CINXE.COM

<!DOCTYPE html> <html class="client-nojs vector-feature-language-in-header-enabled vector-feature-language-in-main-page-header-disabled vector-feature-sticky-header-disabled vector-feature-page-tools-pinned-disabled vector-feature-toc-pinned-clientpref-1 vector-feature-main-menu-pinned-disabled vector-feature-limited-width-clientpref-1 vector-feature-limited-width-content-enabled vector-feature-custom-font-size-clientpref-1 vector-feature-appearance-pinned-clientpref-1 vector-feature-night-mode-enabled skin-theme-clientpref-day vector-toc-available" lang="en" dir="ltr"> <head> <meta charset="UTF-8"> <title>Lux - Wikipedia</title> <script>(function(){var className="client-js vector-feature-language-in-header-enabled vector-feature-language-in-main-page-header-disabled vector-feature-sticky-header-disabled vector-feature-page-tools-pinned-disabled vector-feature-toc-pinned-clientpref-1 vector-feature-main-menu-pinned-disabled vector-feature-limited-width-clientpref-1 vector-feature-limited-width-content-enabled vector-feature-custom-font-size-clientpref-1 vector-feature-appearance-pinned-clientpref-1 vector-feature-night-mode-enabled skin-theme-clientpref-day vector-toc-available";var cookie=document.cookie.match(/(?:^|; )enwikimwclientpreferences=([^;]+)/);if(cookie){cookie[1].split('%2C').forEach(function(pref){className=className.replace(new RegExp('(^| )'+pref.replace(/-clientpref-\w+$|[^\w-]+/g,'')+'-clientpref-\\w+( |$)'),'$1'+pref+'$2');});}document.documentElement.className=className;}());RLCONF={"wgBreakFrames":false,"wgSeparatorTransformTable":["",""],"wgDigitTransformTable":["",""],"wgDefaultDateFormat":"dmy", "wgMonthNames":["","January","February","March","April","May","June","July","August","September","October","November","December"],"wgRequestId":"be65f926-aba6-49d2-bb31-684904f695dd","wgCanonicalNamespace":"","wgCanonicalSpecialPageName":false,"wgNamespaceNumber":0,"wgPageName":"Lux","wgTitle":"Lux","wgCurRevisionId":1255787364,"wgRevisionId":1255787364,"wgArticleId":155869,"wgIsArticle":true,"wgIsRedirect":false,"wgAction":"view","wgUserName":null,"wgUserGroups":["*"],"wgCategories":["All articles with dead external links","Articles with dead external links from September 2018","Articles with permanently dead external links","CS1 maint: unfit URL","CS1 location test","CS1 interwiki-linked names","CS1 German-language sources (de)","CS1 Austrian German-language sources (de-at)","Articles with short description","Short description is different from Wikidata","Use dmy dates from March 2023","All articles with unsourced statements","Articles with unsourced statements from February 2013", "SI derived units","Units of illuminance"],"wgPageViewLanguage":"en","wgPageContentLanguage":"en","wgPageContentModel":"wikitext","wgRelevantPageName":"Lux","wgRelevantArticleId":155869,"wgIsProbablyEditable":true,"wgRelevantPageIsProbablyEditable":true,"wgRestrictionEdit":[],"wgRestrictionMove":[],"wgNoticeProject":"wikipedia","wgCiteReferencePreviewsActive":false,"wgFlaggedRevsParams":{"tags":{"status":{"levels":1}}},"wgMediaViewerOnClick":true,"wgMediaViewerEnabledByDefault":true,"wgPopupsFlags":0,"wgVisualEditor":{"pageLanguageCode":"en","pageLanguageDir":"ltr","pageVariantFallbacks":"en"},"wgMFDisplayWikibaseDescriptions":{"search":true,"watchlist":true,"tagline":false,"nearby":true},"wgWMESchemaEditAttemptStepOversample":false,"wgWMEPageLength":20000,"wgRelatedArticlesCompat":[],"wgEditSubmitButtonLabelPublish":true,"wgULSPosition":"interlanguage","wgULSisCompactLinksEnabled":false,"wgVector2022LanguageInHeader":true,"wgULSisLanguageSelectorEmpty":false,"wgWikibaseItemId": "Q179836","wgCheckUserClientHintsHeadersJsApi":["brands","architecture","bitness","fullVersionList","mobile","model","platform","platformVersion"],"GEHomepageSuggestedEditsEnableTopics":true,"wgGETopicsMatchModeEnabled":false,"wgGEStructuredTaskRejectionReasonTextInputEnabled":false,"wgGELevelingUpEnabledForUser":false};RLSTATE={"ext.globalCssJs.user.styles":"ready","site.styles":"ready","user.styles":"ready","ext.globalCssJs.user":"ready","user":"ready","user.options":"loading","ext.cite.styles":"ready","skins.vector.search.codex.styles":"ready","skins.vector.styles":"ready","skins.vector.icons":"ready","jquery.makeCollapsible.styles":"ready","ext.wikimediamessages.styles":"ready","ext.visualEditor.desktopArticleTarget.noscript":"ready","ext.uls.interlanguage":"ready","wikibase.client.init":"ready","ext.wikimediaBadges":"ready"};RLPAGEMODULES=["ext.cite.ux-enhancements","site","mediawiki.page.ready","jquery.makeCollapsible","mediawiki.toc","skins.vector.js","ext.centralNotice.geoIP", "ext.centralNotice.startUp","ext.gadget.ReferenceTooltips","ext.gadget.switcher","ext.urlShortener.toolbar","ext.centralauth.centralautologin","mmv.bootstrap","ext.popups","ext.visualEditor.desktopArticleTarget.init","ext.visualEditor.targetLoader","ext.echo.centralauth","ext.eventLogging","ext.wikimediaEvents","ext.navigationTiming","ext.uls.interface","ext.cx.eventlogging.campaigns","ext.cx.uls.quick.actions","wikibase.client.vector-2022","ext.checkUser.clientHints","ext.growthExperiments.SuggestedEditSession","wikibase.sidebar.tracking"];</script> <script>(RLQ=window.RLQ||[]).push(function(){mw.loader.impl(function(){return["user.options@12s5i",function($,jQuery,require,module){mw.user.tokens.set({"patrolToken":"+\\","watchToken":"+\\","csrfToken":"+\\"}); }];});});</script> <link rel="stylesheet" href="/w/load.php?lang=en&modules=ext.cite.styles%7Cext.uls.interlanguage%7Cext.visualEditor.desktopArticleTarget.noscript%7Cext.wikimediaBadges%7Cext.wikimediamessages.styles%7Cjquery.makeCollapsible.styles%7Cskins.vector.icons%2Cstyles%7Cskins.vector.search.codex.styles%7Cwikibase.client.init&only=styles&skin=vector-2022"> <script async="" src="/w/load.php?lang=en&modules=startup&only=scripts&raw=1&skin=vector-2022"></script> <meta name="ResourceLoaderDynamicStyles" content=""> <link rel="stylesheet" href="/w/load.php?lang=en&modules=site.styles&only=styles&skin=vector-2022"> <meta name="generator" content="MediaWiki 1.44.0-wmf.5"> <meta name="referrer" content="origin"> <meta name="referrer" content="origin-when-cross-origin"> <meta name="robots" content="max-image-preview:standard"> <meta name="format-detection" content="telephone=no"> <meta property="og:image" content="https://upload.wikimedia.org/wikipedia/commons/f/f1/Lux_meter.jpg"> <meta property="og:image:width" content="1200"> <meta property="og:image:height" content="1175"> <meta property="og:image" content="https://upload.wikimedia.org/wikipedia/commons/thumb/f/f1/Lux_meter.jpg/800px-Lux_meter.jpg"> <meta property="og:image:width" content="800"> <meta property="og:image:height" content="783"> <meta property="og:image" content="https://upload.wikimedia.org/wikipedia/commons/thumb/f/f1/Lux_meter.jpg/640px-Lux_meter.jpg"> <meta property="og:image:width" content="640"> <meta property="og:image:height" content="627"> <meta name="viewport" content="width=1120"> <meta property="og:title" content="Lux - Wikipedia"> <meta property="og:type" content="website"> <link rel="preconnect" href="//upload.wikimedia.org"> <link rel="alternate" media="only screen and (max-width: 640px)" href="//en.m.wikipedia.org/wiki/Lux"> <link rel="alternate" type="application/x-wiki" title="Edit this page" href="/w/index.php?title=Lux&action=edit"> <link rel="apple-touch-icon" href="/static/apple-touch/wikipedia.png"> <link rel="icon" href="/static/favicon/wikipedia.ico"> <link rel="search" type="application/opensearchdescription+xml" href="/w/rest.php/v1/search" title="Wikipedia (en)"> <link rel="EditURI" type="application/rsd+xml" href="//en.wikipedia.org/w/api.php?action=rsd"> <link rel="canonical" href="https://en.wikipedia.org/wiki/Lux"> <link rel="license" href="https://creativecommons.org/licenses/by-sa/4.0/deed.en"> <link rel="alternate" type="application/atom+xml" title="Wikipedia Atom feed" href="/w/index.php?title=Special:RecentChanges&feed=atom"> <link rel="dns-prefetch" href="//meta.wikimedia.org" /> <link rel="dns-prefetch" href="//login.wikimedia.org"> </head> <body class="skin--responsive skin-vector skin-vector-search-vue mediawiki ltr sitedir-ltr mw-hide-empty-elt ns-0 ns-subject mw-editable page-Lux rootpage-Lux skin-vector-2022 action-view"><a class="mw-jump-link" href="#bodyContent">Jump to content</a> <div class="vector-header-container"> <header class="vector-header mw-header"> <div class="vector-header-start"> <nav class="vector-main-menu-landmark" aria-label="Site"> <div id="vector-main-menu-dropdown" class="vector-dropdown vector-main-menu-dropdown vector-button-flush-left vector-button-flush-right" > <input type="checkbox" id="vector-main-menu-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-main-menu-dropdown" class="vector-dropdown-checkbox " aria-label="Main menu" > <label id="vector-main-menu-dropdown-label" for="vector-main-menu-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-menu mw-ui-icon-wikimedia-menu"></span> <span class="vector-dropdown-label-text">Main menu</span> </label> <div class="vector-dropdown-content"> <div id="vector-main-menu-unpinned-container" class="vector-unpinned-container"> <div id="vector-main-menu" class="vector-main-menu vector-pinnable-element"> <div class="vector-pinnable-header vector-main-menu-pinnable-header vector-pinnable-header-unpinned" data-feature-name="main-menu-pinned" data-pinnable-element-id="vector-main-menu" data-pinned-container-id="vector-main-menu-pinned-container" data-unpinned-container-id="vector-main-menu-unpinned-container" > <div class="vector-pinnable-header-label">Main menu</div> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-main-menu.pin">move to sidebar</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-main-menu.unpin">hide</button> </div> <div id="p-navigation" class="vector-menu mw-portlet mw-portlet-navigation" > <div class="vector-menu-heading"> Navigation </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="n-mainpage-description" class="mw-list-item"><a href="/wiki/Main_Page" title="Visit the main page [z]" accesskey="z"><span>Main page</span></a></li><li id="n-contents" class="mw-list-item"><a href="/wiki/Wikipedia:Contents" title="Guides to browsing Wikipedia"><span>Contents</span></a></li><li id="n-currentevents" class="mw-list-item"><a href="/wiki/Portal:Current_events" title="Articles related to current events"><span>Current events</span></a></li><li id="n-randompage" class="mw-list-item"><a href="/wiki/Special:Random" title="Visit a randomly selected article [x]" accesskey="x"><span>Random article</span></a></li><li id="n-aboutsite" class="mw-list-item"><a href="/wiki/Wikipedia:About" title="Learn about Wikipedia and how it works"><span>About Wikipedia</span></a></li><li id="n-contactpage" class="mw-list-item"><a href="//en.wikipedia.org/wiki/Wikipedia:Contact_us" title="How to contact Wikipedia"><span>Contact us</span></a></li> </ul> </div> </div> <div id="p-interaction" class="vector-menu mw-portlet mw-portlet-interaction" > <div class="vector-menu-heading"> Contribute </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="n-help" class="mw-list-item"><a href="/wiki/Help:Contents" title="Guidance on how to use and edit Wikipedia"><span>Help</span></a></li><li id="n-introduction" class="mw-list-item"><a href="/wiki/Help:Introduction" title="Learn how to edit Wikipedia"><span>Learn to edit</span></a></li><li id="n-portal" class="mw-list-item"><a href="/wiki/Wikipedia:Community_portal" title="The hub for editors"><span>Community portal</span></a></li><li id="n-recentchanges" class="mw-list-item"><a href="/wiki/Special:RecentChanges" title="A list of recent changes to Wikipedia [r]" accesskey="r"><span>Recent changes</span></a></li><li id="n-upload" class="mw-list-item"><a href="/wiki/Wikipedia:File_upload_wizard" title="Add images or other media for use on Wikipedia"><span>Upload file</span></a></li> </ul> </div> </div> </div> </div> </div> </div> </nav> <a href="/wiki/Main_Page" class="mw-logo"> <img class="mw-logo-icon" src="/static/images/icons/wikipedia.png" alt="" aria-hidden="true" height="50" width="50"> <span class="mw-logo-container skin-invert"> <img class="mw-logo-wordmark" alt="Wikipedia" src="/static/images/mobile/copyright/wikipedia-wordmark-en.svg" style="width: 7.5em; height: 1.125em;"> <img class="mw-logo-tagline" alt="The Free Encyclopedia" src="/static/images/mobile/copyright/wikipedia-tagline-en.svg" width="117" height="13" style="width: 7.3125em; height: 0.8125em;"> </span> </a> </div> <div class="vector-header-end"> <div id="p-search" role="search" class="vector-search-box-vue vector-search-box-collapses vector-search-box-show-thumbnail vector-search-box-auto-expand-width vector-search-box"> <a href="/wiki/Special:Search" class="cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only search-toggle" title="Search Wikipedia [f]" accesskey="f"><span class="vector-icon mw-ui-icon-search mw-ui-icon-wikimedia-search"></span> <span>Search</span> </a> <div class="vector-typeahead-search-container"> <div class="cdx-typeahead-search cdx-typeahead-search--show-thumbnail cdx-typeahead-search--auto-expand-width"> <form action="/w/index.php" id="searchform" class="cdx-search-input cdx-search-input--has-end-button"> <div id="simpleSearch" class="cdx-search-input__input-wrapper" data-search-loc="header-moved"> <div class="cdx-text-input cdx-text-input--has-start-icon"> <input class="cdx-text-input__input" type="search" name="search" placeholder="Search Wikipedia" aria-label="Search Wikipedia" autocapitalize="sentences" title="Search Wikipedia [f]" accesskey="f" id="searchInput" > <span class="cdx-text-input__icon cdx-text-input__start-icon"></span> </div> <input type="hidden" name="title" value="Special:Search"> </div> <button class="cdx-button cdx-search-input__end-button">Search</button> </form> </div> </div> </div> <nav class="vector-user-links vector-user-links-wide" aria-label="Personal tools"> <div class="vector-user-links-main"> <div id="p-vector-user-menu-preferences" class="vector-menu mw-portlet emptyPortlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> </ul> </div> </div> <div id="p-vector-user-menu-userpage" class="vector-menu mw-portlet emptyPortlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> </ul> </div> </div> <nav class="vector-appearance-landmark" aria-label="Appearance"> <div id="vector-appearance-dropdown" class="vector-dropdown " title="Change the appearance of the page's font size, width, and color" > <input type="checkbox" id="vector-appearance-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-appearance-dropdown" class="vector-dropdown-checkbox " aria-label="Appearance" > <label id="vector-appearance-dropdown-label" for="vector-appearance-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-appearance mw-ui-icon-wikimedia-appearance"></span> <span class="vector-dropdown-label-text">Appearance</span> </label> <div class="vector-dropdown-content"> <div id="vector-appearance-unpinned-container" class="vector-unpinned-container"> </div> </div> </div> </nav> <div id="p-vector-user-menu-notifications" class="vector-menu mw-portlet emptyPortlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> </ul> </div> </div> <div id="p-vector-user-menu-overflow" class="vector-menu mw-portlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="pt-sitesupport-2" class="user-links-collapsible-item mw-list-item user-links-collapsible-item"><a data-mw="interface" href="https://donate.wikimedia.org/wiki/Special:FundraiserRedirector?utm_source=donate&utm_medium=sidebar&utm_campaign=C13_en.wikipedia.org&uselang=en" class=""><span>Donate</span></a> </li> <li id="pt-createaccount-2" class="user-links-collapsible-item mw-list-item user-links-collapsible-item"><a data-mw="interface" href="/w/index.php?title=Special:CreateAccount&returnto=Lux" title="You are encouraged to create an account and log in; however, it is not mandatory" class=""><span>Create account</span></a> </li> <li id="pt-login-2" class="user-links-collapsible-item mw-list-item user-links-collapsible-item"><a data-mw="interface" href="/w/index.php?title=Special:UserLogin&returnto=Lux" title="You're encouraged to log in; however, it's not mandatory. [o]" accesskey="o" class=""><span>Log in</span></a> </li> </ul> </div> </div> </div> <div id="vector-user-links-dropdown" class="vector-dropdown vector-user-menu vector-button-flush-right vector-user-menu-logged-out" title="Log in and more options" > <input type="checkbox" id="vector-user-links-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-user-links-dropdown" class="vector-dropdown-checkbox " aria-label="Personal tools" > <label id="vector-user-links-dropdown-label" for="vector-user-links-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-ellipsis mw-ui-icon-wikimedia-ellipsis"></span> <span class="vector-dropdown-label-text">Personal tools</span> </label> <div class="vector-dropdown-content"> <div id="p-personal" class="vector-menu mw-portlet mw-portlet-personal user-links-collapsible-item" title="User menu" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="pt-sitesupport" class="user-links-collapsible-item mw-list-item"><a href="https://donate.wikimedia.org/wiki/Special:FundraiserRedirector?utm_source=donate&utm_medium=sidebar&utm_campaign=C13_en.wikipedia.org&uselang=en"><span>Donate</span></a></li><li id="pt-createaccount" class="user-links-collapsible-item mw-list-item"><a href="/w/index.php?title=Special:CreateAccount&returnto=Lux" title="You are encouraged to create an account and log in; however, it is not mandatory"><span class="vector-icon mw-ui-icon-userAdd mw-ui-icon-wikimedia-userAdd"></span> <span>Create account</span></a></li><li id="pt-login" class="user-links-collapsible-item mw-list-item"><a href="/w/index.php?title=Special:UserLogin&returnto=Lux" title="You're