{"id":144,"date":"2018-08-14T11:28:35","date_gmt":"2018-08-14T11:28:35","guid":{"rendered":"https:\/\/live-optics-wp.pantheonsite.io\/oscoutreach\/?p=144"},"modified":"2025-03-18T12:26:13","modified_gmt":"2025-03-18T19:26:13","slug":"schlieren-imaging","status":"publish","type":"post","link":"https:\/\/wp.optics.arizona.edu\/oscoutreach\/schlieren-imaging\/","title":{"rendered":"Schlieren Imaging"},"content":{"rendered":"\r\n<p><strong>Overview<\/strong>: Schlieren works by imaging deflected rays of light in a transparent medium. By deflecting the rays of light it enables us to see the flow of warm air around objects.\u00a0<\/p>\r\n\r\n\r\n\r\n<p><strong>Supplies<\/strong>: Schlieren mirror, pinhole light source, knife edge such as a razor blade, stand for the knife edge, camera with a lens, computer with software for the camera, TV for larger audience projection of the camera image, various heat sources such as a candle or a hair dryer<\/p>\r\n<p><strong style=\"font-size: 0.95em\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1897 \" src=\"http:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-content\/uploads\/sites\/75\/2025\/03\/schlieren-setup-1024x768.jpg\" alt=\"\" width=\"415\" height=\"311\" srcset=\"https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-content\/uploads\/sites\/75\/2025\/03\/schlieren-setup-1024x768.jpg 1024w, https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-content\/uploads\/sites\/75\/2025\/03\/schlieren-setup-300x225.jpg 300w, https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-content\/uploads\/sites\/75\/2025\/03\/schlieren-setup-768x576.jpg 768w, https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-content\/uploads\/sites\/75\/2025\/03\/schlieren-setup-1536x1152.jpg 1536w, https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-content\/uploads\/sites\/75\/2025\/03\/schlieren-setup-2048x1536.jpg 2048w\" sizes=\"auto, (max-width: 415px) 100vw, 415px\" \/><\/strong><\/p>\r\n\r\n\r\n\r\n<p><strong>Objectives<\/strong>: Demonstrate how we can see the changes in an area of air that is heated in various ways when using this unique setup.<\/p>\r\n\r\n\r\n<hr class=\"wp-block-separator has-alpha-channel-opacity\" \/>\r\n\r\n\r\n<p><strong>Setup:<\/strong><\/p>\r\n<ul>\r\n<li>Place the light source and camera side by side at one end of the table<\/li>\r\n<li>Place the Schlieren mirror at the opposite end of the table at the prescribed distance. If the focal length of the mirror is not labeled the FL will need to be determined<\/li>\r\n<li>Place the knife edge in front of the camera<\/li>\r\n<li>Turn on the light source<\/li>\r\n<li>Adjust the light source, mirror and knife edge so the light spot is in focus at the knife edge and bisected by the knife edge<\/li>\r\n<li>Hook up the camera to the laptop and open the camera software<\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n<div class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-9d6595d7 wp-block-columns-is-layout-flex\">\r\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis: 50%\">\r\n<figure class=\"wp-block-image is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"300\" height=\"225\" class=\"wp-image-272\" style=\"aspect-ratio: 1.3333333333333333;width: 404px;height: auto\" src=\"https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-content\/uploads\/sites\/75\/2018\/08\/DSCN0339-300x225.jpg\" alt=\"\" srcset=\"https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-content\/uploads\/sites\/75\/2018\/08\/DSCN0339-300x225.jpg 300w, https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-content\/uploads\/sites\/75\/2018\/08\/DSCN0339-768x576.jpg 768w, https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-content\/uploads\/sites\/75\/2018\/08\/DSCN0339-1024x768.jpg 1024w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/figure>\r\n<\/div>\r\n\r\n\r\n\r\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis: 50%\">\r\n<figure class=\"wp-block-image is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"225\" height=\"300\" class=\"wp-image-271\" style=\"aspect-ratio: 0.75;width: 230px;height: auto\" src=\"https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-content\/uploads\/sites\/75\/2018\/08\/DSCN0334-e1535657843955-225x300.jpg\" alt=\"\" srcset=\"https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-content\/uploads\/sites\/75\/2018\/08\/DSCN0334-e1535657843955-225x300.jpg 225w, https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-content\/uploads\/sites\/75\/2018\/08\/DSCN0334-e1535657843955-768x1024.jpg 768w\" sizes=\"auto, (max-width: 225px) 100vw, 225px\" \/><\/figure>\r\n<\/div>\r\n<\/div>\r\n\r\n\r\n\r\n<p><strong>How to run the demo:<\/strong><\/p>\r\n<ul>\r\n<li>Place various heat sources in front of the mirror (NOT TOO CLOSE!!)<\/li>\r\n<li>Items that can be used are a hair dryer, a candle, even rubbing your hands together to create heat and placing your hand face up in front of the mirror<\/li>\r\n<li>Bottles of isoporpyl alcohol can be gently squeezed to expel the alcohol vapor (not the liquid)<\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n<div class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-9d6595d7 wp-block-columns-is-layout-flex\">\r\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\r\n<figure class=\"wp-block-image is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"300\" height=\"225\" class=\"wp-image-269\" style=\"aspect-ratio: 1.3333333333333333;width: 433px;height: auto\" src=\"https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-content\/uploads\/sites\/75\/2018\/08\/DSCN0343-300x225.jpg\" alt=\"\" srcset=\"https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-content\/uploads\/sites\/75\/2018\/08\/DSCN0343-300x225.jpg 