{"id":7623,"date":"2017-02-07T09:24:19","date_gmt":"2017-02-07T13:24:19","guid":{"rendered":"http:\/\/phsc.ca\/camera\/?p=7623"},"modified":"2017-02-06T13:29:45","modified_gmt":"2017-02-06T17:29:45","slug":"a-wide-view-vista","status":"publish","type":"post","link":"https:\/\/phsc.ca\/camera\/a-wide-view-vista\/","title":{"rendered":"A Wide View Vista"},"content":{"rendered":"
\"\"<\/a>

An air nozzle used to operate a spinner on the Goerz Hypergon lens of 1900.<\/p><\/div>\n

Toronto<\/strong>. The earliest camera lens designers were more concerned with plate coverage than aperture. Often a lens was described in terms of coverage – \u00a0half plate, full plate, etc.<\/p>\n

Numerous strategies were used to allow a greater coverage – mechanical devices like the little air fan Goerz used in its Hypergon<\/a> lens to lower the light from the central rays, a special filter to reduce the light from the central\u00a0rays like Zeiss used for its 1970s 15mm Hologon<\/a> lens – or simply reduced apertures like the Leitz Hector 28mm f\/6.3 and many other lenses used.<\/p>\n

The Hypergon<\/a> used its spinner for about 5\/6 of the exposure to hold back light from the\u00a0central rays. The last 1\/6 of exposure, the little fan was flipped back and the central rays allowed to exposed the plate too.<\/p>\n

The special Zeiss filter for the zeiss hologon filter<\/a> was designed to reduce the light from the inner\u00a0rays by being dark\u00a0in the middle and progressively lighter\u00a0to the edge. A neutral density coating was used so colour could be recorded.<\/p>\n

In the case of reduced aperture, the smaller apertures have less fall off at the edges allowing a greater degree of coverage. For example Leitz limited the widest aperture of its earliest 28mm lens, the Hektor, to f\/6.3<\/a>. The Zeiss Protar<\/a> series is catalogued in terms of coverage at maximum aperture size.<\/p>\n

Normal and long focus lenses seemed to be more straight forward so the designer could concentrate on higher resolution, or lower distortion, or a larger aperture. The 135mm Hector\/Elmar lenses by Leitz were often noted as having a wide coverage suitable as a normal lens for a larger camera than 35mm – a full plate camera for example.<\/p>\n","protected":false},"excerpt":{"rendered":"

Toronto. The earliest camera lens designers were more concerned with plate coverage than aperture. Often a lens was described in terms of coverage – \u00a0half plate, full plate, etc. Numerous strategies were used to allow a greater coverage – mechanical … Continue reading →<\/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":[923,922,921,920,279],"class_list":["post-7623","post","type-post","status-publish","format-standard","hentry","category-camera","tag-28mm","tag-hektor","tag-hologon","tag-hypergon","tag-lenses"],"_links":{"self":[{"href":"https:\/\/phsc.ca\/camera\/wp-json\/wp\/v2\/posts\/7623","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=7623"}],"version-history":[{"count":4,"href":"https:\/\/phsc.ca\/camera\/wp-json\/wp\/v2\/posts\/7623\/revisions"}],"predecessor-version":[{"id":7629,"href":"https:\/\/phsc.ca\/camera\/wp-json\/wp\/v2\/posts\/7623\/revisions\/7629"}],"wp:attachment":[{"href":"https:\/\/phsc.ca\/camera\/wp-json\/wp\/v2\/media?parent=7623"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/phsc.ca\/camera\/wp-json\/wp\/v2\/categories?post=7623"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/phsc.ca\/camera\/wp-json\/wp\/v2\/tags?post=7623"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}