encouraged to log in; however, it's not mandatory. [o]" accesskey="o"><span class="vector-icon mw-ui-icon-logIn mw-ui-icon-wikimedia-logIn"></span> <span>Log in</span></a></li> </ul> </div> </div> <div id="p-user-menu-anon-editor" class="vector-menu mw-portlet mw-portlet-user-menu-anon-editor" > <div class="vector-menu-heading"> Pages for logged out editors <a href="/wiki/Help:Introduction" aria-label="Learn more about editing"><span>learn more</span></a> </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="pt-anoncontribs" class="mw-list-item"><a href="/wiki/Special:MyContributions" title="A list of edits made from this IP address [y]" accesskey="y"><span>Contributions</span></a></li><li id="pt-anontalk" class="mw-list-item"><a href="/wiki/Special:MyTalk" title="Discussion about edits from this IP address [n]" accesskey="n"><span>Talk</span></a></li> </ul> </div> </div> </div> </div> </nav> </div> </header> </div> <div class="mw-page-container"> <div class="mw-page-container-inner"> <div class="vector-sitenotice-container"> <div id="siteNotice"></div> </div> <div class="vector-column-start"> <div class="vector-main-menu-container"> <div id="mw-navigation"> <nav id="mw-panel" class="vector-main-menu-landmark" aria-label="Site"> <div id="vector-main-menu-pinned-container" class="vector-pinned-container"> </div> </nav> </div> </div> <div class="vector-sticky-pinned-container"> <nav id="mw-panel-toc" aria-label="Contents" data-event-name="ui.sidebar-toc" class="mw-table-of-contents-container vector-toc-landmark"> <div id="vector-toc-pinned-container" class="vector-pinned-container"> <div id="vector-toc" class="vector-toc vector-pinnable-element"> <div class="vector-pinnable-header vector-toc-pinnable-header vector-pinnable-header-pinned" data-feature-name="toc-pinned" data-pinnable-element-id="vector-toc" > <h2 class="vector-pinnable-header-label">Contents</h2> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-toc.pin">move to sidebar</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-toc.unpin">hide</button> </div> <ul class="vector-toc-contents" id="mw-panel-toc-list"> <li id="toc-mw-content-text" class="vector-toc-list-item vector-toc-level-1"> <a href="#" class="vector-toc-link"> <div class="vector-toc-text">(Top)</div> </a> </li> <li id="toc-Explanation" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Explanation"> <div class="vector-toc-text"> <span class="vector-toc-numb">1</span> <span>Explanation</span> </div> </a> <button aria-controls="toc-Explanation-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Toggle Explanation subsection</span> </button> <ul id="toc-Explanation-sublist" class="vector-toc-list"> <li id="toc-Illuminance" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Illuminance"> <div class="vector-toc-text"> <span class="vector-toc-numb">1.1</span> <span>Illuminance</span> </div> </a> <ul id="toc-Illuminance-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Relationship_between_illuminance_and_irradiance" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Relationship_between_illuminance_and_irradiance"> <div class="vector-toc-text"> <span class="vector-toc-numb">1.2</span> <span>Relationship between illuminance and irradiance</span> </div> </a> <ul id="toc-Relationship_between_illuminance_and_irradiance-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-Use_in_video-camera_specifications" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Use_in_video-camera_specifications"> <div class="vector-toc-text"> <span class="vector-toc-numb">2</span> <span>Use in video-camera specifications</span> </div> </a> <ul id="toc-Use_in_video-camera_specifications-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Non-SI_units_of_illuminance" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Non-SI_units_of_illuminance"> <div class="vector-toc-text"> <span class="vector-toc-numb">3</span> <span>Non-SI units of illuminance</span> </div> </a> <ul id="toc-Non-SI_units_of_illuminance-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Legacy_Unicode_symbol" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Legacy_Unicode_symbol"> <div class="vector-toc-text"> <span class="vector-toc-numb">4</span> <span>Legacy Unicode symbol</span> </div> </a> <ul id="toc-Legacy_Unicode_symbol-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-SI_photometry_units" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#SI_photometry_units"> <div class="vector-toc-text"> <span class="vector-toc-numb">5</span> <span>SI photometry units</span> </div> </a> <ul id="toc-SI_photometry_units-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-See_also" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#See_also"> <div class="vector-toc-text"> <span class="vector-toc-numb">6</span> <span>See also</span> </div> </a> <ul id="toc-See_also-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-References" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#References"> <div class="vector-toc-text"> <span class="vector-toc-numb">7</span> <span>References</span> </div> </a> <ul id="toc-References-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-External_links" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#External_links"> <div class="vector-toc-text"> <span class="vector-toc-numb">8</span> <span>External links</span> </div> </a> <ul id="toc-External_links-sublist" class="vector-toc-list"> </ul> </li> </ul> </div> </div> </nav> </div> </div> <div class="mw-content-container"> <main id="content" class="mw-body"> <header class="mw-body-header vector-page-titlebar"> <nav aria-label="Contents" class="vector-toc-landmark"> <div id="vector-page-titlebar-toc" class="vector-dropdown vector-page-titlebar-toc vector-button-flush-left" > <input type="checkbox" id="vector-page-titlebar-toc-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-page-titlebar-toc" class="vector-dropdown-checkbox " aria-label="Toggle the table of contents" > <label id="vector-page-titlebar-toc-label" for="vector-page-titlebar-toc-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-listBullet mw-ui-icon-wikimedia-listBullet"></span> <span class="vector-dropdown-label-text">Toggle the table of contents</span> </label> <div class="vector-dropdown-content"> <div id="vector-page-titlebar-toc-unpinned-container" class="vector-unpinned-container"> </div> </div> </div> </nav> <h1 id="firstHeading" class="firstHeading mw-first-heading"><span class="mw-page-title-main">Lux</span></h1> <div id="p-lang-btn" class="vector-dropdown mw-portlet mw-portlet-lang" > <input type="checkbox" id="p-lang-btn-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-p-lang-btn" class="vector-dropdown-checkbox mw-interlanguage-selector" aria-label="Go to an article in another language. Available in 63 languages" > <label id="p-lang-btn-label" for="p-lang-btn-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--action-progressive mw-portlet-lang-heading-63" aria-hidden="true" ><span class="vector-icon mw-ui-icon-language-progressive mw-ui-icon-wikimedia-language-progressive"></span> <span class="vector-dropdown-label-text">63 languages</span> </label> <div class="vector-dropdown-content"> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li class="interlanguage-link interwiki-ar mw-list-item"><a href="https://ar.wikipedia.org/wiki/%D9%84%D9%83%D8%B3" title="لكس – Arabic" lang="ar" hreflang="ar" data-title="لكس" data-language-autonym="العربية" data-language-local-name="Arabic" class="interlanguage-link-target"><span>العربية</span></a></li><li class="interlanguage-link interwiki-ast mw-list-item"><a href="https://ast.wikipedia.org/wiki/Lux" title="Lux – Asturian" lang="ast" hreflang="ast" data-title="Lux" data-language-autonym="Asturianu" data-language-local-name="Asturian" class="interlanguage-link-target"><span>Asturianu</span></a></li><li class="interlanguage-link interwiki-bn mw-list-item"><a href="https://bn.wikipedia.org/wiki/%E0%A6%B2%E0%A6%BE%E0%A6%95%E0%A7%8D%E0%A6%B8_(%E0%A6%8F%E0%A6%95%E0%A6%95)" title="লাক্স (একক) – Bangla" lang="bn" hreflang="bn" data-title="লাক্স (একক)" data-language-autonym="বাংলা" data-language-local-name="Bangla" class="interlanguage-link-target"><span>বাংলা</span></a></li><li class="interlanguage-link interwiki-zh-min-nan mw-list-item"><a href="https://zh-min-nan.wikipedia.org/wiki/Lux" title="Lux – Minnan" lang="nan" hreflang="nan" data-title="Lux" data-language-autonym="閩南語 / Bân-lâm-gú" data-language-local-name="Minnan" class="interlanguage-link-target"><span>閩南語 / Bân-lâm-gú</span></a></li><li class="interlanguage-link interwiki-be mw-list-item"><a href="https://be.wikipedia.org/wiki/%D0%9B%D1%8E%D0%BA%D1%81" title="Люкс – Belarusian" lang="be" hreflang="be" data-title="Люкс" data-language-autonym="Беларуская" data-language-local-name="Belarusian" class="interlanguage-link-target"><span>Беларуская</span></a></li><li class="interlanguage-link interwiki-be-x-old mw-list-item"><a href="https://be-tarask.wikipedia.org/wiki/%D0%9B%D1%8E%D0%BA%D1%81" title="Люкс – Belarusian (Taraškievica orthography)" lang="be-tarask" hreflang="be-tarask" data-title="Люкс" data-language-autonym="Беларуская (тарашкевіца)" data-language-local-name="Belarusian (Taraškievica orthography)" class="interlanguage-link-target"><span>Беларуская (тарашкевіца)</span></a></li><li class="interlanguage-link interwiki-bg mw-list-item"><a href="https://bg.wikipedia.org/wiki/%D0%9B%D1%83%D0%BA%D1%81" title="Лукс – Bulgarian" lang="bg" hreflang="bg" data-title="Лукс" data-language-autonym="Български" data-language-local-name="Bulgarian" class="interlanguage-link-target"><span>Български</span></a></li><li class="interlanguage-link interwiki-bo mw-list-item"><a href="https://bo.wikipedia.org/wiki/%E0%BD%A3%E0%BC%8B%E0%BD%81%E0%BD%B2%E0%BC%8B%E0%BD%A6%E0%BD%B2%E0%BC%8D" title="ལ་ཁི་སི། – Tibetan" lang="bo" hreflang="bo" data-title="ལ་ཁི་སི།" data-language-autonym="བོད་ཡིག" data-language-local-name="Tibetan" class="interlanguage-link-target"><span>བོད་ཡིག</span></a></li><li class="interlanguage-link interwiki-bs mw-list-item"><a href="https://bs.wikipedia.org/wiki/Luks" title="Luks – Bosnian" lang="bs" hreflang="bs" data-title="Luks" data-language-autonym="Bosanski" data-language-local-name="Bosnian" class="interlanguage-link-target"><span>Bosanski</span></a></li><li class="interlanguage-link interwiki-ca mw-list-item"><a href="https://ca.wikipedia.org/wiki/Lux" title="Lux – Catalan" lang="ca" hreflang="ca" data-title="Lux" data-language-autonym="Català" data-language-local-name="Catalan" class="interlanguage-link-target"><span>Català</span></a></li><li class="interlanguage-link interwiki-cs mw-list-item"><a href="https://cs.wikipedia.org/wiki/Lux_(jednotka)" title="Lux (jednotka) – Czech" lang="cs" hreflang="cs" data-title="Lux (jednotka)" data-language-autonym="Čeština" data-language-local-name="Czech" class="interlanguage-link-target"><span>Čeština</span></a></li><li class="interlanguage-link interwiki-da mw-list-item"><a href="https://da.wikipedia.org/wiki/Lux" title="Lux – Danish" lang="da" hreflang="da" data-title="Lux" data-language-autonym="Dansk" data-language-local-name="Danish" class="interlanguage-link-target"><span>Dansk</span></a></li><li class="interlanguage-link interwiki-de mw-list-item"><a href="https://de.wikipedia.org/wiki/Lux_(Einheit)" title="Lux (Einheit) – German" lang="de" hreflang="de" data-title="Lux (Einheit)" data-language-autonym="Deutsch" data-language-local-name="German" class="interlanguage-link-target"><span>Deutsch</span></a></li><li class="interlanguage-link interwiki-et mw-list-item"><a href="https://et.wikipedia.org/wiki/Luks" title="Luks – Estonian" lang="et" hreflang="et" data-title="Luks" data-language-autonym="Eesti" data-language-local-name="Estonian" class="interlanguage-link-target"><span>Eesti</span></a></li><li class="interlanguage-link interwiki-el mw-list-item"><a href="https://el.wikipedia.org/wiki/%CE%9B%CE%BF%CF%85%CE%BE_(%CE%BC%CE%BF%CE%BD%CE%AC%CE%B4%CE%B1_%CE%BC%CE%AD%CF%84%CF%81%CE%B7%CF%83%CE%B7%CF%82)" title="Λουξ (μονάδα μέτρησης) – Greek" lang="el" hreflang="el" data-title="Λουξ (μονάδα μέτρησης)" data-language-autonym="Ελληνικά" data-language-local-name="Greek" class="interlanguage-link-target"><span>Ελληνικά</span></a></li><li class="interlanguage-link interwiki-es mw-list-item"><a href="https://es.wikipedia.org/wiki/Lux" title="Lux – Spanish" lang="es" hreflang="es" data-title="Lux" data-language-autonym="Español" data-language-local-name="Spanish" class="interlanguage-link-target"><span>Español</span></a></li><li class="interlanguage-link interwiki-eo mw-list-item"><a href="https://eo.wikipedia.org/wiki/Lukso_(mezurunuo)" title="Lukso (mezurunuo) – Esperanto" lang="eo" hreflang="eo" data-title="Lukso (mezurunuo)" data-language-autonym="Esperanto" data-language-local-name="Esperanto" class="interlanguage-link-target"><span>Esperanto</span></a></li><li class="interlanguage-link interwiki-eu mw-list-item"><a href="https://eu.wikipedia.org/wiki/Lux_(unitatea)" title="Lux (unitatea) – Basque" lang="eu" hreflang="eu" data-title="Lux (unitatea)" data-language-autonym="Euskara" data-language-local-name="Basque" class="interlanguage-link-target"><span>Euskara</span></a></li><li class="interlanguage-link interwiki-fa mw-list-item"><a href="https://fa.wikipedia.org/wiki/%D9%84%D9%88%DA%A9%D8%B3" title="لوکس – Persian" lang="fa" hreflang="fa" data-title="لوکس" data-language-autonym="فارسی" data-language-local-name="Persian" class="interlanguage-link-target"><span>فارسی</span></a></li><li class="interlanguage-link interwiki-fr mw-list-item"><a href="https://fr.wikipedia.org/wiki/Lux_(unit%C3%A9)" title="Lux (unité) – French" lang="fr" hreflang="fr" data-title="Lux (unité)" data-language-autonym="Français" data-language-local-name="French" class="interlanguage-link-target"><span>Français</span></a></li><li class="interlanguage-link interwiki-ga mw-list-item"><a href="https://ga.wikipedia.org/wiki/Lucsa" title="Lucsa – Irish" lang="ga" hreflang="ga" data-title="Lucsa" data-language-autonym="Gaeilge" data-language-local-name="Irish" class="interlanguage-link-target"><span>Gaeilge</span></a></li><li class="interlanguage-link interwiki-gl mw-list-item"><a href="https://gl.wikipedia.org/wiki/Lux" title="Lux – Galician" lang="gl" hreflang="gl" data-title="Lux" data-language-autonym="Galego" data-language-local-name="Galician" class="interlanguage-link-target"><span>Galego</span></a></li><li class="interlanguage-link interwiki-ko mw-list-item"><a href="https://ko.wikipedia.org/wiki/%EB%9F%AD%EC%8A%A4" title="럭스 – Korean" lang="ko" hreflang="ko" data-title="럭스" data-language-autonym="한국어" data-language-local-name="Korean" class="interlanguage-link-target"><span>한국어</span></a></li><li class="interlanguage-link interwiki-hy mw-list-item"><a href="https://hy.wikipedia.org/wiki/%D4%BC%D5%B5%D5%B8%D6%82%D6%84%D5%BD_(%D5%B9%D5%A1%D6%83%D5%B4%D5%A1%D5%B6_%D5%B4%D5%AB%D5%A1%D5%BE%D5%B8%D6%80)" title="Լյուքս (չափման միավոր) – Armenian" lang="hy" hreflang="hy" data-title="Լյուքս (չափման միավոր)" data-language-autonym="Հայերեն" data-language-local-name="Armenian" class="interlanguage-link-target"><span>Հայերեն</span></a></li><li class="interlanguage-link interwiki-hi mw-list-item"><a href="https://hi.wikipedia.org/wiki/%E0%A4%B2%E0%A4%95%E0%A5%8D%E0%A4%B8" title="लक्स – Hindi" lang="hi" hreflang="hi" data-title="लक्स" data-language-autonym="हिन्दी" data-language-local-name="Hindi" class="interlanguage-link-target"><span>हिन्दी</span></a></li><li class="interlanguage-link interwiki-hr mw-list-item"><a href="https://hr.wikipedia.org/wiki/Luks" title="Luks – Croatian" lang="hr" hreflang="hr" data-title="Luks" data-language-autonym="Hrvatski" data-language-local-name="Croatian" class="interlanguage-link-target"><span>Hrvatski</span></a></li><li class="interlanguage-link interwiki-id mw-list-item"><a href="https://id.wikipedia.org/wiki/Lux" title="Lux – Indonesian" lang="id" hreflang="id" data-title="Lux" data-language-autonym="Bahasa Indonesia" data-language-local-name="Indonesian" class="interlanguage-link-target"><span>Bahasa Indonesia</span></a></li><li class="interlanguage-link interwiki-is mw-list-item"><a href="https://is.wikipedia.org/wiki/L%C3%BAx" title="Lúx – Icelandic" lang="is" hreflang="is" data-title="Lúx" data-language-autonym="Íslenska" data-language-local-name="Icelandic" class="interlanguage-link-target"><span>Íslenska</span></a></li><li class="interlanguage-link interwiki-it mw-list-item"><a href="https://it.wikipedia.org/wiki/Lux" title="Lux – Italian" lang="it" hreflang="it" data-title="Lux" data-language-autonym="Italiano" data-language-local-name="Italian" class="interlanguage-link-target"><span>Italiano</span></a></li><li class="interlanguage-link interwiki-he mw-list-item"><a href="https://he.wikipedia.org/wiki/%D7%9C%D7%95%D7%A7%D7%A1" title="לוקס – Hebrew" lang="he" hreflang="he" data-title="לוקס" data-language-autonym="עברית" data-language-local-name="Hebrew" class="interlanguage-link-target"><span>עברית</span></a></li><li class="interlanguage-link interwiki-ka mw-list-item"><a href="https://ka.wikipedia.org/wiki/%E1%83%9A%E1%83%A3%E1%83%A5%E1%83%A1%E1%83%98" title="ლუქსი – Georgian" lang="ka" hreflang="ka" data-title="ლუქსი" data-language-autonym="ქართული" data-language-local-name="Georgian" class="interlanguage-link-target"><span>ქართული</span></a></li><li class="interlanguage-link interwiki-kk mw-list-item"><a href="https://kk.wikipedia.org/wiki/%D0%9B%D1%8E%D0%BA%D1%81" title="Люкс – Kazakh" lang="kk" hreflang="kk" data-title="Люкс" data-language-autonym="Қазақша" data-language-local-name="Kazakh" class="interlanguage-link-target"><span>Қазақша</span></a></li><li class="interlanguage-link interwiki-ky mw-list-item"><a href="https://ky.wikipedia.org/wiki/%D0%9B%D1%8E%D0%BA%D1%81" title="Люкс – Kyrgyz" lang="ky" hreflang="ky" data-title="Люкс" data-language-autonym="Кыргызча" data-language-local-name="Kyrgyz" class="interlanguage-link-target"><span>Кыргызча</span></a></li><li class="interlanguage-link interwiki-lv mw-list-item"><a href="https://lv.wikipedia.org/wiki/Lukss" title="Lukss – Latvian" lang="lv" hreflang="lv" data-title="Lukss" data-language-autonym="Latviešu" data-language-local-name="Latvian" class="interlanguage-link-target"><span>Latviešu</span></a></li><li class="interlanguage-link interwiki-lt mw-list-item"><a href="https://lt.wikipedia.org/wiki/Liuksas" title="Liuksas – Lithuanian" lang="lt" hreflang="lt" data-title="Liuksas" data-language-autonym="Lietuvių" data-language-local-name="Lithuanian" class="interlanguage-link-target"><span>Lietuvių</span></a></li><li class="interlanguage-link interwiki-hu mw-list-item"><a href="https://hu.wikipedia.org/wiki/Lux" title="Lux – Hungarian" lang="hu" hreflang="hu" data-title="Lux" data-language-autonym="Magyar" data-language-local-name="Hungarian" class="interlanguage-link-target"><span>Magyar</span></a></li><li class="interlanguage-link interwiki-mk mw-list-item"><a href="https://mk.wikipedia.org/wiki/%D0%9B%D1%83%D0%BA%D1%81" title="Лукс – Macedonian" lang="mk" hreflang="mk" data-title="Лукс" data-language-autonym="Македонски" data-language-local-name="Macedonian" class="interlanguage-link-target"><span>Македонски</span></a></li><li class="interlanguage-link interwiki-ms mw-list-item"><a href="https://ms.wikipedia.org/wiki/Lux" title="Lux – Malay" lang="ms" hreflang="ms" data-title="Lux" data-language-autonym="Bahasa Melayu" data-language-local-name="Malay" class="interlanguage-link-target"><span>Bahasa Melayu</span></a></li><li class="interlanguage-link interwiki-mn mw-list-item"><a href="https://mn.wikipedia.org/wiki/%D0%9B%D1%8E%D0%BA%D1%81_(%D0%BD%D1%8D%D0%B3%D0%B6)" title="Люкс (нэгж) – Mongolian" lang="mn" hreflang="mn" data-title="Люкс (нэгж)" data-language-autonym="Монгол" data-language-local-name="Mongolian" class="interlanguage-link-target"><span>Монгол</span></a></li><li class="interlanguage-link interwiki-nl mw-list-item"><a href="https://nl.wikipedia.org/wiki/Lux_(eenheid)" title="Lux (eenheid) – Dutch" lang="nl" hreflang="nl" data-title="Lux (eenheid)" data-language-autonym="Nederlands" data-language-local-name="Dutch" class="interlanguage-link-target"><span>Nederlands</span></a></li><li class="interlanguage-link interwiki-ja mw-list-item"><a href="https://ja.wikipedia.org/wiki/%E3%83%AB%E3%82%AF%E3%82%B9" title="ルクス – Japanese" lang="ja" hreflang="ja" data-title="ルクス" data-language-autonym="日本語" data-language-local-name="Japanese" class="interlanguage-link-target"><span>日本語</span></a></li><li class="interlanguage-link interwiki-no mw-list-item"><a href="https://no.wikipedia.org/wiki/Lux" title="Lux – Norwegian Bokmål" lang="nb" hreflang="nb" data-title="Lux" data-language-autonym="Norsk bokmål" data-language-local-name="Norwegian Bokmål" class="interlanguage-link-target"><span>Norsk bokmål</span></a></li><li class="interlanguage-link interwiki-nn mw-list-item"><a href="https://nn.wikipedia.org/wiki/Lux" title="Lux – Norwegian Nynorsk" lang="nn" hreflang="nn" data-title="Lux" data-language-autonym="Norsk nynorsk" data-language-local-name="Norwegian Nynorsk" class="interlanguage-link-target"><span>Norsk nynorsk</span></a></li><li class="interlanguage-link interwiki-uz mw-list-item"><a href="https://uz.wikipedia.org/wiki/Lyuks_(o%CA%BBlchov_birligi)" title="Lyuks (oʻlchov birligi) – Uzbek" lang="uz" hreflang="uz" data-title="Lyuks (oʻlchov birligi)" data-language-autonym="Oʻzbekcha / ўзбекча" data-language-local-name="Uzbek" class="interlanguage-link-target"><span>Oʻzbekcha / ўзбекча</span></a></li><li class="interlanguage-link interwiki-pl mw-list-item"><a href="https://pl.wikipedia.org/wiki/Luks_(fotometria)" title="Luks (fotometria) – Polish" lang="pl" hreflang="pl" data-title="Luks (fotometria)" data-language-autonym="Polski" data-language-local-name="Polish" class="interlanguage-link-target"><span>Polski</span></a></li><li class="interlanguage-link interwiki-pt mw-list-item"><a href="https://pt.wikipedia.org/wiki/Lux" title="Lux – Portuguese" lang="pt" hreflang="pt" data-title="Lux" data-language-autonym="Português" data-language-local-name="Portuguese" class="interlanguage-link-target"><span>Português</span></a></li><li class="interlanguage-link interwiki-ro mw-list-item"><a href="https://ro.wikipedia.org/wiki/Lux" title="Lux – Romanian" lang="ro" hreflang="ro" data-title="Lux" data-language-autonym="Română" data-language-local-name="Romanian" class="interlanguage-link-target"><span>Română</span></a></li><li class="interlanguage-link interwiki-ru mw-list-item"><a href="https://ru.wikipedia.org/wiki/%D0%9B%D1%8E%D0%BA%D1%81" title="Люкс – Russian" lang="ru" hreflang="ru" data-title="Люкс" data-language-autonym="Русский" data-language-local-name="Russian" class="interlanguage-link-target"><span>Русский</span></a></li><li class="interlanguage-link interwiki-scn mw-list-item"><a href="https://scn.wikipedia.org/wiki/Lux" title="Lux – Sicilian" lang="scn" hreflang="scn" data-title="Lux" data-language-autonym="Sicilianu" data-language-local-name="Sicilian" class="interlanguage-link-target"><span>Sicilianu</span></a></li><li class="interlanguage-link interwiki-sk mw-list-item"><a href="https://sk.wikipedia.org/wiki/Lux_(jednotka)" title="Lux (jednotka) – Slovak" lang="sk" hreflang="sk" data-title="Lux (jednotka)" data-language-autonym="Slovenčina" data-language-local-name="Slovak" class="interlanguage-link-target"><span>Slovenčina</span></a></li><li class="interlanguage-link interwiki-sl mw-list-item"><a href="https://sl.wikipedia.org/wiki/Luks" title="Luks – Slovenian" lang="sl" hreflang="sl" data-title="Luks" data-language-autonym="Slovenščina" data-language-local-name="Slovenian" class="interlanguage-link-target"><span>Slovenščina</span></a></li><li class="interlanguage-link interwiki-sr mw-list-item"><a href="https://sr.wikipedia.org/wiki/%D0%9B%D1%83%D0%BA%D1%81" title="Лукс – Serbian" lang="sr" hreflang="sr" data-title="Лукс" data-language-autonym="Српски / srpski" data-language-local-name="Serbian" class="interlanguage-link-target"><span>Српски / srpski</span></a></li><li class="interlanguage-link interwiki-sh mw-list-item"><a href="https://sh.wikipedia.org/wiki/Luks" title="Luks – Serbo-Croatian" lang="sh" hreflang="sh" data-title="Luks" data-language-autonym="Srpskohrvatski / српскохрватски" data-language-local-name="Serbo-Croatian" class="interlanguage-link-target"><span>Srpskohrvatski / српскохрватски</span></a></li><li class="interlanguage-link interwiki-fi mw-list-item"><a href="https://fi.wikipedia.org/wiki/Luksi" title="Luksi – Finnish" lang="fi" hreflang="fi" data-title="Luksi" data-language-autonym="Suomi" data-language-local-name="Finnish" class="interlanguage-link-target"><span>Suomi</span></a></li><li class="interlanguage-link interwiki-sv mw-list-item"><a href="https://sv.wikipedia.org/wiki/Lux_(enhet)" title="Lux (enhet) – Swedish" lang="sv" hreflang="sv" data-title="Lux (enhet)" data-language-autonym="Svenska" data-language-local-name="Swedish" class="interlanguage-link-target"><span>Svenska</span></a></li><li class="interlanguage-link interwiki-ta mw-list-item"><a href="https://ta.wikipedia.org/wiki/%E0%AE%B2%E0%AE%95%E0%AF%8D%E0%AE%9A%E0%AF%81" title="லக்சு – Tamil" lang="ta" hreflang="ta" data-title="லக்சு" data-language-autonym="தமிழ்" data-language-local-name="Tamil" class="interlanguage-link-target"><span>தமிழ்</span></a></li><li class="interlanguage-link interwiki-th mw-list-item"><a href="https://th.wikipedia.org/wiki/%E0%B8%A5%E0%B8%B1%E0%B8%81%E0%B8%8B%E0%B9%8C" title="ลักซ์ – Thai" lang="th" hreflang="th" data-title="ลักซ์" data-language-autonym="ไทย" data-language-local-name="Thai" class="interlanguage-link-target"><span>ไทย</span></a></li><li class="interlanguage-link interwiki-tr mw-list-item"><a href="https://tr.wikipedia.org/wiki/L%C3%BCks_(birim)" title="Lüks (birim) – Turkish" lang="tr" hreflang="tr" data-title="Lüks (birim)" data-language-autonym="Türkçe" data-language-local-name="Turkish" class="interlanguage-link-target"><span>Türkçe</span></a></li><li class="interlanguage-link interwiki-uk mw-list-item"><a href="https://uk.wikipedia.org/wiki/%D0%9B%D1%8E%D0%BA%D1%81" title="Люкс – Ukrainian" lang="uk" hreflang="uk" data-title="Люкс" data-language-autonym="Українська" data-language-local-name="Ukrainian" class="interlanguage-link-target"><span>Українська</span></a></li><li class="interlanguage-link interwiki-vi mw-list-item"><a href="https://vi.wikipedia.org/wiki/Lux" title="Lux – Vietnamese" lang="vi" hreflang="vi" data-title="Lux" data-language-autonym="Tiếng Việt" data-language-local-name="Vietnamese" class="interlanguage-link-target"><span>Tiếng Việt</span></a></li><li class="interlanguage-link interwiki-wuu mw-list-item"><a href="https://wuu.wikipedia.org/wiki/%E5%8B%92%E5%85%8B%E6%96%AF" title="勒克斯 – Wu" lang="wuu" hreflang="wuu" data-title="勒克斯" data-language-autonym="吴语" data-language-local-name="Wu" class="interlanguage-link-target"><span>吴语</span></a></li><li class="interlanguage-link interwiki-zh-yue mw-list-item"><a href="https://zh-yue.wikipedia.org/wiki/%E5%8B%92%E5%85%8B%E6%96%AF" title="勒克斯 – Cantonese" lang="yue" hreflang="yue" data-title="勒克斯" data-language-autonym="粵語" data-language-local-name="Cantonese" class="interlanguage-link-target"><span>粵語</span></a></li><li class="interlanguage-link interwiki-zh mw-list-item"><a href="https://zh.wikipedia.org/wiki/%E5%8B%92%E5%85%8B%E6%96%AF" title="勒克斯 – Chinese" lang="zh" hreflang="zh" data-title="勒克斯" data-language-autonym="中文" data-language-local-name="Chinese" class="interlanguage-link-target"><span>中文</span></a></li> </ul> <div class="after-portlet after-portlet-lang"><span class="wb-langlinks-edit wb-langlinks-link"><a href="https://www.wikidata.org/wiki/Special:EntityPage/Q179836#sitelinks-wikipedia" title="Edit interlanguage links" class="wbc-editpage">Edit links</a></span></div> </div> </div> </div> </header> <div class="vector-page-toolbar"> <div class="vector-page-toolbar-container"> <div id="left-navigation"> <nav aria-label="Namespaces"> <div id="p-associated-pages" class="vector-menu vector-menu-tabs mw-portlet mw-portlet-associated-pages" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="ca-nstab-main" class="selected vector-tab-noicon mw-list-item"><a href="/wiki/Lux" title="View the content page [c]" accesskey="c"><span>Article</span></a></li><li id="ca-talk" class="vector-tab-noicon mw-list-item"><a href="/wiki/Talk:Lux" rel="discussion" title="Discuss improvements to the content page [t]" accesskey="t"><span>Talk</span></a></li> </ul> </div> </div> <div id="vector-variants-dropdown" class="vector-dropdown emptyPortlet" > <input type="checkbox" id="vector-variants-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-variants-dropdown" class="vector-dropdown-checkbox " aria-label="Change language variant" > <label id="vector-variants-dropdown-label" for="vector-variants-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet" aria-hidden="true" ><span class="vector-dropdown-label-text">English</span> </label> <div class="vector-dropdown-content"> <div id="p-variants" class="vector-menu mw-portlet mw-portlet-variants emptyPortlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> </ul> </div> </div> </div> </div> </nav> </div> <div id="right-navigation" class="vector-collapsible"> <nav aria-label="Views"> <div id="p-views" class="vector-menu vector-menu-tabs mw-portlet mw-portlet-views" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="ca-view" class="selected vector-tab-noicon mw-list-item"><a href="/wiki/Lux"><span>Read</span></a></li><li id="ca-edit" class="vector-tab-noicon mw-list-item"><a href="/w/index.php?title=Lux&action=edit" title="Edit this page [e]" accesskey="e"><span>Edit</span></a></li><li id="ca-history" class="vector-tab-noicon mw-list-item"><a href="/w/index.php?title=Lux&action=history" title="Past revisions of this page [h]" accesskey="h"><span>View history</span></a></li> </ul> </div> </div> </nav> <nav class="vector-page-tools-landmark" aria-label="Page tools"> <div id="vector-page-tools-dropdown" class="vector-dropdown vector-page-tools-dropdown" > <input type="checkbox" id="vector-page-tools-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-page-tools-dropdown" class="vector-dropdown-checkbox " aria-label="Tools" > <label id="vector-page-tools-dropdown-label" for="vector-page-tools-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet" aria-hidden="true" ><span class="vector-dropdown-label-text">Tools</span> </label> <div class="vector-dropdown-content"> <div id="vector-page-tools-unpinned-container" class="vector-unpinned-container"> <div id="vector-page-tools" class="vector-page-tools vector-pinnable-element"> <div class="vector-pinnable-header vector-page-tools-pinnable-header vector-pinnable-header-unpinned" data-feature-name="page-tools-pinned" data-pinnable-element-id="vector-page-tools" data-pinned-container-id="vector-page-tools-pinned-container" data-unpinned-container-id="vector-page-tools-unpinned-container" > <div class="vector-pinnable-header-label">Tools</div> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-page-tools.pin">move to sidebar</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-page-tools.unpin">hide</button> </div> <div id="p-cactions" class="vector-menu mw-portlet mw-portlet-cactions emptyPortlet vector-has-collapsible-items" title="More options" > <div class="vector-menu-heading"> Actions </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="ca-more-view" class="selected vector-more-collapsible-item mw-list-item"><a href="/wiki/Lux"><span>Read</span></a></li><li id="ca-more-edit" class="vector-more-collapsible-item mw-list-item"><a href="/w/index.php?title=Lux&action=edit" title="Edit this page [e]" accesskey="e"><span>Edit</span></a></li><li id="ca-more-history" class="vector-more-collapsible-item mw-list-item"><a href="/w/index.php?title=Lux&action=history"><span>View history</span></a></li> </ul> </div> </div> <div id="p-tb" class="vector-menu mw-portlet mw-portlet-tb" > <div class="vector-menu-heading"> General </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="t-whatlinkshere" class="mw-list-item"><a href="/wiki/Special:WhatLinksHere/Lux" title="List of all English Wikipedia pages containing links to this page [j]" accesskey="j"><span>What links here</span></a></li><li id="t-recentchangeslinked" class="mw-list-item"><a href="/wiki/Special:RecentChangesLinked/Lux" rel="nofollow" title="Recent changes in pages linked from this page [k]" accesskey="k"><span>Related changes</span></a></li><li id="t-upload" class="mw-list-item"><a href="/wiki/Wikipedia:File_Upload_Wizard" title="Upload files [u]" accesskey="u"><span>Upload file</span></a></li><li id="t-specialpages" class="mw-list-item"><a href="/wiki/Special:SpecialPages" title="A list of all special pages [q]" accesskey="q"><span>Special pages</span></a></li><li id="t-permalink" class="mw-list-item"><a href="/w/index.php?title=Lux&oldid=1255787364" title="Permanent link to this revision of this page"><span>Permanent link</span></a></li><li id="t-info" class="mw-list-item"><a href="/w/index.php?title=Lux&action=info" title="More information about this page"><span>Page information</span></a></li><li id="t-cite" class="mw-list-item"><a href="/w/index.php?title=Special:CiteThisPage&page=Lux&id=1255787364&wpFormIdentifier=titleform" title="Information on how to cite this page"><span>Cite this page</span></a></li><li id="t-urlshortener" class="mw-list-item"><a href="/w/index.php?title=Special:UrlShortener&url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FLux"><span>Get shortened URL</span></a></li><li id="t-urlshortener-qrcode" class="mw-list-item"><a href="/w/index.php?title=Special:QrCode&url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FLux"><span>Download QR code</span></a></li> </ul> </div> </div> <div id="p-coll-print_export" class="vector-menu mw-portlet mw-portlet-coll-print_export" > <div class="vector-menu-heading"> Print/export </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="coll-download-as-rl" class="mw-list-item"><a href="/w/index.php?title=Special:DownloadAsPdf&page=Lux&action=show-download-screen" title="Download this page as a PDF file"><span>Download as PDF</span></a></li><li id="t-print" class="mw-list-item"><a href="/w/index.php?title=Lux&printable=yes" title="Printable version of this page [p]" accesskey="p"><span>Printable version</span></a></li> </ul> </div> </div> <div id="p-wikibase-otherprojects" class="vector-menu mw-portlet mw-portlet-wikibase-otherprojects" > <div class="vector-menu-heading"> In other projects </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="t-wikibase" class="wb-otherproject-link wb-otherproject-wikibase-dataitem mw-list-item"><a href="https://www.wikidata.org/wiki/Special:EntityPage/Q179836" title="Structured data on this page hosted by Wikidata [g]" accesskey="g"><span>Wikidata item</span></a></li> </ul> </div> </div> </div> </div> </div> </div> </nav> </div> </div> </div> <div class="vector-column-end"> <div class="vector-sticky-pinned-container"> <nav class="vector-page-tools-landmark" aria-label="Page tools"> <div id="vector-page-tools-pinned-container" class="vector-pinned-container"> </div> </nav> <nav class="vector-appearance-landmark" aria-label="Appearance"> <div id="vector-appearance-pinned-container" class="vector-pinned-container"> <div id="vector-appearance" class="vector-appearance vector-pinnable-element"> <div class="vector-pinnable-header vector-appearance-pinnable-header vector-pinnable-header-pinned" data-feature-name="appearance-pinned" data-pinnable-element-id="vector-appearance" data-pinned-container-id="vector-appearance-pinned-container" data-unpinned-container-id="vector-appearance-unpinned-container" > <div class="vector-pinnable-header-label">Appearance</div> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-appearance.pin">move to sidebar</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-appearance.unpin">hide</button> </div> </div> </div> </nav> </div> </div> <div id="bodyContent" class="vector-body" aria-labelledby="firstHeading" data-mw-ve-target-container> <div class="vector-body-before-content"> <div class="mw-indicators"> </div> <div id="siteSub" class="noprint">From Wikipedia, the free encyclopedia</div> </div> <div id="contentSub"><div id="mw-content-subtitle"></div></div> <div id="mw-content-text" class="mw-body-content"><div class="mw-content-ltr mw-parser-output" lang="en" dir="ltr"><div class="shortdescription nomobile noexcerpt noprint searchaux" style="display:none">SI derived unit of illuminance</div> <style data-mw-deduplicate="TemplateStyles:r1236090951">.mw-parser-output .hatnote{font-style:italic}.mw-parser-output div.hatnote{padding-left:1.6em;margin-bottom:0.5em}.mw-parser-output .hatnote i{font-style:normal}.mw-parser-output .hatnote+link+.hatnote{margin-top:-0.5em}@media print{body.ns-0 .mw-parser-output .hatnote{display:none!important}}</style><div role="note" class="hatnote navigation-not-searchable">For other uses, see <a href="/wiki/Lux_(disambiguation)" class="mw-disambig" title="Lux (disambiguation)">Lux (disambiguation)</a>.