All webcams work in broadly the same way: they use an image sensor chip to catch moving images and convert them into streams of digits that are uploaded over the Internet. The image sensor chip is the heart of a webcam—so how does that bit work? Let's take a webcam apart and find out.
Take the outer case off a webcam and you'll find it's little more than a plastic lens mounted directly onto a tiny electronic circuit board underneath. The lens screws in and out to increase its focal length, controlling the focus of your cam:
Now take the lens off and you can see the image sensor (CCD or CMOS chip): it's the square thing in the middle of this circuit. Only the tiny, green-colored central part is light-sensitive: the rest of the chip is concerned with connecting the light detector to the bigger circuit that surrounds it:
Here's a closeup:
So the image sensor is the "electronic eye" of a webcam or a digital camera. It's a semiconductor chip made of millions of tiny, light-sensitive squares arranged in a grid pattern. These squares are called pixels. Basic webcams use relatively small sensors with just a few hundred thousand pixels (typically a grid of 640 × 480. Good digital cameras use sensors with many more pixels; that's why cameras are compared by how many megapixels (millions of pixels) they have. A basic webcam has about 0.3 megapixels (300,000, in other words), while a digital camera with 6 megapixels has over 20 times more—probably arranged in a rectangle with three thousand across and two thousand down (3000 x 2000 = 6 million). A better camera rated at 12 megapixels would have a 4000 x 3000 pixel sensor. Take a photo the same size with those two cameras and the 12 megapixel one is going to give you 1000 more dots horizontally and 1000 more vertically—smaller dots giving more detail and higher resolution. A single pixel in a really good sensor is something like 10 micrometers (10μm) in diameter (5–10 times smaller than the diameter of a typical human hair)!
When you take a digital photo or stare into your webcam, light zooms into the lens. This incoming "picture" hits the image sensor, which breaks it up into individual pixels that are converted into numeric form.
CCDs and CMOS chips, the two kinds of image sensor, do this job in slightly different ways. Both initially convert incoming light rays into electricity, much like photoelectric cells (used in things like "magic eye" intruder alarms or restroom washbasins that switch on automatically when you put your hands under the faucet). But a CCD is essentially an analog optical chip that converts light into varying electrical signals, which are then passed on to one or more other chips where they're digitized (turned into numbers). By contrast, a CMOS chip does everything in one place: it captures light rays and turns them into digital signals all on the one chip. So it's essentially a digital device where a CCD is an analog one. CMOS chips work faster and are cheaper to make in high volume than CCDs, so they're now used in most low-cost cellphone cameras and webcams. But CCDs are still widely used in some applications, such as low-light astronomy.
Whether images are being generated by a CMOS sensor or a CCD and other circuitry, the basic process is the same: an incoming image is converted into an outgoing pattern of digital pixels. Let's just refer to "the image sensor" from now on (and forget about whether it's a CCD and other chips or a CMOS sensor). First, the image sensor measures how much light is arriving at each pixel. This information is turned into a number that can be stored on a memory chip inside the camera. Thus, taking a digital photograph converts the picture you see into a very long string of numbers. Each number describes one pixel in the image—how bright or dark and what color it is.
The CCD was invented in fall 1969 by Canadian-born Willard S. Boyle (1924–) and American George E. Smith (1930–), two colleagues working at Bell Laboratories (a famous American research center in New Jersey responsible for all kinds of amazing inventions, most famous of which is the transistor). Boyle and Smith were trying to develop a new kind of computer memory—in their notes, originally called a charge "bubble" device—but what they actually invented proved far more useful for capturing and storing images in digital form.
Photo: Albert Einstein—ultimate father of the webcam? Photo courtesy of US Library of Congress.
The science behind the CCD (turning light energy into electrical energy) dates back much further—to 1905. Known as the photoelectric effect, it was the first major scientific discovery by Albert Einstein (1879–1955). Einstein showed how a light beam could give up its energy when it hit the surface of a material, knocking out electrons that would then form an electric current—and a quantity of electrical energy that could be related directly to the frequency of the incoming light. It was for this early piece of work (and not his much more famous later work on relativity) that Einstein was awarded the Nobel Prize in Physics 1921. Boyle and Smith earned their own place in history almost 90 years later when they won the Nobel Prize in Physics 2009 (shared with fiber-optic pioneer Charles Kao).
