{"id":11890,"date":"2018-06-23T06:42:44","date_gmt":"2018-06-23T10:42:44","guid":{"rendered":"http:\/\/phsc.ca\/camera\/?p=11890"},"modified":"2018-06-24T13:54:35","modified_gmt":"2018-06-24T17:54:35","slug":"a-free-lesson-in-optics","status":"publish","type":"post","link":"https:\/\/phsc.ca\/camera\/a-free-lesson-in-optics\/","title":{"rendered":"a free lesson in  optics"},"content":{"rendered":"<div id=\"attachment_11893\" style=\"width: 153px\" class=\"wp-caption alignleft\"><a href=\"http:\/\/phsc.ca\/camera\/wp-content\/uploads\/2018\/06\/Leitz-Lens-Tables.jpg\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-11893\" class=\"size-full wp-image-11893\" src=\"http:\/\/phsc.ca\/camera\/wp-content\/uploads\/2018\/06\/Leitz-Lens-Tables-sm.jpg\" alt=\"\" width=\"143\" height=\"225\" \/><\/a><p id=\"caption-attachment-11893\" class=\"wp-caption-text\">Leitz New York booklet<br \/>7427a dated July 1936<\/p><\/div>\n<p><strong>Toronto<\/strong>. In July, 1936 Ernst Leitz in Wetzlar published a free booklet called <em>Lens Tables for use with the Leica Camera<\/em>. The version I have was produced for and made available from the New York distributor for Leitz products. \u00a0It explains the optical theory behind <em>depth of focus<\/em> and its relation to <em>focal length<\/em>. It also instructed the reader on the concept of <em>hyperfocal<\/em> distance.<\/p>\n<p>I often used the hyperfocal distance on my Leica M4 lenses to get a maximum range of in focus distance without need to fiddle with settings before shooting.<\/p>\n<p>The little booklet used many tables to simplify the task. Knowing the lens focal length and f\/stop, the correct table immediately indicated the sharpest near distance and far distance in feet. The booklet was especially important when using the supplementary lenses alone on the camera or in conjunction with the 1935 BEEOY spider legs accessory which set the closeup framing.<\/p>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Toronto. In July, 1936 Ernst Leitz in Wetzlar published a free booklet called Lens Tables for use with the Leica Camera. The version I have was produced for and made available from the New York distributor for Leitz products. \u00a0It &hellip; <a href=\"https:\/\/phsc.ca\/camera\/a-free-lesson-in-optics\/\">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":[20],"tags":[2008,2007,2006,61,2010,279,2009],"class_list":["post-11890","post","type-post","status-publish","format-standard","hentry","category-book","tag-depth-of-focus","tag-hyperfocal","tag-iiic","tag-leica","tag-lens-tables","tag-lenses","tag-plane-of-focus"],"_links":{"self":[{"href":"https:\/\/phsc.ca\/camera\/wp-json\/wp\/v2\/posts\/11890","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=11890"}],"version-history":[{"count":3,"href":"https:\/\/phsc.ca\/camera\/wp-json\/wp\/v2\/posts\/11890\/revisions"}],"predecessor-version":[{"id":11911,"href":"https:\/\/phsc.ca\/camera\/wp-json\/wp\/v2\/posts\/11890\/revisions\/11911"}],"wp:attachment":[{"href":"https:\/\/phsc.ca\/camera\/wp-json\/wp\/v2\/media?parent=11890"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/phsc.ca\/camera\/wp-json\/wp\/v2\/categories?post=11890"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/phsc.ca\/camera\/wp-json\/wp\/v2\/tags?post=11890"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}