{"id":25034,"date":"2023-01-26T01:03:15","date_gmt":"2023-01-26T05:03:15","guid":{"rendered":"https:\/\/phsc.ca\/camera\/?p=25034"},"modified":"2023-01-25T00:47:44","modified_gmt":"2023-01-25T04:47:44","slug":"a-hot-time-in-the-old-town-tonight","status":"publish","type":"post","link":"https:\/\/phsc.ca\/camera\/a-hot-time-in-the-old-town-tonight\/","title":{"rendered":"a hot time in the old town tonight"},"content":{"rendered":"<div id=\"attachment_25035\" style=\"width: 131px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/phsc.ca\/camera\/wp-content\/uploads\/2023\/01\/Lanthanum-Popular-Mechanics-March-1950.jpg\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-25035\" class=\"size-full wp-image-25035\" src=\"https:\/\/phsc.ca\/camera\/wp-content\/uploads\/2023\/01\/Lanthanum-Popular-Mechanics-March-1950-sm.jpg\" alt=\"\" width=\"121\" height=\"225\" \/><\/a><p id=\"caption-attachment-25035\" class=\"wp-caption-text\">A March 1950 ad by Kodak touting the use of Lanthanum glass in its lenses<\/p><\/div>\n<p><strong>Toronto<\/strong>. When I first saw this March 1950 ad for a Kodak lens that used <a href=\"https:\/\/en.wikipedia.org\/wiki\/Lanthanum\">Lanthanum<\/a>, I immediately thought about the\u00a0<a href=\"https:\/\/petapixel.com\/2018\/06\/07\/a-radioactive-lens\/\">radio-active Leitz lenses<\/a> I remembered reading about.<\/p>\n<p>To create unique glass characteristics, many glasses were melted with pinches of stuff like rare earths such as Lanthanum added. I looked up Lanthanum and learned that most Lanthanum is inert &#8211; except that there is a very small percentage of a Lanthanum isotope that is radio-active.<\/p>\n<p>Looking further the next day, it turned out that <a href=\"https:\/\/camerapedia.fandom.com\/wiki\/Radioactive_lenses\">certain high end lenses from the 1950s were indeed slightly radio-active<\/a> due to using elements made from glass with slight amounts of <a href=\"https:\/\/en.wikipedia.org\/wiki\/Thorium\">Thorium \u00a0Oxide<\/a> which is radio-active with a very long half life.<\/p>\n<p>So indeed some 1950 era lenses were slightly radio-active &#8211; but not from using glass made with a touch of Lanthanum rare-earth added!<\/p>\n<p>Thanks to my good friend, George Dunbar for discovering and sharing the March, 1950 ad from Popular Mechanics.<\/p>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Toronto. When I first saw this March 1950 ad for a Kodak lens that used Lanthanum, I immediately thought about the\u00a0radio-active Leitz lenses I remembered reading about. To create unique glass characteristics, many glasses were melted with pinches of stuff &hellip; <a href=\"https:\/\/phsc.ca\/camera\/a-hot-time-in-the-old-town-tonight\/\">Continue reading <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1944],"tags":[398,21,4273,279,4274],"class_list":["post-25034","post","type-post","status-publish","format-standard","hentry","category-history","tag-camera","tag-kodak","tag-lanthanum","tag-lenses","tag-thorium"],"_links":{"self":[{"href":"https:\/\/phsc.ca\/camera\/wp-json\/wp\/v2\/posts\/25034","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/phsc.ca\/camera\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/phsc.ca\/camera\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/phsc.ca\/camera\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/phsc.ca\/camera\/wp-json\/wp\/v2\/comments?post=25034"}],"version-history":[{"count":3,"href":"https:\/\/phsc.ca\/camera\/wp-json\/wp\/v2\/posts\/25034\/revisions"}],"predecessor-version":[{"id":25039,"href":"https:\/\/phsc.ca\/camera\/wp-json\/wp\/v2\/posts\/25034\/revisions\/25039"}],"wp:attachment":[{"href":"https:\/\/phsc.ca\/camera\/wp-json\/wp\/v2\/media?parent=25034"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/phsc.ca\/camera\/wp-json\/wp\/v2\/categories?post=25034"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/phsc.ca\/camera\/wp-json\/wp\/v2\/tags?post=25034"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}