Take apart any webcam and you'll end up with much the same bits and pieces: an image sensor chip, mounted on a circuit board, lurking behind a lens. That doesn't mean that all webcams are exactly the same or that one is just as good as another. In fact, there are two key measurements that tell you how well a webcam will perform: resolution and frame rate.
While a good digital camera is designed to capture high-resolution (finely detailed) pictures, a webcam deliberately captures much lower resolution (more blurred, grainy, and "pixelated") images. A standard definition webcam makes images that are about one tenth the size of a typical digital camera, typically either 320 × 240 or 640 × 480 pixels, so each uncompressed still frame would be several hundred kilobytes instead of several megabytes. That means webcam snapshots can be sent over the Internet much more quickly than large digital photos, because there are far fewer bytes to upload and download. Webcams like this can work effectively even with slow, dialup Internet. Modern HD (high-definition webcams) make higher-resolution images than older cams (typically either 1280 × 720 or 1600 × 1200), but still use much smaller-sized files than a really good digital camera. Since they're sending much bigger images, they need decent broadband Internet connections. If you're broadcasting with a webcam, you'll need reasonably good uploading speed (usually 1MBps upload speed or better), whereas conventional web browsing relies mainly on fast downloading speeds.
The frame rate (also called the refresh rate) is the number of frames per second (FPS) that a webcam can handle. Lower-quality cams manage about 24 frames per second, while better ones might reach 50–60. The Microsoft VX-1000 and VS-800 cams in the photos up above come in at a pretty average 30 fps with a resolution of 640 × 480.
What kind of frame rate do you need? The higher the rate, the more movement your cam will capture. In practice, even a low frame rate is good enough for video chat (since you're mostly sitting still staring at the camera) and if all you're doing is uploading still webcam images to a web page (once a minute or so), the frame rate is pretty much irrelevant.
If your Internet connection is too slow, you won't be able to manage more than a very modest frame rate (perhaps just 5–10 frames per second or maybe not even that): even then, you might see a "laggy" image that isn't synchronized with the sound you hear or a "jerky" image with sudden changes in movement. If a high frame rate is important, switching to a lower resolution (or perhaps using black and white instead of color) might cure the problem. You could also try using more lighting (with an angled desk lamp) and simplifying the picture that you're transmitting (put up a white sheet as a plain background behind you or film yourself against a plain wall and wear plain clothes, not crazily patterned ones). If you can reduce the amount of information being transmitted in each frame, you should, in theory, be able to send more frames per second with your limited bandwidth.
In practice, then, you need to strike a balance between resolution and frame rate according to the limited speed of your connection. With a very fast broadband connection, you should be able to manage both a high frame rate and a high resolution.
Most of us have smartphones with built-in cameras, and easy-to-use video chat apps like Zoom and FaceTime (or WhatsApp and Snapchat if you prefer), so why on Earth would you want a separate webcam?
Some people still prefer to do things the old fashioned way. With a smartphone, all you can really do is speak and chat; with a webcam, running on a desktop computer, you can also type, exchange files, share your desktop, and other things that may be tricky on a mobile. So there's still very much a place for old-style webcams in the age of Android smartphones and iPhones.
Webcams are also handy if you want to publish a frequently updated still image of a particular place for others to view on the Internet. For example, a zoo might publish live pictures from its zebra or giraffe house. Webcams are relatively inexpensive—much cheaper than smartphones—so you're going to care much less if they're damaged or stolen.
The third reason is for security. Maybe you want to monitor your home while you're on vacation, check your dog is fed and watered, or keep an eye on a sick or elderly relative. Webcams let you do all these things. Wireless cams, connected to your home router, can be especially discreet and convenient.
And one final reason: a webcam, connected by a cable or wireless, can show you things a smartcam can't. Want to cut your own hair? An easy way to see round the back is to place a webcam behind you and watch the screen as you chop. You can't really do that with a phone, where the screen and the camera are built into a single unit.
To chat to someone online, you both need a device with a webcam (or a smartphone with a built-in cam) and you both need to be running the same video chat program on your computer or mobile. Skype, the best known chat program, runs on pretty much any type of computer or mobile device (though it no longer runs on older machines with operating systems like Windows XP or old versions of Linux). FaceTime works only on Apple (iOS) devices. And Google Hangouts runs on desktop machines, Apple (iOS) devices, and Android mobiles.
