{"id":2609,"date":"2026-01-13T07:15:54","date_gmt":"2026-01-13T07:15:54","guid":{"rendered":"https:\/\/lightingrecipe.com\/?page_id=2609"},"modified":"2026-01-21T08:37:35","modified_gmt":"2026-01-21T08:37:35","slug":"tm-30-and-sdcm","status":"publish","type":"page","link":"https:\/\/lightingrecipe.com\/zh\/tm-30-and-sdcm\/","title":{"rendered":"TM-30 \u8207 SDCM"},"content":{"rendered":"<div class=\"wp-block-columns alignwide is-layout-flex wp-container-core-columns-is-layout-9d6595d7 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:100%\">\n<p class=\"has-black-color has-text-color has-link-color has-medium-font-size wp-elements-8f828a81b18da370d5e1260766f70e8a\"><strong><em>\u4ec0\u9ebc\u662f TM-30\uff1f<\/em><\/strong><\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-ed88e78adb91fbe3e930775373b27c2c\" style=\"font-size:15px\"><br><br>IES TM-30 \u662f\u7531 \u7f8e\u570b\u7167\u660e\u5de5\u7a0b\u5b78\u6703\uff08IES\uff09 \u65bc 2015 \u5e74 \u63a8\u51fa\u7684\u986f\u8272\u8a55\u4f30\u65b9\u6cd5\uff0c\u65e8\u5728\u514b\u670d\u50b3\u7d71 Ra\uff08CRI\uff09 \u6307\u6a19\u7684\u9650\u5236\u3002\nTM-30 \u63d0\u4f9b\u4e00\u7a2e\u66f4\u5168\u9762\u4e14\u66f4\u7cbe\u78ba\u7684\u65b9\u5f0f\u4f86\u8a55\u4f30\u5149\u6e90\u7684\u986f\u8272\u6027\u80fd\uff0c\u76f8\u8f03\u65bc Ra \u7b49\u50b3\u7d71\u6307\u6a19\uff0c\u80fd\u5e36\u4f86\u66f4\u6df1\u5165\u7684\u8272\u5f69\u8868\u73fe\u6d1e\u5bdf\u3002<br>\u4e0d\u540c\u65bc\u50c5\u4f7f\u7528 8 \u500b\u8272\u6a23 \u7684 CRI\uff0cTM-30 \u63a1\u7528 99 \u500b\u8272\u6a23 \u9032\u884c\u8a55\u4f30\uff0c\u4f7f\u5176\u5c0d\u5149\u6e90\u986f\u8272\u8868\u73fe\u7684\u5206\u6790\u66f4\u70ba\u5168\u9762\u4e14\u66f4\u8cbc\u8fd1\u771f\u5be6\u8996\u89ba\u611f\u53d7\u3002<br><br><strong>\u8272\u5f69\u4fdd\u771f\u6307\u6578\uff08Rf\uff09<\/strong><br>Rf\uff08\u8272\u5f69\u4fdd\u771f\u6307\u6578\uff09 \u7528\u65bc\u8861\u91cf\u5149\u6e90\u76f8\u5c0d\u65bc\u53c3\u8003\u5149\u6e90\u7684\u8272\u5f69\u518d\u73fe\u6e96\u78ba\u5ea6\uff0c\u5176\u6982\u5ff5\u8207 CRI \u985e\u4f3c\uff0c\u4f46\u63a1\u7528 TM-30 \u64f4\u5c55\u7684 99 \u500b\u8272\u6a23 \u9032\u884c\u8a08\u7b97\u3002\nRf \u6578\u503c\u8d8a\u9ad8\uff0c\u4ee3\u8868\u986f\u8272\u6e96\u78ba\u5ea6\u8d8a\u4f73\uff1b\u5176\u4e2d 100 \u70ba\u6eff\u5206\uff0c\u8868\u793a\u8a72\u5149\u6e90\u5728\u8272\u5f69\u5448\u73fe\u4e0a\u8207\u53c3\u8003\u5149\u6e90\u5b8c\u5168\u4e00\u81f4\u3002<br><br><strong>\u8272\u57df\u6307\u6578\uff08Rg\uff09<\/strong><br>Rg\uff08\u8272\u57df\u6307\u6578\uff09 \u7528\u65bc\u8861\u91cf\u5149\u6e90\u76f8\u5c0d\u65bc\u53c3\u8003\u5149\u6e90\u6240\u5448\u73fe\u7684\u8272\u5f69\u98fd\u548c\u5ea6\uff0c\u53ef\u63d0\u4f9b\u95dc\u65bc\u8272\u5f69\u5f37\u5ea6\u8207\u9bae\u8c54\u5ea6\u7684\u91cd\u8981\u8cc7\u8a0a\u3002<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-99bb9111e66e8593d32f1a812e67a24c\" style=\"font-size:15px\">\ud83d\udd39<strong>Rg = 100<\/strong>\uff1a\u8207\u53c3\u8003\u5149\u6e90\u7684\u8272\u5f69\u98fd\u548c\u5ea6\u76f8\u7b26<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-18a004ab581f03bb4faedf476c1e282f\" style=\"font-size:15px\">\ud83d\udd39<strong>Rg &gt; 100<\/strong>\uff1a\u8868\u793a\u8272\u5f69\u904e\u5ea6\u98fd\u548c\uff08\u984f\u8272\u770b\u8d77\u4f86\u66f4\u70ba\u5f37\u70c8\uff09<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-49bbe8c036f81d0c63b04b16380d8391\" style=\"font-size:15px\">\ud83d\udd39<strong>Rg &lt; 100<\/strong>\uff1a\u8868\u793a\u8272\u5f69\u53bb\u98fd\u548c\uff08\u984f\u8272\u770b\u8d77\u4f86\u8f03\u70ba\u67d4\u548c\uff09<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-c1121da8230a2e8a29658eb148f2c244\" style=\"font-size:15px\">Rf \u8207 Rg \u7d50\u5408\u4f7f\u7528\uff0c\u53ef\u5168\u9762\u5448\u73fe\u5149\u6e90\u7684\u8272\u5f69\u8868\u73fe\uff0c\u5176\u4e2d Rg \u88dc\u5145\u4e86\u95dc\u65bc\u8272\u5f69\u9bae\u8c54\u5ea6\u8207\u5f37\u5ea6\u7684\u91cd\u8981\u8cc7\u8a0a\u3002<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-a34f5293e80b788fdbca6fea81cafa0c\" style=\"font-size:15px\"><br><br><strong>\u8272\u5f69\u5411\u91cf\u5716\uff08Color Vector Graphic\uff09<\/strong><br>Rf \u8207 Rg \u63d0\u4f9b\u7684\u662f\u6578\u503c\u6307\u6a19\uff0c\u800c\u8272\u5f69\u5411\u91cf\u5716\uff08Color Vector Graphic\uff09\u5247\u4ee5\u8996\u89ba\u5316\u65b9\u5f0f\u5448\u73fe\u8272\u5f69\u98fd\u548c\u5ea6\u7684\u5dee\u7570\u3002<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-2ec88cde354dc0d26192093c521eb955\" style=\"font-size:15px\">\ud83d\udd39 \u9ed1\u8272\u5713\u5f62<strong> <\/strong>\uff1d\u53c3\u8003\u5149\u6e90<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-35b2a5652805173952bf1d748e83042a\" style=\"font-size:15px\">\ud83d\udd39 \u7d05\u8272\u5716\u5f62 = \u6e2c\u8a66\u5149\u6e90<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-75d851862f095cb0b5791754bb24e9fc\" style=\"font-size:15px\">\ud83d\udd39 \u9ed1\u8272\u5713\u5f62\u5167\u7684\u7d05\u8272\u7dda\u689d = \u8a72\u8272\u76f8\u51fa\u73fe\u53bb\u98fd\u548c<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-c7c952e06b179aec978f6764d62cdc4b\" style=\"font-size:15px\">\ud83d\udd39 \u9ed1\u8272\u5713\u5f62\u5916\u7684\u7d05\u8272\u7dda\u689d = \u8a72\u8272\u76f8\u51fa\u73fe\u904e\u5ea6\u98fd\u548c<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-ed6caa22446d3ebef491ef941a7d75b8\" style=\"font-size:15px\">\ud83d\udd39 \u7dda\u689d\u91cd\u758a = \u7121\u8b8a\u5316\uff1b\u8272\u76f8\u5448\u73fe\u8207\u53c3\u8003\u5149\u6e90\u76f8\u540c<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-61e86a58bf09354602fdf196d2d28532\" style=\"font-size:15px\"><\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color has-medium-font-size wp-elements-e4ab2a608fc0d0656e9320e3f885fa9d\"><strong><em>\u4ec0\u9ebc\u662f SDCM\uff08\u6a19\u6e96\u8272\u5dee\u5339\u914d\uff09\uff1f<\/em><\/strong><\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-26e89f19e580ee9381919fd62b04a28a\" style=\"font-size:15px\"><br><br>SDCM \u8207 MacAdam \u6a62\u5713\u5177\u6709\u76f8\u540c\u7684\u610f\u7fa9\u3002\n\u5b83\u662f\u7167\u660e\u9818\u57df\u4e2d\u7528\u4f86\u63cf\u8ff0\u67d0\u4e00\u984f\u8272\u76f8\u5c0d\u65bc\u53c3\u8003\u984f\u8272\u504f\u96e2\u7a0b\u5ea6\u7684\u55ae\u4f4d\u3002\nSDCM \u5b9a\u7fa9\u4e86\u5728 CIE\uff08x, y\uff09\u8272\u5f69\u7a7a\u9593\u4e2d\u3001\u65bc\u7279\u5b9a\u8272\u6eab\u4e0b\u4eba\u773c\u53ef\u611f\u77e5\u7684\u8272\u5f69\u5dee\u7570\u7bc4\u570d\u3002<br><br>\u7f8e\u570b\u6a19\u6e96 ANSI C78.376-2014 \u898f\u5b9a\u4e86 \u516d\u7d44 MacAdam \u6a62\u5713 \u7684\u53c3\u8003\u9ede\u8207\u5c3a\u5bf8\uff0c\u6bcf\u4e00\u7d44\u7686\u5c0d\u61c9\u65bc\u4e00\u500b\u7279\u5b9a\u7684\u8272\u6eab\u3002<br><br>SDCM \u6578\u503c\u8d8a\u9ad8\uff0c\u4ee3\u8868\u8272\u5f69\u504f\u5dee\u8d8a\u5927\uff0c\u4e14\u5dee\u7570\u8d8a\u660e\u986f\uff1b\u76f8\u53cd\u5730\uff0cSDCM \u6578\u503c\u8d8a\u4f4e\uff0c\u8868\u793a\u8272\u5f69\u504f\u79fb\u8d8a\u5c0f\uff0c\u4eba\u773c\u8d8a\u4e0d\u6613\u5bdf\u89ba\u3002<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-81fc26e776ad73dd9bc2d2d1feceaa4d\" style=\"font-size:15px\">\u7c21\u55ae\u4f86\u8aaa\uff1a<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-6213186e026d8843addef615794ea94d\" style=\"font-size:15px\">\ud83d\udd39 1 SDCM\uff1a\u7121\u53ef\u898b\u8272\u5dee<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-968895fb5b2329791a7267d5551d2f2b\" style=\"font-size:15px\">\ud83d\udd39 2\u20133 