</div> <p class="mw-empty-elt"> </p> <style data-mw-deduplicate="TemplateStyles:r1257001546">.mw-parser-output .infobox-subbox{padding:0;border:none;margin:-3px;width:auto;min-width:100%;font-size:100%;clear:none;float:none;background-color:transparent}.mw-parser-output .infobox-3cols-child{margin:auto}.mw-parser-output .infobox .navbar{font-size:100%}@media screen{html.skin-theme-clientpref-night .mw-parser-output .infobox-full-data:not(.notheme)>div:not(.notheme)[style]{background:#1f1f23!important;color:#f8f9fa}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .infobox-full-data:not(.notheme) div:not(.notheme){background:#1f1f23!important;color:#f8f9fa}}@media(min-width:640px){body.skin--responsive .mw-parser-output .infobox-table{display:table!important}body.skin--responsive .mw-parser-output .infobox-table>caption{display:table-caption!important}body.skin--responsive .mw-parser-output .infobox-table>tbody{display:table-row-group}body.skin--responsive .mw-parser-output .infobox-table tr{display:table-row!important}body.skin--responsive .mw-parser-output .infobox-table th,body.skin--responsive .mw-parser-output .infobox-table td{padding-left:inherit;padding-right:inherit}}</style><table class="infobox ib-unit"><tbody><tr><th colspan="2" class="infobox-above">lux</th></tr><tr><td colspan="2" class="infobox-image notheme" style="background-color: #f8f9fa;"><span class="mw-default-size" typeof="mw:File/Frameless"><a href="/wiki/File:Lux_meter.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/f/f1/Lux_meter.jpg/220px-Lux_meter.jpg" decoding="async" width="220" height="215" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/f/f1/Lux_meter.jpg/330px-Lux_meter.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/f/f1/Lux_meter.jpg/440px-Lux_meter.jpg 2x" data-file-width="1156" data-file-height="1132" /></a></span><div class="infobox-caption">A lux meter for measuring illuminance</div></td></tr><tr><th colspan="2" class="infobox-header">General information</th></tr><tr><th scope="row" class="infobox-label"><a href="/wiki/System_of_units_of_measurement" title="System of units of measurement">Unit system</a></th><td class="infobox-data"><a href="/wiki/SI" class="mw-redirect" title="SI">SI</a></td></tr><tr><th scope="row" class="infobox-label">Unit of</th><td class="infobox-data"><a href="/wiki/Illuminance" title="Illuminance">illuminance</a></td></tr><tr><th scope="row" class="infobox-label">Symbol</th><td class="infobox-data">lx</td></tr><tr><th colspan="2" class="infobox-header">Conversions </th></tr><tr class="nowrap"><td>1 lx <i>in ...</i></td><td><i>... is equal to ...</i></td></tr><tr style="display:none"><th colspan="2"> </th></tr><tr><th scope="row" class="infobox-label"><span class="nowrap">   </span><a href="/wiki/SI_base_unit" title="SI base unit">SI base units</a></th><td class="infobox-data"><span class="nowrap">   </span><a href="/wiki/Candela" title="Candela">cd</a>⋅<a href="/wiki/Steradian" title="Steradian">sr</a>⋅<a href="/wiki/Metre" title="Metre">m</a><sup>−2</sup></td></tr><tr><th scope="row" class="infobox-label"><span class="nowrap">   </span><a href="/wiki/United_States_customary_units" title="United States customary units">US customary units</a></th><td class="infobox-data"><span class="nowrap">   </span>0.0929 <a href="/wiki/Foot-candle" title="Foot-candle">fc</a></td></tr><tr><th scope="row" class="infobox-label"><span class="nowrap">   </span><a href="/wiki/Centimetre%E2%80%93gram%E2%80%93second_system_of_units" title="Centimetre–gram–second system of units">CGS</a> units</th><td class="infobox-data"><span class="nowrap">   </span><span class="nowrap"><span data-sort-value="6996100000000000000♠"></span>10<sup>−4</sup> <a href="/wiki/Phot" title="Phot">ph</a></span></td></tr></tbody></table><style data-mw-deduplicate="TemplateStyles:r1236303919">@media screen{html.skin-theme-clientpref-night .mw-parser-output .infobox-has-images-with-white-backgrounds img{background:white}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .infobox-has-images-with-white-backgrounds img{background:white}}</style> <p>The <b>lux</b> (symbol: <b>lx</b>) is the unit of <a href="/wiki/Illuminance" title="Illuminance">illuminance</a>, or <a href="/wiki/Luminous_flux" title="Luminous flux">luminous flux</a> per unit area, in the <a href="/wiki/International_System_of_Units" title="International System of Units">International System of Units</a> (SI).<sup id="cite_ref-SIBrochure9thEd_1-0" class="reference"><a href="#cite_note-SIBrochure9thEd-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-2" class="reference"><a href="#cite_note-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup> It is equal to one <a href="/wiki/Lumen_(unit)" title="Lumen (unit)">lumen</a> per square metre. In <a href="/wiki/Photometry_(optics)" title="Photometry (optics)">photometry</a>, this is used as a measure of the <a href="/wiki/Irradiance" title="Irradiance">irradiance</a>, as perceived by the spectrally unequally responding human eye, of <a href="/wiki/Light" title="Light">light</a> that hits or passes through a surface. It is analogous to the <a href="/wiki/Radiometry" title="Radiometry">radiometric</a> unit <a href="/wiki/Irradiance" title="Irradiance">watt per square metre</a>, but with the power at each <a href="/wiki/Wavelength" title="Wavelength">wavelength</a> weighted according to the <a href="/wiki/Luminosity_function" class="mw-redirect" title="Luminosity function">luminosity function</a>, a model of <a href="/wiki/Human" title="Human">human</a> visual brightness perception, standardized by the CIE and <a href="/wiki/International_Organization_for_Standardization" title="International Organization for Standardization">ISO</a>.<sup id="cite_ref-3" class="reference"><a href="#cite_note-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup> In English, "lux" is used as both the singular and plural form.<sup id="cite_ref-4" class="reference"><a href="#cite_note-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup> The word is derived from the <a href="/wiki/Latin" title="Latin">Latin</a> word for "light", <a href="https://en.wiktionary.org/wiki/lux" class="extiw" title="wikt:lux">lux</a>. </p> <meta property="mw:PageProp/toc" /> <div class="mw-heading mw-heading2"><h2 id="Explanation">Explanation</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Lux&action=edit&section=1" title="Edit section: Explanation"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <div class="mw-heading mw-heading3"><h3 id="Illuminance">Illuminance</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Lux&action=edit&section=2" title="Edit section: Illuminance"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Illuminance is a measure of how much <a href="/wiki/Luminous_flux" title="Luminous flux">luminous flux</a> is spread over a given area. One can think of luminous flux (with the unit <a href="/wiki/Lumen_(unit)" title="Lumen (unit)">lumen</a>) as a measure of the total "amount" of visible light present, and the illuminance as a measure of the intensity of illumination on a surface. A given amount of light will illuminate a surface more dimly if it is spread over a larger area, so illuminance is inversely proportional to area when the luminous flux is held constant. </p><p>One lux is equal to one lumen per <a href="/wiki/Square_metre" title="Square metre">square metre</a>: </p> <dl><dd>1 lx = 1 lm/m<sup>2</sup> = 1 <a href="/wiki/Candela" title="Candela">cd</a>·<a href="/wiki/Steradian" title="Steradian">sr</a>/m<sup>2</sup>.</dd></dl> <p>A flux of 1000 lumens, spread uniformly over an area of 1 square metre, lights up that square metre with an illuminance of 1000 lux. However, the same 1000 lumens spread out over 10 square metres produces a dimmer illuminance of only 100 lux. </p><p>Achieving an illuminance of 500 lx might be possible in a home kitchen with a single <a href="/wiki/Fluorescent_light" class="mw-redirect" title="Fluorescent light">fluorescent light</a> fixture with an output of <span class="nowrap"><span data-sort-value="7004120000000000000♠"></span>12<span style="margin-left:.25em;">000</span> lumens</span>. To light a factory floor with dozens of times the area of the kitchen would require dozens of such fixtures. Thus, lighting a larger area to the same illuminance (lux) requires a greater luminous flux (lumen). </p><p>As with other named SI units, <a href="/wiki/SI_prefixes" class="mw-redirect" title="SI prefixes">SI prefixes</a> can be used. For example, 1 kilolux (klx) is 1000 lx. </p><p>Here are some examples of the illuminance provided under various conditions: </p> <table class="wikitable"> <tbody><tr> <th>Illuminance (lux)</th> <th style="text-align:left;">Surfaces illuminated by </th></tr> <tr> <td>0.0001</td> <td>Moonless, overcast night sky (<a href="/wiki/Starlight" title="Starlight">starlight</a>)<sup id="cite_ref-radfaq_5-0" class="reference"><a href="#cite_note-radfaq-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup> </td></tr> <tr> <td>0.002</td> <td>Moonless clear night sky with <a href="/wiki/Airglow" title="Airglow">airglow</a><sup id="cite_ref-radfaq_5-1" class="reference"><a href="#cite_note-radfaq-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup> </td></tr> <tr> <td>0.05–0.3</td> <td>Full moon on a clear night<sup id="cite_ref-6" class="reference"><a href="#cite_note-6"><span class="cite-bracket">[</span>6<span class="cite-bracket">]</span></a></sup> </td></tr> <tr> <td>3.4</td> <td>Dark limit of <a href="/wiki/Twilight#Civil_twilight" title="Twilight">civil twilight</a> under a clear sky<sup id="cite_ref-7" class="reference"><a href="#cite_note-7"><span class="cite-bracket">[</span>7<span class="cite-bracket">]</span></a></sup> </td></tr> <tr> <td>20–50</td> <td>Public areas with dark surroundings<sup id="cite_ref-NOAO_CaRLLI_8-0" class="reference"><a href="#cite_note-NOAO_CaRLLI-8"><span class="cite-bracket">[</span>8<span class="cite-bracket">]</span></a></sup> </td></tr> <tr> <td>50</td> <td>Family living room lights (Australia, 1998)<sup id="cite_ref-energyrating_9-0" class="reference"><a href="#cite_note-energyrating-9"><span class="cite-bracket">[</span>9<span class="cite-bracket">]</span></a></sup> </td></tr> <tr> <td>80</td> <td>Office building hallway/<a href="/wiki/Toilet_(room)" title="Toilet (room)">toilet</a> lighting<sup id="cite_ref-10" class="reference"><a href="#cite_note-10"><span class="cite-bracket">[</span>10<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-11" class="reference"><a href="#cite_note-11"><span class="cite-bracket">[</span>11<span class="cite-bracket">]</span></a></sup> </td></tr> <tr> <td>100</td> <td>Very dark overcast day<sup id="cite_ref-radfaq_5-2" class="reference"><a href="#cite_note-radfaq-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup> </td></tr> <tr> <td>150</td> <td>Train station platforms<sup id="cite_ref-12" class="reference"><a href="#cite_note-12"><span class="cite-bracket">[</span>12<span class="cite-bracket">]</span></a></sup> </td></tr> <tr> <td>320–500</td> <td>Office lighting<sup id="cite_ref-energyrating_9-1" class="reference"><a href="#cite_note-energyrating-9"><span class="cite-bracket">[</span>9<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-13" class="reference"><a href="#cite_note-13"><span class="cite-bracket">[</span>13<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-14" class="reference"><a href="#cite_note-14"><span class="cite-bracket">[</span>14<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-15" class="reference"><a href="#cite_note-15"><span class="cite-bracket">[</span>15<span class="cite-bracket">]</span></a></sup> </td></tr> <tr> <td>400</td> <td><a href="/wiki/Sunrise" title="Sunrise">Sunrise</a> or <a href="/wiki/Sunset" title="Sunset">sunset</a> on a clear day. </td></tr> <tr> <td>1000</td> <td>Overcast day;<sup id="cite_ref-radfaq_5-3" class="reference"><a href="#cite_note-radfaq-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup> typical <a href="/wiki/TV_studio" class="mw-redirect" title="TV studio">TV studio</a> lighting </td></tr> <tr> <td>10,000–25,000</td> <td>Full <a href="/wiki/Daylight" title="Daylight">daylight</a> (not direct sun)<sup id="cite_ref-radfaq_5-4" class="reference"><a href="#cite_note-radfaq-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup> </td></tr> <tr> <td>32,000–100,000</td> <td>Direct <a href="/wiki/Sunlight" title="Sunlight">sunlight</a> </td></tr></tbody></table> <p>The illuminance provided by a light source on a surface perpendicular to the direction to the source is a measure of the strength of that source as perceived from that location. For instance, a star of <a href="/wiki/Apparent_magnitude" title="Apparent magnitude">apparent magnitude</a> 0 provides 2.08 microlux (μlx) at the Earth's surface.<sup id="cite_ref-Schlyter7_16-0" class="reference"><a href="#cite_note-Schlyter7-16"><span class="cite-bracket">[</span>16<span class="cite-bracket">]</span></a></sup> A barely perceptible magnitude 6 star provides 8 nanolux (nlx).<sup id="cite_ref-17" class="reference"><a href="#cite_note-17"><span class="cite-bracket">[</span>17<span class="cite-bracket">]</span></a></sup> The unobscured Sun provides an illumination of up to 100 kilolux (klx) on the Earth's surface, the exact value depending on time of year and atmospheric conditions. This direct normal illuminance is related to the <a href="/wiki/Solar_illuminance_constant" class="mw-redirect" title="Solar illuminance constant">solar illuminance constant</a> <i>E</i><sub>sc</sub>, equal to <span class="nowrap"><span data-sort-value="7005128000000000000♠"></span>128<span style="margin-left:.25em;">000</span> lux</span> (see <a href="/wiki/Sunlight" title="Sunlight">Sunlight</a> and <a href="/wiki/Solar_constant" title="Solar constant">Solar constant</a>). </p><p>The illuminance on a surface depends on how the surface is tilted with respect to the source. For example, a pocket flashlight aimed at a wall will produce a given level of illumination if aimed perpendicular to the wall, but if the flashlight is aimed at increasing angles to the perpendicular (maintaining the same distance), the illuminated spot becomes larger and so is less highly illuminated. When a surface is tilted at an angle to a source, the illumination provided on the surface is reduced because the tilted surface subtends a smaller solid angle from the source, and therefore it receives less light. For a point source, the illumination on the tilted surface is reduced by a factor equal to the cosine of the angle between a ray coming from the source and the <a href="/wiki/Surface_normal" class="mw-redirect" title="Surface normal">normal</a> to the surface.