Video chat programs work just like still webcams—only they're uploading photos constantly. Suppose I am video chatting with you. My camera captures a picture of me, turns it into digital format, and sends it my computer. The chat program on my machine "streams" the image information across the Internet to your computer. The chat program on your machine receives the image information and converts it back into a picture, which it displays on your screen. Meanwhile, your camera is doing exactly the same thing with a picture of you and sending it in the opposite direction. This two-way process happens constantly, so each of us gets a constantly updated picture of the other. To speed things up, video chat programs like Skype make a direct connection between your machine and mine, bypassing centralized servers. This very efficient way of using the Net is called (VOIP) Voice Over Internet Protocol and is an example of what's known as P2P (peer-to-peer) networking..
Suppose you want to broadcast images of your garden on a website and update them at regular intervals. You can do that with a webcam. You simply point the cam at your garden, hook it up to your computer, and install a special piece of software. The software captures an image from the cam every five minutes (or at some preset interval) and copies it onto your website using a simple process called FTP (file-transfer protocol). Every time a new image is uploaded, it replaces the previous one on your website. When people look at your site, they see the latest image that your cam has uploaded. Most people design their cam pages so they do what's called a "meta refresh" (automatically reload) every few minutes. That ensures they're always showing the latest image.
Here are some examples of webcams that work this way:
Photo: Do my plants need watering? If you have an old smartphone or tablet you no longer use, it's easy to set it up as a Wi-Fi-connected security camera you can monitor remotely. There are quite a few apps that will help you do this (search your favorite app store for "home security monitor").
Thanks to the Internet, lots more people are getting interested in smart home technology, which lets you monitor and control things like your home heating, lighting, and appliances using smartphone apps (or a simple web interface you can log on to) while you're away.
Monitoring what's happening at home with a webcam used to be quite tricky. You needed both a PC (which had to be running all the time) and a webcam, which you had to set up to upload intermittent still photos (just as though you were setting up a still webcam in a zebra house). Now it's much easier. All you need is a Wi-Fi enabled webcam that can automatically upload images using your wireless router. It doesn't need to be plugged into a computer and you don't need any complicated software either. Some Wi-Fi cams will stream live images; some will record and store them for a few days or weeks in flash memory; still others will upload them to the cloud, where you can browse or watch them later. Home monitoring and security Wi-Fi cams are made by Dropcam (now a part of Google's Nest), Tenvis, Simplicam, Oco, and many others, and tend to be quite a bit more expensive than the kind of basic cams you get for online chat.
If you've got a digital camera already and a webcam is essentially the same thing, it might occur to you to use your ordinary cam as a webcam. Some digital cameras even have a built-in webcam button or mode making it very easy. For others, you'll need to find out if there's a driver available (that's a small file that tells your computer how to use a plug-in device in a certain way). Sometimes people write their own programs and drivers and make them available online for others, so Googling something like "use canon ixus as webcam" will often bring up helpful results.
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However, there's one thing you do need to be very wary of. A USB connection contains a 5-volt power supply as well as a data connection to and from your computer. Plug a digital camera into a USB socket on your PC and it will draw power the whole time it's connected. Digital cameras are not normally meant to be plugged into computers for more than a minute or two at a time (while you're uploading your photos). Leave a camera plugged in for a long time (half an hour or a couple of hours) while you're using it as a webcam and it can heat up considerably, either damaging the camera or overcharging the batteries. Consider that a good digital camera costs perhaps 10–50 times more than a basic webcam and you'll see what a risk you're taking. The message is simple: if you plan on using a webcam regularly, or for any length of time, buy a proper USB webcam. They're not expensive (you can get one for less than $20/£10)—and you'll save damage to your digital camera, which probably was expensive!
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A webcam is a video camera which is designed to record or stream to a computer or computer network. They are primarily used in video telephony, live streaming and social media, and security. Webcams can be built-in computer hardware or peripheral devices, and are commonly connected to a device using USB or wireless protocols.
Webcams have been used on the Internet as early as 1993, and the first widespread commercial one became available in 1994. Early webcam usage on the Internet was primarily limited to stationary shots streamed to web sites. In the late 1990s and early 2000s, instant messaging clients added support for webcams, increasing their popularity in video conferencing. Computer manufacturers also started integrating webcams into laptop hardware. In 2020, the COVID-19 pandemic caused a shortage of webcams due to the increased number of people working from home.
