View source for Webcam

{{Short description|Video camera connected to a computer or network}}
[[File:Logicool StreamCam (cropped).jpg|alt=Small box with a lens inside|thumb|A [[Logitech]]-branded webcam attached to a laptop]]
A '''webcam''' is a [[video camera]] which is designed to record or stream to a [[computer]] or [[computer network]]. They are primarily used in [[Videotelephony|video telephony]], [[live streaming]] and [[social media]], and [[Closed-circuit television|security]]. Webcams can be [[Built-in function|built-in]] computer hardware, like a laptop, or [[Peripheral|peripheral devices]], and are commonly connected to a device using [[USB]] or [[Internet protocol suite|wireless protocol]]. 

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 later started integrating webcams into [[laptop]] hardware. In 2020, the [[COVID-19 pandemic]] caused a shortage of webcams due to the increased number of people [[Remote work|working from home]] and children attending school remotely.

== History ==
{{See also|History of videotelephony}}
=== Early development (early 1990s) ===
[[File:Trojan Room coffee pot xcoffee.png|thumb|The [[Trojan Room coffee pot]], as displayed in XCoffee]]

First developed in 1991, a webcam was pointed at the [[Trojan Room coffee pot]] in the [[University of Cambridge|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.<ref>[http://www.cl.cam.ac.uk/coffee/coffee.html CoffeeCam] {{Webarchive|url=https://web.archive.org/web/20120313093700/http://www.cl.cam.ac.uk/coffee/coffee.html |date=2012-03-13 }}, University of Cambridge.</ref><ref>{{cite web|url=http://www.spiegel.de/static/popup/coffeecam/cam2.html|title=Trojan Room Coffee Pot – Spiegel Online |access-date=29 July 2015|archive-url=https://web.archive.org/web/20150925043554/http://www.spiegel.de/static/popup/coffeecam/cam2.html|archive-date=25 September 2015|url-status=live}}</ref> The oldest continuously operating webcam, [[San Francisco State University]]'s [[FogCam]], has run since 1994 and is still operating {{as of|lc=y|2025|10|post=.}} It updates every 20 seconds.<ref>{{cite web |title='World's oldest webcam' to be switched off |url=https://www.bbc.co.uk/news/technology-49408335 |website=BBC News |access-date=20 August 2019 |date=20 August 2019 |archive-url=https://web.archive.org/web/20190820170350/https://www.bbc.co.uk/news/technology-49408335 |archive-date=20 August 2019 |url-status=live }}</ref>[[File:Silicon Graphics camera IMG 4205.jpg|thumb|SGI IndyCam|left]]

The [[SGI Indy]], released in 1993, is the first commercial computer to have a standard video camera,<ref name="MD camera">{{cite magazine|date=August 13, 1993|title=Low-cost, high-speed SGI Indy comes with camera|url=https://www.proquest.com/docview/217148786|magazine=Machine Design|volume=65|issue=16|page=84|id={{ProQuest|217148786}}|access-date=March 5, 2021|url-access=registration|archive-date=July 13, 2021|archive-url=https://web.archive.org/web/20210713165154/https://www.proquest.com/docview/217148786|url-status=live}}</ref> and the first SGI computer to have standard video inputs.<ref name="ED Video input">{{cite magazine|author=DB|date=July 22, 1993|title=Video input becoming workstation standard.|magazine=Electronic Design|volume=41|issue=15|page=30|issn=0013-4872}}</ref>

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 [[R4600]]PC CPU, for example, may require the input resolution to be reduced before storage or processing. However, the Vino hardware is capable of [[Direct memory access|DMA]]ing 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.<ref>Edwards, Benj. [http://www.pcworld.com/article/199112/victorian_scifi.html History of Video Calls: From Fantasy to Flops to Facetime] {{Webarchive|url=https://web.archive.org/web/20111010182111/http://www.pcworld.com/article/199112/victorian_scifi.html |date=2011-10-10 }}, [[PC World (magazine)|PC World Magazine]], June 17, 2010.</ref> These cams were tested on several [[Delta II launch]] using a variety of communication protocols including CDMA, TDMA, GSM and HF.