SDCM\uff1a\u5e7e\u4e4e\u96e3\u4ee5\u5bdf\u89ba<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-8ed62bd672f5e2743409b5b1b2e0b1fc\" style=\"font-size:15px\">\ud83d\udd39 4+ SDCM\uff1a\u660e\u986f\u53ef\u5bdf\u89ba<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-61e86a58bf09354602fdf196d2d28532\" style=\"font-size:15px\"><\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-bb21544f732a3a5029ba8b7ded761013\" style=\"font-size:15px\"><strong>Rf\u2013Rg \u95dc\u4fc2\u5716<\/strong><br>\u6b64\u5716\u8868\u5c07 Rf \u8207 Rg \u9032\u884c\u5c0d\u7167\u7e6a\u88fd\uff0c\u80fd\u5920\u6e05\u695a\u5730\u4ee5\u8996\u89ba\u65b9\u5f0f\u6bd4\u8f03\u4e0d\u540c\u5149\u6e90\u4e4b\u9593\u7684\u986f\u8272\u54c1\u8cea\u3002\n\u5b83\u662f\u4e00\u9805\u5be6\u7528\u4e14\u5177\u6d1e\u5bdf\u529b\u7684\u5de5\u5177\uff0c\u53ef\u5354\u52a9\u9032\u884c\u7167\u660e\u8a55\u4f30\u8207\u9078\u578b\u3002<\/p>\n<\/div>\n<\/div>\n\n\n\n<figure class=\"wp-block-video alignwide\"><video height=\"1080\" style=\"aspect-ratio: 1920 \/ 1080;\" width=\"1920\" controls src=\"https:\/\/lightingrecipe.com\/wp-content\/uploads\/2025\/07\/Lighting-Fundamentals-Part-2-1.mp4\"><\/video><\/figure>","protected":false},"excerpt":{"rendered":"<p>What is TM-30? The IES TM-30 is a color rendering evaluation method introduced by the Illuminating Engineering Society (IES) in 2015 to overcome the limitations of the traditional Ra (CRI) metric. TM-30 offers a more comprehensive and accurate approach to assessing the color rendering performance of a light source, providing a much deeper insight than conventional indices like Ra.Unlike CRI, which only uses 8 color samples, TM-30 evaluates 99 color samples\u2014resulting in a more robust and realistic assessment of how a light source renders colors. Color Fidelity Index (Rf)The Rf measures how accurately a light source reproduces colors compared to a reference light source\u2014similar to the CRI method but using TM-30\u2019s expanded 99 color samples. A higher Rf score indicates better color accuracy, with a perfect score of 100 representing a light source that renders colors identically to the reference source. Gamut Index (Rg)The Rg measures the saturation of colors rendered by a light source compared to a reference. It provides valuable information about the intensity and vibrancy of colors. \ud83d\udd39Rg = 100: Matches the reference source\u2019s color saturation \ud83d\udd39Rg &gt; 100: Indicates oversaturation (colors appear more intense) \ud83d\udd39Rg &lt; 100: Indicates desaturation (colors appear more muted) Together, Rf and Rg provide a complete picture of a light source&#8217;s color performance, with Rg adding valuable information on color vividness and intensity. Color Vector GraphicWhile Rf and Rg provide numeric values, the Color Vector Graphic gives a visual representation of color saturation differences. \ud83d\udd39Black circle = Reference light \ud83d\udd39Red shape = Test light \ud83d\udd39Red lines inside the black circle = Desaturation of those hues \ud83d\udd39Red lines outside the black circle = Oversaturation of those hues \ud83d\udd39Overlapping lines = No change; hues are rendered the same What is SDCM (Standard Deviation Color Matching)? SDCM has the same meaning as a MacAdam ellipse. It\u2019s a unit used in lighting to describe how much a color deviates from a reference color. SDCM defines a zone in the CIE (x, y) color space within which people can perceive color variations at a given color temperature. The American standard ANSI C78.376-2014 specifies reference points and sizes for six MacAdam ellipse sets, each corresponding to a specific color temperature. The higher the SDCM number, the greater the color deviation and the more noticeable the difference. Conversely, a lower SDCM number indicates a smaller, less perceptible color shift. In simple terms: \ud83d\udd391 SDCM: No visible color difference \ud83d\udd392\u20133 SDCM: Barely noticeable \ud83d\udd394+ SDCM: Clearly noticeable Rf-Rg Plot GraphThis plot simply graphs Rf against Rg, offering a clear visual comparison of color rendering quality across different light sources. It\u2019s a practical and insightful tool for evaluating and selecting lighting.