History
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Early development (early 1990s)
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The Trojan Room coffee pot, as displayed in XCoffeeFirst developed in 1991, a webcam was pointed at the Trojan Room coffee pot in the Cambridge University Computer Science Department (initially operating over a local network instead of the web). The camera was finally switched off on August 22, 2001. The final image captured by the camera can still be viewed at its homepage.[1][2] The oldest continuously operating webcam, San Francisco State University's FogCam, has run since 1994 and is still operating as of February 2024. It updates every 20 seconds.[3]
SGI IndyCamThe SGI Indy, released in 1993, is the first commercial computer to have a standard video camera,[4] and the first SGI computer to have standard video inputs.[5]
The maximum supported input resolution is 640×480 for NTSC or 768×576 for PAL. A fast machine is required to capture at either of these resolutions, though; an Indy with slower R4600PC CPU, for example, may require the input resolution to be reduced before storage or processing. However, the Vino hardware is capable of DMAing video fields directly into the frame buffer with minimal CPU overhead.
The first widespread commercial webcam, the black-and-white QuickCam, entered the marketplace in 1994, created by the U.S. computer company Connectix. QuickCam was available in August 1994 for the Apple Macintosh, connecting via a serial port, at a cost of $100. Jon Garber, the designer of the device, had wanted to call it the "Mac-camera", but was overruled by Connectix's marketing department; a version with a PC-compatible parallel port and software for Microsoft Windows was launched in October 1995. The original Quick Cam provided 320x240-pixel resolution with a grayscale depth of 16 shades at 60 frames per second, or 256 shades at 15 frames per second.[6] These cam were tested on several Delta II launch using a variety of communication protocols including CDMA, TDMA, GSM and HF.
Videoconferencing via computers already existed, and at the time client-server based videoconferencing software such as CU-SeeMe had started to become popular.
The first widely known laptop with integrated webcam option, at a pricepoint starting at US$ 12,000, was an IBM RS/6000 860 laptop[7][8] and its related ThinkPad 850,[9] released in 1996.
Entering the mainstream (late 1990s)
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iSight webcam, released in 2003One of the most widely reported-on webcam sites was JenniCam, created in 1996, which allowed Internet users to observe the life of its namesake constantly, in the same vein as the reality TV series Big Brother, launched four years later.[10] Other cameras are mounted overlooking bridges, public squares, and other public places, their output made available on a public web page in accordance with the original concept of a "webcam". Aggregator websites have also been created, providing thousands of live video streams or up-to-date still pictures, allowing users to find live video streams based on location or other criteria.
In the late 1990s, Microsoft NetMeeting was the only videoconferencing software on PC in widespread use, making use of webcams.[11] In the following years, instant messaging clients started adding webcam support: Yahoo Messenger introduced this with version 5.5 in 2002, allowing video calling in 20 frames per second using a webcam.[12] MSN Messenger gained this in version 5.0 in 2003.[13]
Around the turn of the 21st century, computer hardware manufacturers began building webcams directly into laptop and desktop screens, thus eliminating the need to use an external USB or FireWire camera. Gradually webcams came to be used more for telecommunications, or videotelephony, between two people, or among several people, than for offering a view on a Web page to an unknown public.
For less than US$100 in 2012, a three-dimensional space webcam became available, producing videos and photos in 3D anaglyph image with a resolution up to 1280 × 480 pixels. Both sender and receiver of the images must use 3D glasses to see the effect of three dimensional image.[14]
Webcams are considered an essential accessory for remote work, mainly to compensate for lower quality video processing with the built-in camera of the average laptop. During the COVID-19 pandemic, there was a shortage of webcams.[15] Most laptops before and during the pandemic were made with cameras capping out at 720p recording quality at best, compared to the industry standard of 1080p or 4K seen in smartphones and televisions from the same period.[16] The backlog on new developments for built-in webcams is the result of a design flaw with laptops being too thin to support the 7mm camera modules to fit inside, instead resorting to ~2.5mm.[17][18] Also the camera components are more expensive and not a high level of demand for this feature, [19][20] Smartphones started to be used as a backup option or webcam replacement, with kits including lighting and tripods or downloadable apps.[21]
Technology
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Image sensor
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Charge-coupled device (CCD) image sensor of a webcamImage sensors can be CMOS or CCD, the former being dominant for low-cost cameras, but CCD cameras do not necessarily outperform CMOS-based cameras in the low-price range. Most consumer webcams are capable of providing VGA-resolution video at a frame rate of 30 frames per second. Many newer devices can produce video in multi-megapixel resolutions, and a few can run at high frame rates such as the PlayStation Eye, which can produce 320×240 video at 120 frames per second.[22] Most image sensors are sourced from Omnivision or Sony.