[[Videotelephony|Videoconferencing]] via computers already existed, and at the time [[Client–server model|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 price point starting at US$ 12,000, was an IBM [[RS/6000]] 860 laptop<ref>{{cite web|url=http://ps-2.kev009.com/aixtp/Brochure/4249-860.pdf|title=RS/6000 Notebook 860|website=kev009.com|access-date=2020-12-30|archive-date=2021-02-25|archive-url=https://web.archive.org/web/20210225170148/http://ps-2.kev009.com/aixtp/Brochure/4249-860.pdf|url-status=live}}</ref><ref>{{Cite web|date=2000-06-28|title=US - IBM RS/6000 Notebook 860 Model 860|url=https://www-01.ibm.com/common/ssi/rep_sm/0/897/ENUS7249-860/index.html|access-date=2020-12-30|website=www-01.ibm.com|language=en-US|archive-date=2020-09-19|archive-url=https://web.archive.org/web/20200919231326/https://www-01.ibm.com/common/ssi/rep_sm/0/897/ENUS7249-860/index.html|url-status=live}}</ref> and its related [[ThinkPad 850]],<ref>{{Cite web|date=1996-07-09|title=IBM ThinkPad Power Series 820 and 850|url=https://www-01.ibm.com/common/ssi/printableversion.wss?docURL=/common/ssi/rep_ca/8/877/ENUSZG96-0188/index.html&request_locale=en|access-date=2020-12-30|website=www-01.ibm.com|language=en-US}}</ref> released in 1996.

===Entering the mainstream (late 1990s)===
[[File:ISights (cropped).jpg|alt=Cylindrical metal camera mounted on a laptop|thumb|[[iSight]] webcam, released in 2003]]
One 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 (TV series)|Big Brother]]'', launched four years later.<ref>[https://www.theguardian.com/international/story/0,,1115262,00.html "Plug pulled on live website seen by millions"] {{Webarchive|url=https://web.archive.org/web/20220819104528/https://www.theguardian.com/technology/2004/jan/03/usnews.internationalnews |date=2022-08-19 }} by Oliver Burkeman in ''The Guardian'', January 3, 2004</ref> 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.<ref>{{Cite web|url=https://www.chicagotribune.com/news/ct-xpm-1999-05-24-9905240145-story.html|title=Video-Conference Program Allows More Private Face-To-Face Time|website=[[Chicago Tribune]]|date=24 May 1999 |access-date=2021-07-03|archive-date=2022-04-21|archive-url=https://web.archive.org/web/20220421193845/https://www.chicagotribune.com/news/ct-xpm-1999-05-24-9905240145-story.html|url-status=live}}</ref> 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.<ref>{{Cite web|url=https://www.computerweekly.com/news/2240047061/Yahoo-instant-messenger-unveils-broadband-Webcam|title=Yahoo! Instant messenger unveils broadband Webcam|access-date=2021-07-03|archive-date=2021-07-09|archive-url=https://web.archive.org/web/20210709183222/https://www.computerweekly.com/news/2240047061/Yahoo-instant-messenger-unveils-broadband-Webcam|url-status=live}}</ref> [[MSN Messenger]] gained this in version 5.0 in 2003.<ref>{{Cite web|url=https://www.computerweekly.com/news/2240049915/MSN-Messenger-gains-webcam-functionality|title=MSN Messenger gains webcam functionality|access-date=2021-07-03|archive-date=2021-07-09|archive-url=https://web.archive.org/web/20210709184853/https://www.computerweekly.com/news/2240049915/MSN-Messenger-gains-webcam-functionality|url-status=live}}</ref>

=== 2000s–2019 ===
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|three-dimensional space]] webcam became available, producing videos and photos in 3D [[anaglyph image]] with a resolution up to 1280 × 480 pixels. Viewers must use 3D glasses to see the effect of three-dimensional images.<ref>{{cite news |last=Lanxon |first=Nate |url=https://www.cnet.com/pictures/3d-photos-minoru-3d-webcam-hands-on/ |title=3D photos: Minoru 3D webcam hands-on | work=[[CNET]] |date=July 16, 2009 |archive-url=https://web.archive.org/web/20101205030408/http://crave.cnet.co.uk/gadgets/3d-photos-minoru-3d-webcam-hands-on-49303012/ |archive-date=2010-12-05 |url-status=live}}</ref>