<\/p>","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_coblocks_attr":"","_coblocks_dimensions":"","_coblocks_responsive_height":"","_coblocks_accordion_ie_support":"","_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"_glsr_average":0,"_glsr_ranking":0,"_glsr_reviews":0,"footnotes":""},"class_list":["post-2609","page","type-page","status-publish","hentry"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v28.0 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>TM-30 and SDCM -<\/title>\n<meta name=\"robots\" content=\"noindex, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<meta property=\"og:locale\" content=\"zh_TW\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"TM-30 and SDCM -\" \/>\n<meta property=\"og:description\" content=\"What is TM-30? The IES TM-30 is a color rendering evaluation method introduced by the Illuminating Engineering Society (IES) in 2015 to overcome the limitations of the traditional Ra (CRI) metric. TM-30 offers a more comprehensive and accurate approach to assessing the color rendering performance of a light source, providing a much deeper insight than conventional indices like Ra.Unlike CRI, which only uses 8 color samples, TM-30 evaluates 99 color samples\u2014resulting in a more robust and realistic assessment of how a light source renders colors. Color Fidelity Index (Rf)The Rf measures how accurately a light source reproduces colors compared to a reference light source\u2014similar to the CRI method but using TM-30\u2019s expanded 99 color samples. A higher Rf score indicates better color accuracy, with a perfect score of 100 representing a light source that renders colors identically to the reference source. Gamut Index (Rg)The Rg measures the saturation of colors rendered by a light source compared to a reference. It provides valuable information about the intensity and vibrancy of colors. \ud83d\udd39Rg = 100: Matches the reference source\u2019s color saturation \ud83d\udd39Rg &gt; 100: Indicates oversaturation (colors appear more intense) \ud83d\udd39Rg &lt; 100: Indicates desaturation (colors appear more muted) Together, Rf and Rg provide a complete picture of a light source&#8217;s color performance, with Rg adding valuable information on color vividness and intensity. Color Vector GraphicWhile Rf and Rg provide numeric values, the Color Vector Graphic gives a visual representation of color saturation differences. \ud83d\udd39Black circle = Reference light \ud83d\udd39Red shape = Test light \ud83d\udd39Red lines inside the black circle = Desaturation of those hues \ud83d\udd39Red lines outside the black circle = Oversaturation of those hues \ud83d\udd39Overlapping lines = No change; hues are rendered the same What is SDCM (Standard Deviation Color Matching)? SDCM has the same meaning as a MacAdam ellipse. It\u2019s a unit used in lighting to describe how much a color deviates from a reference color. SDCM defines a zone in the CIE (x, y) color space within which people can perceive color variations at a given color temperature. The American standard ANSI C78.376-2014 specifies reference points and sizes for six MacAdam ellipse sets, each corresponding to a specific color temperature. The higher the SDCM number, the greater the color deviation and the more noticeable the difference. Conversely, a lower SDCM number indicates a smaller, less perceptible color shift. In simple terms: \ud83d\udd391 SDCM: No visible color difference \ud83d\udd392\u20133 SDCM: Barely noticeable \ud83d\udd394+ SDCM: Clearly noticeable Rf-Rg Plot GraphThis plot simply graphs Rf against Rg, offering a clear visual comparison of color rendering quality across different light sources. It\u2019s a practical and insightful tool for evaluating and selecting lighting.