As webcams evolved simultaneously with display technologies, USB interface speeds and broadband internet speeds, the resolution went up from gradually from 320×240, to 640×480, and some now even offer 1280×720 (aka 720p) or 1920×1080 (aka 1080p) resolution.[23][24][25] Despite the low cost, the resolution offered as of 2019 is impressive, with now the low-end webcams offering resolutions of 720p, mid-range webcams offering 1080p resolution, and high-end webcams offering 4K resolution at 60 fps.
Optics
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S-mount lens, designed to attach to the webcam's PCBVarious lenses are available, the most common in consumer-grade webcams being a plastic lens that can be manually moved in and out to focus the camera. Fixed-focus lenses, which have no provision for adjustment, are also available. As a camera system's depth of field is greater for small image formats and is greater for lenses with a large f-number (small aperture), the systems used in webcams have a sufficiently large depth of field that the use of a fixed-focus lens does not impact image sharpness to a great extent.
Most models use simple, focal-free optics (fixed focus, factory-set for the usual distance from the monitor to which it is fastened to the user) or manual focus.
Webcams can come with different presets and fields of view. Individual users can make use of less than 90° horizontal FOV for home offices and live streaming. Webcams with as much as 360° horizontal FOV can be used for small- to medium-sized rooms (sometimes even large rooms). Depending on the users' purposes, webcams in the market can display the whole room or just the general vicinity.
Internal software
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As the bayer filter is proprietary, any webcam contains some built-in image processing, separate from compression. Digital video streams are represented by huge amounts of data, burdening its transmission (from the image sensor, where the data is continuously created) and storage alike. Most if not all cheap webcams come with built-in ASIC to do video compression in real-time.
Support electronics read the image from the sensor and transmit it to the host computer. Most webcams come with a controller that translates video over USB from Sonix, Suyin, Ricoh, Realtek or others. Typically, each frame is transmitted uncompressed in RGB or YUV or compressed as JPEG. Some cameras, such as mobile-phone cameras, use a CMOS sensor with supporting electronics "on die", i.e. the sensor and the support electronics are built on a single silicon chip to save space and manufacturing costs. Most webcams feature built-in microphones to make video calling and videoconferencing more convenient.
Interface and external software
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A picture taken by a webcam in 2010, showing a large amount of noiseTypical interfaces used by articles marketed as a "webcam" are USB, Ethernet and IEEE 802.11 (denominated as IP camera). Further interfaces such as e.g. Composite video, S-Video or FireWire were also available. The USB video device class (UVC) specification allows inter-connectivity of webcams to computers without the need for proprietary device drivers.
Various proprietary as well as free and open-source software is available to handle the UVC stream. One could use Guvcview or GStreamer and GStreamer-based software to handle the UVC stream. Another could use multiple USB cameras attached to the host computer the software resides on, and broadcast multiple streams at once over (Wireless) Ethernet, such as MotionEye. MotionEye can either be installed onto a Raspberry Pi as MotionEyeOs, or afterwards on Raspbian as well. MotionEye can also be set up on Debian, Raspbian is a variant of Debian. MotionEye V4.1.1 ( Aug '21 ) can only run on Debian 10 Buster ( oldstable ) and Python 2.7. Newer versions such as 3.X are not supported at this point of time according to Ccrisan, foundator and author of MotionEye.
Various software tools in wide use can be employed to take video and pictures, such as PicMaster and Microsoft's Camera app (for use with Windows operating systems), Photo Booth (Mac), or Cheese (with Unix systems). For a more complete list see Comparison of webcam software.
Uses
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The most popular use of webcams is the establishment of video links, permitting computers to act as videophones or videoconference stations. For example, Apple's iSight camera, which is built into Apple laptops, iMacs and a majority of iPhones, can be used for video chat sessions, using the Messages instant messaging program. Other popular uses include security surveillance, computer vision, video broadcasting, and for recording social videos.
Videotelephony
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A video call session with use of webcamsWebcams can be added to instant messaging, text chat services such as AOL Instant Messenger, and VoIP services such as Skype, one-to-one live video communication over the Internet has now reached millions of mainstream PC users worldwide. Improved video quality has helped webcams encroach on traditional video conferencing systems. New features such as automatic lighting controls, real-time enhancements (retouching, wrinkle smoothing and vertical stretch), automatic face tracking and autofocus, assist users by providing substantial ease-of-use, further increasing the popularity of webcams.
