{"id":7801,"date":"2017-02-26T08:57:43","date_gmt":"2017-02-26T12:57:43","guid":{"rendered":"http:\/\/phsc.ca\/camera\/?p=7801"},"modified":"2017-02-25T00:41:10","modified_gmt":"2017-02-25T04:41:10","slug":"not-only-fish-and-snakes-have-scales","status":"publish","type":"post","link":"https:\/\/phsc.ca\/camera\/not-only-fish-and-snakes-have-scales\/","title":{"rendered":"Not only fish and snakes have scales"},"content":{"rendered":"<div id=\"attachment_7803\" style=\"width: 165px\" class=\"wp-caption alignleft\"><a href=\"http:\/\/phsc.ca\/camera\/wp-content\/uploads\/2017\/02\/Harrold-Exposure-Scale.jpg\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-7803\" class=\"size-full wp-image-7803\" src=\"http:\/\/phsc.ca\/camera\/wp-content\/uploads\/2017\/02\/Harrold-Exposure-Scale-sm.jpg\" alt=\"\" width=\"155\" height=\"225\" \/><\/a><p id=\"caption-attachment-7803\" class=\"wp-caption-text\"><a href=\"http:\/\/americanhistory.si.edu\/collections\/search\/object\/nmah_1321370\">Harrold Exposure Scale<\/a> c1922<\/p><\/div>\n<p><strong>Toronto<\/strong>. An option to actinometers or extinction meters was the more sophisticated scales and nomographs. These devices like the<a href=\"http:\/\/phsc.ca\/camera\/wp-content\/uploads\/2017\/02\/Harrold-Exposure-Scale.jpg\"> Harrold Exposure Scale<\/a> patented in 1922, or the <a href=\"http:\/\/www.mathsinstruments.me.uk\/page67.html\">Johnson<\/a> &#8220;<a href=\"http:\/\/phsc.ca\/camera\/wp-content\/uploads\/2017\/02\/JOHNSON-Standard-Exposure-Calculator.jpg\">Standard Exposure<\/a>&#8221; calculator, allowed a photographer to describe a scene and the lighting and then determine various combinations of speed and apertures needed to make a perfect exposure. <a href=\"http:\/\/www.photomemorabilia.co.uk\/Johnsons_of_Hendon\/JoH_Chemicals.html\">Johnson<\/a> was a British company that was known for its darkroom chemicals.<\/p>\n<p>In the mid to late quarter of the last century each film contained a sheet of paper with a small table of\u00a0the suggested exposures and\u00a0a given speed and aperture combination. All films <a href=\"https:\/\/en.wikipedia.org\/wiki\/Film_speed\">used a standard ASA (ISO) or DIN rating <\/a>for film speed,\u00a0making such simple papers of use for those without a sophisticated light meter.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Toronto. An option to actinometers or extinction meters was the more sophisticated scales and nomographs. These devices like the Harrold Exposure Scale patented in 1922, or the Johnson &#8220;Standard Exposure&#8221; calculator, allowed a photographer to describe a scene and the &hellip; <a href=\"https:\/\/phsc.ca\/camera\/not-only-fish-and-snakes-have-scales\/\">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":[24],"tags":[957,958,959,960,961],"class_list":["post-7801","post","type-post","status-publish","format-standard","hentry","category-camera","tag-exposure-calculator","tag-harrold","tag-johnson","tag-nomograph","tag-scale"],"_links":{"self":[{"href":"https:\/\/phsc.ca\/camera\/wp-json\/wp\/v2\/posts\/7801","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=7801"}],"version-history":[{"count":7,"href":"https:\/\/phsc.ca\/camera\/wp-json\/wp\/v2\/posts\/7801\/revisions"}],"predecessor-version":[{"id":7811,"href":"https:\/\/phsc.ca\/camera\/wp-json\/wp\/v2\/posts\/7801\/revisions\/7811"}],"wp:attachment":[{"href":"https:\/\/phsc.ca\/camera\/wp-json\/wp\/v2\/media?parent=7801"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/phsc.ca\/camera\/wp-json\/wp\/v2\/categories?post=7801"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/phsc.ca\/camera\/wp-json\/wp\/v2\/tags?post=7801"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}