{"id":5146,"date":"2024-10-27T09:51:55","date_gmt":"2024-10-27T08:51:55","guid":{"rendered":"http:\/\/symbiogenese.fr\/?page_id=5146"},"modified":"2026-01-16T14:13:04","modified_gmt":"2026-01-16T13:13:04","slug":"cyanotypes","status":"publish","type":"page","link":"https:\/\/symbiogenese.fr\/?page_id=5146","title":{"rendered":"Cyanotypes"},"content":{"rendered":"\n<figure class=\"wp-block-image size-large\"><img fetchpriority=\"high\" decoding=\"async\" width=\"1024\" height=\"401\" src=\"https:\/\/symbiogenese.fr\/wp-content\/uploads\/2026\/01\/SP17_A31082022-1-1024x401.jpg\" alt=\"\" class=\"wp-image-5558\" srcset=\"https:\/\/symbiogenese.fr\/wp-content\/uploads\/2026\/01\/SP17_A31082022-1-1024x401.jpg 1024w, https:\/\/symbiogenese.fr\/wp-content\/uploads\/2026\/01\/SP17_A31082022-1-300x117.jpg 300w, https:\/\/symbiogenese.fr\/wp-content\/uploads\/2026\/01\/SP17_A31082022-1-768x300.jpg 768w, https:\/\/symbiogenese.fr\/wp-content\/uploads\/2026\/01\/SP17_A31082022-1-1536x601.jpg 1536w, https:\/\/symbiogenese.fr\/wp-content\/uploads\/2026\/01\/SP17_A31082022-1.jpg 1649w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\">Cyanotype PaysageSP17_A31082022_sur papier arche platine Dim : 38x45cm_ collection de l&rsquo;artiste<\/figcaption><\/figure>\n\n\n\n<figure class=\"wp-block-image size-large\"><img decoding=\"async\" width=\"1024\" height=\"716\" src=\"https:\/\/symbiogenese.fr\/wp-content\/uploads\/2026\/01\/SP5_B17092022_web-1-1024x716.jpg\" alt=\"\" class=\"wp-image-5560\" srcset=\"https:\/\/symbiogenese.fr\/wp-content\/uploads\/2026\/01\/SP5_B17092022_web-1-1024x716.jpg 1024w, https:\/\/symbiogenese.fr\/wp-content\/uploads\/2026\/01\/SP5_B17092022_web-1-300x210.jpg 300w, https:\/\/symbiogenese.fr\/wp-content\/uploads\/2026\/01\/SP5_B17092022_web-1-768x537.jpg 768w, https:\/\/symbiogenese.fr\/wp-content\/uploads\/2026\/01\/SP5_B17092022_web-1.jpg 1512w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\">Cyanotype_SP5_B17092022_ La Vergne_Charente_ Dim : 38x45cm _ collection de l&rsquo;atiste<\/figcaption><\/figure>\n\n\n\n<h4 class=\"wp-block-heading\"><strong>Qu\u2019est-ce qu\u2019un\ncyanotype ?<\/strong><\/h4>\n\n\n\n<p>Le cyanotype est un proc\u00e9d\u00e9\nphotographique monochrome n\u00e9gatif ancien, par le biais duquel on\nobtient un tirage photographique bleu de Prusse, bleu cyan. Cette\ntechnique a \u00e9t\u00e9 mise au point en 1842 par le scientifique et\nastronome anglais John Frederick William Herschel. \n<\/p>\n\n\n\n<p>Le proc\u00e9d\u00e9 utilise deux produits\nchimiques&nbsp;: \n<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Citrate d&rsquo;ammonium ferrique (vert<br>\tou brun &#8211; il ne semble pas que cela ait des cons\u00e9quences sur la<br>\tqualit\u00e9 du tirage)\u00a0; <br><\/li>\n\n\n\n<li>Ferricyanure de potassium (rouge).<br><\/li>\n<\/ul>\n\n\n\n<p>Le premier livre illustr\u00e9 par des photogrammes est British Algae (1843-1853) de la <strong>Britannique Anna Atkins <\/strong>(1799-1871)1, qui utilise des cyanotypes.  <\/p>\n\n\n\n<p>\nProc\u00e9d\u00e9<\/p>\n\n\n\n<p>On m\u00e9lange en volumes \u00e9gaux une\nsolution \u00e0 8&nbsp;% (masse sur volume) de ferricyanure de potassium\net une solution \u00e0 20&nbsp;% de citrate d&rsquo;ammonium ferrique. Ce\nm\u00e9lange photosensible est ensuite appliqu\u00e9 sur une surface, par\nexemple sur une feuille de papier, \u00e0 l&rsquo;aide d&rsquo;un pinceau en couche\nhomog\u00e8ne. On laisse s\u00e9cher dans l&rsquo;obscurit\u00e9 ce support pr\u00e9par\u00e9.