Webcams can also encourage remote work, enabling people to work remotely via the Internet. This usage was crucial to the survival of many businesses during the COVID-19 pandemic, when in-person office work was discouraged. Businesses, schools, and individuals have relied on video conferencing instead of spending on business travel for meetings. Moreover, the number of video conferencing cameras and software have multiplied since then due to their popularity.
Webcam features and performance can vary by program, computer operating system, and also by the computer's processor capabilities. Video calling support has also been added to several popular instant messaging programs.
Webcams allow for inexpensive, real-time video chat and webcasting, in both amateur and professional pursuits. They are frequently used in online dating and for online personal services offered mainly by women when camgirling. However, the ease of webcam use through the Internet for video chat has also caused issues. For example, moderation system of various video chat websites such as Omegle has been criticized as being ineffective, with sexual content still rampant.[26] In a 2013 case, the transmission of nude photos and videos via Omegle from a teenage girl to a schoolteacher resulted in a child pornography charge.[27]
The popularity of webcams among teenagers with Internet access has raised concern about the use of webcams for cyber-bullying.[28] Webcam recordings of teenagers, including underage teenagers, are frequently posted on popular Web forums and imageboards such as 4chan.[29][30]
Monitoring
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Webcam mounted on a building, used as a CCTVWebcams can be used as security cameras. Software is available to allow PC-connected cameras to watch for movement and sound, recording both when they are detected. These recordings can then be saved to the computer, e-mailed, or uploaded to the Internet. In one well-publicised case,[31] a computer e-mailed images of the burglar during the theft of the computer, enabling the owner to give police a clear picture of the burglar's face even after the computer had been stolen.
In December 2011, Russia announced that 290,000 Webcams would be installed in 90,000 polling stations to monitor the 2012 Russian presidential election.[32] Webcams may be installed at places such as childcare centres, offices, shops and private areas to monitor security and general activity.
Astrophotography
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An image of the Moon created by stitching images from a webcamWith very-low-light capability, a few specific models of webcams are very popular to photograph the night sky by astronomers and astro photographers. Mostly, these are manual-focus cameras and contain an old CCD array instead of comparatively newer CMOS array. The lenses of the cameras are removed and then these are attached to telescopes to record images, video, still, or both. In newer techniques, videos of very faint objects are taken for a couple of seconds and then all the frames of the video are "stacked" together to obtain a still image of respectable contrast.[33]
Laser beam profiling
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A webcam's CCD response is linearly proportional to the incoming light.[34] Therefore, webcams are suitable to record laser beam profiles, after the lens is removed. The resolution of a laser beam profiler depends on the pixel size. Commercial webcams are usually designed to record color images. The size of a webcam's color pixel depends on the model and may lie in the range of 5 to 10 µm. However, a color pixel consists of four black and white pixels each equipped with a color filter (for details see Bayer filter). Although these color filters work well in the visible, they may be rather transparent in the near infrared. By switching a webcam into the Bayer-mode it is possible to access the information of the single pixels and a resolution below 3 µm was possible.[35]
Privacy concerns
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Tape over the built-in laptop webcam to block spies from viewing activitiesMany users do not wish the continuous exposure for which webcams were originally intended, but rather prefer privacy.[36] Such privacy is lost when malware allow malicious hackers to activate the webcam without the user's knowledge, providing the hackers with a live video and audio feed.[37] This is a particular concern on many laptop computers, as such cameras normally cannot be physically disabled if hijacked by such a Trojan Horse program or other similar spyware programs.
Cameras such as Apple's older external iSight cameras include lens covers to thwart this. Some webcams have built-in hardwired LED indicators that light up whenever the camera is active, sometimes only in video mode.[38] However, it is possible, depending on the circuit design of a webcam, for malware to circumvent the indicator and activate the camera surreptitiously, as researchers demonstrated in the case of a MacBook's built-in camera in 2013.[38]
Various companies sell sliding lens covers and stickers that allow users to retrofit a computer or smartphone to close access to the camera lens as needed.[38] One such company reported having sold more than 250,000 such items from 2013 to 2016.[38] However, any opaque material will work just as well.[38]
The process of attempting to hack into a person's webcam and activate it without the webcam owner's permission has been called camfecting, a portmanteau of cam and infecting. The remotely activated webcam can be used to watch anything within the webcam's field of vision. Camfecting is most often carried out by infecting the victim's computer with a computer virus.
See also
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References
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Further reading
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