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/lightingrecipe.com\/zh\/tm-30-and-sdcm\/\" \/>\n<meta property=\"article:modified_time\" content=\"2026-01-21T08:37:35+00:00\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"\u9810\u4f30\u95b1\u8b80\u6642\u9593\" \/>\n\t<meta name=\"twitter:data1\" content=\"2 \u5206\u9418\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/lightingrecipe.com\\\/tm-30-and-sdcm\\\/\",\"url\":\"https:\\\/\\\/lightingrecipe.com\\\/tm-30-and-sdcm\\\/\",\"name\":\"TM-30 and SDCM -\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/lightingrecipe.com\\\/#website\"},\"datePublished\":\"2026-01-13T07:15:54+00:00\",\"dateModified\":\"2026-01-21T08:37:35+00:00\",\"breadcrumb\":{\"@id\":\"https:\\\/\\\/lightingrecipe.com\\\/tm-30-and-sdcm\\\/#breadcrumb\"},\"inLanguage\":\"zh-TW\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\\\/\\\/lightingrecipe.com\\\/tm-30-and-sdcm\\\/\"]}]},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\\\/\\\/lightingrecipe.com\\\/tm-30-and-sdcm\\\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\\\/\\\/lightingrecipe.com\\\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"TM-30 and SDCM\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\\\/\\\/lightingrecipe.com\\\/#website\",\"url\":\"https:\\\/\\\/lightingrecipe.com\\\/\",\"name\":\"\",\"description\":\"\",\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\\\/\\\/lightingrecipe.com\\\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"zh-TW\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"TM-30 and SDCM -","robots":{"index":"noindex","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"og_locale":"zh_TW","og_type":"article","og_title":"TM-30 and SDCM -","og_description":"What is TM-30? The IES TM-30 is a color rendering evaluation method introduced by the Illuminating Engineering Society (IES) in 2015 to overcome the limitations of the traditional Ra (CRI) metric. TM-30 offers a more comprehensive and accurate approach to assessing the color rendering performance of a light source, providing a much deeper insight than conventional indices like Ra.Unlike CRI, which only uses 8 color samples, TM-30 evaluates 99 color samples\u2014resulting in a more robust and realistic assessment of how a light source renders colors. Color Fidelity Index (Rf)The Rf measures how accurately a light source reproduces colors compared to a reference light source\u2014similar to the CRI method but using TM-30\u2019s expanded 99 color samples. A higher Rf score indicates better color accuracy, with a perfect score of 100 representing a light source that renders colors identically to the reference source. Gamut Index (Rg)The Rg measures the saturation of colors rendered by a light source compared to a reference. It provides valuable information about the intensity and vibrancy of colors. \ud83d\udd39Rg = 100: Matches the reference source\u2019s color saturation \ud83d\udd39Rg &gt; 100: Indicates oversaturation (colors appear more intense) \ud83d\udd39Rg &lt; 100: Indicates desaturation (colors appear more muted) Together, Rf and Rg provide a complete picture of a light source&#8217;s