<sup id="cite_ref-18" class="reference"><a href="#cite_note-18"><span class="cite-bracket">[</span>18<span class="cite-bracket">]</span></a></sup> In practical lighting problems, given information on the way light is emitted from each source and the distance and geometry of the lighted area, a numerical calculation can be made of the illumination on a surface by adding the contributions of every point on every light source. </p> <div class="mw-heading mw-heading3"><h3 id="Relationship_between_illuminance_and_irradiance">Relationship between illuminance and irradiance</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Lux&action=edit&section=3" title="Edit section: Relationship between illuminance and irradiance"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Like all <a href="/wiki/Photometry_(optics)" title="Photometry (optics)">photometric units</a>, the lux has a corresponding "<a href="/wiki/Radiometry" title="Radiometry">radiometric</a>" unit. The difference between any photometric unit and its corresponding radiometric unit is that radiometric units are based on physical power, with all wavelengths being weighted equally, while photometric units take into account the fact that the human eye's image-forming visual system is more sensitive to some wavelengths than others, and accordingly every wavelength is given a different weight. The weighting factor is known as the <a href="/wiki/Luminosity_function" class="mw-redirect" title="Luminosity function">luminosity function</a>. </p><p>The lux is one lumen per square metre (lm/m<sup>2</sup>), and the corresponding radiometric unit, which measures <a href="/wiki/Irradiance" title="Irradiance">irradiance</a>, is the watt per square metre (W/m<sup>2</sup>). There is no single conversion factor between lux and W/m<sup>2</sup>; there is a different conversion factor for every wavelength, and it is not possible to make a conversion unless one knows the spectral composition of the light. </p><p>The peak of the luminosity function is at 555 <a href="/wiki/Nanometre" title="Nanometre">nm</a> (green); the eye's image-forming visual system is more sensitive to light of this wavelength than any other. For monochromatic light <i>of this wavelength</i>, the amount of illuminance for a given amount of irradiance is maximum: 683.002 lx per 1 W/m<sup>2</sup>; the irradiance needed to make 1 lx at this wavelength is about 1.464 <a href="/wiki/Milliwatt" class="mw-redirect" title="Milliwatt">mW</a>/m<sup>2</sup>. Other wavelengths of visible light produce fewer lux per watt-per-meter-squared. The luminosity function falls to zero for wavelengths outside the <a href="/wiki/Visible_spectrum" title="Visible spectrum">visible spectrum</a>. </p><p>For a light source with mixed wavelengths, the number of lumens per watt can be calculated by means of the luminosity function. In order to appear reasonably "white", a light source cannot consist solely of the green light to which the eye's image-forming visual photoreceptors are most sensitive, but must include a generous mixture of red and blue wavelengths, to which they are much less sensitive. </p><p>This means that white (or whitish) light sources produce far fewer lumens per watt than the theoretical maximum of 683.002 lm/W. The ratio between the actual number of lumens per watt and the theoretical maximum is expressed as a percentage known as the <a href="/wiki/Luminous_efficiency" class="mw-redirect" title="Luminous efficiency">luminous efficiency</a>. For example, a typical <a href="/wiki/Incandescent_light_bulb" title="Incandescent light bulb">incandescent light bulb</a> has a luminous efficiency of only about 2%. </p><p>In reality, individual eyes vary slightly in their luminosity functions. However, photometric units are precisely defined and precisely measurable. They are based on an agreed-upon standard luminosity function based on measurements of the spectral characteristics of image-forming <i>visual photoreception</i> in many individual human eyes. </p> <div class="mw-heading mw-heading2"><h2 id="Use_in_video-camera_specifications">Use in video-camera specifications</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Lux&action=edit&section=4" title="Edit section: Use in video-camera specifications"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Specifications for <a href="/wiki/Video_camera" title="Video camera">video cameras</a> such as <a href="/wiki/Camcorder" title="Camcorder">camcorders</a> and <a href="/wiki/Surveillance_camera" class="mw-redirect" title="Surveillance camera">surveillance cameras</a> often include a minimal illuminance level in lux at which the camera will record a satisfactory image.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (February 2013)">citation needed</span></a></i>]</sup> A camera with good low-light capability will have a lower lux rating. <a href="/wiki/Still_camera" class="mw-redirect" title="Still camera">Still cameras</a> do not use such a specification, since longer <a href="/wiki/Exposure_time" class="mw-redirect" title="Exposure time">exposure times</a> can generally be used to make pictures at very low illuminance levels, as opposed to the case in video cameras, where a maximal exposure time is generally set by the <a href="/wiki/Frame_rate" title="Frame rate">frame rate</a>. </p><p><span class="anchor" id="Lux_versus_footcandle"></span> </p> <div class="mw-heading mw-heading2"><h2 id="Non-SI_units_of_illuminance">Non-SI units of illuminance</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Lux&action=edit&section=5" title="Edit section: Non-SI units of illuminance"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The corresponding unit in English and American traditional units is the <a href="/wiki/Foot-candle" title="Foot-candle">foot-candle</a>. One foot candle is about 10.764 lx. Since one foot-candle is the illuminance cast on a surface by a one-candela source one foot away, a lux could be thought of as a "metre-candle", although this term is discouraged because it does not conform to SI standards for unit names. </p><p>One <a href="/wiki/Phot" title="Phot">phot</a> (ph) equals 10 kilolux (10 klx). </p><p><span class="anchor" id="Nox"></span>One nox (nx) equals 1 millilux (1 mlx) at light color 2042 K or 2046 K (formerly 2360 K).<sup id="cite_ref-Lohse-Stille_1948_19-0" class="reference"><a href="#cite_note-Lohse-Stille_1948-19"><span class="cite-bracket">[</span>19<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-Westphal_1952_20-0" class="reference"><a href="#cite_note-Westphal_1952-20"><span class="cite-bracket">[</span>20<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-Grimsehl_1988_21-0" class="reference"><a href="#cite_note-Grimsehl_1988-21"><span class="cite-bracket">[</span>21<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-Keplinger_2021_22-0" class="reference"><a href="#cite_note-Keplinger_2021-22"><span class="cite-bracket">[</span>22<span class="cite-bracket">]</span></a></sup> </p><p>In <a href="/wiki/Astronomy" title="Astronomy">astronomy</a>, <a href="/wiki/Apparent_magnitude" title="Apparent magnitude">apparent magnitude</a> is a measure of the illuminance of a star on the Earth's atmosphere. A star with apparent magnitude 0 is 2.54 microlux outside the earth's atmosphere, and 82% of that (2.08 microlux) under clear skies.<sup id="cite_ref-Schlyter7_16-1" class="reference"><a href="#cite_note-Schlyter7-16"><span class="cite-bracket">[</span>16<span class="cite-bracket">]</span></a></sup> A magnitude 6 star (just barely visible under good conditions) would be 8.3 nanolux. A standard candle (one candela) a kilometre away would provide an illuminance of 1 microlux—about the same as a magnitude 1 star. </p> <div class="mw-heading mw-heading2"><h2 id="Legacy_Unicode_symbol">Legacy Unicode symbol</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Lux&action=edit&section=6" title="Edit section: Legacy Unicode symbol"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p><a href="/wiki/Unicode" title="Unicode">Unicode</a> includes a symbol for "lx": <span class="nowrap"><style data-mw-deduplicate="TemplateStyles:r886049734">.mw-parser-output .monospaced{font-family:monospace,monospace}</style><span class="monospaced">U+33D3</span> </span><span style="font-size:125%;line-height:1em">㏓</span> <span style="font-variant: small-caps; text-transform: lowercase;">SQUARE LX</span>. It is a legacy code to accommodate old <a href="/wiki/Code_page" title="Code page">code pages</a> in some <a href="/wiki/Asia" title="Asia">Asian</a> languages. Use of this code is not recommended in new documents. </p> <div class="mw-heading mw-heading2"><h2 id="SI_photometry_units">SI photometry units</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Lux&action=edit&section=7" title="Edit section: SI photometry units"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p><span class="anchor" id="table-si-photometry-units"></span> </p> <table class="wikitable plainrowheaders"> <caption><style data-mw-deduplicate="TemplateStyles:r1045256916">.mw-parser-output .navbar-header{text-align:center;position:relative;white-space:nowrap}.mw-parser-output .navbar-header .navbar{position:absolute;right:0;top:0;margin:0 5px}</style><div class="navbar-header"><span style="font-size:130%;">SI photometry quantities</span><style data-mw-deduplicate="TemplateStyles:r1129693374">.mw-parser-output .hlist dl,.mw-parser-output .hlist ol,.mw-parser-output .hlist ul{margin:0;padding:0}.mw-parser-output .hlist dd,.mw-parser-output .hlist dt,.mw-parser-output .hlist li{margin:0;display:inline}.mw-parser-output .hlist.inline,.mw-parser-output .hlist.inline dl,.mw-parser-output .hlist.inline ol,.mw-parser-output .hlist.inline ul,.mw-parser-output .hlist dl dl,.mw-parser-output .hlist dl ol,.mw-parser-output .hlist dl ul,.mw-parser-output .hlist ol dl,.mw-parser-output .hlist ol ol,.mw-parser-output .hlist ol ul,.mw-parser-output .hlist ul dl,.mw-parser-output .hlist ul ol,.mw-parser-output .hlist ul ul{display:inline}.mw-parser-output .hlist .mw-empty-li{display:none}.mw-parser-output .hlist dt::after{content:": "}.mw-parser-output .hlist dd::after,.mw-parser-output .hlist li::after{content:" · ";font-weight:bold}.mw-parser-output .hlist dd:last-child::after,.mw-parser-output .hlist dt:last-child::after,.mw-parser-output .hlist li:last-child::after{content:none}.mw-parser-output .hlist dd dd:first-child::before,.mw-parser-output .hlist dd dt:first-child::before,.mw-parser-output .hlist dd li:first-child::before,.mw-parser-output .hlist dt dd:first-child::before,.mw-parser-output .hlist dt dt:first-child::before,.mw-parser-output .hlist dt li:first-child::before,.mw-parser-output .hlist li dd:first-child::before,.mw-parser-output .hlist li dt:first-child::before,.mw-parser-output .hlist li li:first-child::before{content:" (";font-weight:normal}.mw-parser-output .hlist dd dd:last-child::after,.mw-parser-output .hlist dd dt:last-child::after,.mw-parser-output .hlist dd li:last-child::after,.mw-parser-output .hlist dt dd:last-child::after,.mw-parser-output .hlist dt dt:last-child::after,.mw-parser-output .hlist dt li:last-child::after,.mw-parser-output .hlist li dd:last-child::after,.mw-parser-output .hlist li dt:last-child::after,.mw-parser-output .hlist li li:last-child::after{content:")";font-weight:normal}.mw-parser-output .hlist ol{counter-reset:listitem}.mw-parser-output .hlist ol>li{counter-increment:listitem}.mw-parser-output .hlist ol>li::before{content:" "counter(listitem)"\a0 "}.mw-parser-output .hlist dd ol>li:first-child::before,.mw-parser-output .hlist dt ol>li:first-child::before,.mw-parser-output .hlist li ol>li:first-child::before{content:" ("counter(listitem)"\a0 "}</style><style data-mw-deduplicate="TemplateStyles:r1239400231">.mw-parser-output .navbar{display:inline;font-size:88%;font-weight:normal}.mw-parser-output .navbar-collapse{float:left;text-align:left}.mw-parser-output .navbar-boxtext{word-spacing:0}.mw-parser-output .navbar ul{display:inline-block;white-space:nowrap;line-height:inherit}.mw-parser-output .navbar-brackets::before{margin-right:-0.125em;content:"[ "}.mw-parser-output .navbar-brackets::after{margin-left:-0.125em;content:" ]"}.mw-parser-output .navbar li{word-spacing:-0.125em}.mw-parser-output .navbar a>span,.mw-parser-output .navbar a>abbr{text-decoration:inherit}.mw-parser-output .navbar-mini abbr{font-variant:small-caps;border-bottom:none;text-decoration:none;cursor:inherit}.mw-parser-output .navbar-ct-full{font-size:114%;margin:0 7em}.mw-parser-output .navbar-ct-mini{font-size:114%;margin:0 4em}html.skin-theme-clientpref-night .mw-parser-output .navbar li a abbr{color:var(--color-base)!important}@media(prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .navbar li a abbr{color:var(--color-base)!important}}@media print{.mw-parser-output .navbar{display:none!important}}</style><div class="navbar plainlinks hlist navbar-mini"><ul><li class="nv-view"><a href="/wiki/Template:SI_light_units" title="Template:SI light units"><abbr title="View this template">v</abbr></a></li><li class="nv-talk"><a href="/wiki/Template_talk:SI_light_units" title="Template talk:SI light units"><abbr title="Discuss this template">t</abbr></a></li><li class="nv-edit"><a href="/wiki/Special:EditPage/Template:SI_light_units" title="Special:EditPage/Template:SI light units"><abbr title="Edit this template">e</abbr></a></li></ul></div></div> </caption> <tbody><tr> <th scope="col" colspan="2">Quantity </th> <th scope="col" colspan="2">Unit </th> <th scope="col" rowspan="2">Dimension<br /><sup id="cite_ref-note-dimension-symbol_23-0" class="reference"><a href="#cite_note-note-dimension-symbol-23"><span class="cite-bracket">[</span>nb 1<span class="cite-bracket">]</span></a></sup> </th> <th scope="col" rowspan="2">Notes </th></tr> <tr> <th scope="col">Name </th> <th scope="col">Symbol<sup id="cite_ref-note-suffix-v_24-0" class="reference"><a href="#cite_note-note-suffix-v-24"><span class="cite-bracket">[</span>nb 2<span class="cite-bracket">]</span></a></sup> </th> <th scope="col">Name </th> <th scope="col">Symbol </th></tr> <tr> <th scope="row"><a href="/wiki/Luminous_energy" title="Luminous energy">Luminous energy</a> </th> <td><span class="texhtml"><i>Q</i><sub>v</sub></span><sup id="cite_ref-note-alternative-symbol-photometric_25-0" class="reference"><a href="#cite_note-note-alternative-symbol-photometric-25"><span class="cite-bracket">[</span>nb 3<span class="cite-bracket">]</span></a></sup> </td> <td><a href="/wiki/Lumen_second" title="Lumen second">lumen second</a> </td> <td><a href="/wiki/Lumen_(unit)" title="Lumen (unit)">lm</a>⋅s </td> <td><b>T</b>⋅<b>J</b> </td> <td>The lumen second is sometimes called the <i>talbot</i>. </td></tr> <tr> <th scope="row"><a href="/wiki/Luminous_flux" title="Luminous flux">Luminous flux</a>, luminous power </th> <td><span class="texhtml">Φ<sub><a href="/wiki/Luminosity_function" class="mw-redirect" title="Luminosity function">v</a></sub></span><sup id="cite_ref-note-alternative-symbol-photometric_25-1" class="reference"><a href="#cite_note-note-alternative-symbol-photometric-25"><span class="cite-bracket">[</span>nb 3<span class="cite-bracket">]</span></a></sup> </td> <td><a href="/wiki/Lumen_(unit)" title="Lumen (unit)">lumen</a> (= candela <a href="/wiki/Steradian" title="Steradian">steradian</a>) </td> <td>lm (= cd⋅sr) </td> <td><b>J</b> </td> <td>Luminous energy per unit time </td></tr> <tr> <th scope="row"><a href="/wiki/Luminous_intensity" title="Luminous intensity">Luminous intensity</a> </th> <td><span class="texhtml"><i>I</i><sub>v</sub></span> </td> <td><a href="/wiki/Candela" title="Candela">candela</a> (= lumen per steradian) </td> <td><a href="/wiki/Candela" title="Candela">cd</a> (= lm/sr) </td> <td><b>J</b> </td> <td>Luminous flux per unit <a href="/wiki/Solid_angle" title="Solid angle">solid angle</a> </td></tr> <tr> <th scope="row"><a href="/wiki/Luminance" title="Luminance">Luminance</a> </th> <td><span class="texhtml"><i>L</i><sub>v</sub></span> </td> <td><a href="/wiki/Candela_per_square_metre" title="Candela per square metre">candela per square metre</a> </td> <td>cd/m<sup>2</sup> (= lm/(sr⋅m<sup>2</sup>)) </td> <td><b>L</b><sup>−2</sup>⋅<b>J</b> </td> <td>Luminous flux per unit solid angle per unit <i>projected</i> source area. The candela per square metre is sometimes called the <i><a href="/wiki/Nit_(unit)" class="mw-redirect" title="Nit (unit)">nit</a></i>. </td></tr> <tr> <th scope="row"><a href="/wiki/Illuminance" title="Illuminance">Illuminance</a> </th> <td><span class="texhtml"><i>E</i><sub>v</sub></span> </td> <td><a class="mw-selflink selflink">lux</a> (= lumen per square metre) </td> <td><a class="mw-selflink selflink">lx</a> (= lm/m<sup>2</sup>) </td> <td><b>L</b><sup>−2</sup>⋅<b>J</b> </td> <td>Luminous flux <i>incident</i> on a surface </td></tr> <tr> <th scope="row"><a href="/wiki/Luminous_exitance" class="mw-redirect" title="Luminous exitance">Luminous exitance</a>, luminous emittance </th> <td><span class="texhtml"><i>M</i><sub>v</sub></span> </td> <td>lumen per square metre </td> <td>lm/m<sup>2</sup> </td> <td><b>L</b><sup>−2</sup>⋅<b>J</b> </td> <td>Luminous flux <i>emitted</i> from a surface </td></tr> <tr> <th scope="row"><a href="/wiki/Luminous_exposure" class="mw-redirect" title="Luminous exposure">Luminous exposure</a> </th> <td><span class="texhtml"><i>H</i><sub>v</sub></span> </td> <td><a href="/wiki/Lux_second" class="mw-redirect" title="Lux second">lux second</a> </td> <td>lx⋅s </td> <td><b>L</b><sup>−2</sup>⋅<b>T</b>⋅<b>J</b> </td> <td>Time-integrated illuminance </td></tr> <tr> <th scope="row">Luminous energy density </th> <td><span class="texhtml"><i>ω</i><sub>v</sub></span> </td> <td>lumen second per cubic metre </td> <td>lm⋅s/m<sup>3</sup> </td> <td><b>L</b><sup>−3</sup>⋅<b>T</b>⋅<b>J</b> </td> <td> </td></tr> <tr> <th scope="row"><a href="/wiki/Luminous_efficacy" title="Luminous efficacy">Luminous efficacy</a> (of radiation) </th> <td><span class="texhtml"><i>K</i></span> </td> <td>lumen per <a href="/wiki/Watt" title="Watt">watt</a> </td> <td>lm/<a href="/wiki/Watt" title="Watt">W</a> </td> <td><b>M</b><sup>−1</sup>⋅<b>L</b><sup>−2</sup>⋅<b>T</b><sup>3</sup>⋅<b>J</b> </td> <td>Ratio of luminous flux to <a href="/wiki/Radiant_flux" title="Radiant flux">radiant flux</a> </td></tr> <tr> <th scope="row"><a href="/wiki/Luminous_efficacy" title="Luminous efficacy">Luminous efficacy</a> (of a source) </th> <td><span class="texhtml mvar" style="font-style:italic;">η</span><sup id="cite_ref-note-alternative-symbol-photometric_25-2" class="reference"><a href="#cite_note-note-alternative-symbol-photometric-25"><span class="cite-bracket">[</span>nb 3<span class="cite-bracket">]</span></a></sup> </td> <td>lumen per <a href="/wiki/Watt" title="Watt">watt</a> </td> <td>lm/<a href="/wiki/Watt" title="Watt">W</a> </td> <td><b>M</b><sup>−1</sup>⋅<b>L</b><sup>−2</sup>⋅<b>T</b><sup>3</sup>⋅<b>J</b> </td> <td>Ratio of luminous flux to power consumption </td></tr> <tr> <th scope="row"><a href="/wiki/Luminous_efficiency" class="mw-redirect" title="Luminous efficiency">Luminous efficiency</a>, luminous coefficient </th> <td><span class="texhtml mvar" style="font-style:italic;">V</span> </td> <td> </td> <td> </td> <td><b>1</b> </td> <td>Luminous efficacy normalized by the maximum possible efficacy </td></tr> <tr> <td style="text-align:center;" colspan="6">See also: <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><div class="hlist inline"><ul><li><a href="/wiki/SI" class="mw-redirect" title="SI">SI</a></li><li><a href="/wiki/Photometry_(optics)" title="Photometry (optics)">Photometry</a></li><li><a href="/wiki/Radiometry" title="Radiometry">Radiometry</a></li></ul></div> </td></tr></tbody></table><style data-mw-deduplicate="TemplateStyles:r1239543626">.mw-parser-output .reflist{margin-bottom:0.5em;list-style-type:decimal}@media screen{.mw-parser-output .reflist{font-size:90%}}.mw-parser-output .reflist .references{font-size:100%;margin-bottom:0;list-style-type:inherit}.mw-parser-output .reflist-columns-2{column-width:30em}.mw-parser-output .reflist-columns-3{column-width:25em}.mw-parser-output .reflist-columns{margin-top:0.3em}.mw-parser-output .reflist-columns ol{margin-top:0}.mw-parser-output .reflist-columns li{page-break-inside:avoid;break-inside:avoid-column}.mw-parser-output .reflist-upper-alpha{list-style-type:upper-alpha}.mw-parser-output .reflist-upper-roman{list-style-type:upper-roman}.mw-parser-output .reflist-lower-alpha{list-style-type:lower-alpha}.mw-parser-output .reflist-lower-greek{list-style-type:lower-greek}.mw-parser-output .reflist-lower-roman{list-style-type:lower-roman}</style><div class="reflist"> <div class="mw-references-wrap"><ol class="references"> <li id="cite_note-note-dimension-symbol-23"><span class="mw-cite-backlink"><b><a href="#cite_ref-note-dimension-symbol_23-0">^</a></b></span> <span class="reference-text">The symbols in this column denote <a href="/wiki/Dimensional_analysis#Definition" title="Dimensional analysis">dimensions</a>; "<b>L</b>", "<b>T</b>" and "<b>J</b>" are for length, time and luminous intensity respectively, not the symbols for the <a href="/wiki/Unit_of_measurement" title="Unit of measurement">units</a> litre, tesla and joule.