=== 2020–present ===

With [[remote work]] entering the mainstream, the built-in cameras of average laptops were sometimes considered inadequate. Consequently,
during the [[COVID-19 pandemic]], a shortage of external webcams in retail occurred.<ref>{{Cite news |url=https://www.theverge.com/2020/4/9/21199521/webcam-shortage-price-raise-logitech-razer-amazon-best-buy-ebay |title=Webcams have become impossible to find, and prices are skyrocketing |work=[[The Verge]] |date=9 April 2020 |access-date=4 May 2021 |archive-date=19 May 2021 |archive-url=https://web.archive.org/web/20210519105831/https://www.theverge.com/2020/4/9/21199521/webcam-shortage-price-raise-logitech-razer-amazon-best-buy-ebay |url-status=live }}</ref> 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.<ref>{{Cite web |url=https://www.techradar.com/news/computing-components/peripherals/what-webcam-5-reviewed-and-rated-1027972 |title=Best webcams 2021: Top picks for working from home |work=[[TechRadar]] |date=5 August 2021 |access-date=4 May 2021 |archive-date=6 May 2021 |archive-url=https://web.archive.org/web/20210506195713/https://www.techradar.com/news/computing-components/peripherals/what-webcam-5-reviewed-and-rated-1027972 |url-status=live }}</ref> 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.<ref>{{Cite web |url=https://www.theverge.com/2018/2/25/17050098/huawei-matebook-x-pro-webcam-mwc-2018 |title=Huawei's new laptop has a mechanical pop-up webcam in the keyboard |work=[[The Verge]] |date=25 February 2018 |access-date=4 May 2021 |archive-date=4 May 2021 |archive-url=https://web.archive.org/web/20210504002531/https://www.theverge.com/2018/2/25/17050098/huawei-matebook-x-pro-webcam-mwc-2018 |url-status=live }}</ref><ref>{{Cite web|url = https://www.digitaltrends.com/computing/laptops-need-better-webcams/|title = In the Age of Zoom, Bad Laptop Webcams Are a Big Problem|date = 8 April 2020|access-date = 4 May 2021|archive-date = 4 May 2021|archive-url = https://web.archive.org/web/20210504002532/https://www.digitaltrends.com/computing/laptops-need-better-webcams/|url-status = live}}</ref> Also, the camera components are more expensive, and there has not been a high level of demand for this feature.<ref>{{Cite web |title=New MacBook Pro Finally Features a 1080p Webcam Within a Notch |url=https://www.macrumors.com/2021/10/18/new-macbook-pro-1080p-facetime-camera/ |access-date=2023-04-25 |website=MacRumors |date=18 October 2021 |language=en}}</ref><ref>{{Cite web|url=https://www.imore.com/macbook-air-2020-so-much-love-except-crappy-facetime-camera|title=Dear Apple, please stop putting crummy cameras on your MacBooks|date=19 March 2020|access-date=4 May 2021|archive-date=4 May 2021|archive-url=https://web.archive.org/web/20210504002533/https://www.imore.com/macbook-air-2020-so-much-love-except-crappy-facetime-camera|url-status=live}}</ref> Smartphones started to be used as a backup option or webcam replacement, with kits including lighting and tripods or downloadable apps.<ref>{{Cite magazine|url = https://www.wired.com/story/use-your-phone-as-webcam/|title = How to Turn Your Smartphone into a Webcam|magazine = Wired|access-date = 2021-05-04|archive-date = 2021-05-13|archive-url = https://web.archive.org/web/20210513121455/https://www.wired.com/story/use-your-phone-as-webcam/|url-status = live}}</ref>

