image over a Universal Serial Bus (USB), serial, or even Internet Protocol (IP) data connection to an attached computer, where the image can be further processed, manipulated, displayed or shared.
- When an attached computer receives an image from a webcam, the action it takes depends largely on the configuration of webcam sharing software. If the software is configured to display images on an attached monitor, or if no network connection is available, the computer simply displays the data it receives from the webcam and, if configured to do so, stores it for later retrieval. If the software is configured to share the data, it uses file transfer protocol (FTP; a protocol used for transferring files between machines on the Internet) to place the images on a server where they can be retrieved by other users with an Internet connection. If the software is not loaded, or is not operating properly, the machine simply discards data received from the webcam and takes no further action.
- If the webcam is configured to serve as a video camera, it actually takes a number of stationary images, known as frames, over a period of time. A high number of frames taken over a short period of time can serve to capture and display motion. Most people perceive 15 frames per second as smooth motion, though, depending on the quality of the webcam and the bandwidth of the Internet connection, some webcams may capture and display as many as 30 or even 60 frames per second to create a smooth, high-quality video feed.