</span> </li> <li id="cite_note-note-suffix-v-24"><span class="mw-cite-backlink"><b><a href="#cite_ref-note-suffix-v_24-0">^</a></b></span> <span class="reference-text"><a href="/wiki/Standards_organization" title="Standards organization">Standards organizations</a> recommend that photometric quantities be denoted with a subscript "v" (for "visual") to avoid confusion with radiometric or <a href="/wiki/Photon" title="Photon">photon</a> quantities. For example: <i>USA Standard Letter Symbols for Illuminating Engineering</i> USAS Z7.1-1967, Y10.18-1967</span> </li> <li id="cite_note-note-alternative-symbol-photometric-25"><span class="mw-cite-backlink">^ <a href="#cite_ref-note-alternative-symbol-photometric_25-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-note-alternative-symbol-photometric_25-1"><sup><i><b>b</b></i></sup></a> <a href="#cite_ref-note-alternative-symbol-photometric_25-2"><sup><i><b>c</b></i></sup></a></span> <span class="reference-text">Alternative symbols sometimes seen: <span class="texhtml mvar" style="font-style:italic;">W</span> for luminous energy, <span class="texhtml mvar" style="font-style:italic;">P</span> or <span class="texhtml mvar" style="font-style:italic;">F</span> for luminous flux, and <span class="texhtml mvar" style="font-style:italic;">ρ</span> for luminous efficacy of a source.</span> </li> </ol></div></div> <div class="mw-heading mw-heading2"><h2 id="See_also">See also</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Lux&action=edit&section=8" title="Edit section: See also"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a href="/wiki/Exposure_value" title="Exposure value">Exposure value</a></li></ul> <div class="mw-heading mw-heading2"><h2 id="References">References</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Lux&action=edit&section=9" title="Edit section: References"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1239543626"><div class="reflist"> <div class="mw-references-wrap mw-references-columns"><ol class="references"> <li id="cite_note-SIBrochure9thEd-1"><span class="mw-cite-backlink"><b><a href="#cite_ref-SIBrochure9thEd_1-0">^</a></b></span> <span class="reference-text"><style data-mw-deduplicate="TemplateStyles:r1238218222">.mw-parser-output cite.citation{font-style:inherit;word-wrap:break-word}.mw-parser-output .citation q{quotes:"\"""\"""'""'"}.mw-parser-output .citation:target{background-color:rgba(0,127,255,0.133)}.mw-parser-output .id-lock-free.id-lock-free a{background:url("//upload.wikimedia.org/wikipedia/commons/6/65/Lock-green.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-limited.id-lock-limited a,.mw-parser-output .id-lock-registration.id-lock-registration a{background:url("//upload.wikimedia.org/wikipedia/commons/d/d6/Lock-gray-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-subscription.id-lock-subscription a{background:url("//upload.wikimedia.org/wikipedia/commons/a/aa/Lock-red-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .cs1-ws-icon a{background:url("//upload.wikimedia.org/wikipedia/commons/4/4c/Wikisource-logo.svg")right 0.1em center/12px no-repeat}body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-free a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-limited a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-registration a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-subscription a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .cs1-ws-icon a{background-size:contain;padding:0 1em 0 0}.mw-parser-output .cs1-code{color:inherit;background:inherit;border:none;padding:inherit}.mw-parser-output .cs1-hidden-error{display:none;color:var(--color-error,#d33)}.mw-parser-output .cs1-visible-error{color:var(--color-error,#d33)}.mw-parser-output .cs1-maint{display:none;color:#085;margin-left:0.3em}.mw-parser-output .cs1-kern-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right{padding-right:0.2em}.mw-parser-output .citation .mw-selflink{font-weight:inherit}@media screen{.mw-parser-output .cs1-format{font-size:95%}html.skin-theme-clientpref-night .mw-parser-output .cs1-maint{color:#18911f}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .cs1-maint{color:#18911f}}</style><cite id="CITEREFInternational_Bureau_of_Weights_and_Measures2019" class="citation cs2"><a href="/wiki/New_SI" class="mw-redirect" title="New SI">International Bureau of Weights and Measures</a> (2019-05-20), <a rel="nofollow" class="external text" href="https://www.bipm.org/utils/common/pdf/si-brochure/SI-Brochure-9.pdf"><i>The International System of Units (SI)</i></a> <span class="cs1-format">(PDF)</span> (9th ed.), <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-92-822-2272-0" title="Special:BookSources/978-92-822-2272-0"><bdi>978-92-822-2272-0</bdi></a>, <a rel="nofollow" class="external text" href="https://web.archive.org/web/20211018184555/https://www.bipm.org/documents/20126/41483022/SI-Brochure-9.pdf/fcf090b2-04e6-88cc-1149-c3e029ad8232">archived</a> from the original on 2021-10-18</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=The+International+System+of+Units+%28SI%29&rft.edition=9th&rft.date=2019-05-20&rft.isbn=978-92-822-2272-0&rft.au=International+Bureau+of+Weights+and+Measures&rft_id=https%3A%2F%2Fwww.bipm.org%2Futils%2Fcommon%2Fpdf%2Fsi-brochure%2FSI-Brochure-9.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3ALux" class="Z3988"></span></span> </li> <li id="cite_note-2"><span class="mw-cite-backlink"><b><a href="#cite_ref-2">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFCIE2020" class="citation book cs1">CIE (2020). <a rel="nofollow" class="external text" href="https://cie.co.at/eilvterm/17-21-085"><i>CIE S 017:2020 ILV: International Lighting Vocabulary, 2nd edition</i></a> (2 ed.). CIE.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=CIE+S+017%3A2020+ILV%3A+International+Lighting+Vocabulary%2C+2nd+edition.&rft.edition=2&rft.pub=CIE&rft.date=2020&rft.au=CIE&rft_id=https%3A%2F%2Fcie.co.at%2Feilvterm%2F17-21-085&rfr_id=info%3Asid%2Fen.wikipedia.org%3ALux" class="Z3988"></span></span> </li> <li id="cite_note-3"><span class="mw-cite-backlink"><b><a href="#cite_ref-3">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation book cs1"><a rel="nofollow" class="external text" href="https://www.iso.org/standard/83178.html"><i>ISO/CIE 23539:2023 CIE TC 2-93 Photometry — The CIE system of physical photometry</i></a>. ISO/CIE. 2023. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.25039%2FIS0.CIE.23539.2023">10.25039/IS0.CIE.23539.2023</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=ISO%2FCIE+23539%3A2023+CIE+TC+2-93+Photometry+%E2%80%94+The+CIE+system+of+physical+photometry&rft.pub=ISO%2FCIE&rft.date=2023&rft_id=info%3Adoi%2F10.25039%2FIS0.CIE.23539.2023&rft_id=https%3A%2F%2Fwww.iso.org%2Fstandard%2F83178.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3ALux" class="Z3988"></span></span> </li> <li id="cite_note-4"><span class="mw-cite-backlink"><b><a href="#cite_ref-4">^</a></b></span> <span class="reference-text"><a rel="nofollow" class="external text" href="https://www.nist.gov/pml/special-publication-811/nist-guide-si-chapter-9-rules-and-style-conventions-spelling-unit-names">NIST Guide to SI Units. Chapter 9 – Rules and Style Conventions for Spelling Unit Names</a>, National Institute of Standards and Technology.</span> </li> <li id="cite_note-radfaq-5"><span class="mw-cite-backlink">^ <a href="#cite_ref-radfaq_5-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-radfaq_5-1"><sup><i><b>b</b></i></sup></a> <a href="#cite_ref-radfaq_5-2"><sup><i><b>c</b></i></sup></a> <a href="#cite_ref-radfaq_5-3"><sup><i><b>d</b></i></sup></a> <a href="#cite_ref-radfaq_5-4"><sup><i><b>e</b></i></sup></a></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFSchlyter1997–2009" class="citation web cs1">Schlyter, Paul (1997–2009). <a rel="nofollow" class="external text" href="http://stjarnhimlen.se/comp/radfaq.html#10">"Radiometry and photometry in astronomy"</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Radiometry+and+photometry+in+astronomy&rft.date=1997%2F2009&rft.aulast=Schlyter&rft.aufirst=Paul&rft_id=http%3A%2F%2Fstjarnhimlen.se%2Fcomp%2Fradfaq.html%2310&rfr_id=info%3Asid%2Fen.wikipedia.org%3ALux" class="Z3988"></span><br />Starlight illuminance coincides with the human eye's minimum illuminance while moonlight coincides with the human eye's minimum colour vision illuminance (IEE Reviews, 1972, <a rel="nofollow" class="external text" href="https://books.google.com/books?id=00dJAQAAIAAJ&q=minimum+illumination+for+human+colour+vision+lx">page 1183</a>).</span> </li> <li id="cite_note-6"><span class="mw-cite-backlink"><b><a href="#cite_ref-6">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFKybaMoharPosch2017" class="citation journal cs1">Kyba, Christopher C. M.; Mohar, Andrej; Posch, Thomas (2017-02-01). <a rel="nofollow" class="external text" href="https://gfzpublic.gfz-potsdam.de/pubman/item/item_2022891_4/component/file_2029888/2022891.pdf">"How bright is moonlight?"</a> <span class="cs1-format">(PDF)</span>. <i>Astronomy & Geophysics</i>. <b>58</b> (1): 1.31–1.32. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1093%2Fastrogeo%2Fatx025">10.1093/astrogeo/atx025</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Astronomy+%26+Geophysics&rft.atitle=How+bright+is+moonlight%3F&rft.volume=58&rft.issue=1&rft.pages=1.31-1.32&rft.date=2017-02-01&rft_id=info%3Adoi%2F10.1093%2Fastrogeo%2Fatx025&rft.aulast=Kyba&rft.aufirst=Christopher+C.+M.&rft.au=Mohar%2C+Andrej&rft.au=Posch%2C+Thomas&rft_id=https%3A%2F%2Fgfzpublic.gfz-potsdam.de%2Fpubman%2Fitem%2Fitem_2022891_4%2Fcomponent%2Ffile_2029888%2F2022891.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3ALux" class="Z3988"></span></span> </li> <li id="cite_note-7"><span class="mw-cite-backlink"><b><a href="#cite_ref-7">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://www.photonis.com/attachment.php?id_attachment=95">"Electro-Optics Handbook"</a> <span class="cs1-format">(pdf)</span>. <i>photonis.com</i>. p. 63<span class="reference-accessdate">. Retrieved <span class="nowrap">2012-04-02</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=photonis.com&rft.atitle=Electro-Optics+Handbook&rft.pages=63&rft_id=http%3A%2F%2Fwww.photonis.com%2Fattachment.php%3Fid_attachment%3D95&rfr_id=info%3Asid%2Fen.wikipedia.org%3ALux" class="Z3988"></span><sup class="noprint Inline-Template"><span style="white-space: nowrap;">[<i><a href="/wiki/Wikipedia:Link_rot" title="Wikipedia:Link rot"><span title=" Dead link tagged September 2018">permanent dead link</span></a></i><span style="visibility:hidden; color:transparent; padding-left:2px">‍</span>]</span></sup></span> </li> <li id="cite_note-NOAO_CaRLLI-8"><span class="mw-cite-backlink"><b><a href="#cite_ref-NOAO_CaRLLI_8-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20210706034730/https://www.noao.edu/education/QLTkit/ACTIVITY_Documents/Safety/LightLevels_outdoor+indoor.pdf">"NOAO Common and Recommended Light Levels Indoor"</a> <span class="cs1-format">(PDF)</span>. Archived from <a rel="nofollow" class="external text" href="https://www.noao.edu/education/QLTkit/ACTIVITY_Documents/Safety/LightLevels_outdoor+indoor.pdf">the original</a> <span class="cs1-format">(PDF)</span> on 2021-07-06<span class="reference-accessdate">. Retrieved <span class="nowrap">2016-11-13</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=NOAO+Common+and+Recommended+Light+Levels+Indoor&rft_id=https%3A%2F%2Fwww.noao.edu%2Feducation%2FQLTkit%2FACTIVITY_Documents%2FSafety%2FLightLevels_outdoor%2Bindoor.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3ALux" class="Z3988"></span></span> </li> <li id="cite_note-energyrating-9"><span class="mw-cite-backlink">^ <a href="#cite_ref-energyrating_9-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-energyrating_9-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFPears1998" class="citation book cs1">Pears, Alan (June 1998). "Chapter 7: Appliance technologies and scope for emission reduction". <a rel="nofollow" class="external text" href="https://web.archive.org/web/20110302110649/http://www.energyrating.gov.au/library/pubs/pears-ago1998.pdf"><i>Strategic Study of Household Energy and Greenhouse Issues: A report for Environment Australia</i></a> <span class="cs1-format">(PDF)</span>. Department of Industry and Science, Commonwealth of Australia. p. 61. Archived from the original on 2011-03-02<span class="reference-accessdate">. Retrieved <span class="nowrap">2008-06-26</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=bookitem&rft.atitle=Chapter+7%3A+Appliance+technologies+and+scope+for+emission+reduction&rft.btitle=Strategic+Study+of+Household+Energy+and+Greenhouse+Issues%3A+A+report+for+Environment+Australia&rft.pages=61&rft.pub=Department+of+Industry+and+Science%2C+Commonwealth+of+Australia&rft.date=1998-06&rft.aulast=Pears&rft.aufirst=Alan&rft_id=http%3A%2F%2Fwww.energyrating.com.au%2Flibrary%2Fpubs%2Fpears-ago1998.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3ALux" class="Z3988"></span><span class="cs1-maint citation-comment"><code class="cs1-code">{{<a href="/wiki/Template:Cite_book" title="Template:Cite book">cite book</a>}}</code>: CS1 maint: unfit URL (<a href="/wiki/Category:CS1_maint:_unfit_URL" title="Category:CS1 maint: unfit URL">link</a>)</span></span> </li> <li id="cite_note-10"><span class="mw-cite-backlink"><b><a href="#cite_ref-10">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFAustralian_Greenhouse_Office2005" class="citation book cs1">Australian Greenhouse Office (May 2005). "Chapter 5: Assessing lighting savings". <a rel="nofollow" class="external text" href="https://web.archive.org/web/20070415151053/http://www.greenhouse.gov.au/lgmodules/wep/lights/training/training9.html"><i>Working Energy Resource and Training Kit: Lighting</i></a>. Archived from <a rel="nofollow" class="external text" href="http://www.greenhouse.gov.au/lgmodules/wep/lights/index.html">the original</a> on 2007-04-15<span class="reference-accessdate">. Retrieved <span class="nowrap">2007-03-17</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=bookitem&rft.atitle=Chapter+5%3A+Assessing+lighting+savings&rft.btitle=Working+Energy+Resource+and+Training+Kit%3A+Lighting&rft.date=2005-05&rft.au=Australian+Greenhouse+Office&rft_id=http%3A%2F%2Fwww.greenhouse.gov.au%2Flgmodules%2Fwep%2Flights%2Findex.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3ALux" class="Z3988"></span></span> </li> <li id="cite_note-11"><span class="mw-cite-backlink"><b><a href="#cite_ref-11">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20130615074318/http://scopecalc.com/">"Low-Light Performance Calculator"</a>. Archived from <a rel="nofollow" class="external text" href="http://www.scopecalc.com/">the original</a> on 2013-06-15<span class="reference-accessdate">. Retrieved <span class="nowrap">2010-09-27</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Low-Light+Performance+Calculator&rft_id=http%3A%2F%2Fwww.scopecalc.com%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3ALux" class="Z3988"></span></span> </li> <li id="cite_note-12"><span class="mw-cite-backlink"><b><a href="#cite_ref-12">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFDarlington2017" class="citation web cs1">Darlington, Paul (2017-12-05). <a rel="nofollow" class="external text" href="https://web.archive.org/web/20181116020106/https://www.railengineer.uk/2017/12/05/london-underground-keeping-the-lights-on/">"London Underground: Keeping the lights on"</a>. <i>Rail Engineer</i>. Archived from <a rel="nofollow" class="external text" href="https://www.railengineer.uk/2017/12/05/london-underground-keeping-the-lights-on/">the original</a> on 2018-11-16<span class="reference-accessdate">. Retrieved <span class="nowrap">2017-12-20</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=Rail+Engineer&rft.atitle=London+Underground%3A+Keeping+the+lights+on&rft.date=2017-12-05&rft.aulast=Darlington&rft.aufirst=Paul&rft_id=https%3A%2F%2Fwww.railengineer.uk%2F2017%2F12%2F05%2Flondon-underground-keeping-the-lights-on%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3ALux" class="Z3988"></span></span> </li> <li id="cite_note-13"><span class="mw-cite-backlink"><b><a href="#cite_ref-13">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20110707054658/http://www.resourcesmart.vic.gov.au/documents/lux_meter.pdf">"How to use a lux meter (Australian recommendation)"</a> <span class="cs1-format">(PDF)</span>. Sustainability Victoria. April 2010. Archived from <a rel="nofollow" class="external text" href="http://www.resourcesmart.vic.gov.au/documents/lux_meter.pdf">the original</a> <span class="cs1-format">(PDF)</span> on 2011-07-07.