== Technology ==

=== Image sensor ===
{{Main|Image sensor}}
[[File:Webcam CCD closeup.jpg|thumb|[[Charge-coupled device]] (CCD) image sensor of a webcam]]
Image sensors can be [[CMOS]] or [[Charge-coupled device|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 [[Video Graphics Array|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 [[Quarter VGA|320×240]] video at 120 frames per second.<ref>{{Cite web |url=https://www.cnet.com/reviews/samsung-700g7c-review/ |title=Cnet |access-date=2021-07-19 |archive-date=2021-07-14 |archive-url=https://web.archive.org/web/20210714184641/https://www.cnet.com/reviews/samsung-700g7c-review/ |url-status=live }}</ref> 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 gradually from 320×240, to 640×480, and some now even offer 1280×720 (aka [[720p]]) or 1920×1080 (aka [[1080p]]) resolution.<ref>{{cite web |title=How Much Resolution is Enough? Picking a Webcam |url=http://www.ebay.com/gds/How-Much-Resolution-is-Enough-Picking-a-Webcam-/10000000177742678/g.html |url-status=live |archive-url=https://web.archive.org/web/20150704045758/http://www.ebay.com/gds/How-Much-Resolution-is-Enough-Picking-a-Webcam-/10000000177742678/g.html |archive-date=4 July 2015 |access-date=29 July 2015 |work=eBay}}</ref><ref>{{cite web |author=Jonathan Knoder |date=9 May 2013 |title=1080p, 2.0 Mega Pixels? Understanding Webcam Technical Terms |url=http://webcam-review.toptenreviews.com/1080p-2.0-mega-pixels-understanding-webcam-technical-terms.html |url-status=live |archive-url=https://web.archive.org/web/20150810121755/http://webcam-review.toptenreviews.com/1080p-2.0-mega-pixels-understanding-webcam-technical-terms.html |archive-date=10 August 2015 |access-date=29 July 2015 |work=Top Ten Reviews}}</ref><ref>{{cite web |author=Alan Henry |date=18 November 2012 |title=Five Best Webcams |url=http://lifehacker.com/5961369/five-best-webcams |url-status=live |archive-url=https://web.archive.org/web/20150729132917/http://lifehacker.com/5961369/five-best-webcams |archive-date=29 July 2015 |access-date=29 July 2015 |work=Lifehacker |publisher=Gawker Media}}</ref> Despite the low cost, the [[Image resolution|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 ===
[[File:Board Lens.jpg|left|thumb|[[S-mount (CCTV lens)|S-mount]] lens, designed to attach to the webcam's [[Printed circuit board|PCB]]]]
Various lenses are available, the most common in consumer-grade webcams being a plastic [[Lens (optics)|lens]] that can be manually moved in and out to focus the camera. [[Fixed-focus lens]]es, 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 [[Field of view|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 ===
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 [[Application-specific integrated circuit|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 [[Universal Serial Bus|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 [[camera phone|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 [[Integrated circuit|silicon chip]] to save space and manufacturing costs. Most webcams feature built-in [[microphone]]s to make [[videotelephone|video calling]] and [[videoconferencing]] more convenient.

=== Interface and external software ===
[[File:1975 Alvarez guitar (2010-10-18 03.14.15 by fenderfish).jpg|alt=Very noisy image, filled with color specks|thumb|A picture taken by a webcam in 2010, showing a large amount of noise]]Typical [[Interface (computing)|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, founder 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 (computer)|Mac]]), or [[Cheese (software)|Cheese]] (with [[Unix]] systems). For a more complete list see [[Comparison of webcam software]].

== Uses ==
The most popular use of webcams is the establishment of [[Videotelephony|video links]], permitting computers to act as [[Videotelephony|videophone]]s or [[Videotelephony|videoconference station]]s. For example, [[Apple Inc.|Apple]]'s [[iSight]] camera, which is built into Apple laptops, iMacs and a majority of [[iPhone]]s, can be used for video chat sessions, using the [[Messages (Apple)|Messages]] instant messaging program. Other popular uses include security surveillance, [[computer vision]], video broadcasting, and recording social videos.

=== Videotelephony ===
{{Further|Videotelephony||}}
[[File:TJ Cox talks with Caruthers Unified and CSBA.jpg|alt=Six people talking|thumb|A video call session with use of webcams]]
Webcams 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 [[Personal computer|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 [[Facial motion capture|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 [[computer program|program]], [[operating system|computer operating system]], and also by the computer's [[Central processing unit|processor]] capabilities. Video calling support has also been added to several [[List of video telecommunication services and product brands#Software clients –free instant messaging programs|popular instant messaging programs]].