\nUne fois sec, il pr\u00e9sente une couleur jaune tirant sur le vert. \n<\/p>\n\n\n\n<p>Les cyanotypes peuvent \u00eatre r\u00e9alis\u00e9s\nsur tout support capable d&rsquo;\u00eatre rendu photosensibles par cette\npr\u00e9paration. Le papier \u00e0 dessin \u00e9pais est le m\u00e9dium le plus\ncourant, mais du tissu ou une surface non poreuse recouverte de\ng\u00e9latine peuvent \u00eatre utilis\u00e9s. \n<\/p>\n\n\n\n<p>Sous l&rsquo;exposition \u00e0 des rayons\nultraviolets, le fer des surfaces expos\u00e9es est r\u00e9duit, formant sur\nle papier une couleur bleu de Prusse \u00e0 bleu cyan. L&rsquo;intensit\u00e9 du\nchangement de couleur d\u00e9pend de la quantit\u00e9 de rayons UV, mais on\npeut obtenir des r\u00e9sultats satisfaisants apr\u00e8s trois \u00e0 six minutes\nd&rsquo;exposition en plein soleil en \u00e9t\u00e9. \n<\/p>\n\n\n\n<p>Les motifs,\nqui apparaissent en clair2 sur fond sombre, peuvent \u00eatre obtenus par\ncontact avec tous formats de n\u00e9gatifs, sachant qu&rsquo;il n&rsquo;y a\n\u00e9videmment aucun agrandissement dans ce cas. N&rsquo;importe quel type\nd&rsquo;objet peut aussi \u00eatre utilis\u00e9 pour obtenir des photogrammes. \n<\/p>\n\n\n\n<p>Apr\u00e8s l&rsquo;exposition, le fer qui n&rsquo;a pas r\u00e9agi (jaune-vert) est \u00e9limin\u00e9 par rin\u00e7age \u00e0 l&rsquo;eau courante. Le cyanotype obtenu est ensuite s\u00e9ch\u00e9 \u00e0 l&rsquo;air libre.  <\/p>\n\n\n\n<p><a href=\"https:\/\/fr.wikipedia.org\/wiki\/Cyanotype\">Source Wikipedia<\/a><\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large\"><img decoding=\"async\" width=\"1024\" height=\"744\" src=\"http:\/\/symbiogenese.fr\/wp-content\/uploads\/2024\/10\/SP-070919vc1_30-07-2020-1024x744.jpg\" alt=\"\" class=\"wp-image-5310\" srcset=\"https:\/\/symbiogenese.fr\/wp-content\/uploads\/2024\/10\/SP-070919vc1_30-07-2020-1024x744.jpg 1024w, https:\/\/symbiogenese.fr\/wp-content\/uploads\/2024\/10\/SP-070919vc1_30-07-2020-300x218.jpg 300w, https:\/\/symbiogenese.fr\/wp-content\/uploads\/2024\/10\/SP-070919vc1_30-07-2020-768x558.jpg 768w, https:\/\/symbiogenese.fr\/wp-content\/uploads\/2024\/10\/SP-070919vc1_30-07-2020.jpg 1404w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\">Cyanotype SP13_C30072020 Charente_ vir\u00e9 au tanin v\u00e9g\u00e9tal &#8211; Tirage du 30\/07\/2020 -collection de l&rsquo;artiste<\/figcaption><\/figure><\/div>\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"768\" src=\"http:\/\/symbiogenese.fr\/wp-content\/uploads\/2024\/10\/Cellulaire-292-cyanotype-1024x768.jpg\" alt=\"\" class=\"wp-image-5312\" srcset=\"https:\/\/symbiogenese.fr\/wp-content\/uploads\/2024\/10\/Cellulaire-292-cyanotype-1024x768.jpg 1024w, https:\/\/symbiogenese.fr\/wp-content\/uploads\/2024\/10\/Cellulaire-292-cyanotype-300x225.jpg 300w, https:\/\/symbiogenese.fr\/wp-content\/uploads\/2024\/10\/Cellulaire-292-cyanotype-768x576.jpg 768w, https:\/\/symbiogenese.fr\/wp-content\/uploads\/2024\/10\/Cellulaire-292-cyanotype.jpg 1115w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\">Cyanotype SPCellulaire292_ C17092020_sur papier Arche platine : Dim 38 x 29 cm -collection de l&rsquo;artiste<\/figcaption><\/figure>\n\n\n\n<p><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Qu\u2019est-ce qu\u2019un cyanotype ? Le cyanotype est un proc\u00e9d\u00e9 photographique monochrome n\u00e9gatif ancien, par le biais duquel on obtient un tirage photographique bleu de Prusse, bleu cyan. Cette technique a \u00e9t\u00e9 mise au point en 1842 par le scientifique et astronome anglais John Frederick William Herschel. Le proc\u00e9d\u00e9 utilise deux<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-5146","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/symbiogenese.fr\/index.php?rest_route=\/wp\/v2\/pages\/5146","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/symbiogenese.fr\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/symbiogenese.fr\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/symbiogenese.fr\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/symbiogenese.fr\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=5146"}],"version-history":[{"count":8,"href":"https:\/\/symbiogenese.fr\/index.php?rest_route=\/wp\/v2\/pages\/5146\/revisions"}],"predecessor-version":[{"id":5561,"href":"https:\/\/symbiogenese.fr\/index.php?rest_route=\/wp\/v2\/pages\/5146\/revisions\/5561"}],"wp:attachment":[{"href":"https:\/\/symbiogenese.fr\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=5146"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}