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=How+to+use+a+lux+meter+%28Australian+recommendation%29&rft.pub=Sustainability+Victoria&rft.date=2010-04&rft_id=http%3A%2F%2Fwww.resourcesmart.vic.gov.au%2Fdocuments%2Flux_meter.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3ALux" class="Z3988"></span></span> </li> <li id="cite_note-14"><span class="mw-cite-backlink"><b><a href="#cite_ref-14">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20090508051301/https://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=10630">"Illumination. - 1926.56"</a>. <i>Regulations (Standards - 29 CFR)</i>. Occupational Safety and Health Administration, US Dept. of Labor. Archived from <a rel="nofollow" class="external text" href="https://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=10630">the original</a> on 2009-05-08.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=Regulations+%28Standards+-+29+CFR%29&rft.atitle=Illumination.+-+1926.56&rft_id=https%3A%2F%2Fwww.osha.gov%2Fpls%2Foshaweb%2Fowadisp.show_document%3Fp_table%3DSTANDARDS%26p_id%3D10630&rfr_id=info%3Asid%2Fen.wikipedia.org%3ALux" class="Z3988"></span></span> </li> <li id="cite_note-15"><span class="mw-cite-backlink"><b><a href="#cite_ref-15">^</a></b></span> <span class="reference-text">European law UNI EN 12464</span> </li> <li id="cite_note-Schlyter7-16"><span class="mw-cite-backlink">^ <a href="#cite_ref-Schlyter7_16-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-Schlyter7_16-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://stjarnhimlen.se/comp/radfaq.html#7">Schlyter, Section 7</a>.</span> </li> <li id="cite_note-17"><span class="mw-cite-backlink"><b><a href="#cite_ref-17">^</a></b></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://stjarnhimlen.se/comp/radfaq.html#14">Schlyter, Section 14</a>.</span> </li> <li id="cite_note-18"><span class="mw-cite-backlink"><b><a href="#cite_ref-18">^</a></b></span> <span class="reference-text">Jack L. Lindsey, <i>Applied Illumination Engineering</i>, The Fairmont Press, Inc., 1997 <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/0881732125" title="Special:BookSources/0881732125">0881732125</a> page 218</span> </li> <li id="cite_note-Lohse-Stille_1948-19"><span class="mw-cite-backlink"><b><a href="#cite_ref-Lohse-Stille_1948_19-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFLohseStille1948" class="citation journal cs1 cs1-prop-location-test cs1-prop-interwiki-linked-name cs1-prop-foreign-lang-source">Lohse, Bernhard; <a href="https://de.wikipedia.org/wiki/Ulrich_Stille" class="extiw" title="de:Ulrich Stille">Stille, Ulrich</a> <span class="cs1-format">[in German]</span> (January 1948) [1947-08-19]. Written at Braunschweig, Germany. <a href="/wiki/Deutsche_Physikalische_Gesellschaft" class="mw-redirect" title="Deutsche Physikalische Gesellschaft">Deutsche Physikalische Gesellschaft</a> (ed.). <a rel="nofollow" class="external text" href="https://books.google.com/books?id=fxJXDwKAjX8C">"Einführung und Bestimmung des Lichtäquivalents"</a>. <i><a href="/wiki/Zeitschrift_f%C3%BCr_Physik" title="Zeitschrift für Physik">Zeitschrift für Physik</a></i> (in German). <b>125</b> (1–3). Berlin / Göttingen / Heidelberg, Germany: <a href="/wiki/Springer-Verlag" class="mw-redirect" title="Springer-Verlag">Springer-Verlag</a>: 133–158. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/1948ZPhy..125..133L">1948ZPhy..125..133L</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1007%2FBF01337623">10.1007/BF01337623</a>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0044-3328">0044-3328</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:125512557">125512557</a><span class="reference-accessdate">. Retrieved <span class="nowrap">2023-03-19</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Zeitschrift+f%C3%BCr+Physik&rft.atitle=Einf%C3%BChrung+und+Bestimmung+des+Licht%C3%A4quivalents&rft.volume=125&rft.issue=1%E2%80%933&rft.pages=133-158&rft.date=1948-01&rft_id=info%3Adoi%2F10.1007%2FBF01337623&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A125512557%23id-name%3DS2CID&rft.issn=0044-3328&rft_id=info%3Abibcode%2F1948ZPhy..125..133L&rft.aulast=Lohse&rft.aufirst=Bernhard&rft.au=Stille%2C+Ulrich&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3DfxJXDwKAjX8C&rfr_id=info%3Asid%2Fen.wikipedia.org%3ALux" class="Z3988"></span></span> </li> <li id="cite_note-Westphal_1952-20"><span class="mw-cite-backlink"><b><a href="#cite_ref-Westphal_1952_20-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFWestphal1952" class="citation book cs1 cs1-prop-foreign-lang-source"><a href="/wiki/Wilhelm_Heinrich_Westphal" class="mw-redirect" title="Wilhelm Heinrich Westphal">Westphal, Wilhelm Heinrich</a> (1952). <a rel="nofollow" class="external text" href="https://books.google.com/books?id=QaCFBwAAQBAJ&pg=RA1-PA125">"Nox, Dunkelleuchtdichte, Skot"</a>. In Westphal, Wilhelm H. (ed.). <i>Physikalisches Wörterbuch</i> (in German) (1 ed.). Berlin / Göttingen / Heidelberg, Germany: <a href="/wiki/Springer-Verlag_OHG" class="mw-redirect" title="Springer-Verlag OHG">Springer-Verlag OHG</a>. pp. 125, 271, 389. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1007%2F978-3-662-12706-3">10.1007/978-3-662-12706-3</a>. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-3-662-12707-0" title="Special:BookSources/978-3-662-12707-0"><bdi>978-3-662-12707-0</bdi></a><span class="reference-accessdate">. Retrieved <span class="nowrap">2023-03-16</span></span>. pp. 125, 271: <q>Nox, abgek[ürzt] nx, Einheit der Dunkelbeleuchtungsstärke (Dunkelleuchtdichte), welche für zahlenmäßige Angaben und zum Anschluß der Dunkelbeleuchtungsstärke an die normale Beleuchtungsstärke 1940 von der <a href="/w/index.php?title=German_Lighting_Society&action=edit&redlink=1" class="new" title="German Lighting Society (page does not exist)">Deutschen Lichttechnischen Gesellschaft</a><span class="noprint" style="font-size:85%; font-style: normal;"> [<a href="https://de.wikipedia.org/wiki/Deutsche_Lichttechnische_Gesellschaft" class="extiw" title="de:Deutsche Lichttechnische Gesellschaft">de</a>]</span> geschaffen wurde. Bezüglich der Farbtemperatur der Strahlung und des Anschlusses von Zahlenwerten der Beleuchtungsstärke <i>E</i> und der Dunkelbeleuchtungsstärke <i><span style="text-decoration:overline;">E</span></i> gelten analog die gleichen Festlegungen wie bei der Dunkelleuchtdichte und dem Skot (sk). Für eine Strahlung der Farbtemperatur <i>T</i><sub>1</sub> = 2360 K gilt: 1 nx = 10<sup>−3</sup> lx (Lux). Für eine beliebige Strahlung <i>bekannter</i> spektraler Strahlungsleistung <i>S</i><sub>1</sub> lautet die Verknüpfungsbeziehung zwischen in 10<sup>−3</sup> lx gemessenem Zahlenwert {<i>E</i>} der Beleuchtungsstärke und in nx gemessenem Zahlenwert {<i><span style="text-decoration:overline;">E</span></i>} der Dunkelbeleuchtungsstärke: {<i><span style="text-decoration:overline;">E</span></i>}<sub>nx</sub> = (2,161 ± 0,001) · {<i>E</i>}<sub>10<sup>−3</sup> lx</sub> · ∫ <i>S</i><sub>λ</sub> <i><span style="text-decoration:overline;">V</span></i><sub>λ,W</sub> <i>dλ</i> / ∫ <i>S</i><sub>λ</sub> <i>V</i><sub>λ</sub> <i>dλ</i>, wobei <i>V</i><sub>λ</sub> die relative spektrale Hellempfindlichkeit und <i><span style="text-decoration:overline;">V</span></i><sub>λ,W</sub> die relative spektrale Dämmerungsempfindlichkeit des menschlichen Auges nach Weaver<sup><a href="#CITEREFLohseStille1948">[A]</a></sup> bedeuten. [...] Dunkelleuchtdichte. [...] Ist das Auge dunkeladaptiert, d.h. einer Leuchtdichte von weniger als 0,01 <a href="/wiki/Apostilb" title="Apostilb">asb</a> ausgesetzt, so gilt infolge des <a href="/wiki/Purkinje_effect" title="Purkinje effect">Purkinje-Phänomens</a> eine von der spektralen Hellempfindlichkeitskurve abweichende, nach dem kurzwelligen Ende des Spektrums hin verschobene Empfindlichkeitskurve des Auges, die Stäbchenkurve des <a href="/wiki/Scotopic_vision" title="Scotopic vision">Dämmerungssehens</a>. Unter Zugrundelegung dieser Empfindlichkeitskurve hat man 1940 in Deutschland die Dunkelleuchtdichte mit der Einheit <a href="/wiki/Skot_(unit)" title="Skot (unit)">Skot</a> (sk) so festgesetzt, daß bei einem Licht der Farbtemperatur 2360 °<a href="/wiki/Kelvin_(unit)" class="mw-redirect" title="Kelvin (unit)">K</a> 1 sk = 10<sup>−3</sup> asb gilt. 1948 ist von der <a href="/wiki/Internationale_Beleuchtungskommission" class="mw-redirect" title="Internationale Beleuchtungskommission">Internationalen Beleuchtungskommission</a> (IBK) die Bezugstemperatur auf 2046 K, die Erstarrungstemperatur des <a href="/wiki/Platinum" title="Platinum">Platins</a>, festgesetzt worden. Die Bezeichnung Skot wurde von der IBK nicht übernommen, dafür soll "<a href="/wiki/Skotopisches_Stilb" class="mw-redirect" title="Skotopisches Stilb">skotopisches Stilb</a>" gesagt werden. Als höchstzulässiger Grenzwert für die Dunkelleuchtdichte ist in Deutschland 10 Skot festgesetzt worden, um eine Verwendung der Dunkelleuchtdichte im Gebiet des gemischten <a href="/wiki/Photopic_vision" title="Photopic vision">Zapfen</a>- und <a href="/wiki/Scotopic_vision" title="Scotopic vision">Stäbchensehens</a> zu vermeiden, da in diesem Bereich die photometrischen Maßgrößen wegen der allmählich gleitenden Augenempfindlichkeitskurve ihren Sinn verlieren.</q></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=bookitem&rft.atitle=Nox%2C+Dunkelleuchtdichte%2C+Skot&rft.btitle=Physikalisches+W%C3%B6rterbuch&rft.place=Berlin+%2F+G%C3%B6ttingen+%2F+Heidelberg%2C+Germany&rft.pages=125%2C+271%2C+389&rft.edition=1&rft.pub=Springer-Verlag+OHG&rft.date=1952&rft_id=info%3Adoi%2F10.1007%2F978-3-662-12706-3&rft.isbn=978-3-662-12707-0&rft.aulast=Westphal&rft.aufirst=Wilhelm+Heinrich&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3DQaCFBwAAQBAJ%26pg%3DRA1-PA125&rfr_id=info%3Asid%2Fen.wikipedia.org%3ALux" class="Z3988"></span></span> </li> <li id="cite_note-Grimsehl_1988-21"><span class="mw-cite-backlink"><b><a href="#cite_ref-Grimsehl_1988_21-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFGrimsehlSchallreuter1988" class="citation book cs1 cs1-prop-interwiki-linked-name cs1-prop-foreign-lang-source"><a href="https://de.wikipedia.org/wiki/Ernst_Grimsehl" class="extiw" title="de:Ernst Grimsehl">Grimsehl, Ernst</a> <span class="cs1-format">[in German]</span>; <a href="https://de.wikipedia.org/wiki/Walter_Schallreuter" class="extiw" title="de:Walter Schallreuter">Schallreuter, Walter</a> <span class="cs1-format">[in German]</span> (1988) [1976]. <a rel="nofollow" class="external text" href="https://books.google.com/books?id=pkbQBgAAQBAJ&pg=PA37">"1. Licht: 1.4. Photometrie: 1.4.1. Grundbegriffe"</a>. In Haferkorn, Heinz (ed.). <i>Lehrbuch der Physik: Optik</i> (in German). Vol. 3 (19 ed.). Leipzig, Germany: <a href="/wiki/BSB_BG_Teubner_Verlagsgesellschaft" class="mw-redirect" title="BSB BG Teubner Verlagsgesellschaft">BSB BG Teubner Verlagsgesellschaft</a>. pp. 33–38 [37–38]. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1007%2F978-3-322-96431-1">10.1007/978-3-322-96431-1</a>. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-3-322-96432-8" title="Special:BookSources/978-3-322-96432-8"><bdi>978-3-322-96432-8</bdi></a>. Order No. 6666211, VLN 294-375/84/88, LSV 1164<span class="reference-accessdate">. Retrieved <span class="nowrap">2023-03-16</span></span>. pp. 37–38: <q>Dunkelsehen [...] Für das Dunkelsehen, bei dem nur die <a href="/wiki/Rod_cell" title="Rod cell">Stäbchen</a> angeregt werden, definiert man die Dunkelleuchtdichte mit der Einheit <i><a href="/wiki/Skot_(unit)" title="Skot (unit)">Skot</a></i> (sk) und die Dunkelbeleuchtungsstärke mit der Einheit <i>Nox</i> (nx). Die Umrechnungsfaktoren zwischen den Hell- und Dunkelgrößen hängen von der spektralen Zusammensetzung des Lichtes ab. Sie werden deshalb für die Farbtemperatur 2042 K (früher 2360 K) festgelegt. Bei dieser ist 1 sk = 10<sup>−3</sup> asb und 1 nx = 10<sup>−3</sup> lx.</q></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=bookitem&rft.atitle=1.+Licht%3A+1.4.+Photometrie%3A+1.4.1.+Grundbegriffe&rft.btitle=Lehrbuch+der+Physik%3A+Optik&rft.place=Leipzig%2C+Germany&rft.pages=33-38+37-38&rft.edition=19&rft.pub=BSB+BG+Teubner+Verlagsgesellschaft&rft.date=1988&rft_id=info%3Adoi%2F10.1007%2F978-3-322-96431-1&rft.isbn=978-3-322-96432-8&rft.aulast=Grimsehl&rft.aufirst=Ernst&rft.au=Schallreuter%2C+Walter&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3DpkbQBgAAQBAJ%26pg%3DPA37&rfr_id=info%3Asid%2Fen.wikipedia.org%3ALux" class="Z3988"></span></span> </li> <li id="cite_note-Keplinger_2021-22"><span class="mw-cite-backlink"><b><a href="#cite_ref-Keplinger_2021_22-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFKeplinger2021" class="citation web cs1 cs1-prop-foreign-lang-source">Keplinger, Thomas (2021-03-29). <a rel="nofollow" class="external text" href="https://www.worteimdunkel.at/?p=14007">"1939 bis 1945 – Im Keller glüht das Lumogen"</a>. <i>Worte im Dunkel</i> (in Austrian German). Vienna, Austria. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20230316194909/https://www.worteimdunkel.at/?p=14007">Archived</a> from the original on 2023-03-16<span class="reference-accessdate">. Retrieved <span class="nowrap">2023-03-16</span></span>. <q>Skot und Nox [...] Interessant ist in diesem Zusammenhang die Einführung neuer Messeinheiten. Die Voraussetzungen der Forschung beziehungsweise die Erfordernisse an die Leuchtfarben unterschieden sich so stark von allen bis dahin erforschten Gebieten, dass die <a href="/w/index.php?title=German_Lighting_Society&action=edit&redlink=1" class="new" title="German Lighting Society (page does not exist)">Deutsche Lichttechnische Gesellschaft</a><span class="noprint" style="font-size:85%; font-style: normal;"> [<a href="https://de.wikipedia.org/wiki/Deutsche_Lichttechnische_Gesellschaft" class="extiw" title="de:Deutsche Lichttechnische Gesellschaft">de</a>]</span> 1940 eigene Einheiten ins Leben rief: Die Dunkelleuchtdichte wurde in <a href="/wiki/Skot_(unit)" title="Skot (unit)">Skot</a> und die Dunkelbeleuchtungsstärke in Nox gemessen.<sup><a href="#CITEREFWestphal1952">[B]</a></sup> Diese Einheiten grenzten an die bereits bestehenden Größen der <a href="/wiki/Luminance" title="Luminance">Leuchtdichte</a> und <a href="/wiki/Illuminance" title="Illuminance">Beleuchtungsstärke</a> an und dienten der zahlenmäßigen Erfassung geringster Lichtwerte. So entsprach etwa ein Nox 10<sup>−3</sup> Lux.</q></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=Worte+im+Dunkel&rft.atitle=1939+bis+1945+%E2%80%93+Im+Keller+gl%C3%BCht+das+Lumogen&rft.date=2021-03-29&rft.aulast=Keplinger&rft.aufirst=Thomas&rft_id=https%3A%2F%2Fwww.worteimdunkel.at%2F%3Fp%3D14007&rfr_id=info%3Asid%2Fen.wikipedia.org%3ALux" class="Z3988"></span></span> </li> </ol></div></div> <div class="mw-heading mw-heading2"><h2 id="External_links">External links</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Lux&action=edit&section=10" title="Edit section: External links"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a rel="nofollow" class="external text" href="https://web.archive.org/web/20130313095139/http://fp.optics.arizona.edu/Palmer/rpfaq/rpfaq.htm">Radiometry and photometry FAQ</a> Professor Jim Palmer's Radiometry FAQ page (<a href="/wiki/University_of_Arizona" title="University of Arizona">University of Arizona</a>).