Webcams allow for inexpensive, real-time [[Videotelephony|video chat]] and [[webcast]]ing, in both amateur and professional pursuits. They are frequently used in [[online dating]] and for online personal services offered mainly by women when [[camgirl]]ing. 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.<ref>{{cite web |title=The Problems with Omegle Girls and Free Chat Services |url=http://www.omeglegirlschat.com/omegle-controversy |url-status=dead |archive-url=https://web.archive.org/web/20130903121614/http://www.omeglegirlschat.com/omegle-controversy |archive-date=3 September 2013 |access-date=14 May 2013 |publisher=OmegleGirlsChat}}</ref> 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.<ref>{{cite web |title=Ex-band teacher pleads guilty to porn charge with girl, 16 |url=http://www.jconline.com/article/20130426/NEWS03/304260027/child-porn-former-teacher-nude-photos |access-date=14 May 2013 |publisher=jconline.com}}</ref>

The popularity of webcams among teenagers with Internet access has raised concern about the use of webcams for [[cyber-bullying]].<ref>Poeter, Damon. "[https://www.pcmag.com/article2/0,2817,2401701,00.asp Webcam Peeper Convicted in Rutgers Cyberbullying Case] {{Webarchive|url=https://web.archive.org/web/20170810211439/https://www.pcmag.com/article2/0,2817,2401701,00.asp|date=2017-08-10}}," ''[[PC Magazine]],'' March 16, 2012.</ref> Webcam recordings of teenagers, including underage teenagers, are frequently posted on popular Web forums and [[imageboard]]s such as [[4chan]].<ref>[http://www.thesmokinggun.com/buster/4chan-reports-child-pornographer-769123 Tip From 4chan Leads To Arrest Of Site Visitor On Child Porn Charges] {{Webarchive|url=https://web.archive.org/web/20120328075524/http://www.thesmokinggun.com/buster/4chan-reports-child-pornographer-769123|date=2012-03-28}}," ''[[The Smoking Gun]],'' February 27, 2012.</ref><ref>Goodin, Dan. [https://www.theregister.co.uk/2009/10/13/predator_indictment/ Feds: bald man posing as 17-year-old secretly taped teens] {{Webarchive|url=https://web.archive.org/web/20171210191631/http://www.theregister.co.uk/2009/10/13/predator_indictment|date=2017-12-10}}," ''[[The Register]]'' (UK), October 13, 2009.</ref>

=== Monitoring ===
[[File:Webcam (5282372873).jpg|left|thumb|Webcam mounted on a building, used as a [[Closed-circuit television|CCTV]]]]
Webcams can be used as [[security camera]]s. 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,<ref>[https://news.bbc.co.uk/2/hi/uk_news/england/cambridgeshire/4272041.stm Serial burglar caught on webcam]  [[BBC News]], February 16, 2005, retrieved January 3, 2006.</ref> 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]].<ref>[https://blogs.wsj.com/emergingeurope/2012/01/16/russia-election-webcams-linked-to-site-blamed-for-piracy/ Russia Election Webcams] {{Webarchive|url=https://web.archive.org/web/20170922011049/https://blogs.wsj.com/emergingeurope/2012/01/16/russia-election-webcams-linked-to-site-blamed-for-piracy/ |date=2017-09-22 }} ''The Wall Street Journal'', January 16, 2012.</ref> Webcams may be installed at places such as childcare centres, offices, shops and private areas to monitor security and general activity.

=== Astrophotography ===
[[File:3rd quarter plus 12hrs - Flickr - chipdatajeffb.jpg|thumb|An image of the [[Moon]] created by [[Image stitching|stitching images]] from a webcam]]
With 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.<ref>{{Cite book |last=North |first=Gerald |url= |title=Observing the Moon: The modern astronomer's guide |publisher=[[Cambridge University Press]] |year=2007 |isbn=978-0-511-29054-1 |edition=2nd |location=Cambridge, UK |pages=109–120 |language=en |oclc=772458173}}</ref>

===Laser beam profiling===
A webcam's CCD response is linearly proportional to the incoming light.<ref>Cignoli F, De Iuliis S, Zizak GA. Webcam as a light probe beam profiler. Appl. Spectrosc. 58, (2004), 1372.</ref> 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&nbsp;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&nbsp;μm was possible.<ref>G. Langer et al., A webcam in Bayer-mode as a light beam profiler for the near infrared, Optics and Lasers in Engineering 51 (2013) 571–575</ref>