300w, https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-content\/uploads\/sites\/75\/2018\/08\/DSCN0343-768x576.jpg 768w, https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-content\/uploads\/sites\/75\/2018\/08\/DSCN0343-1024x768.jpg 1024w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/figure>\r\n<\/div>\r\n\r\n\r\n\r\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\r\n<figure class=\"wp-block-image is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"1280\" height=\"1024\" class=\"wp-image-145\" style=\"aspect-ratio: 1.25;width: 405px;height: auto\" src=\"https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-content\/uploads\/sites\/75\/2018\/08\/Hair-Dryer.gif\" alt=\"\" \/><\/figure>\r\n<\/div>\r\n<\/div>\r\n\r\n\r\n\r\n<div class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-9d6595d7 wp-block-columns-is-layout-flex\">\r\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis: 50%\">\r\n<figure class=\"wp-block-image is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"300\" height=\"225\" class=\"wp-image-270\" style=\"aspect-ratio: 1.3333333333333333;width: 439px;height: auto\" src=\"https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-content\/uploads\/sites\/75\/2018\/08\/DSCN0344-300x225.jpg\" alt=\"\" srcset=\"https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-content\/uploads\/sites\/75\/2018\/08\/DSCN0344-300x225.jpg 300w, https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-content\/uploads\/sites\/75\/2018\/08\/DSCN0344-768x576.jpg 768w, https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-content\/uploads\/sites\/75\/2018\/08\/DSCN0344-1024x768.jpg 1024w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/figure>\r\n<\/div>\r\n\r\n\r\n\r\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis: 50%\">\r\n<figure class=\"wp-block-image is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"1280\" height=\"1024\" class=\"wp-image-146\" style=\"aspect-ratio: 1.25;width: 410px;height: auto\" src=\"https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-content\/uploads\/sites\/75\/2018\/08\/Isopropanol.gif\" alt=\"\" \/><\/figure>\r\n<\/div>\r\n<\/div>\r\n\r\n\r\n<hr class=\"wp-block-separator has-alpha-channel-opacity\" \/>\r\n\r\n\r\n<p><strong>What&#8217;s Happening?<\/strong><\/p>\r\n\r\n\r\n\r\n<p>Light rays bend when they pass through different densities of air. Warmer air has a different density than cooler air. When we put a heat source through a path of parallel light, the light rays encountering the warmer section will bend, or refract. Because the knife edge is at the focal point of the mirror the refracted rays of light hit the knife edge instead of continuing through to the camera. The resulting image shows dark areas where the density gradients are present.<\/p>\r\n<div id=\"attachment_1909\" style=\"width: 811px\" class=\"wp-caption alignnone\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-1909\" class=\"wp-image-1909 size-full\" src=\"http:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-content\/uploads\/sites\/75\/2018\/08\/schlieren-diagram.jpeg\" alt=\"\" width=\"801\" height=\"534\" srcset=\"https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-content\/uploads\/sites\/75\/2018\/08\/schlieren-diagram.jpeg 801w, https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-content\/uploads\/sites\/75\/2018\/08\/schlieren-diagram-300x200.jpeg 300w, https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-content\/uploads\/sites\/75\/2018\/08\/schlieren-diagram-768x512.jpeg 768w\" sizes=\"auto, (max-width: 801px) 100vw, 801px\" \/><p id=\"caption-attachment-1909\" class=\"wp-caption-text\">Image courtesy of https:\/\/www.instructables.com\/Schlieren-Imaging-How-to-see-air-flow\/<\/p><\/div>\r\n\r\n\r\n<hr class=\"wp-block-separator has-alpha-channel-opacity\" \/>\r\n\r\n\r\n<p><strong>Learn more:\u00a0<\/strong>(external links)<\/p>\r\n\r\n\r\n\r\n<p class=\"wp-embed-aspect-16-9 wp-has-aspect-ratio\"><a href=\"https:\/\/youtu.be\/jFoKtiPEsGQ\">Schlierin Imaging Demo<\/a><\/p>\r\n\r\n\r\n\r\n<p class=\"wp-embed-aspect-16-9 wp-has-aspect-ratio\"><a href=\"https:\/\/www.youtube.com\/watch?v=NmMXt6wR78Q&amp;list=PL6DwVv2hudGZHkS34wAV-4NQ7Fw3zPTxf&amp;index=27\">Another Schlieren Imaging Demo<\/a><\/p>\r\n","protected":false},"excerpt":{"rendered":"<p>You can deflect rays of light with a knife edge to produce variations in light intensity from a single source.<\/p>\n","protected":false},"author":43,"featured_media":269,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[8],"tags":[],"class_list":["post-144","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-physical-optics"],"_links":{"self":[{"href":"https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-json\/wp\/v2\/posts\/144","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-json\/wp\/v2\/users\/43"}],"replies":[{"embeddable":true,"href":"https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-json\/wp\/v2\/comments?post=144"}],"version-history":[{"count":25,"href":"https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-json\/wp\/v2\/posts\/144\/revisions"}],"predecessor-version":[{"id":1910,"href":"https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-json\/wp\/v2\/posts\/144\/revisions\/1910"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-json\/wp\/v2\/media\/269"}],"wp:attachment":[{"href":"https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-json\/wp\/v2\/media?parent=144"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-json\/wp\/v2\/categories?post=144"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-json\/wp\/v2\/tags?post=144"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}