color performance, with Rg adding valuable information on color vividness and intensity. Color Vector GraphicWhile Rf and Rg provide numeric values, the Color Vector Graphic gives a visual representation of color saturation differences. \ud83d\udd39Black circle = Reference light \ud83d\udd39Red shape = Test light \ud83d\udd39Red lines inside the black circle = Desaturation of those hues \ud83d\udd39Red lines outside the black circle = Oversaturation of those hues \ud83d\udd39Overlapping lines = No change; hues are rendered the same What is SDCM (Standard Deviation Color Matching)? SDCM has the same meaning as a MacAdam ellipse. It\u2019s a unit used in lighting to describe how much a color deviates from a reference color. SDCM defines a zone in the CIE (x, y) color space within which people can perceive color variations at a given color temperature. The American standard ANSI C78.376-2014 specifies reference points and sizes for six MacAdam ellipse sets, each corresponding to a specific color temperature. The higher the SDCM number, the greater the color deviation and the more noticeable the difference. Conversely, a lower SDCM number indicates a smaller, less perceptible color shift. In simple terms: \ud83d\udd391 SDCM: No visible color difference \ud83d\udd392\u20133 SDCM: Barely noticeable \ud83d\udd394+ SDCM: Clearly noticeable Rf-Rg Plot GraphThis plot simply graphs Rf against Rg, offering a clear visual comparison of color rendering quality across different light sources. It\u2019s a practical and insightful tool for evaluating and selecting lighting.","og_url":"https:\/\/lightingrecipe.com\/zh\/tm-30-and-sdcm\/","article_modified_time":"2026-01-21T08:37:35+00:00","twitter_card":"summary_large_image","twitter_misc":{"\u9810\u4f30\u95b1\u8b80\u6642\u9593":"2 \u5206\u9418"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"WebPage","@id":"https:\/\/lightingrecipe.com\/tm-30-and-sdcm\/","url":"https:\/\/lightingrecipe.com\/tm-30-and-sdcm\/","name":"TM-30 and SDCM -","isPartOf":{"@id":"https:\/\/lightingrecipe.com\/#website"},"datePublished":"2026-01-13T07:15:54+00:00","dateModified":"2026-01-21T08:37:35+00:00","breadcrumb":{"@id":"https:\/\/lightingrecipe.com\/tm-30-and-sdcm\/#breadcrumb"},"inLanguage":"zh-TW","potentialAction":[{"@type":"ReadAction","target":["https:\/\/lightingrecipe.com\/tm-30-and-sdcm\/"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/lightingrecipe.com\/tm-30-and-sdcm\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/lightingrecipe.com\/"},{"@type":"ListItem","position":2,"name":"TM-30 and SDCM"}]},{"@type":"WebSite","@id":"https:\/\/lightingrecipe.com\/#website","url":"https:\/\/lightingrecipe.com\/","name":"","description":"","potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/lightingrecipe.com\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"zh-TW"}]}},"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/lightingrecipe.com\/zh\/wp-json\/wp\/v2\/pages\/2609","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/lightingrecipe.com\/zh\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/lightingrecipe.com\/zh\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/lightingrecipe.com\/zh\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/lightingrecipe.com\/zh\/wp-json\/wp\/v2\/comments?post=2609"}],"version-history":[{"count":3,"href":"https:\/\/lightingrecipe.com\/zh\/wp-json\/wp\/v2\/pages\/2609\/revisions"}],"predecessor-version":[{"id":2691,"href":"https:\/\/lightingrecipe.com\/zh\/wp-json\/wp\/v2\/pages\/2609\/revisions\/2691"}],"wp:attachment":[{"href":"https:\/\/lightingrecipe.com\/zh\/wp-json\/wp\/v2\/media?parent=2609"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}