== Privacy concerns ==
[[File:Tape over laptop webcam.jpg|alt=see caption|thumb|Tape over the built-in laptop webcam to block spies from viewing activities]]
Many users do not wish the continuous exposure for which webcams were originally intended, but rather prefer privacy.<ref>{{cite web |date=13 November 2012 |title=Jogador esquece webcam ligada e transmite sexo com namorada |url=http://br.noticias.yahoo.com/jogador-esquece-webcam-ligada-transmite-sexo-namorada.html |url-status=live |archive-url=https://web.archive.org/web/20151126181746/https://br.noticias.yahoo.com/jogador-esquece-webcam-ligada-transmite-sexo-namorada.html |archive-date=26 November 2015 |access-date=29 July 2015 |work=Yahoo Notícias}}</ref> Such privacy is lost when [[malware]] allow [[Hacker (computer security)|malicious hackers]] to activate the webcam without the user's knowledge, providing the hackers with a live video and audio feed.<ref>{{cite book |last=Gray |first=Leon |url=https://books.google.com/books?id=B2utHHdYJOcC&q=ivacy+is+lost+when+Trojan+horse+programs+allow+malicious+hackers+to+activate+the+webcam+&pg=PA5 |title=Virtual crime! : solving cybercrime |publisher=Enslow Publishers |year=2009 |isbn=978-0766033764 |location=Berkeley Heights, NJ |access-date=2020-10-11 |archive-date=2021-07-24 |archive-url=https://web.archive.org/web/20210724230054/https://books.google.com/books?id=B2utHHdYJOcC&q=ivacy+is+lost+when+Trojan+horse+programs+allow+malicious+hackers+to+activate+the+webcam+&pg=PA5 |url-status=live }}</ref> This is a particular concern on many laptop computers, as such cameras normally cannot be physically disabled if hijacked by such a [[Trojan horse (computing)|Trojan Horse]] program or other similar [[spyware]] programs.

Cameras such as [[Apple Computer|Apple]]'s older external [[iSight]] cameras include lens covers to thwart this. Some webcams have built-in hardwired [[Light-emitting diode|LED]] indicators that light up whenever the camera is active, sometimes only in video mode.<ref name=":0">{{Cite web |last=Yadron |first=Danny |date=2016-06-06 |title=Why is everyone covering up their laptop cameras? |url=https://www.theguardian.com/world/2016/jun/06/surveillance-camera-laptop-smartphone-cover-tape |access-date=2016-06-13 |website=the Guardian |archive-date=2019-04-13 |archive-url=https://web.archive.org/web/20190413165025/https://www.theguardian.com/world/2016/jun/06/surveillance-camera-laptop-smartphone-cover-tape |url-status=live }}</ref> 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.<ref name=":0" />

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.<ref name=":0" /> One such company reported having sold more than 250,000 such items from 2013 to 2016.<ref name=":0" /> However, any opaque material will work just as well.<ref name=":0" />

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 ==
* [[Action camera]]
* [[Camera phone]]
* [[IP camera]]
* [[List of video telecommunication services and product brands]]
* [[Trail camera]]

== References ==
{{Reflist|30em}}

==Further reading==
* {{Cite journal |last1=Mühlbach |first1=Lothar |last2=Böcker |first2=A |last3=Prussog |first3=A |date=June 1995 |title=Telepresence in Videocommunications: A Study on Stereoscopy and Individual Eye Contact |journal=[[Human Factors (journal)|Human Factors]] |volume=37 |issue=2 |pages=290–305 |doi=10.1518/001872095779064582 |issn=0018-7208 |id=Gale Document Number: GALE{{!}}A18253819 |pmid=7642183|s2cid=31369406 }} Accessed December 23, 2011 via General Science eCollection (subscription).

==External links==
* {{Commons category inline|Webcams}}

{{Computer-mediated communication}}
{{Basic computer components}}
{{Telecommunications}}
{{Authority control}}

[[Category:Webcams| ]]
[[Category:Articles containing video clips]]
[[Category:Computing input devices]]
[[Category:English inventions]]
[[Category:Film and video technology]]
[[Category:Privacy]]
[[Category:Teleconferencing]]
[[Category:Videotelephony]]