</li></ul> <div class="navbox-styles"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><style data-mw-deduplicate="TemplateStyles:r1236075235">.mw-parser-output .navbox{box-sizing:border-box;border:1px solid #a2a9b1;width:100%;clear:both;font-size:88%;text-align:center;padding:1px;margin:1em auto 0}.mw-parser-output .navbox .navbox{margin-top:0}.mw-parser-output .navbox+.navbox,.mw-parser-output .navbox+.navbox-styles+.navbox{margin-top:-1px}.mw-parser-output .navbox-inner,.mw-parser-output .navbox-subgroup{width:100%}.mw-parser-output .navbox-group,.mw-parser-output .navbox-title,.mw-parser-output .navbox-abovebelow{padding:0.25em 1em;line-height:1.5em;text-align:center}.mw-parser-output .navbox-group{white-space:nowrap;text-align:right}.mw-parser-output .navbox,.mw-parser-output .navbox-subgroup{background-color:#fdfdfd}.mw-parser-output .navbox-list{line-height:1.5em;border-color:#fdfdfd}.mw-parser-output .navbox-list-with-group{text-align:left;border-left-width:2px;border-left-style:solid}.mw-parser-output tr+tr>.navbox-abovebelow,.mw-parser-output tr+tr>.navbox-group,.mw-parser-output tr+tr>.navbox-image,.mw-parser-output tr+tr>.navbox-list{border-top:2px solid #fdfdfd}.mw-parser-output .navbox-title{background-color:#ccf}.mw-parser-output .navbox-abovebelow,.mw-parser-output .navbox-group,.mw-parser-output .navbox-subgroup .navbox-title{background-color:#ddf}.mw-parser-output .navbox-subgroup .navbox-group,.mw-parser-output .navbox-subgroup .navbox-abovebelow{background-color:#e6e6ff}.mw-parser-output .navbox-even{background-color:#f7f7f7}.mw-parser-output .navbox-odd{background-color:transparent}.mw-parser-output .navbox .hlist td dl,.mw-parser-output .navbox .hlist td ol,.mw-parser-output .navbox .hlist td ul,.mw-parser-output .navbox td.hlist dl,.mw-parser-output .navbox td.hlist ol,.mw-parser-output .navbox td.hlist ul{padding:0.125em 0}.mw-parser-output .navbox .navbar{display:block;font-size:100%}.mw-parser-output .navbox-title .navbar{float:left;text-align:left;margin-right:0.5em}body.skin--responsive .mw-parser-output .navbox-image img{max-width:none!important}@media print{body.ns-0 .mw-parser-output .navbox{display:none!important}}</style></div><div role="navigation" class="navbox" aria-labelledby="SI_units" style="padding:3px"><table class="nowraplinks hlist mw-collapsible autocollapse navbox-inner" style="border-spacing:0;background:transparent;color:inherit"><tbody><tr><th scope="col" class="navbox-title" colspan="2"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1239400231"><div class="navbar plainlinks hlist navbar-mini"><ul><li class="nv-view"><a href="/wiki/Template:SI_units" title="Template:SI units"><abbr title="View this template">v</abbr></a></li><li class="nv-talk"><a href="/wiki/Template_talk:SI_units" title="Template talk:SI units"><abbr title="Discuss this template">t</abbr></a></li><li class="nv-edit"><a href="/wiki/Special:EditPage/Template:SI_units" title="Special:EditPage/Template:SI units"><abbr title="Edit this template">e</abbr></a></li></ul></div><div id="SI_units" style="font-size:114%;margin:0 4em"><a href="/wiki/International_System_of_Units" title="International System of Units">SI units</a></div></th></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/SI_base_unit" title="SI base unit">Base units</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Ampere" title="Ampere">ampere</a></li> <li><a href="/wiki/Candela" title="Candela">candela</a></li> <li><a href="/wiki/Kelvin" title="Kelvin">kelvin</a></li> <li><a href="/wiki/Kilogram" title="Kilogram">kilogram</a></li> <li><a href="/wiki/Metre" title="Metre">metre</a></li> <li><a href="/wiki/Mole_(unit)" title="Mole (unit)">mole</a></li> <li><a href="/wiki/Second" title="Second">second</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/SI_derived_unit" title="SI derived unit">Derived units <br />with special names</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Becquerel" title="Becquerel">becquerel</a></li> <li><a href="/wiki/Coulomb" title="Coulomb">coulomb</a></li> <li><a href="/wiki/Celsius" title="Celsius">degree Celsius</a></li> <li><a href="/wiki/Farad" title="Farad">farad</a></li> <li><a href="/wiki/Gray_(unit)" title="Gray (unit)">gray</a></li> <li><a href="/wiki/Henry_(unit)" title="Henry (unit)">henry</a></li> <li><a href="/wiki/Hertz" title="Hertz">hertz</a></li> <li><a href="/wiki/Joule" title="Joule">joule</a></li> <li><a href="/wiki/Katal" title="Katal">katal</a></li> <li><a href="/wiki/Lumen_(unit)" title="Lumen (unit)">lumen</a></li> <li><a class="mw-selflink selflink">lux</a></li> <li><a href="/wiki/Newton_(unit)" title="Newton (unit)">newton</a></li> <li><a href="/wiki/Ohm" title="Ohm">ohm</a></li> <li><a href="/wiki/Pascal_(unit)" title="Pascal (unit)">pascal</a></li> <li><a href="/wiki/Radian" title="Radian">radian</a></li> <li><a href="/wiki/Siemens_(unit)" title="Siemens (unit)">siemens</a></li> <li><a href="/wiki/Sievert" title="Sievert">sievert</a></li> <li><a href="/wiki/Steradian" title="Steradian">steradian</a></li> <li><a href="/wiki/Tesla_(unit)" title="Tesla (unit)">tesla</a></li> <li><a href="/wiki/Volt" title="Volt">volt</a></li> <li><a href="/wiki/Watt" title="Watt">watt</a></li> <li><a href="/wiki/Weber_(unit)" title="Weber (unit)">weber</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Non-SI_units_mentioned_in_the_SI" title="Non-SI units mentioned in the SI">Other accepted units</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Astronomical_unit" title="Astronomical unit">astronomical unit</a></li> <li><a href="/wiki/Dalton_(unit)" title="Dalton (unit)">dalton</a></li> <li><a href="/wiki/Day" title="Day">day</a></li> <li><a href="/wiki/Decibel" title="Decibel">decibel</a></li> <li><a href="/wiki/Degree_(angle)" title="Degree (angle)">degree of arc</a></li> <li><a href="/wiki/Electronvolt" title="Electronvolt">electronvolt</a></li> <li><a href="/wiki/Hectare" title="Hectare">hectare</a></li> <li><a href="/wiki/Hour" title="Hour">hour</a></li> <li><a href="/wiki/Litre" title="Litre">litre</a></li> <li><a href="/wiki/Minute" title="Minute">minute</a></li> <li><a href="/wiki/Minute_and_second_of_arc" title="Minute and second of arc">minute and second of arc</a></li> <li><a href="/wiki/Neper" title="Neper">neper</a></li> <li><a href="/wiki/Tonne" title="Tonne">tonne</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">See also</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Conversion_of_units" title="Conversion of units">Conversion of units</a></li> <li><a href="/wiki/Metric_prefix" title="Metric prefix">Metric prefixes</a></li> <li><a href="/wiki/Historical_definitions_of_the_SI_base_units" title="Historical definitions of the SI base units">Historical definitions of the SI base units</a></li> <li><a href="/wiki/2019_revision_of_the_SI" title="2019 revision of the SI">2019 revision of the SI</a></li> <li><a href="/wiki/System_of_units_of_measurement" title="System of units of measurement">System of units of measurement</a></li></ul> </div></td></tr><tr><td class="navbox-abovebelow" colspan="2"><div> <ul><li><span class="noviewer" typeof="mw:File"><span title="Category"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/16px-Symbol_category_class.svg.png" decoding="async" width="16" height="16" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/23px-Symbol_category_class.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/31px-Symbol_category_class.svg.png 2x" data-file-width="180" data-file-height="185" /></span></span> <a href="/wiki/Category:SI_units" title="Category:SI units">Category</a></li></ul> </div></td></tr></tbody></table></div> <style data-mw-deduplicate="TemplateStyles:r1130092004">.mw-parser-output .portal-bar{font-size:88%;font-weight:bold;display:flex;justify-content:center;align-items:baseline}.mw-parser-output .portal-bar-bordered{padding:0 2em;background-color:#fdfdfd;border:1px solid #a2a9b1;clear:both;margin:1em auto 0}.mw-parser-output .portal-bar-related{font-size:100%;justify-content:flex-start}.mw-parser-output .portal-bar-unbordered{padding:0 1.7em;margin-left:0}.mw-parser-output .portal-bar-header{margin:0 1em 0 0.5em;flex:0 0 auto;min-height:24px}.mw-parser-output .portal-bar-content{display:flex;flex-flow:row wrap;flex:0 1 auto;padding:0.15em 0;column-gap:1em;align-items:baseline;margin:0;list-style:none}.mw-parser-output .portal-bar-content-related{margin:0;list-style:none}.mw-parser-output .portal-bar-item{display:inline-block;margin:0.15em 0.2em;min-height:24px;line-height:24px}@media screen and (max-width:768px){.mw-parser-output .portal-bar{font-size:88%;font-weight:bold;display:flex;flex-flow:column wrap;align-items:baseline}.mw-parser-output .portal-bar-header{text-align:center;flex:0;padding-left:0.5em;margin:0 auto}.mw-parser-output .portal-bar-related{font-size:100%;align-items:flex-start}.mw-parser-output .portal-bar-content{display:flex;flex-flow:row wrap;align-items:center;flex:0;column-gap:1em;border-top:1px solid #a2a9b1;margin:0 auto;list-style:none}.mw-parser-output .portal-bar-content-related{border-top:none;margin:0;list-style:none}}.mw-parser-output .navbox+link+.portal-bar,.mw-parser-output .navbox+style+.portal-bar,.mw-parser-output .navbox+link+.portal-bar-bordered,.mw-parser-output .navbox+style+.portal-bar-bordered,.mw-parser-output .sister-bar+link+.portal-bar,.mw-parser-output .sister-bar+style+.portal-bar,.mw-parser-output .portal-bar+.navbox-styles+.navbox,.mw-parser-output .portal-bar+.navbox-styles+.sister-bar{margin-top:-1px}</style><div class="portal-bar noprint metadata noviewer portal-bar-bordered" role="navigation" aria-label="Portals"><span class="portal-bar-header"><a href="/wiki/Wikipedia:Contents/Portals" title="Wikipedia:Contents/Portals">Portals</a>:</span><ul class="portal-bar-content"><li class="portal-bar-item"><span class="nowrap"><span typeof="mw:File"><a href="/wiki/File:Stylised_atom_with_three_Bohr_model_orbits_and_stylised_nucleus.svg" class="mw-file-description"><img alt="icon" src="//upload.wikimedia.org/wikipedia/commons/thumb/6/6f/Stylised_atom_with_three_Bohr_model_orbits_and_stylised_nucleus.svg/17px-Stylised_atom_with_three_Bohr_model_orbits_and_stylised_nucleus.svg.png" decoding="async" width="17" height="19" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/6/6f/Stylised_atom_with_three_Bohr_model_orbits_and_stylised_nucleus.svg/26px-Stylised_atom_with_three_Bohr_model_orbits_and_stylised_nucleus.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/6/6f/Stylised_atom_with_three_Bohr_model_orbits_and_stylised_nucleus.svg/34px-Stylised_atom_with_three_Bohr_model_orbits_and_stylised_nucleus.svg.png 2x" data-file-width="530" data-file-height="600" /></a></span> </span><a href="/wiki/Portal:Physics" title="Portal:Physics">Physics</a></li><li class="portal-bar-item"><span class="nowrap"><span typeof="mw:File"><a href="/wiki/File:Crystal_energy.svg" class="mw-file-description"><img alt="icon" src="//upload.wikimedia.org/wikipedia/commons/thumb/1/14/Crystal_energy.svg/20px-Crystal_energy.svg.png" decoding="async" width="20" height="19" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/1/14/Crystal_energy.svg/30px-Crystal_energy.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/1/14/Crystal_energy.svg/40px-Crystal_energy.svg.png 2x" data-file-width="130" data-file-height="124" /></a></span> </span><a href="/wiki/Portal:Energy" title="Portal:Energy">Energy</a></li></ul></div>    </div><noscript><img src="https://login.wikimedia.org/wiki/Special:CentralAutoLogin/start?type=1x1&useformat=desktop" alt="" width="1" height="1" style="border: none; position: absolute;"></noscript> <div class="printfooter" data-nosnippet="">Retrieved from "<a dir="ltr" href="https://en.wikipedia.org/w/index.php?title=Lux&oldid=1255787364">https://en.wikipedia.org/w/index.php?title=Lux&oldid=1255787364</a>"</div></div> <div id="catlinks" class="catlinks" data-mw="interface"><div id="mw-normal-catlinks" class="mw-normal-catlinks"><a href="/wiki/Help:Category" title="Help:Category">Categories</a>: <ul><li><a href="/wiki/Category:SI_derived_units" title="Category:SI derived units">SI derived units</a></li><li><a href="/wiki/Category:Units_of_illuminance" title="Category:Units of illuminance">Units of illuminance</a></li></ul></div><div id="mw-hidden-catlinks" class="mw-hidden-catlinks mw-hidden-cats-hidden">Hidden categories: <ul><li><a href="/wiki/Category:All_articles_with_dead_external_links" title="Category:All articles with dead external links">All articles with dead external links</a></li><li><a href="/wiki/Category:Articles_with_dead_external_links_from_September_2018" title="Category:Articles with dead external links from September 2018">Articles with dead external links from September 2018</a></li><li><a href="/wiki/Category:Articles_with_permanently_dead_external_links" title="Category:Articles with permanently dead external links">Articles with permanently dead external links</a></li><li><a href="/wiki/Category:CS1_maint:_unfit_URL" title="Category:CS1 maint: unfit URL">CS1 maint: unfit URL</a></li><li><a href="/wiki/Category:CS1_location_test" title="Category:CS1 location test">CS1 location test</a></li><li><a href="/wiki/Category:CS1_interwiki-linked_names" title="Category:CS1 interwiki-linked names">CS1 interwiki-linked names</a></li><li><a href="/wiki/Category:CS1_German-language_sources_(de)" title="Category:CS1 German-language sources (de)">CS1 German-language sources (de)</a></li><li><a href="/wiki/Category:CS1_Austrian_German-language_sources_(de-at)" title="Category:CS1 Austrian German-language sources (de-at)">CS1 Austrian German-language sources (de-at)</a></li><li><a href="/wiki/Category:Articles_with_short_description" title="Category:Articles with short description">Articles with short description</a></li><li><a href="/wiki/Category:Short_description_is_different_from_Wikidata" title="Category:Short description is different from Wikidata">Short description is different from Wikidata</a></li><li><a href="/wiki/Category:Use_dmy_dates_from_March_2023" title="Category:Use dmy dates from March 2023">Use dmy dates from March 2023</a></li><li><a href="/wiki/Category:All_articles_with_unsourced_statements" title="Category:All articles with unsourced statements">All articles with unsourced statements</a></li><li><a href="/wiki/Category:Articles_with_unsourced_statements_from_February_2013" title="Category:Articles with unsourced statements from February 2013">Articles with unsourced statements from February 2013</a></li></ul></div></div> </div> </main> </div> <div class="mw-footer-container"> <footer id="footer" class="mw-footer" > <ul id="footer-info"> <li id="footer-info-lastmod"> This page was last edited on 6 November 2024, at 17:48<span class="anonymous-show"> (UTC)</span>.</li> <li id="footer-info-copyright">Text is available under the <a href="/wiki/Wikipedia:Text_of_the_Creative_Commons_Attribution-ShareAlike_4.0_International_License" title="Wikipedia:Text of the Creative Commons Attribution-ShareAlike 4.0 International License">Creative Commons Attribution-ShareAlike 4.0 License</a>; additional terms may apply. By using this site, you agree to the <a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Terms_of_Use" class="extiw" title="foundation:Special:MyLanguage/Policy:Terms of Use">Terms of Use</a> and <a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Privacy_policy" class="extiw" title="foundation:Special:MyLanguage/Policy:Privacy policy">Privacy Policy</a>. Wikipedia® is a registered trademark of the <a rel="nofollow" class="external text" href="https://wikimediafoundation.org/">Wikimedia Foundation, Inc.</a>, a non-profit organization.</li> </ul> <ul id="footer-places"> <li id="footer-places-privacy"><a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Privacy_policy">Privacy policy</a></li> <li id="footer-places-about"><a href="/wiki/Wikipedia:About">About Wikipedia</a></li> <li id="footer-places-disclaimers"><a href="/wiki/Wikipedia:General_disclaimer">Disclaimers</a></li> <li id="footer-places-contact"><a href="//en.wikipedia.org/wiki/Wikipedia:Contact_us">Contact Wikipedia</a></li> <li id="footer-places-wm-codeofconduct"><a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Universal_Code_of_Conduct">Code of Conduct</a></li> <li id="footer-places-developers"><a href="https://developer.wikimedia.org">Developers</a></li> <li id="footer-places-statslink"><a href="https://stats.wikimedia.org/#/en.wikipedia.org">Statistics</a></li> <li id="footer-places-cookiestatement"><a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Cookie_statement">Cookie statement</a></li> <li id="footer-places-mobileview"><a href="//en.m.wikipedia.org/w/index.php?title=Lux&mobileaction=toggle_view_mobile" class="noprint stopMobileRedirectToggle">Mobile view</a></li> </ul> <ul id="footer-icons" class="noprint"> <li id="footer-copyrightico"><a href="https://wikimediafoundation.org/" class="cdx-button cdx-button--fake-button cdx-button--size-large cdx-button--fake-button--enabled"><img src="/static/images/footer/wikimedia-button.svg" width="84" height="29" alt="Wikimedia Foundation" loading="lazy"></a></li> <li id="footer-poweredbyico"><a href="https://www.mediawiki.org/" class="cdx-button cdx-button--fake-button cdx-button--size-large cdx-button--fake-button--enabled"><img src="/w/resources/assets/poweredby_mediawiki.svg" alt="Powered by MediaWiki" width="88" height="31" loading="lazy"></a></li> </ul> </footer> </div> </div> </div> <div class="vector-settings" id="p-dock-bottom"> <ul></ul> </div><script>(RLQ=window.RLQ||[]).push(function(){mw.config.set({"wgHostname":"mw-web.codfw.main-5c59558b9d-pkptl","wgBackendResponseTime":165,"wgPageParseReport":{"limitreport":{"cputime":"0.646","walltime":"0.819","ppvisitednodes":{"value":4272,"limit":1000000},"postexpandincludesize":{"value":81994,"limit":2097152},"templateargumentsize":{"value":5455,"limit":2097152},"expansiondepth":{"value":23,"limit":100},"expensivefunctioncount":{"value":8,"limit":500},"unstrip-depth":{"value":1,"limit":20},"unstrip-size":{"value":96444,"limit":5000000},"entityaccesscount":{"value":0,"limit":400},"timingprofile":["100.00% 714.594 1 -total"," 34.70% 247.967 2 Template:Reflist"," 15.18% 108.468 1 Template:SI_light_units"," 10.96% 78.353 1 Template:Infobox_unit"," 10.82% 77.352 1 Template:Citation"," 9.81% 70.082 1 Template:Infobox"," 9.20% 65.711 1 Template:Short_description"," 8.64% 61.742 1 Template:Navbar-header"," 7.92% 56.623 6 Template:Cite_book"," 6.76% 48.272 2 Template:Fix"]},"scribunto":{"limitreport-timeusage":{"value":"0.344","limit":"10.000"},"limitreport-memusage":{"value":9972351,"limit":52428800}},"cachereport":{"origin":"mw-api-ext.codfw.main-74f675c4bb-fzp2v","timestamp":"20241129143808","ttl":2592000,"transientcontent":false}}});});</script> <script type="application/ld+json">{"@context":"https:\/\/schema.org","@type":"Article","name":"Lux","url":"https:\/\/en.wikipedia.org\/wiki\/Lux","sameAs":"http:\/\/www.wikidata.org\/entity\/Q179836","mainEntity":"http:\/\/www.wikidata.org\/entity\/Q179836","author":{"@type":"Organization","name":"Contributors to Wikimedia projects"},"publisher":{"@type":"Organization","name":"Wikimedia Foundation, Inc.","logo":{"@type":"ImageObject","url":"https:\/\/www.wikimedia.org\/static\/images\/wmf-hor-googpub.png"}},"datePublished":"2002-12-08T19:53:59Z","dateModified":"2024-11-06T17:48:00Z","image":"https:\/\/upload.wikimedia.org\/wikipedia\/commons\/f\/f1\/Lux_meter.jpg","headline":"SI unit of illuminance"}</script> </body> </html>